TY - JOUR A1 - Janz, Anna A1 - Walz, Katharina A1 - Cirnu, Alexandra A1 - Surjanto, Jessica A1 - Urlaub, Daniela A1 - Leskien, Miriam A1 - Kohlhaas, Michael A1 - Nickel, Alexander A1 - Brand, Theresa A1 - Nose, Naoko A1 - Wörsdörfer, Philipp A1 - Wagner, Nicole A1 - Higuchi, Takahiro A1 - Maack, Christoph A1 - Dudek, Jan A1 - Lorenz, Kristina A1 - Klopocki, Eva A1 - Ergün, Süleyman A1 - Duff, Henry J. A1 - Gerull, Brenda T1 - Mutations in DNAJC19 cause altered mitochondrial structure and increased mitochondrial respiration in human iPSC-derived cardiomyocytes JF - Molecular Metabolism N2 - Highlights • Loss of DNAJC19's DnaJ domain disrupts cardiac mitochondrial structure, leading to abnormal cristae formation in iPSC-CMs. • Impaired mitochondrial structures lead to an increased mitochondrial respiration, ROS and an elevated membrane potential. • Mutant iPSC-CMs show sarcomere dysfunction and a trend to more arrhythmias, resembling DCMA-associated cardiomyopathy. Background Dilated cardiomyopathy with ataxia (DCMA) is an autosomal recessive disorder arising from truncating mutations in DNAJC19, which encodes an inner mitochondrial membrane protein. Clinical features include an early onset, often life-threatening, cardiomyopathy associated with other metabolic features. Here, we aim to understand the metabolic and pathophysiological mechanisms of mutant DNAJC19 for the development of cardiomyopathy. Methods We generated induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) of two affected siblings with DCMA and a gene-edited truncation variant (tv) of DNAJC19 which all lack the conserved DnaJ interaction domain. The mutant iPSC-CMs and their respective control cells were subjected to various analyses, including assessments of morphology, metabolic function, and physiological consequences such as Ca\(^{2+}\) kinetics, contractility, and arrhythmic potential. Validation of respiration analysis was done in a gene-edited HeLa cell line (DNAJC19tv\(_{HeLa}\)). Results Structural analyses revealed mitochondrial fragmentation and abnormal cristae formation associated with an overall reduced mitochondrial protein expression in mutant iPSC-CMs. Morphological alterations were associated with higher oxygen consumption rates (OCRs) in all three mutant iPSC-CMs, indicating higher electron transport chain activity to meet cellular ATP demands. Additionally, increased extracellular acidification rates suggested an increase in overall metabolic flux, while radioactive tracer uptake studies revealed decreased fatty acid uptake and utilization of glucose. Mutant iPSC-CMs also showed increased reactive oxygen species (ROS) and an elevated mitochondrial membrane potential. Increased mitochondrial respiration with pyruvate and malate as substrates was observed in mutant DNAJC19tv HeLa cells in addition to an upregulation of respiratory chain complexes, while cellular ATP-levels remain the same. Moreover, mitochondrial alterations were associated with increased beating frequencies, elevated diastolic Ca\(^{2+}\) concentrations, reduced sarcomere shortening and an increased beat-to-beat rate variability in mutant cell lines in response to β-adrenergic stimulation. Conclusions Loss of the DnaJ domain disturbs cardiac mitochondrial structure with abnormal cristae formation and leads to mitochondrial dysfunction, suggesting that DNAJC19 plays an essential role in mitochondrial morphogenesis and biogenesis. Moreover, increased mitochondrial respiration, altered substrate utilization, increased ROS production and abnormal Ca\(^{2+}\) kinetics provide insights into the pathogenesis of DCMA-related cardiomyopathy. KW - cell biology KW - molecular biology KW - dilated cardiomyopathy with ataxia KW - genetics KW - metabolism KW - mitochondria KW - OXPHOS KW - ROS KW - contractility Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-350393 SN - 2212-8778 VL - 79 ER - TY - JOUR A1 - Watermann, Christoph A1 - Meyer, Malin Tordis A1 - Wagner, Steffen A1 - Wittekindt, Claus A1 - Klussmann, Jens Peter A1 - Erguen, Sueleyman A1 - Baumgart-Vogt, Eveline A1 - Karnati, Srikanth T1 - Peroxisomes are highly abundant and heterogeneous in human parotid glands JF - International Journal of Molecular Sciences N2 - The parotid gland is one of the major salivary glands producing a serous secretion, and it plays an essential role in the digestive and immune systems. Knowledge of peroxisomes in the human parotid gland is minimal; furthermore, the peroxisomal compartment and its enzyme composition in the different cell types of the human parotid gland have never been subjected to a detailed investigation. Therefore, we performed a comprehensive analysis of peroxisomes in the human parotid gland’s striated duct and acinar cells. We combined biochemical techniques with various light and electron microscopy techniques to determine the localization of parotid secretory proteins and different peroxisomal marker proteins in parotid gland tissue. Moreover, we analyzed the mRNA of numerous gene encoding proteins localized in peroxisomes using real-time quantitative PCR. The results confirm the presence of peroxisomes in all striated duct and acinar cells of the human parotid gland. Immunofluorescence analyses for various peroxisomal proteins showed a higher abundance and more intense staining in striated duct cells compared to acinar cells. Moreover, human parotid glands comprise high quantities of catalase and other antioxidative enzymes in discrete subcellular regions, suggesting their role in protection against oxidative stress. This study provides the first thorough description of parotid peroxisomes in different parotid cell types of healthy human tissue. KW - peroxisomes KW - parotid gland KW - human KW - catalase KW - differential expression KW - PSP KW - mRNA KW - immunofluorescence Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-311079 SN - 1422-0067 VL - 24 IS - 5 ER - TY - JOUR A1 - Haveman, Rense T1 - Phytosociological notes on hedges in South Ayrshire, Scotland JF - Forum Geobotanicum N2 - On the basis of four relevées of hedges around Straiton en Dailly in South Ayrshire, Scotland, some features of hedges are discussed. On the basis of the brambles, the vegetation of these hedges can be assigned to the Pruno-Rubion sprengelii, which comprises the bramble scrubs of circumneutral and nutrient rich soils in West Europe (Haveman et al. 2017, Haveman & de Ronde 2019). Until now, this alliance was thought to be restricted to the northwestern edge of the European continent, but based on these relevées and the known distribution area of Rubus nemoralis and Rubus polyanthemus, both characteristic for the Pruno-Rubion sprengelii, large parts of North England and Scotland have to be included in the distribution area of the alliance. The Pruno-Rubion sprengelii is optimally developed in rather narrow structures, like hedges, which are pruned every year. Here, brambles and herbs alike can grow with and under the shrubs, facilitated by the light that reaches large parts of the ground. Where the economic base of hedges perishes, they are not longer maintained, and the shrubs can grow out to their natural proportions. This changes the amount of light reaching the surface in the inner parts of the thicket, changing the competition between the species. The brambles as well as the herbs are displaced to the outer edges of the scrub, and the vegetation "dissociates" in a high-growing scrub, a fore-mantle ("cuff") with brambles, and a fringe with perennial herbs. These elements can hardly ever be assigned to the Pruno-Rubion anymore. The Pruno-Rubion sprengelii in optima forma is a scrub in which the three elements (shrubs, brambles, and herbs) grow closely intertwined. This is rarely found in natural landscapes, and thus the alliance is a typical element of the old farmer landscape. What is more: the typical species of the alliance, like Rubus nemoralis and R. polyanthemus, could only evolve after the landscape was opened by farmers in the last six millennia (Matzke-Hajek 1997), giving way to Rubus ulmifolius to expand its distribution area. This caused an explosion of hybrids which stabilised through apomixis into the wealth of Rubus species inhibiting the West European landscape nowadays (Sochor et al. 2015). Many of these species have their original home in a man-made landscape. Therefore, the Pruno-Rubion sprengelii can be characterised as a "farmers alliance" pur sang. KW - agricultural landscape KW - management KW - Pruno-Rubion sprengelii KW - Rhamno-Prunetea KW - vegetation KW - Brombeere Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-312634 UR - http://forum-geobotanicum.net/articles/vol_11-2023/haveman_hedges_pp1-7/FG---haveman-hedges.pdf SN - 1867-9315 VL - 11 ER - TY - JOUR A1 - Gredic, Marija A1 - Karnati, Srikanth A1 - Ruppert, Clemens A1 - Guenther, Andreas A1 - Avdeev, Sergey N. A1 - Kosanovic, Djuro T1 - Combined pulmonary fibrosis and emphysema: when Scylla and Charybdis ally JF - Cells N2 - Combined pulmonary fibrosis and emphysema (CPFE) is a recently recognized syndrome that, as its name indicates, involves the existence of both interstitial lung fibrosis and emphysema in one individual, and is often accompanied by pulmonary hypertension. This debilitating, progressive condition is most often encountered in males with an extensive smoking history, and is presented by dyspnea, preserved lung volumes, and contrastingly impaired gas exchange capacity. The diagnosis of the disease is based on computed tomography imaging, demonstrating the coexistence of emphysema and interstitial fibrosis in the lungs, which might be of various types and extents, in different areas of the lung and several relative positions to each other. CPFE bears high mortality and to date, specific and efficient treatment options do not exist. In this review, we will summarize current knowledge about the clinical attributes and manifestations of CPFE. Moreover, we will focus on pathophysiological and pathohistological lung phenomena and suspected etiological factors of this disease. Finally, since there is a paucity of preclinical research performed for this particular lung pathology, we will review existing animal studies and provide suggestions for the development of additional in vivo models of CPFE syndrome. KW - CPFE KW - lung fibrosis KW - emphysema KW - animal models Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-313571 SN - 2073-4409 VL - 12 IS - 9 ER - TY - JOUR A1 - Wörsdörfer, Philipp A1 - Ergün, Süleyman T1 - “Organoids”: insights from the first issues JF - Organoids N2 - No abstract available KW - organoids KW - editorial Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-313694 SN - 2674-1172 VL - 2 IS - 2 SP - 79 EP - 81 ER - TY - JOUR A1 - Gruschwitz, Philipp A1 - Hartung, Viktor A1 - Kleefeldt, Florian A1 - Ergün, Süleyman A1 - Lichthardt, Sven A1 - Huflage, Henner A1 - Hendel, Robin A1 - Kunz, Andreas Steven A1 - Pannenbecker, Pauline A1 - Kuhl, Philipp Josef A1 - Augustin, Anne Marie A1 - Bley, Thorsten Alexander A1 - Petritsch, Bernhard A1 - Grunz, Jan-Peter T1 - Standardized assessment of vascular reconstruction kernels in photon-counting CT angiographies of the leg using a continuous extracorporeal perfusion model JF - Scientific Reports N2 - This study evaluated the influence of different vascular reconstruction kernels on the image quality of CT angiographies of the lower extremity runoff using a 1st-generation photon-counting-detector CT (PCD-CT) compared with dose-matched examinations on a 3rd-generation energy-integrating-detector CT (EID-CT). Inducing continuous extracorporeal perfusion in a human cadaveric model, we performed CT angiographies of eight upper leg arterial runoffs with radiation dose-equivalent 120 kVp acquisition protocols (CTDIvol 5 mGy). Reconstructions were executed with different vascular kernels, matching the individual modulation transfer functions between scanners. Signal-to-noise-ratios (SNR) and contrast-to-noise-ratios (CNR) were computed to assess objective image quality. Six radiologists evaluated image quality subjectively using a forced-choice pairwise comparison tool. Interrater agreement was determined by calculating Kendall’s concordance coefficient (W). The intraluminal attenuation of PCD-CT images was significantly higher than of EID-CT (414.7 ± 27.3 HU vs. 329.3 ± 24.5 HU; p < 0.001). Using comparable kernels, image noise with PCD-CT was significantly lower than with EID-CT (p ≤ 0.044). Correspondingly, SNR and CNR were approximately twofold higher for PCD-CT (p < 0.001). Increasing the spatial frequency for PCD-CT reconstructions by one level resulted in similar metrics compared to EID-CT (CNRfat; EID-CT Bv49: 21.7 ± 3.7 versus PCD-CT Bv60: 21.4 ± 3.5). Overall image quality of PCD-CTA achieved ratings superior to EID-CTA irrespective of the used reconstruction kernels (best: PCD-CT Bv60; worst: EID-CT Bv40; p < 0.001). Interrater agreement was good (W = 0.78). Concluding, PCD-CT offers superior intraluminal attenuation, SNR, and CNR compared to EID-CT in angiographies of the upper leg arterial runoff. Combined with improved subjective image quality, PCD-CT facilitates the use of sharper convolution kernels and ultimately bears the potential of improved vascular structure assessability. KW - experimental models of disease KW - preclinical research KW - translational research Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357912 VL - 13 ER - TY - JOUR A1 - Patzer, Theresa Sophie A1 - Kunz, Andreas Steven A1 - Huflage, Henner A1 - Conrads, Nora A1 - Luetkens, Karsten Sebastian A1 - Pannenbecker, Pauline A1 - Paul, Mila Marie A1 - Ergün, Süleyman A1 - Bley, Thorsten Alexander A1 - Grunz, Jan-Peter T1 - Ultrahigh-resolution photon-counting CT in cadaveric fracture models: spatial frequency is not everything JF - Diagnostics N2 - In this study, the impact of reconstruction sharpness on the visualization of the appendicular skeleton in ultrahigh-resolution (UHR) photon-counting detector (PCD) CT was investigated. Sixteen cadaveric extremities (eight fractured) were examined with a standardized 120 kVp scan protocol (CTDI\(_{vol}\) 10 mGy). Images were reconstructed with the sharpest non-UHR kernel (Br76) and all available UHR kernels (Br80 to Br96). Seven radiologists evaluated image quality and fracture assessability. Interrater agreement was assessed with the intraclass correlation coefficient. For quantitative comparisons, signal-to-noise-ratios (SNRs) were calculated. Subjective image quality was best for Br84 (median 1, interquartile range 1–3; p ≤ 0.003). Regarding fracture assessability, no significant difference was ascertained between Br76, Br80 and Br84 (p > 0.999), with inferior ratings for all sharper kernels (p < 0.001). Interrater agreement for image quality (0.795, 0.732–0.848; p < 0.001) and fracture assessability (0.880; 0.842–0.911; p < 0.001) was good. SNR was highest for Br76 (3.4, 3.0–3.9) with no significant difference to Br80 and Br84 (p > 0.999). Br76 and Br80 produced higher SNRs than all kernels sharper than Br84 (p ≤ 0.026). In conclusion, PCD-CT reconstructions with a moderate UHR kernel offer superior image quality for visualizing the appendicular skeleton. Fracture assessability benefits from sharp non-UHR and moderate UHR kernels, while ultra-sharp reconstructions incur augmented image noise. KW - photon-counting KW - tomography KW - X-ray computed KW - fracture KW - cancellous bone KW - convolution kernel Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-319281 SN - 2075-4418 VL - 13 IS - 10 ER - TY - JOUR A1 - Huflage, Henner A1 - Grunz, Jan-Peter A1 - Patzer, Theresa Sophie A1 - Pannenbecker, Pauline A1 - Feldle, Philipp A1 - Sauer, Stephanie Tina A1 - Petritsch, Bernhard A1 - Ergün, Süleyman A1 - Bley, Thorsten Alexander A1 - Kunz, Andreas Steven T1 - Potential of unenhanced ultra-low-dose abdominal photon-counting CT with tin filtration: a cadaveric study JF - Diagnostics N2 - Objectives: This study investigated the feasibility and image quality of ultra-low-dose unenhanced abdominal CT using photon-counting detector technology and tin prefiltration. Materials and Methods: Employing a first-generation photon-counting CT scanner, eight cadaveric specimens were examined both with tin prefiltration (Sn 100 kVp) and polychromatic (120 kVp) scan protocols matched for radiation dose at three different levels: standard-dose (3 mGy), low-dose (1 mGy) and ultra-low-dose (0.5 mGy). Image quality was evaluated quantitatively by means of contrast-to-noise-ratios (CNR) with regions of interest placed in the renal cortex and subcutaneous fat. Additionally, three independent radiologists performed subjective evaluation of image quality. The intraclass correlation coefficient was calculated as a measure of interrater reliability. Results: Irrespective of scan mode, CNR in the renal cortex decreased with lower radiation dose. Despite similar mean energy of the applied x-ray spectrum, CNR was superior for Sn 100 kVp over 120 kVp at standard-dose (17.75 ± 3.51 vs. 14.13 ± 4.02), low-dose (13.99 ± 2.6 vs. 10.68 ± 2.17) and ultra-low-dose levels (8.88 ± 2.01 vs. 11.06 ± 1.74) (all p ≤ 0.05). Subjective image quality was highest for both standard-dose protocols (score 5; interquartile range 5–5). While no difference was ascertained between Sn 100 kVp and 120 kVp examinations at standard and low-dose levels, the subjective image quality of tin-filtered scans was superior to 120 kVp with ultra-low radiation dose (p < 0.05). An intraclass correlation coefficient of 0.844 (95% confidence interval 0.763–0.906; p < 0.001) indicated good interrater reliability. Conclusions: Photon-counting detector CT permits excellent image quality in unenhanced abdominal CT with very low radiation dose. Employment of tin prefiltration at 100 kVp instead of polychromatic imaging at 120 kVp increases the image quality even further in the ultra-low-dose range of 0.5 mGy. KW - spectral shaping KW - tin prefiltration KW - abdominal imaging KW - ultra-low-dose CT KW - urinary calculi KW - photon-counting Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-304122 SN - 2075-4418 VL - 13 IS - 4 ER - TY - JOUR A1 - Patzer, Theresa Sophie A1 - Kunz, Andreas Steven A1 - Huflage, Henner A1 - Luetkens, Karsten Sebastian A1 - Conrads, Nora A1 - Gruschwitz, Philipp A1 - Pannenbecker, Pauline A1 - Ergün, Süleyman A1 - Bley, Thorsten Alexander A1 - Grunz, Jan-Peter T1 - Quantitative and qualitative image quality assessment in shoulder examinations with a first-generation photon-counting detector CT JF - Scientific Reports N2 - Photon-counting detector (PCD) CT allows for ultra-high-resolution (UHR) examinations of the shoulder without requiring an additional post-patient comb filter to narrow the detector aperture. This study was designed to compare the PCD performance with a high-end energy-integrating detector (EID) CT. Sixteen cadaveric shoulders were examined with both scanners using dose-matched 120 kVp acquisition protocols (low-dose/full-dose: CTDI\(_{vol}\) = 5.0/10.0 mGy). Specimens were scanned in UHR mode with the PCD-CT, whereas EID-CT examinations were conducted in accordance with the clinical standard as “non-UHR”. Reconstruction of EID data employed the sharpest kernel available for standard-resolution scans (ρ\(_{50}\) = 12.3 lp/cm), while PCD data were reconstructed with both a comparable kernel (11.8 lp/cm) and a sharper dedicated bone kernel (16.5 lp/cm). Six radiologists with 2–9 years of experience in musculoskeletal imaging rated image quality subjectively. Interrater agreement was analyzed by calculation of the intraclass correlation coefficient in a two-way random effects model. Quantitative analyses comprised noise recording and calculating signal-to-noise ratios based on attenuation measurements in bone and soft tissue. Subjective image quality was higher in UHR-PCD-CT than in EID-CT and non-UHR-PCD-CT datasets (all p < 0.001). While low-dose UHR-PCD-CT was considered superior to full-dose non-UHR studies on either scanner (all p < 0.001), ratings of low-dose non-UHR-PCD-CT and full-dose EID-CT examinations did not differ (p > 0.99). Interrater reliability was moderate, indicated by a single measures intraclass correlation coefficient of 0.66 (95% confidence interval: 0.58–0.73; p < 0.001). Image noise was lowest and signal-to-noise ratios were highest in non-UHR-PCD-CT reconstructions at either dose level (p < 0.001). This investigation demonstrates that superior depiction of trabecular microstructure and considerable denoising can be realized without additional radiation dose by employing a PCD for shoulder CT imaging. Allowing for UHR scans without dose penalty, PCD-CT appears as a promising alternative to EID-CT for shoulder trauma assessment in clinical routine. KW - bone KW - musculoskeletal system Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357925 VL - 13 ER - TY - JOUR A1 - Schreiber, Laura M. A1 - Lohr, David A1 - Baltes, Steffen A1 - Vogel, Ulrich A1 - Elabyad, Ibrahim A. A1 - Bille, Maya A1 - Reiter, Theresa A1 - Kosmala, Aleksander A1 - Gassenmaier, Tobias A1 - Stefanescu, Maria R. A1 - Kollmann, Alena A1 - Aures, Julia A1 - Schnitter, Florian A1 - Pali, Mihaela A1 - Ueda, Yuichiro A1 - Williams, Tatiana A1 - Christa, Martin A1 - Hofmann, Ulrich A1 - Bauer, Wolfgang A1 - Gerull, Brenda A1 - Zernecke, Alma A1 - Ergün, Süleyman A1 - Terekhov, Maxim T1 - Ultra-high field cardiac MRI in large animals and humans for translational cardiovascular research JF - Frontiers in Cardiovascular Medicine N2 - A key step in translational cardiovascular research is the use of large animal models to better understand normal and abnormal physiology, to test drugs or interventions, or to perform studies which would be considered unethical in human subjects. Ultrahigh field magnetic resonance imaging (UHF-MRI) at 7 T field strength is becoming increasingly available for imaging of the heart and, when compared to clinically established field strengths, promises better image quality and image information content, more precise functional analysis, potentially new image contrasts, and as all in-vivo imaging techniques, a reduction of the number of animals per study because of the possibility to scan every animal repeatedly. We present here a solution to the dual use problem of whole-body UHF-MRI systems, which are typically installed in clinical environments, to both UHF-MRI in large animals and humans. Moreover, we provide evidence that in such a research infrastructure UHF-MRI, and ideally combined with a standard small-bore UHF-MRI system, can contribute to a variety of spatial scales in translational cardiovascular research: from cardiac organoids, Zebra fish and rodent hearts to large animal models such as pigs and humans. We present pilot data from serial CINE, late gadolinium enhancement, and susceptibility weighted UHF-MRI in a myocardial infarction model over eight weeks. In 14 pigs which were delivered from a breeding facility in a national SARS-CoV-2 hotspot, we found no infection in the incoming pigs. Human scanning using CINE and phase contrast flow measurements provided good image quality of the left and right ventricle. Agreement of functional analysis between CINE and phase contrast MRI was excellent. MRI in arrested hearts or excised vascular tissue for MRI-based histologic imaging, structural imaging of myofiber and vascular smooth muscle cell architecture using high-resolution diffusion tensor imaging, and UHF-MRI for monitoring free radicals as a surrogate for MRI of reactive oxygen species in studies of oxidative stress are demonstrated. We conclude that UHF-MRI has the potential to become an important precision imaging modality in translational cardiovascular research. KW - ultrahigh-field MRI KW - large animal models KW - translational research KW - research infrastructure KW - heart KW - organoid KW - pig KW - cardiovascular MRI Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-317398 SN - 2297-055X VL - 10 ER - TY - JOUR A1 - Pozzi, Nicoló Gabriele A1 - Bolzoni, Francesco A1 - Biella, Gabriele Eliseo Mario A1 - Pezzoli, Gianni A1 - Ip, Chi Wang A1 - Volkmann, Jens A1 - Cavallari, Paolo A1 - Asan, Esther A1 - Isaias, Ioannis Ugo T1 - Brain noradrenergic innervation supports the development of Parkinson’s tremor: a study in a reserpinized rat model JF - Cells N2 - The pathophysiology of tremor in Parkinson’s disease (PD) is evolving towards a complex alteration to monoaminergic innervation, and increasing evidence suggests a key role of the locus coeruleus noradrenergic system (LC-NA). However, the difficulties in imaging LC-NA in patients challenge its direct investigation. To this end, we studied the development of tremor in a reserpinized rat model of PD, with or without a selective lesioning of LC-NA innervation with the neurotoxin DSP-4. Eight male rats (Sprague Dawley) received DSP-4 (50 mg/kg) two weeks prior to reserpine injection (10 mg/kg) (DR-group), while seven male animals received only reserpine treatment (R-group). Tremor, rigidity, hypokinesia, postural flexion and postural immobility were scored before and after 20, 40, 60, 80, 120 and 180 min of reserpine injection. Tremor was assessed visually and with accelerometers. The injection of DSP-4 induced a severe reduction in LC-NA terminal axons (DR-group: 0.024 ± 0.01 vs. R-group: 0.27 ± 0.04 axons/um\(^2\), p < 0.001) and was associated with significantly less tremor, as compared to the R-group (peak tremor score, DR-group: 0.5 ± 0.8 vs. R-group: 1.6 ± 0.5; p < 0.01). Kinematic measurement confirmed the clinical data (tremor consistency (% of tremor during 180 s recording), DR-group: 37.9 ± 35.8 vs. R-group: 69.3 ± 29.6; p < 0.05). Akinetic–rigid symptoms did not differ between the DR- and R-groups. Our results provide preliminary causal evidence for a critical role of LC-NA innervation in the development of PD tremor and foster the development of targeted therapies for PD patients. KW - Parkinson’s disease KW - tremor KW - locus coeruleus KW - noradrenaline KW - reserpinized rat model Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357721 SN - 2073-4409 VL - 12 IS - 21 ER - TY - JOUR A1 - Rockel, Anna F. A1 - Wagner, Nicole A1 - Spenger, Peter A1 - Ergün, Süleyman A1 - Wörsdörfer, Philipp T1 - Neuro-mesodermal assembloids recapitulate aspects of peripheral nervous system development \(in\) \(vitro\) JF - Stem Cell Reports N2 - Summary Here we describe a novel neuro-mesodermal assembloid model that recapitulates aspects of peripheral nervous system (PNS) development such as neural crest cell (NCC) induction, migration, and sensory as well as sympathetic ganglion formation. The ganglia send projections to the mesodermal as well as neural compartment. Axons in the mesodermal part are associated with Schwann cells. In addition, peripheral ganglia and nerve fibers interact with a co-developing vascular plexus, forming a neurovascular niche. Finally, developing sensory ganglia show response to capsaicin indicating their functionality. The presented assembloid model could help to uncover mechanisms of human NCC induction, delamination, migration, and PNS development. Moreover, the model could be used for toxicity screenings or drug testing. The co-development of mesodermal and neuroectodermal tissues and a vascular plexus along with a PNS allows us to investigate the crosstalk between neuroectoderm and mesoderm and between peripheral neurons/neuroblasts and endothelial cells. Highlights •Novel neuro-mesodermal assembloid model of peripheral nervous system development •Model covers neural crest cell induction, migration, and ganglion formation •Ganglia send projections to the mesodermal as well as neural compartment •Peripheral ganglia and nerve fibers interact with a co-developing vascular plexus KW - peripheral nervous system KW - neural crest KW - sensory ganglia KW - sensory neuron KW - vasculature KW - blood vessel KW - neural organoid KW - mesodermal organoid KW - assembloid KW - human induced pluripotent stem cells Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-349925 SN - 2213-6711 VL - 18 IS - 5 ER - TY - JOUR A1 - Ascheid, David A1 - Baumann, Magdalena A1 - Funke, Caroline A1 - Volz, Julia A1 - Pinnecker, Jürgen A1 - Friedrich, Mike A1 - Höhn, Marie A1 - Nandigama, Rajender A1 - Ergün, Süleyman A1 - Nieswandt, Bernhard A1 - Heinze, Katrin G. A1 - Henke, Erik T1 - Image-based modeling of vascular organization to evaluate anti-angiogenic therapy JF - Biology Direct N2 - In tumor therapy anti-angiogenic approaches have the potential to increase the efficacy of a wide variety of subsequently or co-administered agents, possibly by improving or normalizing the defective tumor vasculature. Successful implementation of the concept of vascular normalization under anti-angiogenic therapy, however, mandates a detailed understanding of key characteristics and a respective scoring metric that defines an improved vasculature and thus a successful attempt. Here, we show that beyond commonly used parameters such as vessel patency and maturation, anti-angiogenic approaches largely benefit if the complex vascular network with its vessel interconnections is both qualitatively and quantitatively assessed. To gain such deeper insight the organization of vascular networks, we introduce a multi-parametric evaluation of high-resolution angiographic images based on light-sheet fluorescence microscopy images of tumors. We first could pinpoint key correlations between vessel length, straightness and diameter to describe the regular, functional and organized structure observed under physiological conditions. We found that vascular networks from experimental tumors diverted from those in healthy organs, demonstrating the dysfunctionality of the tumor vasculature not only on the level of the individual vessel but also in terms of inadequate organization into larger structures. These parameters proofed effective in scoring the degree of disorganization in different tumor entities, and more importantly in grading a potential reversal under treatment with therapeutic agents. The presented vascular network analysis will support vascular normalization assessment and future optimization of anti-angiogenic therapy. KW - vascular structure KW - cancer KW - tumor microenvironment KW - optical clearing KW - light sheet fluorescence microscopy KW - 3D image analysis Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357242 VL - 18 ER - TY - JOUR A1 - Madrahimov, Nodir A1 - Mutsenko, Vitalii A1 - Natanov, Ruslan A1 - Radaković, Dejan A1 - Klapproth, André A1 - Hassan, Mohamed A1 - Rosenfeldt, Mathias A1 - Kleefeldt, Florian A1 - Aleksic, Ivan A1 - Ergün, Süleyman A1 - Otto, Christoph A1 - Leyh, Rainer G. A1 - Bening, Constanze T1 - Multiorgan recovery in a cadaver body using mild hypothermic ECMO treatment in a murine model JF - Intensive Care Medicine Experimental N2 - Background Transplant candidates on the waiting list are increasingly challenged by the lack of organs. Most of the organs can only be kept viable within very limited timeframes (e.g., mere 4–6 h for heart and lungs exposed to refrigeration temperatures ex vivo). Donation after circulatory death (DCD) using extracorporeal membrane oxygenation (ECMO) can significantly enlarge the donor pool, organ yield per donor, and shelf life. Nevertheless, clinical attempts to recover organs for transplantation after uncontrolled DCD are extremely complex and hardly reproducible. Therefore, as a preliminary strategy to fulfill this task, experimental protocols using feasible animal models are highly warranted. The primary aim of the study was to develop a model of ECMO-based cadaver organ recovery in mice. Our model mimics uncontrolled organ donation after an “out-of-hospital” sudden unexpected death with subsequent “in-hospital” cadaver management post-mortem. The secondary aim was to assess blood gas parameters, cardiac activity as well as overall organ state. The study protocol included post-mortem heparin–streptokinase administration 10 min after confirmed death induced by cervical dislocation under full anesthesia. After cannulation, veno-arterial ECMO (V–A ECMO) was started 1 h after death and continued for 2 h under mild hypothermic conditions followed by organ harvest. Pressure- and flow-controlled oxygenated blood-based reperfusion of a cadaver body was accompanied by blood gas analysis (BGA), electrocardiography, and histological evaluation of ischemia–reperfusion injury. For the first time, we designed and implemented, a not yet reported, miniaturized murine hemodialysis circuit for the treatment of severe hyperkalemia and metabolic acidosis post-mortem. Results BGA parameters confirmed profound ischemia typical for cadavers and incompatible with normal physiology, including extremely low blood pH, profound negative base excess, and enormously high levels of lactate. Two hours after ECMO implantation, blood pH values of a cadaver body restored from < 6.5 to 7.3 ± 0.05, pCO2 was lowered from > 130 to 41.7 ± 10.5 mmHg, sO2, base excess, and HCO3 were all elevated from below detection thresholds to 99.5 ± 0.6%, − 4 ± 6.2 and 22.0 ± 6.0 mmol/L, respectively (Student T test, p < 0.05). A substantial decrease in hyperlactatemia (from > 20 to 10.5 ± 1.7 mmol/L) and hyperkalemia (from > 9 to 6.9 ± 1.0 mmol/L) was observed when hemodialysis was implemented. On balance, the first signs of regained heart activity appeared on average 10 min after ECMO initiation without cardioplegia or any inotropic and vasopressor support. This was followed by restoration of myocardial contractility with a heart rate of up to 200 beats per minute (bpm) as detected by an electrocardiogram (ECG). Histological examinations revealed no evidence of heart injury 3 h post-mortem, whereas shock-specific morphological changes relevant to acute death and consequent cardiac/circulatory arrest were observed in the lungs, liver, and kidney of both control and ECMO-treated cadaver mice. Conclusions Thus, our model represents a promising approach to facilitate studying perspectives of cadaveric multiorgan recovery for transplantation. Moreover, it opens new possibilities for cadaver organ treatment to extend and potentiate donation and, hence, contribute to solving the organ shortage dilemma. KW - extracorporeal membrane oxygenation KW - cadaver multiorgan preservation KW - mild hypothermia KW - post-mortem heart recovery Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357381 VL - 11 ER - TY - JOUR A1 - Gruschwitz, Philipp A1 - Hartung, Viktor A1 - Ergün, Süleyman A1 - Peter, Dominik A1 - Lichthardt, Sven A1 - Huflage, Henner A1 - Hendel, Robin A1 - Pannenbecker, Pauline A1 - Augustin, Anne Marie A1 - Kunz, Andreas Steven A1 - Feldle, Philipp A1 - Bley, Thorsten Alexander A1 - Grunz, Jan-Peter T1 - Comparison of ultrahigh and standard resolution photon-counting CT angiography of the femoral arteries in a continuously perfused in vitro model JF - European Radiology Experimental N2 - Background With the emergence of photon-counting CT, ultrahigh-resolution (UHR) imaging can be performed without dose penalty. This study aims to directly compare the image quality of UHR and standard resolution (SR) scan mode in femoral artery angiographies. Methods After establishing continuous extracorporeal perfusion in four fresh-frozen cadaveric specimens, photon-counting CT angiographies were performed with a radiation dose of 5 mGy and tube voltage of 120 kV in both SR and UHR mode. Images were reconstructed with dedicated convolution kernels (soft: Body-vascular (Bv)48; sharp: Bv60; ultrasharp: Bv76). Six radiologists evaluated the image quality by means of a pairwise forced-choice comparison tool. Kendall’s concordance coefficient (W) was calculated to quantify interrater agreement. Image quality was further assessed by measuring intraluminal attenuation and image noise as well as by calculating signal-to-noise ratio (SNR) and contrast-to-noise ratios (CNR). Results UHR yielded lower noise than SR for identical reconstructions with kernels ≥ Bv60 (p < 0.001). UHR scans exhibited lower intraluminal attenuation compared to SR (Bv60: 406.4 ± 25.1 versus 418.1 ± 30.1 HU; p < 0.001). Irrespective of scan mode, SNR and CNR decreased while noise increased with sharper kernels but UHR scans were objectively superior to SR nonetheless (Bv60: SNR 25.9 ± 6.4 versus 20.9 ± 5.3; CNR 22.7 ± 5.8 versus 18.4 ± 4.8; p < 0.001). Notably, UHR scans were preferred in subjective assessment when images were reconstructed with the ultrasharp Bv76 kernel, whereas SR was rated superior for Bv60. Interrater agreement was high (W = 0.935). Conclusions Combinations of UHR scan mode and ultrasharp convolution kernel are able to exploit the full image quality potential in photon-counting CT angiography of the femoral arteries. Relevance statement The UHR scan mode offers improved image quality and may increase diagnostic accuracy in CT angiography of the peripheral arterial runoff when optimized reconstruction parameters are chosen. Key points • UHR photon-counting CT improves image quality in combination with ultrasharp convolution kernels. • UHR datasets display lower image noise compared with identically reconstructed standard resolution scans. • Scans in UHR mode show decreased intraluminal attenuation compared with standard resolution imaging. KW - CT angiography KW - femoral arteries KW - photon-counting computed tomography (CT) KW - small pixel effect KW - ultrahigh resolution Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357905 VL - 7 ER - TY - JOUR A1 - Gruschwitz, Philipp A1 - Hartung, Viktor A1 - Kleefeldt, Florian A1 - Peter, Dominik A1 - Lichthardt, Sven A1 - Huflage, Henner A1 - Grunz, Jan-Peter A1 - Augustin, Anne Marie A1 - Ergün, Süleyman A1 - Bley, Thorsten Alexander A1 - Petritsch, Bernhard T1 - Continuous extracorporeal femoral perfusion model for intravascular ultrasound, computed tomography and digital subtraction angiography JF - PLoS One N2 - Objectives We developed a novel human cadaveric perfusion model with continuous extracorporeal femoral perfusion suitable for performing intra-individual comparison studies, training of interventional procedures and preclinical testing of endovascular devices. Objective of this study was to introduce the techniques and evaluate the feasibility for realistic computed tomography angiography (CTA), digital subtraction angiography (DSA) including vascular interventions, and intravascular ultrasound (IVUS). Methods The establishment of the extracorporeal perfusion was attempted using one formalin-fixed and five fresh-frozen human cadavers. In all specimens, the common femoral and popliteal arteries were prepared, introducer sheaths inserted, and perfusion established by a peristaltic pump. Subsequently, we performed CTA and bilateral DSA in five cadavers and IVUS on both legs of four donors. Examination time without unintentional interruption was measured both with and without non-contrast planning CT. Percutaneous transluminal angioplasty and stenting was performed by two interventional radiologists on nine extremities (five donors) using a broad spectrum of different intravascular devices. Results The perfusion of the upper leg arteries was successfully established in all fresh-frozen but not in the formalin-fixed cadaver. The experimental setup generated a stable circulation in each procedure (ten upper legs) for a period of more than six hours. Images acquired with CT, DSA and IVUS offered a realistic impression and enabled the sufficient visualization of all examined vessel segments. Arterial cannulating, percutaneous transluminal angioplasty as well as stent deployment were feasible in a way that is comparable to a vascular intervention in vivo. The perfusion model allowed for introduction and testing of previously not used devices. Conclusions The continuous femoral perfusion model can be established with moderate effort, works stable, and is utilizable for medical imaging of the peripheral arterial system using CTA, DSA and IVUS. Therefore, it appears suitable for research studies, developing skills in interventional procedures and testing of new or unfamiliar vascular devices. KW - continuous extracorporeal femoral perfusion model KW - novel human cadaveric perfusion model KW - computed tomography angiography (CTA) KW - digital subtraction angiography (DSA) KW - intravascular ultrasound (IVUS) Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-350136 SN - 1932-6203 VL - 18 IS - 5 ER - TY - JOUR A1 - Götz, Lisa A1 - Rueckschloss, Uwe A1 - Balk, Gözde A1 - Pfeiffer, Verena A1 - Ergün, Süleyman A1 - Kleefeldt, Florian T1 - The role of carcinoembryonic antigen-related cell adhesion molecule 1 in cancer JF - Frontiers in Immunology N2 - The Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1), also known as CD66a, is a member of the immunoglobulin superfamily. CEACAM1 was shown to be a prognostic marker in patients suffering from cancer. In this review, we summarize pre-clinical and clinical evidence linking CEACAM1 to tumorigenicity and cancer progression. Furthermore, we discuss potential CEACAM1-based mechanisms that may affect cancer biology. KW - CEACAM1 KW - CEA KW - cancer KW - tumor KW - malignancy KW - metastasis KW - signaling Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357250 VL - 14 ER - TY - JOUR A1 - Luetkens, Karsten Sebastian A1 - Grunz, Jan-Peter A1 - Kunz, Andreas Steven A1 - Huflage, Henner A1 - Weißenberger, Manuel A1 - Hartung, Viktor A1 - Patzer, Theresa Sophie A1 - Gruschwitz, Philipp A1 - Ergün, Süleyman A1 - Bley, Thorsten Alexander A1 - Feldle, Philipp T1 - Ultra-high-resolution photon-counting detector CT arthrography of the ankle: a feasibility study JF - Diagnostics N2 - This study was designed to investigate the image quality of ultra-high-resolution ankle arthrography employing a photon-counting detector CT. Bilateral arthrograms were acquired in four cadaveric specimens with full-dose (10 mGy) and low-dose (3 mGy) scan protocols. Three convolution kernels with different spatial frequencies were utilized for image reconstruction (ρ\(_{50}\); Br98: 39.0, Br84: 22.6, Br76: 16.5 lp/cm). Seven radiologists subjectively assessed the image quality regarding the depiction of bone, hyaline cartilage, and ligaments. An additional quantitative assessment comprised the measurement of noise and the computation of contrast-to-noise ratios (CNR). While an optimal depiction of bone tissue was achieved with the ultra-sharp Br98 kernel (S ≤ 0.043), the visualization of cartilage improved with lower modulation transfer functions at each dose level (p ≤ 0.014). The interrater reliability ranged from good to excellent for all assessed tissues (intraclass correlation coefficient ≥ 0.805). The noise levels in subcutaneous fat decreased with reduced spatial frequency (p < 0.001). Notably, the low-dose Br76 matched the CNR of the full-dose Br84 (p 0.999) and superseded Br98 (p < 0.001) in all tissues. Based on the reported results, a photon-counting detector CT arthrography of the ankle with an ultra-high-resolution collimation offers stellar image quality and tissue assessability, improving the evaluation of miniscule anatomical structures. While bone depiction was superior in combination with an ultra-sharp convolution kernel, soft tissue evaluation benefited from employing a lower spatial frequency. KW - photon-counting CT KW - arthrography KW - ankle KW - cartilage KW - radiation dosage Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-362622 SN - 2075-4418 VL - 13 IS - 13 ER - TY - JOUR A1 - Elsner, Clara A1 - Kunz, Andreas Steven A1 - Wagner, Nicole A1 - Huflage, Henner A1 - Hübner, Stefan A1 - Luetkens, Karsten Sebastian A1 - Bley, Thorsten Alexander A1 - Schmitt, Rainer A1 - Ergün, Süleyman A1 - Grunz, Jan-Peter T1 - MRI-based evaluation of the flexor digitorum superficialis anatomy: investigating the prevalence and morphometry of the “chiasma antebrachii” JF - Diagnostics N2 - Recent dissection studies resulted in the introduction of the term “chiasma antebrachii”, which represents an intersection of the flexor digitorum superficialis (FDS) tendons for digits 2 and 3 in the distal third of the forearm. This retrospective investigation aimed to provide an MRI-based morphologic analysis of the chiasma antebrachii. In 89 patients (41 women, 39.3 ± 21.3 years), MRI examinations of the forearm (2010–2021) were reviewed by two radiologists, who evaluated all studies for the presence and length of the chiasma as well as its distance from the distal radioulnar and elbow joint. The chiasma antebrachii was identified in the distal third of the forearm in 88 patients (98.9%), while one intersection was located more proximally in the middle part. The chiasma had a median length of 28 mm (interquartile range: 24–35 mm). Its distances to the distal radioulnar and elbow joint were 16 mm (8–25 mm) and 215 mm (187–227 mm), respectively. T1-weighted post-contrast sequences were found to be superior to T2- or proton-density-weighted sequences in 71 cases (79.8%). To conclude, the chiasma antebrachii is part of the standard FDS anatomy. Knowledge of its morphology is important, e.g., in targeted injections of therapeutics or reconstructive surgery. KW - flexor digitorum superficialis KW - flexor tendon KW - chiasma antebrachii KW - magnetic resonance imaging Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-362631 SN - 2075-4418 VL - 13 IS - 14 ER - TY - JOUR A1 - Jordan, Martin C. A1 - Bröer, David A1 - Fischer, Christian A1 - Heilig, Philipp A1 - Gilbert, Fabian A1 - Hölscher-Doht, Stefanie A1 - Kalogirou, Charis A1 - Popp, Kevin A1 - Grunz, Jan-Peter A1 - Huflage, Henner A1 - Jakubietz, Rafael G. A1 - Ergün, Süleyman A1 - Meffert, Rainer H. T1 - Development and preclinical evaluation of a cable-clamp fixation device for a disrupted pubic symphysis JF - Communications Medicine N2 - Background Traumatic separation of the pubic symphysis can destabilize the pelvis and require surgical fixation to reduce symphyseal gapping. The traditional approach involves open reduction and the implantation of a steel symphyseal plate (SP) on the pubic bone to hold the reposition. Despite its widespread use, SP-fixation is often associated with implant failure caused by screw loosening or breakage. Methods To address the need for a more reliable surgical intervention, we developed and tested two titanium cable-clamp implants. The cable served as tensioning device while the clamp secured the cable to the bone. The first implant design included a steel cable anterior to the pubic symphysis to simplify its placement outside the pelvis, and the second design included a cable encircling the pubic symphysis to stabilize the anterior pelvic ring. Using highly reproducible synthetic bone models and a limited number of cadaver specimens, we performed a comprehensive biomechanical study of implant stability and evaluated surgical feasibility. Results We were able to demonstrate that the cable-clamp implants provide stability equivalent to that of a traditional SP-fixation but without the same risks of implant failure. We also provide detailed ex vivo evaluations of the safety and feasibility of a trans-obturator surgical approach required for those kind of fixation. Conclusion We propose that the developed cable-clamp fixation devices may be of clinical value in treating pubic symphysis separation. KW - pubic symphysis KW - cable-clamp implants KW - SP-fixation Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-299800 VL - 2 IS - 1 ER - TY - JOUR A1 - Kleefeldt, Florian A1 - Upcin, Berin A1 - Bömmel, Heike A1 - Schulz, Christian A1 - Eckner, Georg A1 - Allmanritter, Jan A1 - Bauer, Jochen A1 - Braunger, Barbara A1 - Rueckschloss, Uwe A1 - Ergün, Süleyman T1 - Bone marrow-independent adventitial macrophage progenitor cells contribute to angiogenesis JF - Cell Death & Disease N2 - Pathological angiogenesis promotes tumor growth, metastasis, and atherosclerotic plaque rupture. Macrophages are key players in these processes. However, whether these macrophages differentiate from bone marrow-derived monocytes or from local vascular wall-resident stem and progenitor cells (VW-SCs) is an unresolved issue of angiogenesis. To answer this question, we analyzed vascular sprouting and alterations in aortic cell populations in mouse aortic ring assays (ARA). ARA culture leads to the generation of large numbers of macrophages, especially within the aortic adventitia. Using immunohistochemical fate-mapping and genetic in vivo-labeling approaches we show that 60% of these macrophages differentiate from bone marrow-independent Ly6c\(^{+}\)/Sca-1\(^{+}\) adventitial progenitor cells. Analysis of the NCX\(^{−/-}\) mouse model that genetically lacks embryonic circulation and yolk sac perfusion indicates that at least some of those progenitor cells arise yolk sac-independent. Macrophages represent the main source of VEGF in ARA that vice versa promotes the generation of additional macrophages thereby creating a pro-angiogenetic feedforward loop. Additionally, macrophage-derived VEGF activates CD34\(^{+}\) progenitor cells within the adventitial vasculogenic zone to differentiate into CD31\(^{+}\) endothelial cells. Consequently, depletion of macrophages and VEGFR2 antagonism drastically reduce vascular sprouting activity in ARA. In summary, we show that angiogenic activation induces differentiation of macrophages from bone marrow-derived as well as from bone marrow-independent VW-SCs. The latter ones are at least partially yolk sac-independent, too. Those VW-SC-derived macrophages critically contribute to angiogenesis, making them an attractive target to interfere with pathological angiogenesis in cancer and atherosclerosis as well as with regenerative angiogenesis in ischemic cardiovascular disorders. KW - macrophages KW - angiogenesis KW - bone marrow-derived monocytes Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-299724 VL - 13 IS - 3 ER - TY - JOUR A1 - Bielmeier, Christina B. A1 - Schmitt, Sabrina I. A1 - Kleefeldt, Nikolai A1 - Boneva, Stefaniya K. A1 - Schlecht, Anja A1 - Vallon, Mario A1 - Tamm, Ernst R. A1 - Hillenkamp, Jost A1 - Ergün, Süleyman A1 - Neueder, Andreas A1 - Braunger, Barbara M. T1 - Deficiency in retinal TGFβ signaling aggravates neurodegeneration by modulating pro-apoptotic and MAP kinase pathways JF - International Journal of Molecular Sciences N2 - Transforming growth factor β (TGFβ) signaling has manifold functions such as regulation of cell growth, differentiation, migration, and apoptosis. Moreover, there is increasing evidence that it also acts in a neuroprotective manner. We recently showed that TGFβ receptor type 2 (Tgfbr2) is upregulated in retinal neurons and Müller cells during retinal degeneration. In this study we investigated if this upregulation of TGFβ signaling would have functional consequences in protecting retinal neurons. To this end, we analyzed the impact of TGFβ signaling on photoreceptor viability using mice with cell type-specific deletion of Tgfbr2 in retinal neurons and Müller cells (Tgfbr2\(_{ΔOC}\)) in combination with a genetic model of photoreceptor degeneration (VPP). We examined retinal morphology and the degree of photoreceptor degeneration, as well as alterations of the retinal transcriptome. In summary, retinal morphology was not altered due to TGFβ signaling deficiency. In contrast, VPP-induced photoreceptor degeneration was drastically exacerbated in double mutant mice (Tgfbr2\(_{ΔOC}\); VPP) by induction of pro-apoptotic genes and dysregulation of the MAP kinase pathway. Therefore, TGFβ signaling in retinal neurons and Müller cells exhibits a neuroprotective effect and might pose promising therapeutic options to attenuate photoreceptor degeneration in humans. KW - TGFβ signaling KW - retina KW - retinitis pigmentosa KW - neuro-/photoreceptor degeneration KW - MAP kinase pathway KW - ferroptosis Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-283971 SN - 1422-0067 VL - 23 IS - 5 ER - TY - JOUR A1 - Schlecht, Anja A1 - Wolf, Julian A1 - Boneva, Stefaniya A1 - Prinz, Gabriele A1 - Braunger, Barbara M. A1 - Wieghofer, Peter A1 - Agostini, Hansjürgen A1 - Schlunck, Günther A1 - Lange, Clemens T1 - Transcriptional and distributional profiling of microglia in retinal angiomatous proliferation JF - International Journal of Molecular Sciences N2 - Macular neovascularization type 3, formerly known as retinal angiomatous proliferation (RAP), is a hallmark of age-related macular degeneration and is associated with an accumulation of myeloid cells, such as microglia (MG) and infiltrating blood-derived macrophages (MAC). However, the contribution of MG and MAC to the myeloid cell pool at RAP sites and their exact functions remain unknown. In this study, we combined a microglia-specific reporter mouse line with a mouse model for RAP to identify the contribution of MG and MAC to myeloid cell accumulation at RAP and determined the transcriptional profile of MG using RNA sequencing. We found that MG are the most abundant myeloid cell population around RAP, whereas MAC are rarely, if ever, associated with late stages of RAP. RNA sequencing of RAP-associated MG showed that differentially expressed genes mainly contribute to immune-associated processes, including chemotaxis and migration in early RAP and proliferative capacity in late RAP, which was confirmed by immunohistochemistry. Interestingly, MG upregulated only a few angiomodulatory factors, suggesting a rather low angiogenic potential. In summary, we showed that MG are the dominant myeloid cell population at RAP sites. Moreover, MG significantly altered their transcriptional profile during RAP formation, activating immune-associated processes and exhibiting enhanced proliferation, however, without showing substantial upregulation of angiomodulatory factors. KW - AMD KW - Mactel 2 KW - macular neovascularization KW - MNV type 3 KW - retinal angiomatous proliferation KW - RAP KW - microglia KW - RNA sequencing KW - Cx3cr1 KW - CreERT2 Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-284072 SN - 1422-0067 VL - 23 IS - 7 ER - TY - THES A1 - Upcin, Berin T1 - Contribution of vascular adventitia-resident progenitor cells to new vessel formation in \(ex\) \(vivo\) 3D models T1 - Der Beitrag der Gefäßwandadventitia-residenten Vorläuferzellen zur Neovaskularisation in \(ex\) \(vivo\) 3D Modellen N2 - Ongoing research to fight cancer, one of the dominant diseases of the 21st century has led to big progress especially when it comes to understanding the tumor growth and metastasis. This includes the discovery of the molecular mechanisms of tumor vascularization, which is critically required for establishment of tumor metastasis. Formation of new blood vessels is the first step in tumor vascularization. Therefore, understanding the molecular and cellular basis of tumor vascularization attracted a significant effort studying in biomedical research. The blood vessels for supplying tumor can be formed by sprouting from pre-existing vessels, a process called angiogenesis, or by vasculogenesis, that is de novo formation of blood vessels from not fully differentiated progenitor cell populations. Vasculogenic endothelial progenitor cells (EPCs) can either be activated from populations in the bone marrow reaching the pathological region via the circulation or they can be recruited from local reservoirs. Neovessel formation influences tumor progression, hence therapeutic response model systems of angiogenesis/vasculogenesis are necessary to study the underlying mechanisms. Although, initially the research in this area focused more on angiogenesis, it is now well understood that both angiogenesis and postnatal vasculogenesis contribute to neovessel formation in adult under both most pathological as well as physiological conditions. Studies in the last two decades demonstrate that in addition to the intimal layer of fully differentiated mature endothelial cells (ECs) and various smaller supplying vessels (vasa vasorum) that can serve as a source for new vessels by angiogenesis, especially the adventitia of large and medium size blood vessels harbors various vascular wall-resident stem and progenitor cells (VW-SPCs) populations that serve as a source for new vessels by postnatal vasculogenesis. However, little is known about the potential role of VW-SPCs in tumor vascularization. To this end, the present work started first to establish a modified aortic ring assay (ARA) using mouse aorta in order to study the contribution of vascular adventitia-resident VW-SPCs to neovascularization in general and in presence of tumor cells. ARA is already established an ex vivo model for neovascularization allows to study the morphogenetic events of complex new vessel formation that includes all layers of mature blood vessels, a significant advantage over the assays that employ monolayer endothelial cell cultures. Moreover, in contrast to assays employing endothelial cells monocultures, both angiogenic and vasculogenic events take place during new vessel formation in ARA although the exact contribution of these two processes to new vessel formation cannot be easily distinguished in conventional ARA. Thus, in this study, a modified protocol for the ARA (mdARA) was established by either removing or keeping the aortic adventitia in place. The mdARA allows to distinguish the role of VW-SPCs from those of other aortic layers. The present data show that angiogenic sprouting from mature aortic endothelium was markedly delayed when the adventitial layer was removed. Furthermore, the network between the capillary-like sprouts was significantly reduced in absence of aortic adventitia. Moreover, the stabilization of new sprouts by assembling the NG2+ pericyte-like cells that enwrapped the endothelial sprouts from the outside was improved when the adventitial layer remained in place. Next, mimicking the tumor-vessel adventitia-interaction, multicellular tumor spheroids (MCTS) and aortic rings (ARs) with or without adventitia of C57BL/6-Tg (UBC-GFP) mice were confronted within the collagen gel and cultured ex vivo. This 3D model enabled analysis of the mobilization, migration and capillary-like sprouts formation by VW-SPCs within tumor-vessel wall-interface in comparison to tumor-free side of the ARs. Interestingly, while MCTS preferred the uptake of single vascular adventitia-derived cells, neural spheroids were directly penetrated by capillary-like structures that were sprouted from the aortic adventitia. In summary, the model established in this work allows to study new vessel formation by both postnatal vasculogenesis and angiogenesis under same conditions. It can be applied in various mouse models including reporter mouse models, e.g. Cxcr1 CreER+/mTmG+/- mice, in which GFP-marked macrophages of the vessel wall were directly observed as they mobilized from their niche and migrated into collagen gel. Another benefit of the model is that it can be used for testing different factors such as small molecules, growth factors, cytokines, and drugs with both pro- and anti-angiogenic/vasculogenic effects. N2 - Die Forschungsarbeiten der letzten Jahrzehnte zur Bekämpfung der Krebserkrankung, einer der dominierenden Krankheiten des 21. Jahrhunderts, haben zu großen Fortschritten, insbesondere im Verständnis bezüglich der Tumormetastasierung geführt. Dies schließt die Prozesse der Tumorvaskularisierung als einen der initialen Schritte der Metastasierung mit ein, die nach wie vor nicht ausreichend geklärt sind. Die Blutgefäßbildung zur Versorgung des Tumorgewebes kann durch die Anagiogenese, die als Einsprießen neuer Gefäße aus den bereits vorhandenen Blutgefäßen definiert wird, oder durch die Vaskulogenese, die als Gefäßneubildung aus Stamm- und Vorläuferzellen beschrieben wird, sichergestellt werden. Noch nicht vollständig ausdifferenzierte endotheliale Vorläuferzellen (EPCs) werden dabei nach dem bisherigen Kenntnistand aus dem Knochenmark rekrutiert und erreichen die Regionen der Gefäßneubildung über die Blutzirkulation und können dort zur de novo Formierung neuer Blutgefäße auch beim Erwachsenen beitragen. Untersuchungen der letzten zwei Dekaden haben gezeigt, dass solche Vorläuferzellen auch aus lokalen Reservoiren, wie z.B. aus der Gefäßwandadventitia der bereits existierenden Blutgefäße mobilisiert werden. Da die Bildung neuer Gefäße einen direkten Einfluss auf die Tumorprogression hat, sind entsprechende Modellsysteme notwendig, um die zugrundeliegenden Mechanismen möglichst präzise zu untersuchen. Obwohl sich die Forschung der Tumorvaskularisierung zunächst auf Prozesse der Angiogenese konzentrierte, ist es mittlerweile ausreichend belegt, dass auch die Vaskulogenese zur Tumorvaskularisierung beiträgt und somit die Tumorprogression beeinflusst. Anhand einer Vielzahl an Studien der letzten zwei Jahrzehnte konnte demonstriert werden, dass sich, neben der Intimaschicht, die vollständig differenzierte Endothelzellen (ECs) enthält und kleineren Gefäßwand-versorgenden Blutgefäßen, der sogenannten Vasa vasorum in der Adventitia der großen Gefäße, auch Populationen gefäßwandresidenter Stamm- und Vorläuferzellen (VW-SPCs) in der äußeren Gefäßwandschicht, nämlich der Adventitia fast aller Gefäßabschnitte nachweisen lassen. Obwohl diese als Quelle neuer Gefäße in der postnatalen Vaskulogenese beschrieben sind, ist nach wie vor wenig über die potenzielle Rolle von VW-SPCs in der Tumorvaskularisation bekannt. Daher wurde im Rahmen dieser Arbeit zuerst ein modifiziertes Aortic Ringassay (ARA) unter Verwendung der Mausaorta etabliert, um den Beitrag der VW-SPCs zur Neovaskularisierung im Allgemeinen und zur Tumorvaskularisierung im Speziellen ex vivo untersuchen zu können. ARA ist ein bereits seit einigen Jahrzehnten etabliertes ex vivo Modell zur Untersuchung der Gefäßneubildung durch Angiogenese. Mittels ARA kann die Bildung komplexer vaskulärer Strukturen in Präsenz aller Wandschichten reifer Blutgefäße untersucht werden, was einen wesentlichen Vorteil gegenüber der Verwendung von Endothelzellkulturen in Monolayer bedeutet. Hierbei ist jedoch anzumerken, dass in ARA sowohl angiogene als auch vaskulogene Prozesse zur Gefäßbildung beitragen, aber der genaue Beitrag beider Prozesse schwer oder kaum voneinander unterscheidbar ist. Daher wurde im Rahmen dieser Arbeit ein modifiziertes ARA-Protokoll etabliert (mdARA), in welchem die aortale Adventitia vor dem Beginn des ARA entweder entfernt oder belassen wurde und somit die Rolle der VW-SPCs bei der Gefäßsprossung von den Zellen anderer Aortenwandschichten differenziert studiert werden konnte. Die dabei generierten Daten zeigen, dass sich die angiogene Aussprossung aus dem reifen Aortenendothel nach Entfernung der adventitialen Schicht deutlich verzögerte. Darüber hinaus war das Netzwerk zwischen den kapillarartigen Sprossen in Abwesenheit der Aortenadventitia signifikant reduziert. Mehr noch, das Belassen der adventitialen Wandstruktur führte zu einer verbesserten Stabilisierung neuer Gefäßsprossen. Als sichtbares Korrelat hierfür zeigte sich eine stärkere und bessere Anlagerung der NG2+ Perizyten-ähnlichen Zellen zu den endothelialen Kapillar-ähnlichen Aussprossungen von außen, wie Perizyten an der Kapillarwand in situ. Als nächstes wurden die Aortenringe (ARs) von C57BL/6-Tg (UBC-GFP)-Mäusen mit multizellulären Tumor-Sphäroiden (MCTS) in Kollagengel ko-kultiviert, um die Interaktion zwischen Tumor und Gefäßwand-Adventitia ex vivo nachzuahmen. Dieses 3D Modell ermöglichte die Analyse der Mobilisierung und Migration der VW-SPCs von der aortalen Adventitia sowohl zu der Tumorseite in den Tumor-Gefäßwand-Interfaces als auch zu der tumorfreien Seite der Aortenringe. Interessanterweise wurde die Kapillarsprossung im Tumor-Gefäßwand-Interface an der Grenze zum MCTS gestoppt und die VW-SPCs als Einzelzellen in die MCTS aufgenommen. Demgegenüber wurde auf der tumor-freien Seite der Aortenringe eine deutlich längere Kapillaraussprossung beobachtet. Im Gegensatz zu MCTS resultierte die Ko-Kultivierung der ARs mit neuronalen Spheroiden darin, dass die aus der aortalen Adventitia aussprossenden Kapillar-ähnlichen Strukturen direkt in die neuronalen Spheroide penetrierten. Zusammenfassend berücksichtigt dieses neuartige in vitro 3D-Modell sowohl Angiogenese als auch Vaskulogenese und bietet vielfältige Vorteile, wie zum Beispiel die Kompatibilität zu verschiedenen Mausmodellen einschließlich der Reporter-Mausmodelle, wie z.B. die in dieser Arbeit gezeigte Verwendung der Aorta von Cxcr1 CreER+/mTmG+/- um die GFP-markierten Makrophagen aus der Gefäßwand bei der Gefäßaussprossung studieren zu können. Des Weiteren ist dieses Model auch für Testung unterschiedlicher Faktoren und Therapeutika einschließlich der anti-angiogenen und -vasculogenen Substanzen unter ex vivo Bedingungen geeignet.   KW - Progenitor KW - Adventitia Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-255070 ER - TY - THES A1 - Elsner, Clara Dorothea T1 - Ultrastructural analysis of biogenesis and release of endothelial extracellular vesicles T1 - Ultrastrukturelle Analyse der Biogenese und Freisetzung von endothelialen extrazellulären Vesikeln N2 - Extracellular vesicle (EV)-mediated intercellular communication through exosomes, microvesicles (MVs) and apoptotic bodies has been shown to be implicated in various physiological as well as pathological processes such as the development and progression of atherosclerosis. While the cellular machinery controlling EV formation and composition has been studied extensively, little is known about the underlying morphological processes. This study focuses on a detailed ultrastructural analysis of the different steps of EV formation and release in Myocardial Endothelial (MyEnd) and Aortic Endothelial (AoEnd) cells cultured under serum starvation and inflammatory stimulation with TNF-α. Detailed morphological analyses were conducted applying and comparing different high- resolution light and electron microscopic methods. In this study, we could depict all steps of MV biogenesis named in literature. However, during the study of exosome biogenesis, we discovered a yet undescribed process: Instead of a direct fusion with the plasma membrane, multivesicular bodies were incorporated into a new distinct cellular compartment bound by fenestrated endothelium first. This may present a novel step in exosome biogenesis and warrants further study. Regarding the conditions of cell cultivation, we observed that the commonly used serum starvation causes MyEnd cells, but not AoEnd cells, to enter apoptosis after 48 hours. When preparing functional EV studies, we therefore recommend assessing the morphological condition of the serum-starved cells at different cultivation points first. When evaluating MV production, a statistical analysis showed that the more time AoEnd cells spent in cultivation under serum starvation, the higher the percentage of MV producing cells. However, additional TNF-α stimulation induced a significantly higher MV production than serum starvation alone. Lastly, our results show that TNF-α stimulation of AoEnd cells in vitro leads to the upregulation of CD44, an adhesion molecule critical in the early stages of atherosclerosis. CD44 was then depicted on the surface of generated MVs and exosomes. We conclude that under inflammatory conditions, EVs can mediate the transfer of CD44 from endothelial cells to target cells. This could be a novel mechanism by which MVs contribute to the development and progression of atherosclerotic disease and should be clarified by further studies. N2 - Extrazelluläre Vesikel (EV), darunter Exosomen, Mikrovesikel (MV) und apoptotische Körperchen, werden von fast allen Zellen des Körpers freigesetzt, transportieren zellspezifische Informationen und sind von großer Bedeutung in der Zell-Zell-Kommunikation. Sie spielen eine zentrale Rolle in verschiedensten physiologischen sowie pathologischen Vorgängen, wie etwa der Atherosklerose. Während die zellulären Mechanismen hinter der Entstehung und Komposition der EV bereits intensiv erforscht wurden, ist noch wenig über die zugrundeliegenden morphologischen Prozesse bekannt. Diese Arbeit präsentiert eine detaillierte ultrastrukturelle Analyse der Bildung und Freisetzung von EV in myokardialen (MyEnd) und aortalen Endothelzellen (AoEnd), die unter Serumentzug sowie inflammatorischer Stimulation mit TNF-α kultiviert wurden. Dazu wendeten wir verschiedene hochauflösende licht- und elektronenmikroskopische Techniken an. Wir konnten alle in der Literatur beschriebenen Schritte der MV-Biogenese darstellen. Bei der Untersuchung der exosomalen Biogenese entdeckten wir jedoch einen bisher unbekannten Prozess: Anstelle einer direkten Fusion der multivesikulären Körperchen mit der Plasmamembran, wurden diese zunächst in ein neues, von fenestriertem Endothel begrenztes, zelluläres Kompartiment integriert. Ferner stellten wir fest, dass der häufig durchgeführte Serumentzug während der Kultivierung bei MyEnd- – allerdings nicht AoEnd- – Zellen nach 48 Stunden zur Apoptose führte. Daher empfehlen wir, bei funktionellen Studien von EV zunächst eine morphologische Untersuchung der unter Serumentzug kultivierten Zellen zu verschiedenen Zeitpunkten durchzuführen. Eine statistische Analyse der MV-Produktion zeigte, dass die Zellen umso mehr MV produzierten, je länger sie sich unter Serumentzug befanden. Jedoch induzierte eine zusätzliche Stimulation mit TNF-α eine signifikant höhere MV-Produktion als der alleinige Serumentzug. Wir konnten zeigen, dass eine TNF-α Stimulation von AoEnd Zellen in vitro zu einer vermehrten Expression von CD44 führte – einem vor allem in der Frühphase der Atherosklerose bedeutendem Adhäsionsmolekül. CD44 konnte ebenso auf der Oberfläche von produzierten MV und Exosomen nachgewiesen werden. Wir schließen daraus, dass MV unter inflammatorischen Bedingungen den Transfer von CD44 von Endothelzellen zu Zielzellen vermitteln und so zur Entstehung und Progression von Atherosklerose beitragen können. KW - Vesikel KW - Exosom KW - Endothelzelle KW - Zellkommunikation KW - Atherosklerose KW - Extracellular Vesicles KW - Microvesicles KW - Exosomes KW - Cell-cell communication KW - Electron microscopy Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-288526 ER - TY - JOUR A1 - Gergs, Ulrich A1 - Jahn, Tina A1 - Schulz, Nico A1 - Großmann, Claudia A1 - Rueckschloss, Uwe A1 - Demus, Uta A1 - Buchwalow, Igor B. A1 - Neumann, Joachim T1 - Protein phosphatase 2A improves cardiac functional response to ischemia and sepsis JF - International Journal of Molecular Sciences N2 - Reversible protein phosphorylation is a posttranslational modification of regulatory proteins involved in cardiac signaling pathways. Here, we focus on the role of protein phosphatase 2A (PP2A) for cardiac gene expression and stress response using a transgenic mouse model with cardiac myocyte-specific overexpression of the catalytic subunit of PP2A (PP2A-TG). Gene and protein expression were assessed under basal conditions by gene chip analysis and Western blotting. Some cardiac genes related to the cell metabolism and to protein phosphorylation such as kinases and phosphatases were altered in PP2A-TG compared to wild type mice (WT). As cardiac stressors, a lipopolysaccharide (LPS)-induced sepsis in vivo and a global cardiac ischemia in vitro (stop-flow isolated perfused heart model) were examined. Whereas the basal cardiac function was reduced in PP2A-TG as studied by echocardiography or as studied in the isolated work-performing heart, the acute LPS- or ischemia-induced cardiac dysfunction deteriorated less in PP2A-TG compared to WT. From the data, we conclude that increased PP2A activity may influence the acute stress tolerance of cardiac myocytes. KW - protein phosphorylation KW - PP2A KW - transgenic mice KW - heart KW - LPS KW - sepsis KW - ischemia Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-284035 SN - 1422-0067 VL - 23 IS - 9 ER - TY - JOUR A1 - Behera, Ananyaashree A1 - Jain, Preeti A1 - Ganguli, Geetanjali A1 - Biswas, Mainak A1 - Padhi, Avinash A1 - Pattanaik, Kali Prasad A1 - Nayak, Barsa A1 - Ergün, Süleyman A1 - Hagens, Kristine A1 - Redinger, Natalja A1 - Saqib, Mohd A1 - Mishra, Bibhuti B. A1 - Schaible, Ulrich E. A1 - Karnati, Srikanth A1 - Sonawane, Avinash T1 - Mycobacterium tuberculosis acetyltransferase suppresses oxidative stress by inducing peroxisome formation in macrophages JF - International Journal of Molecular Sciences N2 - Mycobacterium tuberculosis (Mtb) inhibits host oxidative stress responses facilitating its survival in macrophages; however, the underlying molecular mechanisms are poorly understood. Here, we identified a Mtb acetyltransferase (Rv3034c) as a novel counter actor of macrophage oxidative stress responses by inducing peroxisome formation. An inducible Rv3034c deletion mutant of Mtb failed to induce peroxisome biogenesis, expression of the peroxisomal β-oxidation pathway intermediates (ACOX1, ACAA1, MFP2) in macrophages, resulting in reduced intracellular survival compared to the parental strain. This reduced virulence phenotype was rescued by repletion of Rv3034c. Peroxisome induction depended on the interaction between Rv3034c and the macrophage mannose receptor (MR). Interaction between Rv3034c and MR induced expression of the peroxisomal biogenesis proteins PEX5p, PEX13p, PEX14p, PEX11β, PEX19p, the peroxisomal membrane lipid transporter ABCD3, and catalase. Expression of PEX14p and ABCD3 was also enhanced in lungs from Mtb aerosol-infected mice. This is the first report that peroxisome-mediated control of ROS balance is essential for innate immune responses to Mtb but can be counteracted by the mycobacterial acetyltransferase Rv3034c. Thus, peroxisomes represent interesting targets for host-directed therapeutics to tuberculosis. KW - peroxisome KW - Rv3034c KW - acetyltransferase KW - macrophages KW - oxidative stress KW - Mycobacterium tuberculosis Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-284080 SN - 1422-0067 VL - 23 IS - 5 ER - TY - JOUR A1 - Wang, Hongjie A1 - Karnati, Srikanth A1 - Madhusudhan, Thati T1 - Regulation of the homeostatic unfolded protein response in diabetic nephropathy JF - Pharmaceuticals N2 - A growing body of scientific evidence indicates that protein homeostasis, also designated as proteostasis, is causatively linked to chronic diabetic nephropathy (DN). Experimental studies have demonstrated that the insulin signaling in podocytes maintain the homeostatic unfolded protein response (UPR). Insulin signaling via the insulin receptor non-canonically activates the spliced X-box binding protein-1 (sXBP1), a highly conserved endoplasmic reticulum (ER) transcription factor, which regulates the expression of genes that control proteostasis. Defective insulin signaling in mouse models of diabetes or the genetic disruption of the insulin signaling pathway in podocytes propagates hyperglycemia induced maladaptive UPR and DN. Insulin resistance in podocytes specifically promotes activating transcription factor 6 (ATF6) dependent pathogenic UPR. Akin to insulin, recent studies have identified that the cytoprotective effect of anticoagulant serine protease-activated protein C (aPC) in DN is mediated by sXBP1. In mouse models of DN, treatment with chemical chaperones that improve protein folding provides an additional benefit on top of currently used ACE inhibitors. Understanding the molecular mechanisms that transmute renal cell specific adaptive responses and that deteriorate renal function in diabetes will enable researchers to develop new therapeutic regimens for DN. Within this review, we focus on the current understanding of homeostatic mechanisms by which UPR is regulated in DN. KW - unfolded protein response KW - ER stress KW - diabetic nephropathy KW - insulin signaling KW - aPC KW - podocytes KW - XBP1 KW - ATF6 Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-267143 SN - 1424-8247 VL - 15 IS - 4 ER - TY - JOUR A1 - Karnati, Srikanth A1 - Guntas, Gulcan A1 - Rajendran, Ranjithkumar A1 - Shityakov, Sergey A1 - Höring, Marcus A1 - Liebisch, Gerhard A1 - Kosanovic, Djuro A1 - Ergün, Süleyman A1 - Nagai, Michiaki A1 - Förster, Carola Y. T1 - Quantitative lipidomic analysis of Takotsubo syndrome patients' serum JF - Frontiers in Cardiovascular Medicine N2 - Takotsubo syndrome (TTS), also known as the transient left ventricular apical ballooning syndrome, is in contemporary times known as novel acute cardiac syndrome. It is characterized by transient left ventricular apical akinesis and hyperkinesis of the basal left ventricular portions. Although the precise etiology of TTS is unknown, events like the sudden release of stress hormones, such as the catecholamines and the increased inflammatory status might be plausible causes leading to the cardiovascular pathologies. Recent studies have highlighted that an imbalance in lipid accumulation might promote a deviant immune response as observed in TTS. However, there is no information on comprehensive profiling of serum lipids of TTS patients. Therefore, we investigated a detailed quantitative lipid analysis of TTS patients using ES-MSI. Our results showed significant differences in the majority of lipid species composition in the TTS patients compared to the control group. Furthermore, the computational analyses presented was able to link the altered lipids to the pro-inflammatory cytokines and disseminate possible mechanistic pathways involving TNFα and IL-6. Taken together, our study provides an extensive quantitative lipidome of TTS patients, which may provide a valuable Pre-diagnostic tool. This would facilitate the elucidation of the underlying mechanisms of the disease and to prevent the development of TTS in the future. KW - TTS KW - inflammation KW - lipids KW - TNF-α KW - IL6 KW - PIK3R1 KW - NF-kappa-B KW - phosphatidylinositol Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-270832 SN - 2297-055X VL - 9 IS - 797154 ER - TY - JOUR A1 - Kustiati, Ulayatul A1 - Ergün, Suleyman A1 - Karnati, Srikanth A1 - Nugrahaningsih, Dwi Aris Agung A1 - Kusindarta, Dwi Liliek A1 - Wihadmadyatami, Hevi T1 - Ethanolic extract of Ocimum sanctum Linn. Inhibits cell migration of human lung adenocarcinoma cells (A549) by downregulation of integrin αvβ3, α5β1, and VEGF JF - Scientia Pharmaceutica N2 - Adenocarcinoma lung cancer is a type of non-small cell lung carcinoma (NSCLC), which accounts for 85% of lung cancer incidence globally. The therapies that are being applied, both conventional therapies and antibody-based treatments, are still found to have side effects. Several previous studies have demonstrated the ability of the ethanolic extract of Ocimum sanctum Linn. (EEOS) as an ethnomedicine with anti-tumor properties. The aim of this study was to determine the effect of Ocimum sanctum Linn. ethanolic extract in inhibiting the proliferation, angiogenesis, and migration of A549 cells (NSCLC). The adhesion as well as the migration assay was performed. Furthermore, enzyme-linked immunosorbent assay (ELISA) was used to measure the expression of αvβ3 integrins, α5β1 integrins, and VEGF. The cells were divided into the following treatment groups: control (non-treated/NT), positive control (AP3/inhibitor β3 80 µg/mL), cisplatin (9 µg/mL), and EEOS at concentrations of 50, 70, 100, and 200 µg/mL. The results showed that EEOS inhibits the adhesion ability and migration of A549 cells, with an optimal concentration of 200 µg/mL. ELISA testing showed that the group of A549 cells given EEOS 200 µg/mL presented a decrease in the optimal expression of integrin α5β1, integrin αvβ3, and VEGF. KW - EEOS KW - A549 cell line KW - integrin α5β1 KW - integrin αvβ3 KW - VEGF Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-290540 SN - 2218-0532 VL - 90 IS - 4 ER - TY - JOUR A1 - Shityakov, Sergey A1 - Nagai, Michiaki A1 - Ergün, Süleyman A1 - Braunger, Barbara M. A1 - Förster, Carola Y. T1 - The protective effects of neurotrophins and microRNA in diabetic retinopathy, nephropathy and heart failure via regulating endothelial function JF - Biomolecules N2 - Diabetes mellitus is a common disease affecting more than 537 million adults worldwide. The microvascular complications that occur during the course of the disease are widespread and affect a variety of organ systems in the body. Diabetic retinopathy is one of the most common long-term complications, which include, amongst others, endothelial dysfunction, and thus, alterations in the blood-retinal barrier (BRB). This particularly restrictive physiological barrier is important for maintaining the neuroretina as a privileged site in the body by controlling the inflow and outflow of fluid, nutrients, metabolic end products, ions, and proteins. In addition, people with diabetic retinopathy (DR) have been shown to be at increased risk for systemic vascular complications, including subclinical and clinical stroke, coronary heart disease, heart failure, and nephropathy. DR is, therefore, considered an independent predictor of heart failure. In the present review, the effects of diabetes on the retina, heart, and kidneys are described. In addition, a putative common microRNA signature in diabetic retinopathy, nephropathy, and heart failure is discussed, which may be used in the future as a biomarker to better monitor disease progression. Finally, the use of miRNA, targeted neurotrophin delivery, and nanoparticles as novel therapeutic strategies is highlighted. KW - diabetic retinopathy KW - diabetes mellitus KW - microvascular complications KW - diabetic nephropathy KW - heart failure KW - microRNA KW - neurotrophins Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-285966 SN - 2218-273X VL - 12 IS - 8 ER - TY - JOUR A1 - Schmidt, Sven A1 - Alt, Yvonne A1 - Deoghare, Nikita A1 - Krüger, Sarah A1 - Kern, Anna A1 - Rockel, Anna Frederike A1 - Wagner, Nicole A1 - Ergün, Süleyman A1 - Wörsdörfer, Philipp T1 - A blood vessel organoid model recapitulating aspects of vasculogenesis, angiogenesis and vessel wall maturation JF - Organoids N2 - Blood vessel organoids are an important in vitro model to understand the underlying mechanisms of human blood vessel development and for toxicity testing or high throughput drug screening. Here we present a novel, cost-effective, and easy to manufacture vascular organoid model. To engineer the organoids, a defined number of human induced pluripotent stem cells are seeded in non-adhesive agarose coated wells of a 96-well plate and directed towards a lateral plate mesoderm fate by activation of Wnt and BMP4 signaling. We observe the formation of a circular layer of angioblasts around days 5–6. Induced by VEGF application, CD31\(^+\) vascular endothelial cells appear within this vasculogenic zone at approximately day 7 of organoid culture. These cells arrange to form a primitive vascular plexus from which angiogenic sprouting is observed after 10 days of culture. The differentiation outcome is highly reproducible, and the size of organoids is scalable depending on the number of starting cells. We observe that the initial vascular ring forms at the interface between two cell populations. The inner cellular compartment can be distinguished from the outer by the expression of GATA6, a marker of lateral plate mesoderm. Finally, 14-days-old organoids were transplanted on the chorioallantois membrane of chicken embryos resulting in a functional connection of the human vascular network to the chicken circulation. Perfusion of the vessels leads to vessel wall maturation and remodeling as indicated by the formation of a continuous layer of smooth muscle actin expressing cells enwrapping the endothelium. In summary, our organoid model recapitulates human vasculogenesis, angiogenesis as well as vessel wall maturation and therefore represents an easy and cost-effective tool to study all steps of blood vessel development and maturation directly in the human setting without animal experimentation. KW - organoid KW - blood vessel KW - vasculogenesis KW - angiogenesis KW - induced pluripotent stem cells Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-284043 SN - 2674-1172 VL - 1 IS - 1 SP - 41 EP - 53 ER - TY - JOUR A1 - Ergün, Süleyman A1 - Wörsdörfer, Philipp T1 - Organoids, assembloids and embryoids: New avenues for developmental biology, disease modeling, drug testing and toxicity assessment without animal experimentation JF - Organoids N2 - No abstract available KW - developmental biology KW - organoids Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-284101 SN - 2674-1172 VL - 1 IS - 1 SP - 37 EP - 40 ER - TY - JOUR A1 - Feldheim, Jonas A1 - Wend, David A1 - Lauer, Mara J. A1 - Monoranu, Camelia M. A1 - Glas, Martin A1 - Kleinschnitz, Christoph A1 - Ernestus, Ralf-Ingo A1 - Braunger, Barbara M. A1 - Meybohm, Patrick A1 - Hagemann, Carsten A1 - Burek, Malgorzata T1 - Protocadherin Gamma C3 (PCDHGC3) is strongly expressed in glioblastoma and its high expression is associated with longer progression-free survival of patients JF - International Journal of Molecular Sciences N2 - Protocadherins (PCDHs) belong to the cadherin superfamily and represent the largest subgroup of calcium-dependent adhesion molecules. In the genome, most PCDHs are arranged in three clusters, α, β, and γ on chromosome 5q31. PCDHs are highly expressed in the central nervous system (CNS). Several PCDHs have tumor suppressor functions, but their individual role in primary brain tumors has not yet been elucidated. Here, we examined the mRNA expression of PCDHGC3, a member of the PCDHγ cluster, in non-cancerous brain tissue and in gliomas of different World Health Organization (WHO) grades and correlated it with the clinical data of the patients. We generated a PCDHGC3 knockout U343 cell line and examined its growth rate and migration in a wound healing assay. We showed that PCDHGC3 mRNA and protein were significantly overexpressed in glioma tissue compared to a non-cancerous brain specimen. This could be confirmed in glioma cell lines. High PCDHGC3 mRNA expression correlated with longer progression-free survival (PFS) in glioma patients. PCDHGC3 knockout in U343 resulted in a slower growth rate but a significantly faster migration rate in the wound healing assay and decreased the expression of several genes involved in WNT signaling. PCDHGC3 expression should therefore be further investigated as a PFS-marker in gliomas. However, more studies are needed to elucidate the molecular mechanisms underlying the PCDHGC3 effects. KW - glioblastoma multiforme KW - glioma KW - astrocytoma KW - recurrence KW - relapse KW - mRNA KW - protein KW - brain KW - expression KW - PCDHGC3 KW - WNT signaling Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-284433 SN - 1422-0067 VL - 23 IS - 15 ER - TY - JOUR A1 - Rajendran, Ranjithkumar A1 - Rajendran, Vinothkumar A1 - Gupta, Liza A1 - Shirvanchi, Kian A1 - Schunin, Darja A1 - Karnati, Srikanth A1 - Giraldo-Velásquez, Mario A1 - Berghoff, Martin T1 - Interferon beta-1a versus combined interferon beta-1a and oligodendrocyte-specific FGFR1 deletion in experimental autoimmune encephalomyelitis JF - International Journal of Molecular Sciences N2 - Recombinant beta interferons-1 (IFNβ-1) are used as first line therapies in patients with relapsing multiple sclerosis (MS), a chronic inflammatory and neurodegenerative disease of the CNS. IFNβ-1a/b has moderate effects on the prevention of relapses and slowing of disease progression. Fibroblast growth factors (FGFs) and FGF receptors (FGFRs) are known to play a key role in the pathology of MS and its model EAE. To investigate the effects of short-term treatment with s.c. IFNβ-1a versus the combined application of s.c. IFNβ-1a and oligodendrocyte-specific deletion of FGFR1 (Fgfr1\(^{ind−/−}\) mice) in MOG\(_{35-55}\)-induced EAE. IFNβ-1a (30 mg/kg) was applied s.c. from days 0–7 p.i. of EAE in controls and Fgfr1\(^{ind−/−}\) mice. FGFR signaling proteins associated with inflammation/degeneration in MS/EAE were analyzed by western blot in the spinal cord. Further, FGFR1 in Oli-neu oligodendrocytes were inhibited by PD166866 and treated with IFNβ-1a (400 ng/mL). Application of IFNβ-1a over 8 days resulted in less symptoms only at the peak of disease (days 9–11) compared to controls. Application of IFNβ-1a in Fgfr1\(^{ind−/−}\) mice resulted in less symptoms primarily in the chronic phase of EAE. Fgfr1\(^{ind−/−}\) mice treated with IFNβ-1a showed increased expression of pERK and BDNF. In Oli-neu oligodendrocytes, treatment with PD166866 and IFNβ-1a also showed an increased expression of pERK and BDNF/TrkB. These data suggest that the beneficial effects in the chronic phase of EAE and on signaling molecules associated with ERK and BDNF expression are caused by the modulation of FGFR1 and not by interferon beta-1a. FGFR may be a potential target for therapy in MS. KW - FGFR1 KW - interferon beta-1a KW - oligodendrocytes KW - EAE KW - multiple sclerosis Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-290401 SN - 1422-0067 VL - 23 IS - 20 ER - TY - JOUR A1 - Reschke, Moritz A1 - Salvador, Ellaine A1 - Schlegel, Nicolas A1 - Burek, Malgorzata A1 - Karnati, Srikanth A1 - Wunder, Christian A1 - Förster, Carola Y. T1 - Isosteviol sodium (STVNA) reduces pro-inflammatory cytokine IL-6 and GM-CSF in an in vitro murine stroke model of the blood–brain barrier (BBB) JF - Pharmaceutics N2 - Early treatment with glucocorticoids could help reduce both cytotoxic and vasogenic edema, leading to improved clinical outcome after stroke. In our previous study, isosteviol sodium (STVNA) demonstrated neuroprotective effects in an in vitro stroke model, which utilizes oxygen-glucose deprivation (OGD). Herein, we tested the hypothesis that STVNA can activate glucocorticoid receptor (GR) transcriptional activity in brain microvascular endothelial cells (BMECs) as previously published for T cells. STVNA exhibited no effects on transcriptional activation of the glucocorticoid receptor, contrary to previous reports in Jurkat cells. However, similar to dexamethasone, STVNA inhibited inflammatory marker IL-6 as well as granulocyte-macrophage colony-stimulating factor (GM-CSF) secretion. Based on these results, STVNA proves to be beneficial as a possible prevention and treatment modality for brain ischemia-reperfusion injury-induced blood–brain barrier (BBB) dysfunction. KW - IL-6 KW - ischemia KW - isosteviol sodium (STVNA) KW - dexamethasone KW - glucocorticoid receptor KW - cerebEND Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-286275 SN - 1999-4923 VL - 14 IS - 9 ER - TY - JOUR A1 - Rajendran, Ranjithkumar A1 - Böttiger, Gregor A1 - Dentzien, Niklas A1 - Rajendran, Vinothkumar A1 - Sharifi, Bischand A1 - Ergün, Süleyman A1 - Stadelmann, Christine A1 - Karnati, Srikanth A1 - Berghoff, Martin T1 - Effects of FGFR tyrosine kinase inhibition in OLN-93 oligodendrocytes JF - Cells N2 - Fibroblast growth factor (FGF) signaling is involved in the pathogenesis of multiple sclerosis (MS). Data from neuropathology studies suggest that FGF signaling contributes to the failure of remyelination in MS. In MOG\(_{35–55}\)-induced EAE, oligodendrocyte-specific deletion of FGFR1 and FGFR2 resulted in a less severe disease course, reduced inflammation, myelin and axon degeneration and changed FGF/FGFR and BDNF/TrkB signaling. Since signaling cascades in oligodendrocytes could not be investigated in the EAE studies, we here aimed to characterize FGFR-dependent oligodendrocyte-specific signaling in vitro. FGFR inhibition was achieved by application of the multi-kinase-inhibitor dovitinib and the FGFR1/2/3-inhibitor AZD4547. Both substances are potent inhibitors of FGF signaling; they are effective in experimental tumor models and patients with malignancies. Effects of FGFR inhibition in oligodendrocytes were studied by immunofluorescence microscopy, protein and gene analyses. Application of the tyrosine kinase inhibitors reduced FGFR1, phosphorylated ERK and Akt expression, and it enhanced BDNF and TrkB expression. Furthermore, the myelin proteins CNPase and PLP were upregulated by FGFR inhibition. In summary, inhibition of FGFR signaling in oligodendrocytes can be achieved by application of tyrosine kinase inhibitors. Decreased phosphorylation of ERK and Akt is associated with an upregulation of BDNF/TrkB signaling, which may be responsible for the increased production of myelin proteins. Furthermore, these data suggest that application of FGFR inhibitors may have the potential to promote remyelination in the CNS. KW - multiple sclerosis KW - oligodendrocytes KW - dovitinib KW - AZD4547 KW - FGFR signaling KW - myelin Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-239600 SN - 2073-4409 VL - 10 IS - 6 ER - TY - JOUR A1 - Horder, Hannes A1 - Guaza Lasheras, Mar A1 - Grummel, Nadine A1 - Nadernezhad, Ali A1 - Herbig, Johannes A1 - Ergün, Süleyman A1 - Teßmar, Jörg A1 - Groll, Jürgen A1 - Fabry, Ben A1 - Bauer-Kreisel, Petra A1 - Blunk, Torsten T1 - Bioprinting and differentiation of adipose-derived stromal cell spheroids for a 3D breast cancer-adipose tissue model JF - Cells N2 - Biofabrication, including printing technologies, has emerged as a powerful approach to the design of disease models, such as in cancer research. In breast cancer, adipose tissue has been acknowledged as an important part of the tumor microenvironment favoring tumor progression. Therefore, in this study, a 3D-printed breast cancer model for facilitating investigations into cancer cell-adipocyte interaction was developed. First, we focused on the printability of human adipose-derived stromal cell (ASC) spheroids in an extrusion-based bioprinting setup and the adipogenic differentiation within printed spheroids into adipose microtissues. The printing process was optimized in terms of spheroid viability and homogeneous spheroid distribution in a hyaluronic acid-based bioink. Adipogenic differentiation after printing was demonstrated by lipid accumulation, expression of adipogenic marker genes, and an adipogenic ECM profile. Subsequently, a breast cancer cell (MDA-MB-231) compartment was printed onto the adipose tissue constructs. After nine days of co-culture, we observed a cancer cell-induced reduction of the lipid content and a remodeling of the ECM within the adipose tissues, with increased fibronectin, collagen I and collagen VI expression. Together, our data demonstrate that 3D-printed breast cancer-adipose tissue models can recapitulate important aspects of the complex cell–cell and cell–matrix interplay within the tumor-stroma microenvironment KW - adipose-derived stromal cells KW - adipose tissue KW - bioprinting KW - breast cancer model KW - extracellular matrix KW - hyaluronic acid KW - spheroids Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-236496 VL - 10 IS - 4 ER - TY - JOUR A1 - Jordan, Martin C. A1 - Jäckle, Veronika A1 - Scheidt, Sebastian A1 - Gilbert, Fabian A1 - Hölscher-Doht, Stefanie A1 - Ergün, Süleyman A1 - Meffert, Rainer H. A1 - Heintel, Timo M. T1 - Trans-obturator cable fixation of open book pelvic injuries JF - Scientific Reports N2 - Operative treatment of ruptured pubic symphysis by plating is often accompanied by complications. Trans-obturator cable fixation might be a more reliable technique; however, have not yet been tested for stabilization of ruptured pubic symphysis. This study compares symphyseal trans-obturator cable fixation versus plating through biomechanical testing and evaluates safety in a cadaver experiment. APC type II injuries were generated in synthetic pelvic models and subsequently separated into three different groups. The anterior pelvic ring was fixed using a four-hole steel plate in Group A, a stainless steel cable in Group B, and a titan band in Group C. Biomechanical testing was conducted by a single-leg-stance model using a material testing machine under physiological load levels. A cadaver study was carried out to analyze the trans-obturator surgical approach. Peak-to-peak displacement, total displacement, plastic deformation and stiffness revealed a tendency for higher stability for trans-obturator cable/band fixation but no statistical difference to plating was detected. The cadaver study revealed a safe zone for cable passage with sufficient distance to the obturator canal. Trans-obturator cable fixation has the potential to become an alternative for symphyseal fixation with less complications. KW - anatomy KW - medical research Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-261212 VL - 11 IS - 1 ER - TY - THES A1 - Andreska, Thomas T1 - Effects of dopamine on BDNF / TrkB mediated signaling and plasticity on cortico-striatal synapses T1 - Effekte von Dopamin auf BDNF / TrkB vermittelte Signalwege und Plastizität an cortico-striatalen Synapsen N2 - Progressive loss of voluntary movement control is the central symptom of Parkinson's disease (PD). Even today, we are not yet able to cure PD. This is mainly due to a lack of understanding the mechanisms of movement control, network activity and plasticity in motor circuits, in particular between the cerebral cortex and the striatum. Brain-derived neurotrophic factor (BDNF) has emerged as one of the most important factors for the development and survival of neurons, as well as for synaptic plasticity. It is thus an important target for the development of new therapeutic strategies against neurodegenerative diseases. Together with its receptor, the Tropomyosin receptor kinase B (TrkB), it is critically involved in development and function of the striatum. Nevertheless, little is known about the localization of BDNF within presynaptic terminals in the striatum, as well as the types of neurons that produce BDNF in the cerebral cortex. Furthermore, the influence of midbrain derived dopamine on the control of BDNF / TrkB interaction in striatal medium spiny neurons (MSNs) remains elusive so far. Dopamine, however, appears to play an important role, as its absence leads to drastic changes in striatal synaptic plasticity. This suggests that dopamine could regulate synaptic activity in the striatum via modulation of BDNF / TrkB function. To answer these questions, we have developed a sensitive and reliable protocol for the immunohistochemical detection of endogenous BDNF. We find that the majority of striatal BDNF is provided by glutamatergic, cortex derived afferents and not dopaminergic inputs from the midbrain. In fact, we found BDNF in cell bodies of neurons in layers II-III and V of the primary and secondary motor cortex as well as layer V of the somatosensory cortex. These are the brain areas that send dense projections to the dorsolateral striatum for control of voluntary movement. Furthermore, we could show that these projection neurons significantly downregulate the expression of BDNF during the juvenile development of mice between 3 and 12 weeks. In parallel, we found a modulatory effect of dopamine on the translocation of TrkB to the cell surface in postsynaptic striatal Medium Spiny Neurons (MSNs). In MSNs of the direct pathway (dMSNs), which express dopamine receptor 1 (DRD1), we observed the formation of TrkB aggregates in the 6-hydroxydopamine (6-OHDA) model of PD. This suggests that DRD1 activity controls TrkB surface expression in these neurons. In contrast, we found that DRD2 activation has opposite effects in MSNs of the indirect pathway (iMSNs). Activation of DRD2 promotes a rapid decrease in TrkB surface expression which was reversible and depended on cAMP. In parallel, stimulation of DRD2 led to induction of phospho-TrkB (pTrkB). This effect was significantly slower than the effect on TrkB surface expression and indicates that TrkB is transactivated by DRD2. Together, our data provide evidence that dopamine triggers dual modes of plasticity on striatal MSNs by acting on TrkB surface expression in DRD1 and DRD2 expressing MSNs. This surface expression of the receptor is crucial for the binding of BDNF, which is released from corticostriatal afferents. This leads to the induction of TrkB-mediated downstream signal transduction cascades and long-term potentiation (LTP). Therefore, the dopamine-mediated translocation of TrkB could be a mediator that modulates the balance between dopaminergic and glutamatergic signaling to allow synaptic plasticity in a spatiotemporal manner. This information and the fact that TrkB is segregated to persistent aggregates in PD could help to improve our understanding of voluntary movement control and to develop new therapeutic strategies beyond those focusing on dopaminergic supply. N2 - Der fortschreitende Verlust der willkürlichen Bewegungskontrolle ist ein zentrales Symptom der Parkinson-Krankheit (PD). Auch heute sind wir noch nicht in der Lage, PD zu heilen. Dafür verantwortlich ist hauptsächlich ein mangelndes Verständnis von Mechanismen der Bewegungskontrolle, Netzwerkaktivität und Plastizität in motorischen Schaltkreisen, insbesondere zwischen Hirnrinde und Striatum. Der neurotrophe Faktor BDNF ist einer der wichtigsten Faktoren für die Entwicklung und das Überleben von Neuronen sowie für synaptische Plastizität im zentralen Nervensystem. BDNF ist daher ein Target für die Entwicklung neuer therapeutischer Strategien gegen neurodegenerative Erkrankungen. Zusammen mit seinem Rezeptor, der Tropomyosin-Rezeptorkinase B (TrkB), ist BDNF maßgeblich an der Entwicklung und Funktion des Striatums beteiligt. Dennoch ist nur wenig bekannt, wo BDNF an Synapsen im Striatum lokalisiert ist, und wo BDNF in Neuronen der Hirnrinde synthetisiert wird. Außerdem ist der Einfluss von Dopamin aus dem Mittelhirn auf die Kontrolle der BDNF / TrkB-Interaktion in striatalen Medium-Spiny-Neuronen (MSNs) bisher unklar. Dopamin scheint jedoch eine wichtige Rolle zu spielen, da dessen Abwesenheit zu drastischen Veränderungen der striatalen Plastizität führt. Dopamin könnte synaptische Plastizität im Striatum über eine Modulation der BDNF / TrkB-Interaktion regulieren. Um diese Fragen beantworten zu können, haben wir ein sensitives und zuverlässiges Protokoll für den immunhistochemischen Nachweis von endogenem BDNF entwickelt. Wir fanden heraus, dass BDNF im Striatum vor allem in glutamatergen Synapsen von Projektion aus dem Kortex lokalisiert ist und nicht in Terminalen dopaminerger Neurone aus dem Mittelhirn. Tatsächlich fanden wir BDNF in den Zellkörpern von Neuronen in den Schichten II-III und V des primären und sekundären motorischen Kortex sowie Schicht V des somatosensorischen Kortex. Es sind jene Hirnareale, welche dichte Projektionen zum dorsolateralen Striatum senden und entscheidend an der Steuerung von willkürlichen Bewegungen beteiligt sind. Weiterhin konnten wir zeigen, dass eben jene Projektionsneurone die Bildung von BDNF während der juvenilen Entwicklung von Mäusen zwischen 3 und 12 Wochen signifikant herunter regulieren. In striatalen MSN fanden wir zudem einen modulatorischen Effekt von Dopamin auf die Translokation von TrkB zur Zelloberfläche. In MSNs des direkten Signalweges (dMSNs), welche Dopaminrezeptor 1 (DRD1) exprimieren, konnten wir die Bildung von TrkB-Aggregaten im 6-Hydroxydopamin (6-OHDA) - Rattenmodell der Parkinson Erkankung beobachten. Dies deutet darauf hin, dass die DRD1-Aktivität die TrkB-Oberflächenexpression in diesen Neuronen steuert. Im Gegensatz dazu fanden wir heraus, dass die DRD2-Aktivierung in MSNs des indirekten Signalweges (iMSNs) eine gegensätzliche Wirkung hat. Die Aktivierung von DRD2 führt zu einer schnellen Reduktion der TrkB-Oberflächenexpression, die reversibel und von cAMP abhängig ist. Außerdem führte die Stimulation von DRD2 zu einer Induktion von Phospho-TrkB (pTrkB). Dieser Effekt war deutlich langsamer als die Wirkung auf die TrkB-Oberflächenexpression und deutet auf eine Transaktivierung von TrkB über DRD2 hin. Insgesamt scheint Dopamin entgegengesetzte Plastizitätsmodi in striatalen MSNs auszulösen, indem es auf die TrkB-Oberflächenexpression in DRD1- und DRD2-exprimierenden MSNs einwirkt. Diese Oberflächenexpression des Rezeptors ist entscheidend für die Bindung von BDNF, welches aus kortiko-striatalen Afferenzen freigesetzt wird. Dies führt zur Induktion von TrkB-vermittelten-Signaltransduktionskaskaden und Langzeitpotenzierung (LTP). Daher könnte die dopamin-vermittelte Translokalisation von TrkB das Gleichgewicht zwischen dopaminergen und glutamatergen Signalen modulieren, um die synaptische Plastizität in einer räumlich-zeitlich abgestimmten Weise zu ermöglichen. Diese Information und die Tatsache, dass TrkB bei PD stabile Aggregate bildet, könnte dazu beitragen, unser Verständnis der willkürlichen Bewegungskontrolle zu verbessern und neue therapeutische Strategien zu entwickeln, die über jene hinausgehen, welche sich auf die dopaminerge Versorgung konzentrieren. KW - Brain-derived neurotrophic factor KW - Parkinson Krankheit KW - Plastizität KW - Motorisches Lernen KW - Basalganglien KW - Brain-derived neurotrophic factor KW - TrkB KW - Basal Ganglia KW - Motor learning KW - Parkinson's disease KW - Synaptic plasticity KW - Striatum KW - Medium spiny neurons KW - Cortico-striatal projection neurons Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-174317 ER - TY - JOUR A1 - Karnati, Srikanth A1 - Seimetz, Michael A1 - Kleefeldt, Florian A1 - Sonawane, Avinash A1 - Madhusudhan, Thati A1 - Bachhuka, Akash A1 - Kosanovic, Djuro A1 - Weissmann, Norbert A1 - Krüger, Karsten A1 - Ergün, Süleyman T1 - Chronic Obstructive Pulmonary Disease and the Cardiovascular System: Vascular Repair and Regeneration as a Therapeutic Target JF - Frontiers in Cardiovascular Medicine N2 - Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide and encompasses chronic bronchitis and emphysema. It has been shown that vascular wall remodeling and pulmonary hypertension (PH) can occur not only in patients with COPD but also in smokers with normal lung function, suggesting a causal role for vascular alterations in the development of emphysema. Mechanistically, abnormalities in the vasculature, such as inflammation, endothelial dysfunction, imbalances in cellular apoptosis/proliferation, and increased oxidative/nitrosative stress promote development of PH, cor pulmonale, and most probably pulmonary emphysema. Hypoxemia in the pulmonary chamber modulates the activation of key transcription factors and signaling cascades, which propagates inflammation and infiltration of neutrophils, resulting in vascular remodeling. Endothelial progenitor cells have angiogenesis capabilities, resulting in transdifferentiation of the smooth muscle cells via aberrant activation of several cytokines, growth factors, and chemokines. The vascular endothelium influences the balance between vaso-constriction and -dilation in the heart. Targeting key players affecting the vasculature might help in the development of new treatment strategies for both PH and COPD. The present review aims to summarize current knowledge about vascular alterations and production of reactive oxygen species in COPD. The present review emphasizes on the importance of the vasculature for the usually parenchyma-focused view of the pathobiology of COPD. KW - COPD KW - emphysema KW - pulmonary hypertension KW - hypoxia KW - oxidative stress Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-235631 SN - 2297-055X VL - 8 ER - TY - JOUR A1 - Dogan, Leyla A1 - Scheuring, Ruben A1 - Wagner, Nicole A1 - Ueda, Yuichiro A1 - Schmidt, Sven A1 - Wörsdörfer, Philipp A1 - Groll, Jürgen A1 - Ergün, Süleyman T1 - Human iPSC-derived mesodermal progenitor cells preserve their vasculogenesis potential after extrusion and form hierarchically organized blood vessels JF - Biofabrication N2 - Post-fabrication formation of a proper vasculature remains an unresolved challenge in bioprinting. Established strategies focus on the supply of the fabricated structure with nutrients and oxygen and either rely on the mere formation of a channel system using fugitive inks or additionally use mature endothelial cells and/or peri-endothelial cells such as smooth muscle cells for the formation of blood vessels in vitro. Functional vessels, however, exhibit a hierarchical organization and multilayered wall structure that is important for their function. Human induced pluripotent stem cell-derived mesodermal progenitor cells (hiMPCs) have been shown to possess the capacity to form blood vessels in vitro, but have so far not been assessed for their applicability in bioprinting processes. Here, we demonstrate that hiMPCs, after formulation into an alginate/collagen type I bioink and subsequent extrusion, retain their ability to give rise to the formation of complex vessels that display a hierarchical network in a process that mimics the embryonic steps of vessel formation during vasculogenesis. Histological evaluations at different time points of extrusion revealed the initial formation of spheres, followed by lumen formation and further structural maturation as evidenced by building a multilayered vessel wall and a vascular network. These findings are supported by immunostainings for endothelial and peri-endothelial cell markers as well as electron microscopic analyses at the ultrastructural level. Moreover, endothelial cells in capillary-like vessel structures deposited a basement membrane-like matrix at the basal side between the vessel wall and the alginate-collagen matrix. After transplantation of the printed constructs into the chicken chorioallantoic membrane (CAM) the printed vessels connected to the CAM blood vessels and get perfused in vivo. These results evidence the applicability and great potential of hiMPCs for the bioprinting of vascular structures mimicking the basic morphogenetic steps of de novo vessel formation during embryogenesis. KW - vascular biofabrication KW - human iPSC-derived mesodermal cells (hiMPCs) KW - extrusion of hiMPC-containing bioinks alginate + collagen type I KW - multilayered vessel wall with intimate, media and adventitia KW - vascular network and hierarchical organized vessels KW - electron microscopy KW - serial block face EM Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-254046 VL - 13 IS - 4 ER - TY - JOUR A1 - Luetkens, Karsten Sebastian A1 - Ergün, Süleyman A1 - Huflage, Henner A1 - Kunz, Andreas Steven A1 - Gietzen, Carsten Herbert A1 - Conrads, Nora A1 - Pennig, Lenhard A1 - Goertz, Lukas A1 - Bley, Thorsten Alexander A1 - Gassenmaier, Tobias A1 - Grunz, Jan-Peter T1 - Dose reduction potential in cone-beam CT imaging of upper extremity joints with a twin robotic x-ray system JF - Scientific Reports N2 - Cone-beam computed tomography is a powerful tool for 3D imaging of the appendicular skeleton, facilitating detailed visualization of bone microarchitecture. This study evaluated various combinations of acquisition and reconstruction parameters for the cone-beam CT mode of a twin robotic x-ray system in cadaveric wrist and elbow scans, aiming to define the best possible trade-off between image quality and radiation dose. Images were acquired with different combinations of tube voltage and tube current–time product, resulting in five scan protocols with varying volume CT dose indices: full-dose (FD; 17.4 mGy), low-dose (LD; 4.5 mGy), ultra-low-dose (ULD; 1.15 mGy), modulated low-dose (mLD; 0.6 mGy) and modulated ultra-low-dose (mULD; 0.29 mGy). Each set of projection data was reconstructed with three convolution kernels (very sharp [Ur77], sharp [Br69], intermediate [Br62]). Five radiologists subjectively assessed the image quality of cortical bone, cancellous bone and soft tissue using seven-point scales. Irrespective of the reconstruction kernel, overall image quality of every FD, LD and ULD scan was deemed suitable for diagnostic use in contrast to mLD (very sharp/sharp/intermediate: 60/55/70%) and mULD (0/3/5%). Superior depiction of cortical and cancellous bone was achieved in FD\(_{Ur77}\) and LD\(_{Ur77}\) examinations (p < 0.001) with LD\(_{Ur77}\) scans also providing favorable bone visualization compared to FD\(_{Br69}\) and FD\(_{Br62}\) (p < 0.001). Fleiss’ kappa was 0.618 (0.594–0.641; p < 0.001), indicating substantial interrater reliability. In this study, we demonstrate that considerable dose reduction can be realized while maintaining diagnostic image quality in upper extremity joint scans with the cone-beam CT mode of a twin robotic x-ray system. Application of sharper convolution kernels for image reconstruction facilitates superior display of bone microarchitecture. KW - medical research KW - preclinical research Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-270429 VL - 11 IS - 1 ER - TY - JOUR A1 - Meyer, Malin Tordis A1 - Watermann, Christoph A1 - Dreyer, Thomas A1 - Wagner, Steffen A1 - Wittekindt, Claus A1 - Klussmann, Jens Peter A1 - Ergün, Süleyman A1 - Baumgart-Vogt, Eveline A1 - Karnati, Srikanth T1 - Differential expression of peroxisomal proteins in distinct types of parotid gland tumors JF - International Journal of Molecular Sciences N2 - Salivary gland cancers are rare but aggressive tumors that have poor prognosis and lack effective cure. Of those, parotid tumors constitute the majority. Functioning as metabolic machinery contributing to cellular redox balance, peroxisomes have emerged as crucial players in tumorigenesis. Studies on murine and human cells have examined the role of peroxisomes in carcinogenesis with conflicting results. These studies either examined the consequences of altered peroxisomal proliferators or compared their expression in healthy and neoplastic tissues. None, however, examined such differences exclusively in human parotid tissue or extended comparison to peroxisomal proteins and their associated gene expressions. Therefore, we examined differences in peroxisomal dynamics in parotid tumors of different morphologies. Using immunofluorescence and quantitative PCR, we compared the expression levels of key peroxisomal enzymes and proliferators in healthy and neoplastic parotid tissue samples. Three parotid tumor subtypes were examined: pleomorphic adenoma, mucoepidermoid carcinoma and acinic cell carcinoma. We observed higher expression of peroxisomal matrix proteins in neoplastic samples with exceptional down regulation of certain enzymes; however, the degree of expression varied between tumor subtypes. Our findings confirm previous experimental results on other organ tissues and suggest peroxisomes as possible therapeutic targets or markers in all or certain subtypes of parotid neoplasms. KW - peroxisomes KW - parotid gland KW - salivary KW - tumors KW - pleomorphic adenoma KW - mucoepidermoid carcinoma KW - acinic cell carcinoma KW - differential expression KW - immunohistochemistry KW - mRNA Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-261047 SN - 1422-0067 VL - 22 IS - 15 ER - TY - JOUR A1 - Schlecht, Anja A1 - Vallon, Mario A1 - Wagner, Nicole A1 - Ergün, Süleyman A1 - Braunger, Barbara M. T1 - TGFβ-Neurotrophin Interactions in Heart, Retina, and Brain JF - Biomolecules N2 - Ischemic insults to the heart and brain, i.e., myocardial and cerebral infarction, respectively, are amongst the leading causes of death worldwide. While there are therapeutic options to allow reperfusion of ischemic myocardial and brain tissue by reopening obstructed vessels, mitigating primary tissue damage, post-infarction inflammation and tissue remodeling can lead to secondary tissue damage. Similarly, ischemia in retinal tissue is the driving force in the progression of neovascular eye diseases such as diabetic retinopathy (DR) and age-related macular degeneration (AMD), which eventually lead to functional blindness, if left untreated. Intriguingly, the easily observable retinal blood vessels can be used as a window to the heart and brain to allow judgement of microvascular damages in diseases such as diabetes or hypertension. The complex neuronal and endocrine interactions between heart, retina and brain have also been appreciated in myocardial infarction, ischemic stroke, and retinal diseases. To describe the intimate relationship between the individual tissues, we use the terms heart-brain and brain-retina axis in this review and focus on the role of transforming growth factor β (TGFβ) and neurotrophins in regulation of these axes under physiologic and pathologic conditions. Moreover, we particularly discuss their roles in inflammation and repair following ischemic/neovascular insults. As there is evidence that TGFβ signaling has the potential to regulate expression of neurotrophins, it is tempting to speculate, and is discussed here, that cross-talk between TGFβ and neurotrophin signaling protects cells from harmful and/or damaging events in the heart, retina, and brain. KW - heart-brain axis KW - brain-retina axis KW - neurotrophins KW - TGFβ signaling KW - myocardial infarction KW - diabetic retinopathy KW - age-related macular degeneration KW - ischemic stroke Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-246159 SN - 2218-273X VL - 11 IS - 9 ER - TY - JOUR A1 - Schlecht, Anja A1 - Thien, Adrian A1 - Wolf, Julian A1 - Prinz, Gabriele A1 - Agostini, Hansjürgen A1 - Schlunck, Günther A1 - Wieghofer, Peter A1 - Boneva, Stefaniya A1 - Lange, Clemens T1 - Immunosenescence in choroidal neovascularization (CNV) — Transcriptional profiling of naïve and CNV-associated retinal myeloid cells during aging JF - International Journal of Molecular Sciences N2 - Immunosenescence is considered a possible factor in the development of age-related macular degeneration and choroidal neovascularization (CNV). However, age-related changes of myeloid cells (MCs), such as microglia and macrophages, in the healthy retina or during CNV formation are ill-defined. In this study, Cx3cr1-positive MCs were isolated by fluorescence-activated cell sorting from six-week (young) and two-year-old (old) Cx3cr1\(^{GFP/+}\) mice, both during physiological aging and laser-induced CNV development. High-throughput RNA-sequencing was performed to define the age-dependent transcriptional differences in MCs during physiological aging and CNV development, complemented by immunohistochemical characterization and the quantification of MCs, as well as CNV size measurements. These analyses revealed that myeloid cells change their transcriptional profile during both aging and CNV development. In the steady state, senescent MCs demonstrated an upregulation of factors contributing to cell proliferation and chemotaxis, such as Cxcl13 and Cxcl14, as well as the downregulation of microglial signature genes. During CNV formation, aged myeloid cells revealed a significant upregulation of angiogenic factors such as Arg1 and Lrg1 concomitant with significantly enlarged CNV and an increased accumulation of MCs in aged mice in comparison to young mice. Future studies need to clarify whether this observation is an epiphenomenon or a causal relationship to determine the role of immunosenescence in CNV formation. KW - age-related macular degeneration (AMD) KW - choroidal neovascularization (CNV) KW - aging KW - immunosenescence KW - microglia KW - myeloid cells KW - RNA-sequencing Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-284342 SN - 1422-0067 VL - 22 IS - 24 ER - TY - JOUR A1 - Liu, Fengming A1 - Han, Kun A1 - Blair, Robert A1 - Kenst, Kornelia A1 - Qin, Zhongnan A1 - Upcin, Berin A1 - Wörsdörfer, Philipp A1 - Midkiff, Cecily C. A1 - Mudd, Joseph A1 - Belyaeva, Elizaveta A1 - Milligan, Nicholas S. A1 - Rorison, Tyler D. A1 - Wagner, Nicole A1 - Bodem, Jochen A1 - Dölken, Lars A1 - Aktas, Bertal H. A1 - Vander Heide, Richard S. A1 - Yin, Xiao-Ming A1 - Kolls, Jay K. A1 - Roy, Chad J. A1 - Rappaport, Jay A1 - Ergün, Süleyman A1 - Qin, Xuebin T1 - SARS-CoV-2 Infects Endothelial Cells In Vivo and In Vitro JF - Frontiers in Cellular and Infection Microbiology N2 - SARS-CoV-2 infection can cause fatal inflammatory lung pathology, including thrombosis and increased pulmonary vascular permeability leading to edema and hemorrhage. In addition to the lung, cytokine storm-induced inflammatory cascade also affects other organs. SARS-CoV-2 infection-related vascular inflammation is characterized by endotheliopathy in the lung and other organs. Whether SARS-CoV-2 causes endotheliopathy by directly infecting endothelial cells is not known and is the focus of the present study. We observed 1) the co-localization of SARS-CoV-2 with the endothelial cell marker CD31 in the lungs of SARS-CoV-2-infected mice expressing hACE2 in the lung by intranasal delivery of adenovirus 5-hACE2 (Ad5-hACE2 mice) and non-human primates at both the protein and RNA levels, and 2) SARS-CoV-2 proteins in endothelial cells by immunogold labeling and electron microscopic analysis. We also detected the co-localization of SARS-CoV-2 with CD31 in autopsied lung tissue obtained from patients who died from severe COVID-19. Comparative analysis of RNA sequencing data of the lungs of infected Ad5-hACE2 and Ad5-empty (control) mice revealed upregulated KRAS signaling pathway, a well-known pathway for cellular activation and dysfunction. Further, we showed that SARS-CoV-2 directly infects mature mouse aortic endothelial cells (AoECs) that were activated by performing an aortic sprouting assay prior to exposure to SARS-CoV-2. This was demonstrated by co-localization of SARS-CoV-2 and CD34 by immunostaining and detection of viral particles in electron microscopic studies. Moreover, the activated AoECs became positive for ACE-2 but not quiescent AoECs. Together, our results indicate that in addition to pneumocytes, SARS-CoV-2 also directly infects mature vascular endothelial cells in vivo and ex vivo, which may contribute to cardiovascular complications in SARS-CoV-2 infection, including multipleorgan failure. KW - endothelial cell infection KW - animal models KW - SARS-CoV-2 KW - aorta ring KW - hACE2 Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-241948 SN - 2235-2988 VL - 11 ER - TY - JOUR A1 - Rajendran, Ranjithkumar A1 - Rajendran, Vinothkumar A1 - Giraldo-Velasquez, Mario A1 - Megalofonou, Fevronia-Foivi A1 - Gurski, Fynn A1 - Stadelmann, Christine A1 - Karnati, Srikanth A1 - Berghoff, Martin T1 - Oligodendrocyte-specific deletion of FGFR1 reduces cerebellar inflammation and neurodegeneration in MOG\(_{35-55}\)-induced EAE JF - International Journal of Molecular Sciences N2 - Multiple sclerosis (MS) is a chronic inflammatory and degenerative disease of the central nervous system (CNS). MS commonly affects the cerebellum causing acute and chronic symptoms. Cerebellar signs significantly contribute to clinical disability, and symptoms such as tremor, ataxia, and dysarthria are difficult to treat. Fibroblast growth factors (FGFs) and their receptors (FGFRs) are involved in demyelinating pathologies such as MS. In autopsy tissue from patients with MS, increased expression of FGF1, FGF2, FGF9, and FGFR1 was found in lesion areas. Recent research using mouse models has focused on regions such as the spinal cord, and data on the expression of FGF/FGFR in the cerebellum are not available. In recent EAE studies, we detected that oligodendrocyte-specific deletion of FGFRs results in a milder disease course, less cellular infiltrates, and reduced neurodegeneration in the spinal cord. The objective of this study was to characterize the role of FGFR1 in oligodendrocytes in the cerebellum. Conditional deletion of FGFR1 in oligodendrocytes (Fgfr1\(^{ind−/−}\) was achieved by tamoxifen application, EAE was induced using the MOG\(_{35-55}\) peptide. The cerebellum was analyzed by histology, immunohistochemistry, and western blot. At day 62 p.i., Fgfr1\(^{ind−/−}\) mice showed less myelin and axonal degeneration compared to FGFR1-competent mice. Infiltration of CD3(+) T cells, Mac3(+) cells, B220(+) B cells and IgG(+) plasma cells in cerebellar white matter lesions (WML) was less in Fgfr1\(^{ind−/−}\)mice. There were no effects on the number of OPC or mature oligodendrocytes in white matter lesion (WML). Expression of FGF2 and FGF9 associated with less myelin and axonal degeneration, and of the pro-inflammatory cytokines IL-1β, IL-6, and CD200 was downregulated in Fgfr1\(^{ind−/−}\) mice. The FGF/FGFR signaling protein pAkt, BDNF, and TrkB were increased in Fgfr1\(^{ind−/−}\) mice. These data suggest that cell-specific deletion of FGFR1 in oligodendrocytes has anti-inflammatory and neuroprotective effects in the cerebellum in the EAE disease model of MS. KW - FGFR1 KW - oligodendrocytes KW - demyelination KW - inflammation KW - cerebellum KW - EAE KW - MS Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-284296 SN - 1422-0067 VL - 22 IS - 17 ER - TY - JOUR A1 - Wagner, Nicole A1 - Mott, Kristina A1 - Upcin, Berin A1 - Stegner, David A1 - Schulze, Harald A1 - Ergün, Süleyman T1 - CXCL12-abundant reticular (CAR) cells direct megakaryocyte protrusions across the bone marrow sinusoid wall JF - Cells N2 - Megakaryocytes (MKs) release platelets into the lumen of bone marrow (BM) sinusoids while remaining to reside within the BM. The morphogenetic events of this complex process are still not fully understood. We combined confocal laser scanning microscopy with transmission and serial block-face scanning electron microscopy followed by 3D-reconstruction on mouse BM tissue sections. These analyses revealed that MKs in close vicinity to BM sinusoid (BMS) wall first induce the lateral retraction of CXCL12-abundant reticular (CAR) cells (CAR), followed by basal lamina (BL) degradation enabling direct MK-sinusoidal endothelial cells (SECs) interaction. Subsequently, an endothelial engulfment starts that contains a large MK protrusion. Then, MK protrusions penetrate the SEC, transmigrate into the BMS lumen and form proplatelets that are in direct contact to the SEC surface. Furthermore, such processes are induced on several sites, as observed by 3D reconstructions. Our data demonstrate that MKs in interaction with CAR-cells actively induce BMS wall alterations, including CAR-cell retraction, BL degradation, and SEC engulfment containing a large MK protrusion. This results in SEC penetration enabling the migration of MK protrusion into the BMS lumen where proplatelets that are adherent to the luminal SEC surface are formed and contribute to platelet release into the blood circulation. KW - megakaryocytes KW - microvasculature KW - CXCL12-abundant reticular (CAR)-cells Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-234180 SN - 2073-4409 VL - 10 IS - 4 ER - TY - JOUR A1 - Koeniger, Tobias A1 - Bell, Luisa A1 - Mifka, Anika A1 - Enders, Michael A1 - Hautmann, Valentin A1 - Mekala, Subba Rao A1 - Kirchner, Philipp A1 - Ekici, Arif B. A1 - Schulz, Christian A1 - Wörsdörfer, Philipp A1 - Mencl, Stine A1 - Kleinschnitz, Christoph A1 - Ergün, Süleyman A1 - Kuerten, Stefanie T1 - Bone marrow‐derived myeloid progenitors in the leptomeninges of adult mice JF - Stem Cells N2 - Although the bone marrow contains most hematopoietic activity during adulthood, hematopoietic stem and progenitor cells can be recovered from various extramedullary sites. Cells with hematopoietic progenitor properties have even been reported in the adult brain under steady‐state conditions, but their nature and localization remain insufficiently defined. Here, we describe a heterogeneous population of myeloid progenitors in the leptomeninges of adult C57BL/6 mice. This cell pool included common myeloid, granulocyte/macrophage, and megakaryocyte/erythrocyte progenitors. Accordingly, it gave rise to all major myelo‐erythroid lineages in clonogenic culture assays. Brain‐associated progenitors persisted after tissue perfusion and were partially inaccessible to intravenous antibodies, suggesting their localization behind continuous blood vessel endothelium such as the blood‐arachnoid barrier. Flt3\(^{Cre}\) lineage tracing and bone marrow transplantation showed that the precursors were derived from adult hematopoietic stem cells and were most likely continuously replaced via cell trafficking. Importantly, their occurrence was tied to the immunologic state of the central nervous system (CNS) and was diminished in the context of neuroinflammation and ischemic stroke. Our findings confirm the presence of myeloid progenitors at the meningeal border of the brain and lay the foundation to unravel their possible functions in CNS surveillance and local immune cell production. KW - hematopoietic KW - meninges KW - mouse KW - myeloid KW - progenitor Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-224452 VL - 39 IS - 2 SP - 227 EP - 239 ER -