@article{KusanSuratKelmetal.2022, author = {Kusan, Simon and Surat, G{\"u}zin and Kelm, Matthias and Anger, Friedrich and Kim, Mia and Germer, Christoph-Thomas and Schlegel, Nicolas and Flemming, Sven}, title = {Microbial spectrum and antibiotic resistance in patients suffering from penetrating Crohn's disease}, series = {Journal of Clinical Medicine}, volume = {11}, journal = {Journal of Clinical Medicine}, number = {15}, issn = {2077-0383}, doi = {10.3390/jcm11154343}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-281835}, year = {2022}, abstract = {Intraabdominal abscess formation occurs in up to 30\% of patients suffering from Crohn's disease (CD). While international guidelines recommend a step-up approach with a combination of empiric antibiotic therapy and percutaneous drainage to delay or even avoid surgery, evidence about microbial spectrum in penetrating ileitis is sparse. We retrospectively assessed outcomes of 46 patients with terminal penetrating Ileitis where microbial diagnostics have been performed and compared microbial spectrum and antibiotic resistance profile of CD patients with patients suffering from diverticulitis with intraabdominal abscess formation. In both groups, the most frequently isolated pathogen was the gram-negative bacterium E. coli belonging to the family of Enterobacterales. However, overall Enterobacterales were significantly more often verifiable in the control group than in CD patients. Furthermore, microbial analysis showed significant differences regarding isolation of anaerobic pathogens with decreased frequency in patients with CD. Subgroup analysis of CD patients to evaluate a potential influence of immunosuppressive therapy on microbial spectrum only revealed that Enterobacterales was less frequently detected in patients treated with steroids. Immunosuppressive therapy did not show any impact on all other groups of pathogens and did not change antibiotic resistance profile of CD patients. In conclusion, we were able to demonstrate that the microbial spectrum of CD patients does differ only for some pathogen species without increased rate of antibiotic resistance. However, the empiric antibiotic therapy for CD-associated intra-abdominal abscess remains challenging since different points such as local epidemiological and microbiological data, individual patient risk factors, severity of infection, and therapy algorithm including non-surgical and surgical therapy options should be considered before therapeutical decisions are made.}, language = {en} } @article{OttoKastnerSchmidtetal.2022, author = {Otto, Christoph and Kastner, Carolin and Schmidt, Stefanie and Uttinger, Konstantin and Baluapuri, Apoorva and Denk, Sarah and Rosenfeldt, Mathias T. and Rosenwald, Andreas and Roehrig, Florian and Ade, Carsten P. and Schuelein-Voelk, Christina and Diefenbacher, Markus E. and Germer, Christoph-Thomas and Wolf, Elmar and Eilers, Martin and Wiegering, Armin}, title = {RNA polymerase I inhibition induces terminal differentiation, growth arrest, and vulnerability to senolytics in colorectal cancer cells}, series = {Molecular Oncology}, volume = {16}, journal = {Molecular Oncology}, number = {15}, doi = {10.1002/1878-0261.13265}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-312806}, pages = {2788-2809}, year = {2022}, abstract = {Ribosomal biogenesis and protein synthesis are deregulated in most cancers, suggesting that interfering with translation machinery may hold significant therapeutic potential. Here, we show that loss of the tumor suppressor adenomatous polyposis coli (APC), which constitutes the initiating event in the adenoma carcinoma sequence for colorectal cancer (CRC), induces the expression of RNA polymerase I (RNAPOL1) transcription machinery, and subsequently upregulates ribosomal DNA (rDNA) transcription. Targeting RNAPOL1 with a specific inhibitor, CX5461, disrupts nucleolar integrity, and induces a disbalance of ribosomal proteins. Surprisingly, CX5461-induced growth arrest is irreversible and exhibits features of senescence and terminal differentiation. Mechanistically, CX5461 promotes differentiation in an MYC-interacting zinc-finger protein 1 (MIZ1)- and retinoblastoma protein (Rb)-dependent manner. In addition, the inhibition of RNAPOL1 renders CRC cells vulnerable towards senolytic agents. We validated this therapeutic effect of CX5461 in murine- and patient-derived organoids, and in a xenograft mouse model. These results show that targeting ribosomal biogenesis together with targeting the consecutive, senescent phenotype using approved drugs is a new therapeutic approach, which can rapidly be transferred from bench to bedside.}, language = {en} } @article{KelmGermerSchlegeletal.2021, author = {Kelm, Matthias and Germer, Christoph-Thomas and Schlegel, Nicolas and Flemming, Sven}, title = {The revival of surgery in Crohn's disease — early intestinal resection as a reasonable alternative in localized ileitis}, series = {Biomedicines}, volume = {9}, journal = {Biomedicines}, number = {10}, issn = {2227-9059}, doi = {10.3390/biomedicines9101317}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-246296}, year = {2021}, abstract = {Crohn's disease (CD) represents a heterogeneous and complex disease with no curative therapeutic option available to date. Current therapy is mainly antibody-based focusing on the immune system while other treatment alternatives such as surgery are considered to be "last options". However, medical therapy for CD results in mild to severe side effects in a relevant amount of patients and some patients do not respond to the medication. Following that, quality of life is often significantly reduced in this patient cohort, thus, therapeutic alternatives are urgently needed. Updated evidence has revealed that surgery such as ileocecal resection (ICR) might be a potential therapeutic option in case of localized terminal ileitis since resection at early time points improves quality of life and significantly reduces the postoperative need for immunosuppressive medication with low rates of morbidity. In addition, new surgical approaches such as Kono-S anastomosis or inclusion of the mesentery result in significantly reduced rates of disease recurrence and reoperation. Based on the new evidence, the goal of this review is to provide an update on the role of surgery as a reasonable alternative to medical therapy in the interdisciplinary treatment of patients with CD.}, language = {en} } @article{KoehlerReeseKastneretal.2022, author = {K{\"o}hler, Franziska and Reese, Lena and Kastner, Carolin and Hendricks, Anne and M{\"u}ller, Sophie and Lock, Johan F. and Germer, Christoph-Thomas and Wiegering, Armin}, title = {Surgical site infection following single-port appendectomy: a systematic review of the literature and meta-analysis}, series = {Frontiers in Surgery}, volume = {9}, journal = {Frontiers in Surgery}, issn = {2296-875X}, doi = {10.3389/fsurg.2022.919744}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-276943}, year = {2022}, abstract = {Introduction Surgical site infections (SSIs) are one of the most common postoperative complications after appendectomy leading to recurrent surgery, prolonged hospital stay, and the use of antibiotics. Numerous studies and meta-analyses have been published on the effect of open versus conventional laparoscopic appendectomy (CLA) reporting faster postoperative recovery and less postoperative pain for CLA. A development from CLA has been the single-port appendectomy (SPA), associated with a better cosmesis but seemingly having a higher risk of wound infections. The aim of this systematic literature review and meta-analysis is to investigate whether reduced port or SPA alters the ratio of SSIs. Methods Pubmed, Embase, and Cochrane databases were screened for suitable articles. All articles published between January 1, 2002, and March 23, 2022, were included. Articles regarding children below the age of 18 were excluded as well as manuscripts that investigated solemnly open appendectomies. Articles were screened for inclusion criteria by two independent authors. Incidence of SSI was the primary outcome. Duration of operation and length of hospital stay were defined as secondary outcomes. Results A total of 25 studies were found through a database search describing 5484 patients. A total of 2749 patients received SPA and 2735 received CLA. There was no statistical difference in the rate of SSI (P = 0.98). A total of 22 studies including 4699 patients reported the duration of operation (2223 SPA and 2476 CLA). There was a significantly shorter operation time seen in CLA. The length of hospital stay was reported in 23 studies (4735 patients: 2235 SPA and 2500 CLA). A shorter hospital stay was seen in the SPA group (P < 0.00001). Separately performed analysis of randomized controlled trials could not confirm this effect (P = 0.29). Discussion SPA is an equally safe procedure considering SSI compared to CLA and does not lead to an increased risk of SSI. A longer operation time for SPA and a minor difference in the length of stay does lead to the use of SPA in selected patients only.}, language = {en} } @article{HendricksMeirHankiretal.2022, author = {Hendricks, Anne and Meir, Michael and Hankir, Mohammed and Lenschow, Christina and Germer, Christoph-Thomas and Schneider, Michael and Wiegering, Armin and Schlegel, Nicolas}, title = {Suppurative thyroiditis caused by ingested fish bone in the thyroid gland: a case report on its diagnostics and surgical therapy}, series = {BMC Surgery}, volume = {22}, journal = {BMC Surgery}, number = {1}, doi = {10.1186/s12893-022-01542-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-299775}, year = {2022}, abstract = {Background Accidental ingestion of fish bone is a common cause of otolaryngological emergency. Migration of the ingested bone into the thyroid gland, however, occurs very rarely. The associated clinical presentation, symptoms and duration of discomfort are also highly variable between patients and can be diagnostically challenging. Case presentation Here, we report the case of a 71-year-old female patient presenting with an ingested fish bone that migrated into the right thyroid lobe as a rare cause of suppurative thyroiditis with the clinical features of sepsis. We outline the diagnostic approach, peri- and intraoperative management as well as complications. It is proposed that besides endoscopy, imaging methods such as ultrasound or computed tomography may be necessary to verify the diagnosis and location of an ingested fish bone. Prompt surgical removal of the foreign body and resection of the infectious focus is recommended to minimize the risk of local inflammation, recurrent nerve lesions and septic complications arising from the spread of infection. Conclusion Fish bone migration into the thyroid gland is an extremely rare event, the successful detection and surgical management of which can be achieved through a careful interdisciplinary approach.}, language = {en} } @article{WillmsSchwabvonWebskyetal.2022, author = {Willms, A. G. and Schwab, R. and von Websky, M. W. and Berrevoet, F. and Tartaglia, D. and S{\"o}relius, K. and Fortelny, R. H. and Bj{\"o}rck, M. and Monchal, T. and Brennfleck, F. and Bulian, D. and Beltzer, C. and Germer, C. T. and Lock, J. F.}, title = {Factors influencing the fascial closure rate after open abdomen treatment: Results from the European Hernia Society (EuraHS) Registry. Surgical technique matters}, series = {Hernia}, volume = {26}, journal = {Hernia}, number = {1}, organization = {EURAHS Open Abdomen Group}, issn = {1265-4906}, doi = {10.1007/s10029-020-02336-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-234871}, pages = {61-73}, year = {2022}, abstract = {Purpose Definitive fascial closure is an essential treatment objective after open abdomen treatment and mitigates morbidity and mortality. There is a paucity of evidence on factors that promote or prevent definitive fascial closure. Methods A multi-center multivariable analysis of data from the Open Abdomen Route of the European Hernia Society included all cases between 1 May 2015 and 31 December 2019. Different treatment elements, i.e. the use of a visceral protective layer, negative-pressure wound therapy and dynamic closure techniques, as well as patient characteristics were included in the multivariable analysis. The study was registered in the International Clinical Trials Registry Platform via the German Registry for Clinical Trials (DRK00021719). Results Data were included from 630 patients from eleven surgical departments in six European countries. Indications for OAT were peritonitis (46\%), abdominal compartment syndrome (20.5\%), burst abdomen (11.3\%), abdominal trauma (9\%), and other conditions (13.2\%). The overall definitive fascial closure rate was 57.5\% in the intention-to-treat analysis and 71\% in the per-protocol analysis. The multivariable analysis showed a positive correlation of negative-pressure wound therapy (odds ratio: 2.496, p < 0.001) and dynamic closure techniques (odds ratio: 2.687, p < 0.001) with fascial closure and a negative correlation of intra-abdominal contamination (odds ratio: 0.630, p = 0.029) and the number of surgical procedures before OAT (odds ratio: 0.740, p = 0.005) with DFC. Conclusion The clinical course and prognosis of open abdomen treatment can significantly be improved by the use of treatment elements such as negative-pressure wound therapy and dynamic closure techniques, which are associated with definitive fascial closure.}, language = {en} } @article{MetznerHerzogHeckeletal.2022, author = {Metzner, Valentin and Herzog, Gloria and Heckel, Tobias and Bischler, Thorsten and Hasinger, Julia and Otto, Christoph and Fassnacht, Martin and Geier, Andreas and Seyfried, Florian and Dischinger, Ulrich}, title = {Liraglutide + PYY\(_{3-36}\) combination therapy mimics effects of Roux-en-Y bypass on early NAFLD whilst lacking-behind in metabolic improvements}, series = {Journal of Clinical Medicine}, volume = {11}, journal = {Journal of Clinical Medicine}, number = {3}, issn = {2077-0383}, doi = {10.3390/jcm11030753}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-255244}, year = {2022}, abstract = {Background: Treatment options for NAFLD are still limited. Bariatric surgery, such as Roux-en-Y gastric bypass (RYGB), has been shown to improve metabolic and histologic markers of NAFLD. Glucagon-like-peptide-1 (GLP-1) analogues lead to improvements in phase 2 clinical trials. We directly compared the effects of RYGB with a treatment using liraglutide and/or peptide tyrosine tyrosine 3-36 (PYY\(_{3-36}\)) in a rat model for early NAFLD. Methods: Obese male Wistar rats (high-fat diet (HFD)-induced) were randomized into the following treatment groups: RYGB, sham-operation (sham), liraglutide (0.4 mg/kg/day), PYY\(_{3-36}\) (0.1 mg/kg/day), liraglutide+PYY\(_{3-36}\), and saline. After an observation period of 4 weeks, liver samples were histologically evaluated, ELISAs and RNA sequencing + RT-qPCRs were performed. Results: RYGB and liraglutide+PYY\(_{3-36}\) induced a similar body weight loss and, compared to sham/saline, marked histological improvements with significantly less steatosis. However, only RYGB induced significant metabolic improvements (e.g., adiponectin/leptin ratio 18.8 ± 11.8 vs. 2.4 ± 1.2 in liraglutide+PYY\(_{3-36}\)- or 1.4 ± 0.9 in sham-treated rats). Furthermore, RNA sequencing revealed a high number of differentially regulated genes in RYGB treated animals only. Conclusions: The combination therapy of liraglutide+PYY\(_{3-36}\) partly mimics the positive effects of RYGB on weight reduction and on hepatic steatosis, while its effects on metabolic function lack behind RYGB.}, language = {en} } @article{KelmAngerEichlingeretal.2021, author = {Kelm, Matthias and Anger, Friedrich and Eichlinger, Robin and Brand, Markus and Kim, Mia and Reibetanz, Joachim and Krajinovic, Katica and Germer, Christoph-Thomas and Schlegel, Nicolas and Flemming, Sven}, title = {Early Ileocecal Resection Is an Effective Therapy in Isolated Crohn's Disease}, series = {Journal of Clinical Medicine}, volume = {10}, journal = {Journal of Clinical Medicine}, number = {4}, issn = {2077-0383}, doi = {10.3390/jcm10040731}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-228822}, year = {2021}, abstract = {Despite the increasing incidence and prevalence of Crohn's Disease (CD), no curative options exist and treatment remains complex. While therapy has mainly focused on medical approaches in the past, growing evidence reveals that in cases of limited inflammation, surgery can suffice as an alternative primary treatment. We retrospectively assessed the disease course and outcomes of 103 patients with terminal Ileitis who underwent primary surgery (n = 29) or received primary medical treatment followed by surgery (n = 74). Primary endpoint was the need for immunosuppressive medication after surgical treatment (ileocecal resection, ICR) during a two-years follow-up. Rates for laparoscopic ICR were enhanced in case of early surgery, but no differences were seen for postoperative complications. In case of immunosuppressive medication, patients with ICR at an early state of disease needed significantly less anti-inflammatory medication during the two-year postoperative follow-up compared to patients who were primarily treated medically. Furthermore, in a subgroup analysis for patients with localized ileocecal disease manifestation, early surgery consistently resulted in a decreased amount of medical therapy postoperatively. In conclusion primary ICR is safe and effective in patients with limited CD, and the need for immunosuppressive medication during the postoperative follow-up is low compared to patients receiving surgery at a later stage of disease.}, language = {en} } @article{BankogluArnoldHeringetal.2018, author = {Bankoglu, Ezgi Eyluel and Arnold, Charlotte and Hering, Ilona and Hankir, Mohammed and Seyfried, Florian and Stopper, Helga}, title = {Decreased chromosomal damage in lymphocytes of obese patients after bariatric surgery}, series = {Scientific Reports}, volume = {8}, journal = {Scientific Reports}, number = {11195}, doi = {10.1038/s41598-018-29581-6}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-177090}, year = {2018}, abstract = {The number of bariatric surgeries being performed worldwide has markedly risen. While the improvement in obesity-associated comorbidities after bariatric surgery is well-established, very little is known about its impact on cancer risk. The peripheral lymphocyte micronucleus test is a widely used method for the monitoring of chromosomal damage levels in vivo, and micronucleus frequency positively correlates with cancer risk. Therefore, the aim of this study was to compare the micronucleus frequency before and after bariatric surgery in obese subjects. Peripheral blood mononuclear cells were collected from 45 obese subjects before and at two time-points after bariatric surgery (6 and 12 months) to assess spontaneous micronucleus frequency. Consistent with the increased cancer risk previously shown, bariatric surgery-induced weight loss led to a significant reduction in lymphocyte micronucleus frequency after 12 months. Interestingly, comorbidities such as type 2 diabetes mellitus and metabolic syndrome further seemed to have an impact on the lymphocyte micronucleus frequency. Our findings may indicate a successful reduction of cancer risk in patients following weight loss caused by bariatric surgery.}, language = {en} } @article{BelicPageLazariotouetal.2019, author = {Belic, Stanislav and Page, Lukas and Lazariotou, Maria and Waaga-Gasser, Ana Maria and Dragan, Mariola and Springer, Jan and Loeffler, Juergen and Morton, Charles Oliver and Einsele, Hermann and Ullmann, Andrew J. and Wurster, Sebastian}, title = {Comparative Analysis of Inflammatory Cytokine Release and Alveolar Epithelial Barrier Invasion in a Transwell® Bilayer Model of Mucormycosis}, series = {Frontiers in Microbiology}, volume = {9}, journal = {Frontiers in Microbiology}, doi = {10.3389/fmicb.2018.03204}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-252477}, year = {2019}, abstract = {Understanding the mechanisms of early invasion and epithelial defense in opportunistic mold infections is crucial for the evaluation of diagnostic biomarkers and novel treatment strategies. Recent studies revealed unique characteristics of the immunopathology of mucormycoses. We therefore adapted an alveolar Transwell® A549/HPAEC bilayer model for the assessment of epithelial barrier integrity and cytokine response to Rhizopus arrhizus, Rhizomucor pusillus, and Cunninghamella bertholletiae. Hyphal penetration of the alveolar barrier was validated by 18S ribosomal DNA detection in the endothelial compartment. Addition of dendritic cells (moDCs) to the alveolar compartment led to reduced fungal invasion and strongly enhanced pro-inflammatory cytokine response, whereas epithelial CCL2 and CCL5 release was reduced. Despite their phenotypic heterogeneity, the studied Mucorales species elicited the release of similar cytokine patterns by epithelial and dendritic cells. There were significantly elevated lactate dehydrogenase concentrations in the alveolar compartment and epithelial barrier permeability for dextran blue of different molecular weights in Mucorales-infected samples compared to Aspergillus fumigatus infection. Addition of monocyte-derived dendritic cells further aggravated LDH release and epithelial barrier permeability, highlighting the influence of the inflammatory response in mucormycosis-associated tissue damage. An important focus of this study was the evaluation of the reproducibility of readout parameters in independent experimental runs. Our results revealed consistently low coefficients of variation for cytokine concentrations and transcriptional levels of cytokine genes and cell integrity markers. As additional means of model validation, we confirmed that our bilayer model captures key principles of Mucorales biology such as accelerated growth in a hyperglycemic or ketoacidotic environment or reduced epithelial barrier invasion upon epithelial growth factor receptor blockade by gefitinib. Our findings indicate that the Transwell® bilayer model provides a reliable and reproducible tool for assessing host response in mucormycosis.}, language = {en} } @article{BaurOttoStegeretal.2018, author = {Baur, Johannes and Otto, Christoph and Steger, Ulrich and Klein-Hessling, Stefan and Muhammad, Khalid and Pusch, Tobias and Murti, Krisna and Wismer, Rhoda and Germer, Christoph-Thomas and Klein, Ingo and M{\"u}ller, Nora and Serfling, Edgar and Avots, Andris}, title = {The transcription factor NFaTc1 supports the rejection of heterotopic heart allografts}, series = {Frontiers in Immunology}, volume = {9}, journal = {Frontiers in Immunology}, doi = {10.3389/fimmu.2018.01338}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-221530}, year = {2018}, abstract = {The immune suppressants cyclosporin A (CsA) and tacrolimus (FK506) are used worldwide in transplantation medicine to suppress graft rejection. Both CsA and FK506 inhibit the phosphatase calcineurin (CN) whose activity controls the immune receptor-mediated activation of lymphocytes. Downstream targets of CN in lymphocytes are the nuclear factors of activated T cells (NFATs). We show here that the activity of NFATc1, the most prominent NFAT factor in activated lymphocytes supports the acute rejection of heterotopic heart allografts. While ablation of NFATc1 in T cells prevented graft rejection, ectopic expression of inducible NFATc1/αA isoform led to rejection of heart allografts in recipient mice. Acceptance of transplanted hearts in mice bearing NFATc1-deficient T cells was accompanied by a reduction in number and cytotoxicity of graft infiltrating cells. In CD8\(^+\) T cells, NFATc1 controls numerous intracellular signaling pathways that lead to the metabolic switch to aerobic glycolysis and the expression of numerous lymphokines, chemokines, and their receptors, including Cxcr3 that supports the rejection of allogeneic heart transplants. These findings favors NFATc1 as a molecular target for the development of new strategies to control the cytotoxicity of T cells upon organ transplantation.}, language = {en} } @article{AnanyKreckelFuellsacketal.2018, author = {Anany, Mohamed A. and Kreckel, Jennifer and F{\"u}llsack, Simone and Rosenthal, Alevtina and Otto, Christoph and Siegmund, Daniela and Wajant, Harald}, title = {Soluble TNF-like weak inducer of apoptosis (TWEAK) enhances poly(I:C)-induced RIPK1-mediated necroptosis}, series = {Cell Death \& Disease}, volume = {9}, journal = {Cell Death \& Disease}, doi = {10.1038/s41419-018-1137-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-221104}, year = {2018}, abstract = {TNF-like weak inducer of apoptosis (TWEAK) and inhibition of protein synthesis with cycloheximide (CHX) sensitize for poly(I:C)-induced cell death. Notably, although CHX preferentially enhanced poly(I:C)-induced apoptosis, TWEAK enhanced primarily poly(I:C)-induced necroptosis. Both sensitizers of poly(I:C)-induced cell death, however, showed no major effect on proinflammatory poly(I:C) signaling. Analysis of a panel of HeLa-RIPK3 variants lacking TRADD, RIPK1, FADD, or caspase-8 expression revealed furthermore similarities and differences in the way how poly(I:C)/TWEAK, TNF, and TRAIL utilize these molecules for signaling. RIPK1 turned out to be essential for poly(I:C)/TWEAK-induced caspase-8-mediated apoptosis but was dispensable for this response in TNF and TRAIL signaling. TRADD-RIPK1-double deficiency differentially affected poly(I:C)-triggered gene induction but abrogated gene induction by TNF completely. FADD deficiency abrogated TRAIL- but not TNF- and poly(I:C)-induced necroptosis, whereas TRADD elicited protective activity against all three death inducers. A general protective activity against poly(I:C)-, TRAIL-, and TNF-induced cell death was also observed in FLIPL and FLIPS transfectrants.}, language = {en} } @article{BaluapuriHofstetterDudvarskiStankovicetal.2019, author = {Baluapuri, Apoorva and Hofstetter, Julia and Dudvarski Stankovic, Nevenka and Endres, Theresa and Bhandare, Pranjali and Vos, Seychelle Monique and Adhikari, Bikash and Schwarz, Jessica Denise and Narain, Ashwin and Vogt, Markus and Wang, Shuang-Yan and D{\"u}ster, Robert and Jung, Lisa Anna and Vanselow, Jens Thorsten and Wiegering, Armin and Geyer, Matthias and Maric, Hans Michael and Gallant, Peter and Walz, Susanne and Schlosser, Andreas and Cramer, Patrick and Eilers, Martin and Wolf, Elmar}, title = {MYC Recruits SPT5 to RNA Polymerase II to Promote Processive Transcription Elongation}, series = {Molecular Cell}, volume = {74}, journal = {Molecular Cell}, doi = {10.1016/j.molcel.2019.02.031}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-221438}, pages = {674-687}, year = {2019}, abstract = {The MYC oncoprotein binds to promoter-proximal regions of virtually all transcribed genes and enhances RNA polymerase II (Pol II) function, but its precise mode of action is poorly understood. Using mass spectrometry of both MYC and Pol II complexes, we show here that MYC controls the assembly of Pol II with a small set of transcription elongation factors that includes SPT5, a subunit of the elongation factor DSIF. MYC directly binds SPT5, recruits SPT5 to promoters, and enables the CDK7-dependent transfer of SPT5 onto Pol II. Consistent with known functions of SPT5, MYC is required for fast and processive transcription elongation. Intriguingly, the high levels of MYC that are expressed in tumors sequester SPT5 into non-functional complexes, thereby decreasing the expression of growth-suppressive genes. Altogether, these results argue that MYC controls the productive assembly of processive Pol II elongation complexes and provide insight into how oncogenic levels of MYC permit uncontrolled cellular growth.}, language = {en} } @article{ColungaHayworthKressetal.2019, author = {Colunga, Thomas and Hayworth, Miranda and Kreß, Sebastian and Reynolds, David M. and Chen, Luoman and Nazor, Kristopher L. and Baur, Johannes and Singh, Amar M. and Loring, Jeanne F. and Metzger, Marco and Dalton, Stephen}, title = {Human Pluripotent Stem Cell-Derived Multipotent Vascular Progenitors of the Mesothelium Lineage Have Utility in Tissue Engineering and Repair}, series = {Cell Reports}, volume = {26}, journal = {Cell Reports}, doi = {10.1016/j.celrep.2019.02.016}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-223217}, pages = {2566-2579}, year = {2019}, abstract = {In this report we describe a human pluripotent stem cell-derived vascular progenitor (MesoT) cell of the mesothelium lineage. MesoT cells are multipotent and generate smooth muscle cells, endothelial cells, and pericytes and self-assemble into vessel-like networks in vitro. MesoT cells transplanted into mechanically damaged neonatal mouse heart migrate into the injured tissue and contribute to nascent coronary vessels in the repair zone. When seeded onto decellularized vascular scaffolds, MesoT cells differentiate into the major vascular lineages and self-assemble into vasculature capable of supporting peripheral blood flow following transplantation. These findings demonstrate in vivo functionality and the potential utility of MesoT cells in vascular engineering applications.}, language = {en} } @article{MuehlemannZdziebloFriedrichetal.2018, author = {M{\"u}hlemann, Markus and Zdzieblo, Daniela and Friedrich, Alexandra and Berger, Constantin and Otto, Christoph and Walles, Heike and Koepsell, Hermann and Metzger, Marco}, title = {Altered pancreatic islet morphology and function in SGLT1 knockout mice on a glucose-deficient, fat-enriched diet}, series = {Molecular Metabolism}, volume = {13}, journal = {Molecular Metabolism}, doi = {10.1016/j.molmet.2018.05.011}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-224230}, pages = {67-76}, year = {2018}, abstract = {Objectives Glycemic control by medical treatment represents one therapeutic strategy for diabetic patients. The Na+-d-glucose cotransporter 1 (SGLT1) is currently of high interest in this context. SGLT1 is known to mediate glucose absorption and incretin secretion in the small intestine. Recently, inhibition of SGLT1 function was shown to improve postprandial hyperglycemia. In view of the lately demonstrated SGLT1 expression in pancreatic islets, we investigated if loss of SGLT1 affects islet morphology and function. Methods Effects associated with the loss of SGLT1 on pancreatic islet (cyto) morphology and function were investigated by analyzing islets of a SGLT1 knockout mouse model, that were fed a glucose-deficient, fat-enriched diet (SGLT1-/--GDFE) to circumvent the glucose-galactose malabsorption syndrome. To distinguish diet- and Sglt1-/--dependent effects, wildtype mice on either standard chow (WT-SC) or the glucose-free, fat-enriched diet (WT-GDFE) were used as controls. Feeding a glucose-deficient, fat-enriched diet further required the analysis of intestinal SGLT1 expression and function under diet-conditions. Results Consistent with literature, our data provide evidence that small intestinal SGLT1 mRNA expression and function is regulated by nutrition. In contrast, pancreatic SGLT1 mRNA levels were not affected by the applied diet, suggesting different regulatory mechanisms for SGLT1 in diverse tissues. Morphological changes such as increased islet sizes and cell numbers associated with changes in proliferation and apoptosis and alterations of the β- and α-cell population are specifically observed for pancreatic islets of SGLT1-/--GDFE mice. Glucose stimulation revealed no insulin response in SGLT1-/--GDFE mice while WT-GDFE mice displayed only a minor increase of blood insulin. Irregular glucagon responses were observed for both, SGLT1-/--GDFE and WT-GDFE mice. Further, both animal groups showed a sustained release of GLP-1 compared to WT-SC controls. Conclusion Loss or impairment of SGLT1 results in abnormal pancreatic islet (cyto)morphology and disturbed islet function regarding the insulin or glucagon release capacity from β- or α-cells, respectively. Consequently, our findings propose a new, additional role for SGLT1 maintaining proper islet structure and function.}, language = {en} }