@phdthesis{Krampert2024, author = {Krampert, Laura}, title = {Dynamics of cardiac neutrophil diversity in murine myocardial infarction}, doi = {10.25972/OPUS-34957}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-349576}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {After myocardial infarction, an inflammatory response is induced characterized by a sterile inflammation, followed by a reparative phase in order to induce cardiac healing. Neutrophils are the first immune cells that enter the ischemic tissue. Neutrophils have various functions in the ischemic heart, such as phagocytosis, production of reactive oxygen species or release of granule components. These functions can not only directly damage cardiac tissue, but are also necessary for initiating reparative effects in post-ischemic healing, indicating a dual role of neutrophils in cardiac healing after infarction. In recent years, evidence has been growing that neutrophils show phenotypic and functional differences in distinct homeostatic and pathogenic settings. Preliminary data of my working group using single-cell RNA-sequencing revealed the time- dependent heterogeneity of neutrophils, with different populations showing distinct gene expression profiles in ischemic hearts of mice, including the time-dependent appearance of a SiglecFhigh neutrophil population. To better understand the dynamics of neutrophil heterogeneity in the ischemic heart, my work aimed to validate previous findings at the protein level, as well as to investigate whether the distinct neutrophil populations show functional differences. Furthermore, in vivo depletion experiments were performed in order to modulate circulating neutrophil levels. Hearts, blood, bone marrow and spleens were processed and analyzed from mice after 1 day and 3 days after the onset of cardiac ischemia and analyzed using flow cytometry. Results showed that the majority of cardiac neutrophils isolated at day 3 after myocardial infarction were SiglecFhigh, whereas nearly no SiglecFhigh neutrophils could be isolated from ischemic hearts at day 1 after myocardial infarction. No SiglecFhigh neutrophils could be found in the blood, spleen and bone marrow either after 1 day or 3 days after myocardial infarction, indicating that the SiglecFhigh state of neutrophils is unique to the ischemic cardiac tissue. When I compared SiglecFhigh and SiglecFlow neutrophils regarding their phagocytosis activity and ROS production, SiglecFhigh neutrophils showed a higher phagocytosis ability than their SiglecFlow counterparts, as well as higher ROS production capacity. In vivo depletion experiments could not achieve successful and efficient depletion of cardiac neutrophils either 1 day or 3 days after myocardial infarction, but led to a shift of a higher percentage of SiglecFhigh expressing neutrophils in the depletion group. Bone marrow neutrophil levels only showed partial depletion at day 3 after MI. Regarding blood neutrophils, depletion efficiently reduced circulating neutrophils at both time points, 1 and 3 days after MI. To summarize, this work showed the time-dependent presence of different neutrophil states in the ischemic heart. The main population of neutrophils isolated 3 days after MI showed a high expression of SiglecF, a unique state that could not be detected at different time points or other organs. These SiglecFhigh neutrophils showed functional differences regarding their phagocytosis ability and ROS production. Further investigation is needed to reveal what role these SiglecFhigh neutrophils could play within the ischemic heart. To better target neutrophil depletion in vivo, more efficient or different anti-neutrophil strategies are needed.}, subject = {Neutrophiler Granulozyt}, language = {en} } @article{DresenPimientoPateletal.2023, author = {Dresen, Ellen and Pimiento, Jose M. and Patel, Jayshil J. and Heyland, Daren K. and Rice, Todd W. and Stoppe, Christian}, title = {Overview of oxidative stress and the role of micronutrients in critical illness}, series = {Journal of Parenteral and Enteral Nutrition}, volume = {47}, journal = {Journal of Parenteral and Enteral Nutrition}, doi = {10.1002/jpen.2421}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-318186}, pages = {S38 -- S49}, year = {2023}, abstract = {Inflammation and oxidative stress represent physiological response mechanisms to different types of stimuli and injury during critical illness. Its proper regulation is fundamental to cellular and organismal survival and are paramount to outcomes and recovery from critical illness. A proper maintenance of the delicate balance between inflammation, oxidative stress, and immune response is crucial for resolution from critical illness with important implications for patient outcome. The extent of inflammation and oxidative stress under normal conditions is limited by the antioxidant defense system of the human body, whereas the antioxidant capacity is commonly significantly compromised, and serum levels of micronutrients and vitamins significantly depleted in patients who are critically ill. Hence, the provision of antioxidants and anti-inflammatory nutrients may help to reduce the extent of oxidative stress and therefore improve clinical outcomes in patients who are critically ill. As existing evidence of the beneficial effects of antioxidant supplementation in patients who are critically ill is still unclear, actual findings about the most promising anti-inflammatory and antioxidative candidates selenium, vitamin C, zinc, and vitamin D will be discussed in this narrative review. The existing evidence provided so far demonstrates that several factors need to be considered to determine the efficacy of an antioxidant supplementation strategy in patients who are critically ill and indicates the need for adequately designed multicenter prospective randomized control trials to evaluate the clinical significance of different types and doses of micronutrients and vitamins in selected groups of patients with different types of critical illness.}, language = {en} } @article{GlaserKernSpeeretal.2023, author = {Glaser, Kirsten and Kern, David and Speer, Christian P. and Schlegel, Nicolas and Schwab, Michael and Thome, Ulrich H. and H{\"a}rtel, Christoph and Wright, Clyde J.}, title = {Imbalanced inflammatory responses in preterm and term cord blood monocytes and expansion of the CD14\(^+\)CD16\(^+\) subset upon toll-like receptor stimulation}, series = {International Journal of Molecular Sciences}, volume = {24}, journal = {International Journal of Molecular Sciences}, number = {5}, issn = {1422-0067}, doi = {10.3390/ijms24054919}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-311056}, year = {2023}, abstract = {Developmentally regulated features of innate immunity are thought to place preterm and term infants at risk of infection and inflammation-related morbidity. Underlying mechanisms are incompletely understood. Differences in monocyte function including toll-like receptor (TLR) expression and signaling have been discussed. Some studies point to generally impaired TLR signaling, others to differences in individual pathways. In the present study, we assessed mRNA and protein expression of pro- and anti-inflammatory cytokines in preterm and term cord blood (CB) monocytes compared with adult controls stimulated ex vivo with Pam3CSK4, zymosan, polyinosinic:polycytidylic acid, lipopolysaccharide, flagellin, and CpG oligonucleotide, which activate the TLR1/2, TLR2/6, TLR3, TLR4, TLR5, and TLR9 pathways, respectively. In parallel, frequencies of monocyte subsets, stimulus-driven TLR expression, and phosphorylation of TLR-associated signaling molecules were analyzed. Independent of stimulus, pro-inflammatory responses of term CB monocytes equaled adult controls. The same held true for preterm CB monocytes—except for lower IL-1β levels. In contrast, CB monocytes released lower amounts of anti-inflammatory IL-10 and IL-1ra, resulting in higher ratios of pro-inflammatory to anti-inflammatory cytokines. Phosphorylation of p65, p38, and ERK1/2 correlated with adult controls. However, stimulated CB samples stood out with higher frequencies of intermediate monocytes (CD14\(^+\)CD16\(^+\)). Both pro-inflammatory net effect and expansion of the intermediate subset were most pronounced upon stimulation with Pam3CSK4 (TLR1/2), zymosan (TR2/6), and lipopolysaccharide (TLR4). Our data demonstrate robust pro-inflammatory and yet attenuated anti-inflammatory responses in preterm and term CB monocytes, along with imbalanced cytokine ratios. Intermediate monocytes, a subset ascribed pro-inflammatory features, might participate in this inflammatory state.}, language = {en} } @article{OuhaddiCharbonnierPorgeetal.2023, author = {Ouhaddi, Yassine and Charbonnier, Baptiste and Porge, Juliette and Zhang, Yu-Ling and Garcia, Isadora and Gbureck, Uwe and Grover, Liam and Gilardino, Mirko and Harvey, Edward and Makhoul, Nicholas and Barralet, Jake}, title = {Development of neovasculature in axially vascularized calcium phosphate cement scaffolds}, series = {Journal of Functional Biomaterials}, volume = {14}, journal = {Journal of Functional Biomaterials}, number = {2}, issn = {2079-4983}, doi = {10.3390/jfb14020105}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-304026}, year = {2023}, abstract = {Augmenting the vascular supply to generate new tissues, a crucial aspect in regenerative medicine, has been challenging. Recently, our group showed that calcium phosphate can induce the formation of a functional neo-angiosome without the need for microsurgical arterial anastomosis. This was a preclinical proof of concept for biomaterial-induced luminal sprouting of large-diameter vessels. In this study, we investigated if sprouting was a general response to surgical injury or placement of an inorganic construct around the vessel. Cylindrical biocement scaffolds of differing chemistries were placed around the femoral vein. A contrast agent was used to visualize vessel ingrowth into the scaffolds. Cell populations in the scaffold were mapped using immunohistochemistry. Calcium phosphate scaffolds induced 2.7-3 times greater volume of blood vessels than calcium sulphate or magnesium phosphate scaffolds. Macrophage and vSMC populations were identified that changed spatially and temporally within the scaffold during implantation. NLRP3 inflammasome activation peaked at weeks 2 and 4 and then declined; however, IL-1β expression was sustained over the course of the experiment. IL-8, a promoter of angiogenesis, was also detected, and together, these responses suggest a role of sterile inflammation. Unexpectedly, the effect was distinct from an injury response as a result of surgical placement and also was not simply a foreign body reaction as a result of placing a rigid bioceramic next to a vein, since, while the materials tested had similar microstructures, only the calcium phosphates tested elicited an angiogenic response. This finding then reveals a potential path towards a new strategy for creating better pro-regenerative biomaterials.}, language = {en} } @article{GarciaFernandezReinholdUeceyleretal.2023, author = {Garc{\´i}a-Fern{\´a}ndez, Patricia and Reinhold, Colette and {\"U}{\c{c}}eyler, Nurcan and Sommer, Claudia}, title = {Local inflammatory mediators involved in neuropathic pain}, series = {International Journal of Molecular Sciences}, volume = {24}, journal = {International Journal of Molecular Sciences}, number = {9}, issn = {1422-0067}, doi = {10.3390/ijms24097814}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-313613}, year = {2023}, abstract = {Polyneuropathy (PNP) is a term to describe diseases of the peripheral nervous system, 50\% of which present with neuropathic pain. In some types of PNP, pain is restricted to the skin distally in the leg, suggesting a local regulatory process leading to pain. In this study, we proposed a pro-inflammatory pathway mediated by NF-κB that might be involved in the development of pain in patients with painful PNP. To test this hypothesis, we have collected nerve and skin samples from patients with different etiologies and levels of pain. We performed RT-qPCR to analyze the gene expression of the proposed inflammatory pathway components in sural nerve and in distal and proximal skin samples. In sural nerve, we showed a correlation of TLR4 and TNFα to neuropathic pain, and an upregulation of TNFα in patients with severe pain. Patients with an inflammatory PNP also presented a lower expression of TRPV1 and SIRT1. In distal skin, we found a reduced expression of TLR4 and miR-146-5p, in comparison to proximal skin. Our findings thus support our hypothesis of local inflammatory processes involved in pain in PNP, and further show disturbed anti-inflammatory pathways involving TRPV1 and SIRT1 in inflammatory PNP.}, language = {en} } @article{SchanbacherHermannsLorenzetal.2023, author = {Schanbacher, Constanze and Hermanns, Heike M. and Lorenz, Kristina and Wajant, Harald and Lang, Isabell}, title = {Complement 1q/tumor necrosis factor-related proteins (CTRPs): structure, receptors and signaling}, series = {Biomedicines}, volume = {11}, journal = {Biomedicines}, number = {2}, issn = {2227-9059}, doi = {10.3390/biomedicines11020559}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-304136}, year = {2023}, abstract = {Adiponectin and the other 15 members of the complement 1q (C1q)/tumor necrosis factor (TNF)-related protein (CTRP) family are secreted proteins composed of an N-terminal variable domain followed by a stalk region and a characteristic C-terminal trimerizing globular C1q (gC1q) domain originally identified in the subunits of the complement protein C1q. We performed a basic PubMed literature search for articles mentioning the various CTRPs or their receptors in the abstract or title. In this narrative review, we briefly summarize the biology of CTRPs and focus then on the structure, receptors and major signaling pathways of CTRPs. Analyses of CTRP knockout mice and CTRP transgenic mice gave overwhelming evidence for the relevance of the anti-inflammatory and insulin-sensitizing effects of CTRPs in autoimmune diseases, obesity, atherosclerosis and cardiac dysfunction. CTRPs form homo- and heterotypic trimers and oligomers which can have different activities. The receptors of some CTRPs are unknown and some receptors are redundantly targeted by several CTRPs. The way in which CTRPs activate their receptors to trigger downstream signaling pathways is largely unknown. CTRPs and their receptors are considered as promising therapeutic targets but their translational usage is still hampered by the limited knowledge of CTRP redundancy and CTRP signal transduction.}, language = {en} } @article{KollmannBuerkertMeiretal.2023, author = {Kollmann, Catherine and Buerkert, Hannah and Meir, Michael and Richter, Konstantin and Kretzschmar, Kai and Flemming, Sven and Kelm, Matthias and Germer, Christoph-Thomas and Otto, Christoph and Burkard, Natalie and Schlegel, Nicolas}, title = {Human organoids are superior to cell culture models for intestinal barrier research}, series = {Frontiers in Cell and Developmental Biology}, volume = {11}, journal = {Frontiers in Cell and Developmental Biology}, issn = {2296-634X}, doi = {10.3389/fcell.2023.1223032}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-357317}, year = {2023}, abstract = {Loss of intestinal epithelial barrier function is a hallmark in digestive tract inflammation. The detailed mechanisms remain unclear due to the lack of suitable cell-based models in barrier research. Here we performed a detailed functional characterization of human intestinal organoid cultures under different conditions with the aim to suggest an optimized ex-vivo model to further analyse inflammation-induced intestinal epithelial barrier dysfunction. Differentiated Caco2 cells as a traditional model for intestinal epithelial barrier research displayed mature barrier functions which were reduced after challenge with cytomix (TNFα, IFN-γ, IL-1ß) to mimic inflammatory conditions. Human intestinal organoids grown in culture medium were highly proliferative, displayed high levels of LGR5 with overall low rates of intercellular adhesion and immature barrier function resembling conditions usually found in intestinal crypts. WNT-depletion resulted in the differentiation of intestinal organoids with reduced LGR5 levels and upregulation of markers representing the presence of all cell types present along the crypt-villus axis. This was paralleled by barrier maturation with junctional proteins regularly distributed at the cell borders. Application of cytomix in immature human intestinal organoid cultures resulted in reduced barrier function that was accompanied with cell fragmentation, cell death and overall loss of junctional proteins, demonstrating a high susceptibility of the organoid culture to inflammatory stimuli. In differentiated organoid cultures, cytomix induced a hierarchical sequence of changes beginning with loss of cell adhesion, redistribution of junctional proteins from the cell border, protein degradation which was accompanied by loss of epithelial barrier function. Cell viability was observed to decrease with time but was preserved when initial barrier changes were evident. In summary, differentiated intestinal organoid cultures represent an optimized human ex-vivo model which allows a comprehensive reflection to the situation observed in patients with intestinal inflammation. Our data suggest a hierarchical sequence of inflammation-induced intestinal barrier dysfunction starting with loss of intercellular adhesion, followed by redistribution and loss of junctional proteins resulting in reduced barrier function with consecutive epithelial death.}, language = {en} } @phdthesis{Leinweber2022, author = {Leinweber, Jonas}, title = {Untersuchung zur pathophysiologischen Rolle und therapeutischen Relevanz der neuen Inhibitoren der plasmatischen Blutgerinnung Agaphelin und Ixolaris im experimentellen Schlaganfallmodell der Maus}, doi = {10.25972/OPUS-25292}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-252921}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Beim isch{\"a}mischen Schlaganfall f{\"u}hrt ein thrombotischer Verschluss von gehirnversorgenden Arterien zu einer akuten Durchblutungsst{\"o}rung, mit der Folge von neurologischen Defiziten. Prim{\"a}res Therapieziel ist es, diese Blutgerinnsel aufzul{\"o}sen, um die Sauerstoffversorgung des Gehirns wiederherzustellen und den isch{\"a}mischen Hirnschaden zu begrenzen. Dazu stehen die intraven{\"o}sen Thrombolyse mit rt-PA (rekombinanter Gewebe-Plasminogen-Aktivator) sowie die endovaskul{\"a}re mechanische Thrombektomie zur Verf{\"u}gung. H{\"a}ufig kann ein Schlaganfall, trotz erfolgreicher Rekanalisation der Gef{\"a}ße, zu einer weiteren Gr{\"o}ßenzunahme des Infarktes und neurologischen Defiziten bei den Patienten f{\"u}hren. Diese Gr{\"o}ßenzunahme beruht zum einen auf einem sich entwickelnden Hirn{\"o}dem und zum anderen auf entz{\"u}ndlichen Prozessen. Zahlreiche Hinweise deuten darauf hin, dass der Schlaganfall ein Zusammenspiel aus thrombotischen und entz{\"u}ndlichen Ereignissen ist, ein Ph{\"a}nomen, das als Thromboinflammation bezeichnet wird. Aufgrund der begrenzten Behandlungsm{\"o}glichkeiten ist die Entwicklung neuer Therapieans{\"a}tze f{\"u}r den isch{\"a}mischen Schlaganfall besonders wichtig. Agaphelin und Ixolaris sind Proteine aus den Speicheldr{\"u}sen von H{\"a}matophagen, f{\"u}r welche in fr{\"u}heren Studien eine starke antithrombotische Wirkung bei gleichzeitig geringem Blutungsrisiko nachgewiesen wurde. Diese m{\"o}glichen antithrombotischen Effekte wurden in dieser Studie im Hinblick auf ihre Wirksamkeit und Sicherheit im Mausmodell der zerebralen Isch{\"a}mie untersucht. Die Behandlung der M{\"a}use mit Agaphelin 1 Stunde nach transienter Okklusion der Arteria cerebri media (tMCAO) f{\"u}hrte zu kleineren Schlaganfallvolumina und geringeren neurologischen Defiziten an Tag 1 nach dem Schlaganfall. Die Mortalit{\"a}t der M{\"a}use war bis Tag 7 deutlich gesunken. Aus klinischer Sicht ist ebenfalls relevant, dass der starke antithrombotische Effekt von Agaphelin im Mausmodell nicht mit einem erh{\"o}hten Risiko f{\"u}r intrazerebrale Blutungen einherging. Diesem protektiven Effekt von Agaphelin lagen eine verminderte intrazerebrale Thrombusbildung, eine abgeschw{\"a}chte Entz{\"u}ndungsantwort und eine Stabilisierung der Blut-Hirn-Schranke sowie eine Reduzierung der Apoptose zugrunde. Nach der Gabe von Ixolaris 1 Stunde nach tMCAO waren zwar signifikant geringere Infarktgr{\"o}ßen messbar, diese f{\"u}hrten allerdings nicht zu einer Verbesserung der neurologischen Defizite. Zudem verursachte die Gabe von Ixolaris schon 24 Stunden nach tMCAO erhebliche intrazerebrale Blutungen und auch die Mortalit{\"a}t der M{\"a}use war zu diesem Zeitpunkt bereits erh{\"o}ht. Aufgrund dieser massiven Nebenwirkungen scheint Ixolaris kein geeigneter Kandidat f{\"u}r eine humane Anwendung zu sein. Bei Agaphelin hingegen k{\"o}nnte es sich um einen vielversprechenden Kandidaten f{\"u}r die Behandlung des isch{\"a}mischen Schlaganfalls handeln. Vor einer m{\"o}glichen Testung von Agaphelin in klinischen Studien, sind weitere translationale Untersuchungen notwendig, um ein noch pr{\"a}ziseres Verst{\"a}ndnis f{\"u}r die Wirksamkeit und Sicherheit von Agaphelin zu gewinnen. Insgesamt stellt die Hemmung thromboinflammatorischer Prozesse, ohne eine Erh{\"o}hung der Blutungskomplikationen, eine vielversprechende Option zur Behandlung des isch{\"a}mischen Schlaganfalls dar.}, subject = {Schlaganfall}, language = {de} } @article{MaglioccaMoneDiIorioetal.2022, author = {Magliocca, Giorgia and Mone, Pasquale and Di Iorio, Biagio Raffaele and Heidland, August and Marzocco, Stefania}, title = {Short-chain fatty acids in Chronic Kidney Disease: focus on inflammation and oxidative stress regulation}, series = {International Journal of Molecular Sciences}, volume = {23}, journal = {International Journal of Molecular Sciences}, number = {10}, issn = {1422-0067}, doi = {10.3390/ijms23105354}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-284587}, year = {2022}, abstract = {Chronic Kidney Disease (CKD) is a debilitating disease associated with several secondary complications that increase comorbidity and mortality. In patients with CKD, there is a significant qualitative and quantitative alteration in the gut microbiota, which, consequently, also leads to reduced production of beneficial bacterial metabolites, such as short-chain fatty acids. Evidence supports the beneficial effects of short-chain fatty acids in modulating inflammation and oxidative stress, which are implicated in CKD pathogenesis and progression. Therefore, this review will provide an overview of the current knowledge, based on pre-clinical and clinical evidence, on the effect of SCFAs on CKD-associated inflammation and oxidative stress.}, language = {en} } @article{HungDreherDiessneretal.2022, author = {Hung, Sophia and Dreher, Liane and Diessner, Joachim and Schwarz, Stefan and Ohlsen, Knut and Hertlein, Tobias}, title = {MRSA infection in the thigh muscle leads to systemic disease, strong inflammation, and loss of human monocytes in humanized mice}, series = {Frontiers in Immunology}, volume = {13}, journal = {Frontiers in Immunology}, issn = {1664-3224}, doi = {10.3389/fimmu.2022.892053}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-278050}, year = {2022}, abstract = {MRSA (Methicillin-resistant Staphylococcus aureus) is the second-leading cause of deaths by antibiotic-resistant bacteria globally, with more than 100,000 attributable deaths annually. Despite the high urgency to develop a vaccine to control this pathogen, all clinical trials with pre-clinically effective candidates failed so far. The recent development of "humanized" mice might help to edge the pre-clinical evaluation closer to the clinical situation and thus close this gap. We infected humanized NSG mice (huNSG: (NOD)-scid IL2R\(_γ\)\(^{null}\) mice engrafted with human CD34+ hematopoietic stem cells) locally with S. aureus USA300 LAC* lux into the thigh muscle in order to investigate the human immune response to acute and chronic infection. These mice proved not only to be more susceptible to MRSA infection than wild-type or "murinized" mice, but displayed furthermore inferior survival and signs of systemic infection in an otherwise localized infection model. The rate of humanization correlated directly with the severity of disease and survival of the mice. Human and murine cytokine levels in blood and at the primary site of infection were strongly elevated in huNSG mice compared to all control groups. And importantly, differences in human and murine immune cell lineages surfaced during the infection, with human monocyte and B cell numbers in blood and bone marrow being significantly reduced at the later time point of infection. Murine monocytes in contrast behaved conversely by increasing cell numbers. This study demonstrates significant differences in the in vivo behavior of human and murine cells towards S. aureus infection, which might help to sharpen the translational potential of pre-clinical models for future therapeutic approaches.}, language = {en} }