TY - JOUR A1 - Meir, Michael A1 - Kannapin, Felix A1 - Diefenbacher, Markus A1 - Ghoreishi, Yalda A1 - Kollmann, Catherine A1 - Flemming, Sven A1 - Germer, Christoph-Thomas A1 - Waschke, Jens A1 - Leven, Patrick A1 - Schneider, Reiner A1 - Wehner, Sven A1 - Burkard, Natalie A1 - Schlegel, Nicolas T1 - Intestinal epithelial barrier maturation by enteric glial cells is GDNF-dependent JF - International Journal of Molecular Sciences N2 - Enteric glial cells (EGCs) of the enteric nervous system are critically involved in the maintenance of intestinal epithelial barrier function (IEB). The underlying mechanisms remain undefined. Glial cell line-derived neurotrophic factor (GDNF) contributes to IEB maturation and may therefore be the predominant mediator of this process by EGCs. Using GFAP\(^{cre}\) x Ai14\(^{floxed}\) mice to isolate EGCs by Fluorescence-activated cell sorting (FACS), we confirmed that they synthesize GDNF in vivo as well as in primary cultures demonstrating that EGCs are a rich source of GDNF in vivo and in vitro. Co-culture of EGCs with Caco2 cells resulted in IEB maturation which was abrogated when GDNF was either depleted from EGC supernatants, or knocked down in EGCs or when the GDNF receptor RET was blocked. Further, TNFα-induced loss of IEB function in Caco2 cells and in organoids was attenuated by EGC supernatants or by recombinant GDNF. These barrier-protective effects were blunted when using supernatants from GDNF-deficient EGCs or by RET receptor blockade. Together, our data show that EGCs produce GDNF to maintain IEB function in vitro through the RET receptor. KW - enteric glial cells KW - neurotrophic factors KW - intestinal epithelial barrier KW - GDNF5 KW - RET6 KW - inflammatory bowel disease KW - enteric nervous system KW - gut barrier KW - intercellular junctions Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-258913 SN - 1422-0067 VL - 22 IS - 4 ER - TY - JOUR A1 - Lenschow, Christina A1 - Fuss, Carmina Teresa A1 - Kircher, Stefan A1 - Buck, Andreas A1 - Kickuth, Ralph A1 - Reibetanz, Joachim A1 - Wiegering, Armin A1 - Stenzinger, Albrecht A1 - Hübschmann, Daniel A1 - Germer, Christoph Thomas A1 - Fassnacht, Martin A1 - Fröhling, Stefan A1 - Schlegel, Nicolas A1 - Kroiss, Matthias T1 - Case Report: Abdominal Lymph Node Metastases of Parathyroid Carcinoma: Diagnostic Workup, Molecular Diagnosis, and Clinical Management JF - Frontiers in Endocrinology N2 - Parathyroid carcinoma (PC) is an orphan malignancy accounting for only ~1% of all cases with primary hyperparathyroidism. The localization of recurrent PC is of critical importance and can be exceedingly difficult to diagnose and sometimes futile when common sites of recurrence in the neck and chest cannot be confirmed. Here, we present the diagnostic workup, molecular analysis and multimodal therapy of a 46-year old woman with the extraordinary manifestation of abdominal lymph node metastases 12 years after primary diagnosis of PC. The patient was referred to our endocrine tumor center in 2016 with the aim to localize the tumor causative of symptomatic biochemical recurrence. In view of the extensive previous workup we decided to perform [18F]FDG-PET-CT. A pathological lymph node in the liver hilus showed slightly increased FDG-uptake and hence was suspected as site of recurrence. Selective venous sampling confirmed increased parathyroid hormone concentration in liver veins. Abdominal lymph node metastasis was resected and histopathological examination confirmed PC. Within four months, the patient experienced biochemical recurrence and based on high tumor mutational burden detected in the surgical specimen by whole exome sequencing the patient received immunotherapy with pembrolizumab that led to a biochemical response. Subsequent to disease progression repeated abdominal lymph node resection was performed in 10/2018, 01/2019 and in 01/2020. Up to now (12/2020) the patient is biochemically free of disease. In conclusion, a multimodal diagnostic approach and therapy in an interdisciplinary setting is needed for patients with rare endocrine tumors. Molecular analyses may inform additional treatment options including checkpoint inhibitors such as pembrolizumab. KW - parathyroid carcinoma KW - abdominal lymph node metastases KW - molecular diagnostics KW - repeated surgery KW - [18F]FDG-PET-CT KW - immune check inhibitor KW - pembrolizumab Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-233362 SN - 1664-2392 VL - 12 ER - TY - JOUR A1 - Lauruschkat, Chris D. A1 - Page, Lukas A1 - White, P. Lewis A1 - Etter, Sonja A1 - Davies, Helen E. A1 - Duckers, Jamie A1 - Ebel, Frank A1 - Schnack, Elisabeth A1 - Backx, Matthijs A1 - Dragan, Mariola A1 - Schlegel, Nicolas A1 - Kniemeyer, Olaf A1 - Brakhage, Axel A. A1 - Einsele, Hermann A1 - Loeffler, Juergen A1 - Wurster, Sebastian T1 - Development of a simple and robust whole blood assay with dual co-stimulation to quantify the release of T-cellular signature cytokines in response to Aspergillus fumigatus antigens JF - Journal of Fungi N2 - Deeper understanding of mold-induced cytokine signatures could promote advances in the diagnosis and treatment of invasive mycoses and mold-associated hypersensitivity syndromes. Currently, most T-cellular immunoassays in medical mycology require the isolation of mononuclear cells and have limited robustness and practicability, hampering their broader applicability in clinical practice. Therefore, we developed a simple, cost-efficient whole blood (WB) assay with dual α-CD28 and α-CD49d co-stimulation to quantify cytokine secretion in response to Aspergillus fumigatus antigens. Dual co-stimulation strongly enhanced A. fumigatus-induced release of T-cellular signature cytokines detectable by enzyme-linked immunosorbent assay (ELISA) or a multiplex cytokine assay. Furthermore, T-cell-dependent activation and cytokine response of innate immune cells was captured by the assay. The protocol consistently showed little technical variation and high robustness to pre-analytic delays of up to 8 h. Stimulation with an A. fumigatus lysate elicited at least 7-fold greater median concentrations of key T-helper cell signature cytokines, including IL-17 and the type 2 T-helper cell cytokines IL-4 and IL-5 in WB samples from patients with Aspergillus-associated lung pathologies versus patients with non-mold-related lung diseases, suggesting high discriminatory power of the assay. These results position WB-ELISA with dual co-stimulation as a simple, accurate, and robust immunoassay for translational applications, encouraging further evaluation as a platform to monitor host immunity to opportunistic pathogens. KW - immunoassay KW - biomarker KW - Aspergillus KW - cytokines KW - inflammation KW - adaptive immunity Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-241025 SN - 2309-608X VL - 7 IS - 6 ER - TY - JOUR A1 - Lauruschkat, Chris D. A1 - Etter, Sonja A1 - Schnack, Elisabeth A1 - Ebel, Frank A1 - Schäuble, Sascha A1 - Page, Lukas A1 - Rümens, Dana A1 - Dragan, Mariola A1 - Schlegel, Nicolas A1 - Panagiotou, Gianni A1 - Kniemeyer, Olaf A1 - Brakhage, Axel A. A1 - Einsele, Hermann A1 - Wurster, Sebastian A1 - Loeffler, Juergen T1 - Chronic occupational mold exposure drives expansion of Aspergillus-reactive type 1 and type 2 T-helper cell responses JF - Journal of Fungi N2 - Occupational mold exposure can lead to Aspergillus-associated allergic diseases including asthma and hypersensitivity pneumonitis. Elevated IL-17 levels or disbalanced T-helper (Th) cell expansion were previously linked to Aspergillus-associated allergic diseases, whereas alterations to the Th cell repertoire in healthy occupationally exposed subjects are scarcely studied. Therefore, we employed functional immunoassays to compare Th cell responses to A. fumigatus antigens in organic farmers, a cohort frequently exposed to environmental molds, and non-occupationally exposed controls. Organic farmers harbored significantly higher A. fumigatus-specific Th-cell frequencies than controls, with comparable expansion of Th1- and Th2-cell frequencies but only slightly elevated Th17-cell frequencies. Accordingly, Aspergillus antigen-induced Th1 and Th2 cytokine levels were strongly elevated, whereas induction of IL-17A was minimal. Additionally, increased levels of some innate immune cell-derived cytokines were found in samples from organic farmers. Antigen-induced cytokine release combined with Aspergillus-specific Th-cell frequencies resulted in high classification accuracy between organic farmers and controls. Aspf22, CatB, and CipC elicited the strongest differences in Th1 and Th2 responses between the two cohorts, suggesting these antigens as potential candidates for future bio-effect monitoring approaches. Overall, we found that occupationally exposed agricultural workers display a largely balanced co-expansion of Th1 and Th2 immunity with only minor changes in Th17 responses. KW - mold exposure KW - immunoassay KW - biomarker KW - Aspergillus KW - cytokines KW - inflammation KW - adaptive immunity KW - hypersensitivity Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-245202 SN - 2309-608X VL - 7 IS - 9 ER - TY - JOUR A1 - Kelm, Matthias A1 - Germer, Christoph-Thomas A1 - Schlegel, Nicolas A1 - Flemming, Sven T1 - The revival of surgery in Crohn's disease — early intestinal resection as a reasonable alternative in localized ileitis JF - Biomedicines N2 - 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. KW - surgery KW - Crohn's disease KW - terminal ileitis KW - inflammatory bowel disease KW - surgical outcome Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-246296 SN - 2227-9059 VL - 9 IS - 10 ER - TY - JOUR A1 - Kelm, Matthias A1 - Anger, Friedrich A1 - Eichlinger, Robin A1 - Brand, Markus A1 - Kim, Mia A1 - Reibetanz, Joachim A1 - Krajinovic, Katica A1 - Germer, Christoph-Thomas A1 - Schlegel, Nicolas A1 - Flemming, Sven T1 - Early Ileocecal Resection Is an Effective Therapy in Isolated Crohn’s Disease JF - Journal of Clinical Medicine N2 - 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. KW - Crohn’s Disease KW - surgical therapy KW - ileocecal resection Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-228822 SN - 2077-0383 VL - 10 IS - 4 ER - TY - JOUR A1 - Kayisoglu, Özge A1 - Schlegel, Nicolas A1 - Bartfeld, Sina T1 - Gastrointestinal epithelial innate immunity-regionalization and organoids as new model JF - Journal of Molecular Medicine N2 - The human gastrointestinal tract is in constant contact with microbial stimuli. Its barriers have to ensure co-existence with the commensal bacteria, while enabling surveillance of intruding pathogens. At the centre of the interaction lies the epithelial layer, which marks the boundaries of the body. It is equipped with a multitude of different innate immune sensors, such as Toll-like receptors, to mount inflammatory responses to microbes. Dysfunction of this intricate system results in inflammation-associated pathologies, such as inflammatory bowel disease. However, the complexity of the cellular interactions, their molecular basis and their development remains poorly understood. In recent years, stem cell-derived organoids have gained increasing attention as promising models for both development and a broad range of pathologies, including infectious diseases. In addition, organoids enable the study of epithelial innate immunity in vitro. In this review, we focus on the gastrointestinal epithelial barrier and its regional organization to discuss innate immune sensing and development. KW - regionalization and organoids KW - immunity KW - gastrointestinal tract Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-265220 VL - 99 IS - 4 ER - TY - JOUR A1 - Kannapin, Felix A1 - Schmitz, Tobias A1 - Hansmann, Jan A1 - Schlegel, Nicolas A1 - Meir, Michael T1 - Measurements of transepithelial electrical resistance (TEER) are affected by junctional length in immature epithelial monolayers JF - Histochemistry and Cell Biology N2 - The measurement of transepithelial electrical resistance (TEER) is a common technique to determine the barrier integrity of epithelial cell monolayers. However, it is remarkable that absolute TEER values of similar cell types cultured under comparable conditions show an immense heterogeneity. Based on previous observations, we hypothesized that the heterogeneity of absolute TEER measurements can not only be explained by maturation of junctional proteins but rather by dynamics in the absolute length of cell junctions within monolayers. Therefore, we analyzed TEER in epithelial cell monolayers of Caco2 cells during their differentiation, with special emphasis on both changes in the junctional complex and overall cell morphology within monolayers. We found that in epithelial Caco2 monolayers TEER increased until confluency, then decreased for some time, which was then followed by an additional increase during junctional differentiation. In contrast, permeability of macromolecules measured at different time points as 4 kDA fluorescein isothiocyanate (FITC)-dextran flux across monolayers steadily decreased during this time. Detailed analysis suggested that this observation could be explained by alterations of junctional length along the cell borders within monolayers during differentiation. In conclusion, these observations confirmed that changes in cell numbers and consecutive increase of junctional length have a critical impact on TEER values, especially at stages of early confluency when junctions are immature. KW - Caco2 cells KW - TEER KW - barrier models KW - impedance spectroscopy KW - permeability Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-267465 SN - 1432-119X VL - 156 IS - 6 ER - TY - JOUR A1 - Hendricks, Anne A1 - Lenschow, Christina A1 - Kroiss, Matthias A1 - Buck, Andreas A1 - Kickuth, Ralph A1 - Germer, Christoph-Thomas A1 - Schlegel, Nicolas T1 - Evaluation of diagnostic efficacy for localization of parathyroid adenoma in patients with primary hyperparathyroidism undergoing repeat surgery JF - Langenbeck's Archives of Surgery N2 - Purpose Repeat surgery in patients with primary hyperparathyroidism (pHPT) is associated with an increased risk of complications and failure. This stresses the need for optimized strategies to accurately localize a parathyroid adenoma before repeat surgery is performed. However, evidence on the extent of required diagnostics for a structured approach is sparse. Methods A retrospective single-center evaluation of 28 patients with an indication for surgery due to pHPT and previous thyroid or parathyroid surgery was performed. Diagnostic workup, surgical approach, and outcome in terms of complications and successful removement of parathyroid adenoma with biochemical cure were evaluated. Results Neck ultrasound, sestamibi scintigraphy, C11-methionine PET-CT, and selective parathyroid hormone venous sampling, but not MRI imaging, effectively detected the presence of a parathyroid adenoma with high positive predictive values. Biochemical cure was revealed by normalization of calcium and parathormone levels 24-48h after surgery and was achieved in 26/28 patients (92.9%) with an overall low rate of complications. Concordant localization by at least two diagnostic modalities enabled focused surgery with success rates of 100%, whereas inconclusive localization significantly increased the rate of bilateral explorations and significantly reduced the rate of biochemical cure to 80%. Conclusion These findings suggest that two concordant diagnostic modalities are sufficient to accurately localize parathyroid adenoma before repeat surgery for pHPT. In cases of poor localization, extended diagnostic procedures are warranted to enhance surgical success rates. We suggest an algorithm for better orientation when repeat surgery is intended in patients with pHPT. KW - Primary hyperparathyroidism (pHPT) KW - preoperative localization KW - repeat surgery KW - diagnostics KW - imaging Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-267520 SN - 1435-2451 VL - 406 IS - 5 ER - TY - JOUR A1 - Hankir, Mohammed K. A1 - Seyfried, Florian A1 - Schellinger, Isabel N. A1 - Schlegel, Nicolas A1 - Arora, Tulika T1 - Leaky gut as a potential culprit for the paradoxical dysglycemic response to gastric bypass-associated ileal microbiota JF - Metabolites N2 - Altered host-intestinal microbiota interactions are increasingly implicated in the metabolic benefits of Roux-en-Y gastric bypass (RYGB) surgery. We previously found, however, that RYGB-associated ileal microbiota can paradoxically impair host glycemic control when transferred to germ-free mice. Here we present complementary evidence suggesting that this could be due to the heightened development of systemic endotoxemia. Consistently, application of ileal content from RYGB-treated compared with sham-operated rats onto Caco-2 cell monolayers compromised barrier function and decreased expression of the barrier-stabilizing proteins claudin-4 and desmoglein-2. Our findings raise the possibility that RYGB-associated ileal microbiota produce and release soluble metabolites which locally increase intestinal permeability to promote systemic endotoxemia-induced insulin resistance, with potential implications for the treatment of RYGB patients who eventually relapse onto type 2 diabetes. KW - Roux-en-Y gastric bypass surgery KW - intestinal microbiota KW - intestinal epithelial barrier KW - systemic endotoxemia KW - type 2 diabetes Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-234085 SN - 2218-1989 VL - 11 IS - 3 ER - TY - JOUR A1 - Burkard, Natalie A1 - Meir, Michael A1 - Kannapin, Felix A1 - Otto, Christoph A1 - Petzke, Maximilian A1 - Germer, Christoph-Thomas A1 - Waschke, Jens A1 - Schlegel, Nicolas T1 - Desmoglein2 Regulates Claudin2 Expression by Sequestering PI-3-Kinase in Intestinal Epithelial Cells JF - Frontiers in Immunology N2 - Inflammation-induced reduction of intestinal desmosomal cadherin Desmoglein 2 (Dsg2) is linked to changes of tight junctions (TJ) leading to impaired intestinal epithelial barrier (IEB) function by undefined mechanisms. We characterized the interplay between loss of Dsg2 and upregulation of pore-forming TJ protein Claudin2. Intraperitoneal application of Dsg2-stablising Tandem peptide (TP) attenuated impaired IEB function, reduction of Dsg2 and increased Claudin2 in DSS-induced colitis in C57Bl/6 mice. TP blocked loss of Dsg2-mediated adhesion and upregulation of Claudin2 in Caco2 cells challenged with TNFα. In Dsg2-deficient Caco2 cells basal expression of Claudin2 was increased which was paralleled by reduced transepithelial electrical resistance and by augmented phosphorylation of AKT\(^{Ser473}\) under basal conditions. Inhibition of phosphoinositid-3-kinase proved that PI-3-kinase/AKT-signaling is critical to upregulate Claudin2. In immunostaining PI-3-kinase dissociated from Dsg2 under inflammatory conditions. Immunoprecipitations and proximity ligation assays confirmed a direct interaction of Dsg2 and PI-3-kinase which was abrogated following TNFα application. In summary, Dsg2 regulates Claudin2 expression by sequestering PI-3-kinase to the cell borders in intestinal epithelium. KW - Claudin2 KW - Dsg2 KW - inflammation KW - intestinal barrier KW - PI-3-kinase KW - inflammatory bowel disease KW - desmosome KW - tight junction Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-247059 SN - 1664-3224 VL - 12 ER -