Journal of Cellular and Molecular Medicine

Activation of inflammatory pathways in myeloid cells initiates insulin resistance leading to the development of type-2 diabetes and microvascular disease. Currently, there are no therapies available that target inflammation in T2D or microvascular disease. In the present study we investigate if Brutons tyrosine kinase (BTK) may represent a novel therapeutic target using the FDA approved medication ibrutinib. Ibrutinib treatment protected high fat diet (HFD)-fed mice from developing insulin resistance and improved glycaemic control by restoring signalling through IRS-1/Akt/GSK-3{beta} pathway. These improvements were independent of body weight and calorific intake. Treatment with ibrutinib to mice fed a HFD reduced NF-{kappa}B and reduced inflammatory gene expression, this was coupled with decreased activation of the NLRP3 inflammasome in the diabetic liver and kidney. Ibrutinib treatment also protected mice from the development of diabetic nephropathy by reducing monocyte/macrophage infiltration due to reduced expression of the pro-inflammatory chemokines. Ibrutinib treatment to human monocyte derived macrophages significantly reduced pro-inflammatory gene expression and a significant reduction in IL-1{beta} and TNF after LPS stimulation. In the present study we provide proof of concept evidence that BTK is a novel therapeutic target for the treatment of T2D and ibrutinib may be a candidate for drug repurposing in T2D.

Various signaling molecules affecting epithelial restitution and wound healing are dysregulated in ulcerative colitis. Recent evidence demonstrates the necessity of Hippo-YAP/TAZ signaling, interceded by cytoskeletal remodeling, for intestinal regeneration. Death-associated protein kinase 3 (DAPK3) is a regulator of actin cytoskeleton reorganization that controls proliferation and apoptosis. Pharmacological inhibition of DAPK3 in Caco-2 human intestinal epithelial cells (IECs) with the HS38 compound augmented cell proliferation and enhanced wound closure. This phenotype corresponded with the increased colocalization of Yes-associated protein (YAP) with F-actin, which is indicative of YAP activation. The administration of HS38 impeded the resolution of intestinal injury and attenuated epithelial-specific proliferation after acute colitis induced by dextran-sodium-sulphate (DSS) in mice. During recovery from DSS-induced colitis, IEC proliferation was repressed, and mice exhibited increased disease severity when HS38 was applied to inhibit DAPK3. Moreover, HS38 treatment increased YAP nuclear localization in IECs, an indicator of signal activation. In summary, this study established DAPK3 as a key factor in intestinal epithelial regeneration and colitis progression by way of YAP signaling. Nevertheless, the role that DAPK3 play in different cell types will need further investigation to decipher the full consequence of DAPK3 inhibition on epithelial homeostasis.

Vascular calcification is common in chronic kidney disease (CKD), contributing to increased cardiovascular morbidity and mortality. One of the proposed mechanisms of driving vascular calcification is a phenotypic switch of vascular smooth muscle cells (VSMCs). The platelet-derived growth factors (PDGFs) and their receptors (PDGFRs), particularly PDGFR-{beta}, were shown to modulate the VSMC phenotype. However, their role in uremic vascular calcification remained unclear. We adapted an ex vivo calcification model using murine aortas to simulate uremic conditions. Compared to control conditions, incubation with hemodialysate from CKD patients or using aortas from CKD animals both resulted in significantly increased PDGFR-{beta} phosphorylation and vascular calcification. Inhibition of PDGF signaling using soluble PDGFR-{beta} or the small molecule tyrosine kinase inhibitor imatinib significantly reduced uremic calcification and enhanced vascular elasticity. Next, we generated transgenic mice with a VSMC-specific, inducible expression of constitutively active PDGFR-{beta}. The aortas of these mice exhibited significantly increased vascular calcification ex vivo, which was further aggravated by uremic conditions. We established an in vivo model of accelerated vascular calcification and CKD in the transgenic mice, showing significantly aggravated vascular calcification and phenotypic switching of VSMCs compared to non-transgenic littermates. Finally, increased expression of phosphorylated PDGFR-{beta} and a VSMC phenotypic switching were detected in human arteries from patients with CKD compared to those without CKD. In conclusion, PDGFR-{beta} contributes to CKD-associated vascular calcification, representing a potential novel therapeutic target.

Background & AimsPerianal fistulizing Crohns disease (PCD) is a common and debilitating complication with elusive pathophysiology. We examined mucosal cells from patients with PCD and related conditions using a multi-omics approach. MethodsWe recruited patients with PCD (n = 24), CD without perianal disease (NPCD, n = 10), and idiopathic perianal fistulas (IPF, n = 29). Biopsies were taken from fistula tracts, fistula opening, and rectal mucosa. Single-cell RNA-sequencing (scRNA-seq), mass cytometry (CyTOF), spatial transcriptomics (ST), immunohistochemistry, and integrated analysis were performed. ResultsScRNA-seq, CyTOF, and ST unraveled immune and non-immune cell compartments in PCD and IPF fistula tracts. PCD fistulas showed hyperactivated pathogenic pathways including interferon (IFN)G response and TNF signaling in myeloid and stromal cells. Intestinal cells from PCD patients also expressed greater levels of IFNG-responsive and EMT genes compared to NPCD patients. Furthermore, both fistula tracts and ileal mucosa from PCD patients harbored expanded IFNG+ pathogenic Th17 cells, which expressed elevated inflammatory mediators. CyTOF also identified skewed immune cell phenotypes in the fistula tracts, fistula opening, and rectum in PCD patients including expanded Th17 cells, increased pathogenic myeloid cells, and altered T cell exhaustion markers. Further analysis also revealed cellular modules associated with anti-TNF therapy in PCD patients. ConclusionMulti-omics analysis revealed immune, stromal, and epithelial cell landscapes of PCD, which highlight the pathogenic role of hyperactivated IFNG signaling in both fistula tracts and luminal mucosa. This study identified IFNG as a potential therapeutic target for PCD.

Withdrawal StatementThe authors have withdrawn their manuscript owing to further revisions and additional experiments are needed to ensure the accuracy and completeness of the research findings. As a result, we believe it is in the best interest of the scientific community and the integrity of the manuscript to withdraw it at this time. Therefore, the authors do not wish this work to be cited as a reference for the project. If you have any questions, please contact the corresponding author.

BackgroundMyocarditis has emerged as a rare but lethal Immune checkpoint inhibitor (ICI)-associated toxicity. However, the exact mechanism for ICI related myocarditis remains underexplored; and the specific therapeutic targets is still lacking. In this study, we used scRNA-seq to characterize the transcriptomic profiles of single cells from the peripheral blood mononuclear cell (PBMC) of ICI related myocarditis during fulminant myocarditis and disease recovery. MethodsPBMC samples were taken from the patient during fulminant ICI related myocarditis and after disease remission. Cells were isolated from blood samples by density gradient centrifugation over Ficoll-Paque. Single-cell RNA sequencing with 10X genomics was performed. Subpopulation determination, functional analysis, single-cell trajectory and cell-cell interaction analysis were carried out afterwards. ResultsWe presented the altered landscape of immune cells and differential genes in ICI related myocarditis during the disease activity and remission using scRNA-seq. Substantial immune cell composition and intercellular communication were found to be altered. Monocyte, NK cell as well as B cell subpopulations contributed to the regulation of innate immunity and inflammation in ICI related myocarditis. T cell subpopulations highly expressed genes associated with PD-1 inhibitor resistance and hyper-progressor. At last, the intercellular communication in ICI related myocarditis was significantly dysregulated. ConclusionBy identifying altered pathways and highlighting a catalog of marker genes, this study has revealed the diversity of cellular populations in ICI related myocarditis, marked by their distinct transcriptional profiles and biological functions. Our investigation would shed light on the pathophysiological mechanism and potential therapeutic targets of ICI related myocarditis in continuous exploration.

Background and aimsGenetic susceptibility to inflammatory bowel disease (IBD) has been widely studied, whereas the genetic contribution to disease progression over time remains relatively under-investigated. In a Danish nationwide cohort, we aimed to explore if genetic susceptibility to IBD is associated with disease severity. MethodsWe estimated polygenic scores (PGS) for IBD susceptibility for 3,732 patients with Crohns disease (CD), 4,535 patients with ulcerative colitis (UC), and 9,469 controls, and investigated their association with disease outcomes, including inflammatory markers, hospitalizations, major surgeries, and medication use. A composite severity outcome was defined based on the first three years following diagnosis. Lastly, we evaluated disease extent as a possible mediator of the association. ResultsIncreased susceptibility PGS was associated with higher fecal calprotectin and C-reactive protein levels, and decreased hemoglobin levels. When comparing the highest versus lowest PGS quintile, we observed a hazard ratio (HR) for major surgery of 2.74 (P=7.19x10-18) in patients with CD and of 2.04 (P=4.36x10-7) in UC. Patients with severe disease had higher susceptibility PGS than patients with less severe disease (CD: OR=1.25, P=3.36x10-9; UC: OR=1.33, P=1.40x10-15 per SD increase in PGS). Additionally, PGS was associated with a higher need for corticosteroids, immunomodulators, and biologic therapies. Adjusting for disease extent reduced the estimated associations for CD but had little impact on observed associations for UC. ConclusionPatients with higher genetic burden for developing IBD also experience a more severe disease course. For patients with CD this link was largely mediated by disease extent, however, this was not the case for UC, which suggests a shared genetic architecture between disease susceptibility and severity.

Background and AimAn essential issue for Kawasaki Disease (KD) is the development of coronary artery disease. We decided to investigate (VEGF) subtype gene expression in KD due to the proangiogenic nature of Vasoactive Endothelial Growth Factor A (VEGF). VEGF-A is a known angiogenic molecule with pro-inflammatory effects, whereas the role of VEGFB has been less defined. MethodKD Microarray and RNA-seq datasets were selected using a comprehensive search strategy of the NCBI GEO Dataset, which resulted in eight studies from whole blood. This included three extensive studies in KD (KD1-KD3). Further, one study dataset from coronary artery tissue, the Coronary Artery Dataset (CAD), was also included to appreciate end-stage KD. ResultsIn CAD, cases of KD versus controls, VEGF-B was up-regulated (p = 4.932e-02). KD1, KD Acute versus convalescent samples, VEGF-A is up-regulated (p=1.258e-07) and VEGF-B was down-regulated (p=1.42e-28). Similar up regulation of VEGF-A and down regulation of VEGF-B was seen in KD2 (p=1.140e-04; p=1.746e-02) and KD3 (p=1.140e-04; p=1.746e-02), both are KD Versus Controls. VEGF-A up-regulated (p=1.140e-04), VEGF-B down-regulated (p=1.746e-02).KD3, KD versus Control; VEGF-A up-regulated (p=1.140e-04), VEGF-B down regulated (p=1.746e-02). ConclusionsIn acute KD VEGF-A up-regulation, with VEGFB being down-regulated, the reverse being true of the convalescent situation. This suggests a temporal inverse relationship between VEGF-A and VEGF-B may have biomarker implications. Moreover, a dual therapeutic strategy, enhancing VEGFB while minimizing VEGFA effects, could be a possible advancement over current KD related-therapies. Further work defining the relationship of VEGF-A to VEGF-B in KD-related angiogenesis is suggested.

Severe forms of inflammation-induced acute and chronic myocarditis have a poor prognosis. Promising therapeutic efforts focused on monoclonal antibodies (mAbs) inhibiting inflammation-inducing molecules. However, most mAbs target only one or a limited number of such molecules. Since inflammation involves multiple redundant pathways, we postulated that an mAb inhibiting multiple inflammatory pathways would be a potent therapeutic agent. We initially tested the commercially available anti-natural killer (NK) cell mAb (anti-NK1.1), which binds a receptor expressed on NK cells and depletes them. Since NK cells are key cellular orchestrators of inflammation, by reducing their number, we aimed to inhibit multiple inflammatory pathways. Our initial studies demonstrated that administration of this antibody significantly improved myocardial outcomes in mouse models of acute myocardial infarction and of heart failure. Since NK1.1 is not expressed in human cells, we built on these promising preclinical results by developing a novel mAb targeting CD160 on human NK cells for evaluation as an immunosuppressive therapy. We found that the anti-CD160 mAb depletes both murine and human NK cells. We also found that, while CD160+ cells were largely present in the NK population, they also occurred among CD8+ and {gamma}/{delta} T cell subsets in human cells. Anti-CD160 therapy entirely prevented the deterioration of the myocardial function of mice with autoimmune-induced acute myocarditis. This outcome suggests our novel approach for inhibiting multiple inflammatory pathways may provide a potent strategy for improving outcomes of inflammation-driven myocarditis, as well as of other inflammation-driven diseases. Key PointsO_ST_ABSQuestionC_ST_ABSCan the depletion of CD160+ cells prevent autoimmune-induced myocarditis? FindingsIn this study we found that CD160 is expressed by mouse and human natural killer cells and other subtypes of cytotoxic T cells, and that a monoclonal antibody targeting CD160 depletes NK cells. In a preclinical model of experimental autoimmune myocarditis, administration of the anti-CD160 monoclonal antibody prevented myocardial dysfunction and systemic inflammation. MeaningOur results are compatible with the hypothesis that early autoimmune-induced myocardial dysfunction is promoted by CD160+ cells, which elevate inflammation-induced circulating factors (or factors released by tissue-resident cytotoxic immune cells) that cause myocardial dysfunction in the absence of myocardial necrosis or fibrosis, and further, that targeting CD160+cells with a mAb that depletes NK cells (and probably CD160 expressing cytotoxic T cells) entirely prevents the deterioration of myocardial function in such mice. This outcome suggests our novel approach for inhibiting multiple inflammatory pathways may provide a potent strategy for improving outcomes of inflammation-driven myocarditis, as well as of other inflammation-driven diseases.

BackgroundInflammatory bowel disease (IBD) is a chronic inflammatory condition of the intestine with a complex and multifaceted pathogenesis. While various animal models exist to study specific disease mechanisms relevant to human IBD, a comprehensive comparative framework linking these to IBD pathophysiology is lacking. ObjectiveIn our study, we aimed at providing a framework that delineates common and unique features encountered in 13 widely used mouse models comparing them with human IBD to identify translatable pathways in model-cohort pairs. Another aim of our study was to provide an explorable resource for looking up gene and pathway level changes in mouse models assisting in hypothesis testing and minimizing animal burden abiding by the 3R principals. DesignWe employed comparative transcriptomic analyses with curated and a priori statistical correlative methods between mouse models versus established as well as own patient datasets at both bulk and single cell levels. ResultsWe identify IBD-related pathways, ontologies, and cellular processes that are translatable between mouse models and patient cohorts. Moreover, we identify, known and novel IBD-associated subcellular mechanisms and how they are recapitulated in specific mouse models. ConclusionOur findings provide a valuable resource for selecting the most appropriate experimental paradigm to model unique features of IBD pathomechanisms, allowing analysis at the tissue, cellular, and subcellular levels. What is already known on this topicPreclinical modelling of IBD is key to the discovery of pathomechanisms and the evaluation of therapeutic approaches. However, individual models do not recapitulate the complexity of the disease and comprehensive studies comparing modelling paradigms with human IBD are lacking. What this study addsOur study provides a comparative analysis of thirteen commonly used intestinal inflammation models, identifying core-conserved pathways between mouse models and IBD patient cohorts. In addition, our study shows how specific pathways involved in IBD are recapitulated in specific mouse models and introduces a web tool to analyse the models. How this study might affect research, practice or policyBy identifying conserved and discrepant pathways between specific mouse models and IBD patient cohorts, our analysis platform provides an invaluable resource for translational IBD research.

A complex and tissue-specific network of cells including T lymphocytes maintains intestinal homeostasis. To address disease and tissue-specific alterations, we performed a T cell-centric mass cytometry analysis of peripheral and intestinal lymphocytes from patients with Crohns disease (CD) and healthy donor PBMCs. We compared inflamed and not inflamed tissue areas of bowel resections. Chronic inflammation enforced activation, exhaustion and terminal differentiation of CD4+ and CD8+ T cells and an enrichment of CD4+Foxp3+ cells (Tregs) in inflamed intestine. However, tissue-repairing Tregs decreased, while enigmatic rare Foxp3+ T-cell subsets appeared upon inflammation. In vitro assays revealed that those subsets, e.g. CD4+Foxp3+HLA-DR+TIGIT- and CD4+Foxp3+CD56+, express pro-inflammatory IFN-{gamma}. Some T-conventional (Tcon) cells tended towards innateness. In blood of CD patients, not well studied CD4+ and CD8+ subsets of CD16+CCR6+CD127+ T cells appeared anew, a phenotype reproducible by incubation of healthy blood T cells with patient blood plasma. Together, these findings suggest a bias towards innate-like pro-inflammatory Tregs and innate-like Tcon, which act with less specific cytotoxicity. Most likely, this is both cause and consequence of intestinal inflammation during CD. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=177 HEIGHT=200 SRC="FIGDIR/small/22274864v1_ufig1.gif" ALT="Figure 1"> View larger version (81K): org.highwire.dtl.DTLVardef@a72ac0org.highwire.dtl.DTLVardef@e7a7b0org.highwire.dtl.DTLVardef@b21f8forg.highwire.dtl.DTLVardef@36077e_HPS_FORMAT_FIGEXP M_FIG C_FIG

The existence of sodium-glucose cotransporter 2 (SGLT2) in pancreatic alpha cells and its potential roles in glucagon secretion remain controversial, despite its well-established function in renal glucose reabsorption. While some studies suggest SGLT2 presence and its involvement in glucagon regulation, others deny its expression in alpha cells. To clarify this dispute, we investigated the functional effects of highly selective SGLT2 inhibitors, dapagliflozin and empagliflozin, on glucose uptake, intracellular ATP levels, and glucagon secretion in alpha-TC1 cells, a widely used model for glucagon-secreting cells in culture. The SGLT2 inhibitors significantly suppressed basal glucose uptake in alpha-TC1 cells, indicating functional SGLT2 presence. However, the inhibitors did not affect glucagon secretion. Neither the SGLT2 inhibitors nor the more potent glucose transport inhibitor, cytochalasin B, altered intracellular ATP levels or glucagon secretion. In contrast, pharmacological inhibition of K/ATP channels increased glucagon secretion without affecting glucose uptake or ATP levels. These results suggest that while SGLT2 is functionally present at low levels and mediates basal glucose uptake in alpha-TC1 cells, its inhibition has insufficient influence on intracellular ATP levels, and therefore glucagon secretion remains stable. Furthermore, our observations support predominant involvement of K/ATP channels in regulating glucagon secretion. Further studies in human purified pancreatic alpha cells in addition to islets are warranted to fully elucidate SGLT2s role in alpha-cell physiology.

BackgroundParalytic ileus (PI), a condition characterized by reduced bowel motor activity without physical obstruction, can be affected by complications from type 2 diabetes (T2D) and anti-diabetic medications. It is unclear of the causal associations of glucagon-like peptide-1 receptor agonists (GLP-1RAs) with the risk of PI in the context of T2D management. MethodsTo investigate the causal relationship of GLP-1RAs with PI, we conducted a 2-sample mendelian randomization (MR) study based on summary statistics from genome-wide association studies (GWAS). Genetic variants in the GLP1R were identified as genetical proxies of GLP-1RAs by the glycemic control therapy, based on genetic associations with glycated hemoglobin (GWAS n=344,182) and T2D (ncases/controls=228,499/1,178,783). The effects of GLP-1RAs were estimated for PI risk (ncases/controls=517/182,423) using GWAS data from the FinnGen project. ResultsBased on MR analysis, GLP-1RAs are causally associated with a decreased risk of PI (OR per 1 mmol/mol decrease in glycated hemoglobin: 0.21; 95% confidence interval [CI]=0.06-0.69). The magnitude of these benefit exceeded those expected from improved glycemic control more generally. ConclusionsOur studys findings show that GLP-1RAs are causally associated with a lower risk for PI, which provides information to guide clinicians in the selection of appropriate therapies for individuals with T2D while mitigating the risk of developing PI. Investigating the underlying mechanisms that contribute to the lower PI risk associated with GLP-1RAs is essential for a deeper understanding of these associations.

Chondro/osteoclasts and mast cells are cells of interest in the cartilage and bone destruction of joints affected by rheumatoid arthritis (RA). Both are major cellular components of the vascular synovial pannus proliferation characteristic of this disease. Chondroclasts degrade calcified cartilage and osteoclasts degrade bone tissue. Chondroclasts and osteoclasts are identical cell types and differentiate from monocyte precursors. Our studies show a close microanatomical relationship between these cells and new capillary formation (shown by the lectin Psophocarpus tetragonolobus - PTL-11) in the resorption sites of the mineralized tissues. Clast and mast cells express receptors for the lectin lPHA indicating beta1,6-acetylglucosaminal transferase V (GNTase V/MGAT5) activity providing a mechanism for neoangiogenesis. In addition to an angiogenetic function for mast cells it is probable that their products control monocyte differentiation and chondro/osteoclastogenesis.

Aims: This study aimed to explore the biological activities of miR-199a-5p in dextran sulphate sodium (DSS)-induced ulcerative colitis and apoptosis and identify the direct target of miR-199a-5p in this process. Main methods: HT-29 cells and C57BL/6 mice were used to examine the function of miR-199a-5p in vitro and in vivo, respectively. Expression of miRNA and mRNA was measured using quantitative real-time PCR and western blotting was used to measure the change in protein expression. Flow cytometry was subsequently employed to determine cell apoptosis, and a luciferase assay was used to confirm the direct target of miR-199a-5p. Results: Expression of miR-199a-5p was increased by DSS treatment in mice. In parallel, miR-199a-5p is found to be involved in endoplasmic reticulum stress (ERS) and cell apoptosis in HT-29 cells, and its upregulation induced ERS, apoptosis, weight loss, and ulcerative colitis in mice in vivo, which could be prevented by the suppression of miR-199a-5p. Luciferase assay confirmed that the 3' untranslated region (3'-UTR) of XBP1 is the target binding site of miR-199a-5p. Conclusion: miR-199a-5p promotes ulcerative colitis and cell apoptosis by targeting the 3'-UTR of XBP1. Our findings reveal a new regulatory mechanism for ERS signaling and suggest that miR-199a-5p might be a potential target for UC therapy.

Pancreatitis is an inflammatory disease of the pancreas that can arise due to various factors, including environmental risks such as diet, alcohol, and smoking, as well as genetic predispositions. In some cases, pancreatitis may progress and become chronic, leading to irreversible damage and impaired pancreatic function. Genome-wide association studies (GWAS) have identified polymorphisms at the X-linked CLDN2 locus as risk factors for both sporadic and alcohol-related chronic pancreatitis. CLDN2 encodes claudin-2 (CLDN2), a paracellular cation-selective channel localized at tight junctions and expressed in the pancreas and other secretory organs. However, whether and how CLDN2 may modify pancreatitis susceptibility remains poorly understood. We aimed to clarify the potential role of CLDN2 in the onset and progression of pancreatitis. We employed multiple methodologies to examine the role of CLDN2 in human pancreatic tissue, caerulein-induced experimental pancreatitis mouse model, and pancreatic ductal epithelial organoids. In both human chronic pancreatitis tissues and caerulein-induced experimental pancreatitis, CLDN2 protein was significantly upregulated in pancreatic ductal epithelial cells. Our studies using pancreatic ductal epithelial organoids and mice demonstrated the inflammatory cytokine IFN{gamma} upregulates claudin-2 expression at both RNA and protein levels. Following caerulein treatment, Ifng KO mice had diminished upregulation of CLDN2 relative to WT mice, indicating that caerulein-induced claudin-2 expression is partially driven by IFN{gamma}. Functionally, Cldn2 knockout mice developed more severe caerulein-induced experimental pancreatitis, indicating CLDN2 plays a protective role in pancreatitis development. Pancreatic ductal epithelial organoid-based studies demonstrated that CLDN2 is critical for sodium-dependent water transport and necessary for cAMP-driven, CFTR-dependent fluid secretion. These findings suggest that functional crosstalk between CLDN2 and CFTR is essential for fluid transport in pancreatic ductal epithelium, which may protect against pancreatitis by adjusting pancreatic ductal secretion to prevent worsening autodigestion and inflammation. In conclusion, our studies suggest CLDN2 upregulation during pancreatitis may play a protective role in limiting disease development, and decreased CLDN2 function may increase pancreatitis severity. These results point to the possibility of modulating pancreatic ductal CLDN2 function as an approach for therapeutic intervention of pancreatitis.

ObjectiveInflammatory Bowel Disease (IBD) is associated with cardiovascular disease risk and impaired intestinal blood flow, but the functional role of perivascular nerves that control vasomotor function of mesenteric arteries (MAs) perfusing the intestine is unknown in IBD. Because perivascular sensory nerves and their transmitters calcitonin gene-related peptide (CGRP) and substance P (SP) are important mediators of both vasodilation and inflammatory responses, our objective was to identify IBD-related deficits in perivascular sensory nerve function and vascular neurotransmitter signaling. Approach and ResultsIn MAs from an IL-10-/- mouse model, we found that IBD significantly impairs EFS-mediated sensory vasodilation and sensory inhibition of sympathetic vasoconstriction, despite decreased sympathetic nerve density and vasoconstriction. The MA content and EFS-mediated release of both CGRP and SP are slightly decreased with IBD, but IBD has different effects on each transmitter. CGRP nerve density, receptor expression, hyperpolarization and vasodilation are preserved with IBD. In contrast, SP nerve density and receptor expression are increased, and SP hyperpolarization and vasodilation are impaired with IBD. A critical finding is that blocking neurokinin 1 (SP) receptors restored EFS-mediated sensory vasodilation and enhanced CGRP-mediated vasodilation in MAs from IBD but not Control mice. ConclusionsAn aberrant role for the perivascular sensory neurotransmitter SP and its downstream signaling in MAs underlies vascular dysfunction with IBD. With IBD, SP signaling impedes CGRP-mediated sensory vasodilation, contributing to impaired blood flow. Substance P and NK1 receptors may represent an important target for treating vascular dysfunction in IBD.

Background and AimsThe host receptor for SARS-CoV-2, angiotensin-converting enzyme 2 (ACE2), is highly expressed in small intestine. Our aim was to study colonic ACE2 expression in Crohns disease (CD) and non-inflammatory bowel disease (non-IBD) controls. We hypothesized that the colonic expression levels of ACE2 impacts CD course. MethodsWe examined the expression of colon ACE2 using RNA-seq and quantitative (q) RT-PCR from 69 adult CD and 14 NIBD control patients. In a subset of this cohort we validated ACE2 protein expression and localization in formalin-fixed, paraffin-embedded matched colon and ileal tissues using immunohistochemistry. The impact of increased ACE2 expression in CD for the risk of surgery was evaluated by a multivariate regression analysis and a Kaplan-Meier estimator. To provide critical support for the generality of our findings, we analyzed previously published RNA-seq data from two large independent cohorts of CD patients. ResultsColonic ACE2 expression was significantly higher in a subset of adult CD patients (ACE2-high CD). IHC in a sampling of ACE2-high CD patients confirmed high ACE2 protein expression in the colon and ileum compared to ACE2-low CD and NIBD patients. Notably, we found that ACE2-high CD patients are significantly more likely to undergo surgery within 5 years of diagnosis, with a Cox regression analysis finding that high ACE2 levels is an independent risk factor (OR 2.18; 95%CI, 1.05-4.55; p=0.037). ConclusionIncreased intestinal expression of ACE2 is associated with deteriorated clinical outcomes in CD patients. These data point to the need for molecular stratification that may impact CD disease-related outcomes.

During glomerular diseases, podocyte-specific pathways can modulate the intensity of the lesions and prognosis. The therapeutic targeting of these pathways could thus improve the management and prognosis of chronic kidney diseases. The Janus Kinase/ Signal Transducer and Activator of Transcription (JAK/STAT) pathway, classically described in immune cells, has been recently described in intrinsic kidney cells. Here, we show, for the first time, that STAT5 is activated in human podocytes in focal segmental glomerulosclerosis (FSGS). Additionally, Stat5 podocyte-specific inactivation aggravates the functional and structural alterations in a mouse model of FSGS. This could be due, at least in part, to an inhibition of the autophagic flux. Finally, Interleukin 15 (IL-15), a classical activator of STAT5 in immune cells, increases STAT5 phosphorylation in human podocytes and its administration alleviates glomerular injury in vivo by maintaining the autophagy flux in podocytes. In conclusion, activating podocytic STAT5 with commercially available IL-15 represents a new therapeutic avenue with the potential for FSGS.

Previously, genetic lineage tracing based on the mesothelial marker Wt1, appeared to show that peritoneal mesothelial cells have a range of differentiative capacities and are the direct progenitors of vascular smooth muscle in the intestine. However, it was not clear whether this was a temporally limited process or continued throughout postnatal life. Here, using a conditional Wt1-based genetic lineage tracing approach, we demonstrate that the postnatal and adult peritoneum covering intestine, mesentery and body wall only maintained itself and failed to contribute to other visceral tissues. Pulse-chase experiments of up to 6 months revealed that Wt1-expressing cells remained confined to the peritoneum and failed to differentiate into cellular components of blood vessels or other tissues underlying the peritoneum. Ablation of Wt1 in adult mice did not result in changes to the intestinal wall architecture. In the heart, we observed that Wt1-expressing cells maintained the epicardium and contributed to coronary vessels in newborn and adult mice. Our results demonstrate that Wt1-expressing cells in the peritoneum have limited differentiation capacities, and that contribution of Wt1-expressing cells to cardiac vasculature is based on organ-specific mechanisms.