Project description:This SuperSeries is composed of the following subset Series: GSE32542: Murine serum reactivity to common autoantigens in response to immunization with neutrophil extracellular traps GSE32543: Human and murine serum reactivity to specific histone posttranslational modifications in neutrophil extracellular traps Refer to individual Series
Project description:Background: Acute pancreatitis (AP) is a common severe digestive disorder, with severity linked to high-fat diets (HFD). HFD may exacerbate AP by promoting inflammation and altering gut microbiota. Astragalus polysaccharides (APS) possess anti-inflammatory properties, but it is unclear if APS supplementation can mitigate HFD's detrimental effects on AP by modulating gut microbiota. This study investigates the mechanisms by which APS improves HFD-induced AP exacerbation. In this study, C57BL/6 mice were fed HFD or a standard diet, with or without APS, for 12 weeks. AP was induced via intraperitoneal caerulein injection. Analyses included ELISA, Western blotting, histology, immunohistochemistry, immunofluorescence, single-cell RNA sequencing (scRNA-seq), 16S rRNA sequencing of gut microbiota, and short-chain fatty acid (SCFA) analysis to evaluate inflammation and cellular changes. Results: HFD significantly increased AP severity, indicated by elevated serum enzyme and pro-inflammatory cytokine levels, along with extensive pancreatic damage. Single-cell RNA sequencing (scRNA-seq) showed a notable rise in ICAM1+ neutrophils and activation of the NF-κB/necroptosis pathway in HAP mice. APS alleviated these effects by decreasing ICAM1+ neutrophil infiltration, downregulating the NF-κB pathway, and reducing necroptosis. Moreover, APS restored gut microbiota balance, significantly boosting Lactobacillus reuteri (L. reuteri) abundance and propionate (PA) levels. Treatments with L. reuteri and PA independently mitigated HFD-induced AP severity, indicating that APS's protective effects are microbiota-dependent. Conclusion: APS improves HFD-induced gut dysbiosis and intestinal barrier dysfunction by enriching L. reuteri and PA, effectively reducing AP exacerbation. Our findings highlight the gut-pancreas axis as a promising target for addressing AP severity.
Project description:Intracerebral hemorrhage (ICH) induces alterations in the gut microbiota composition, significantly impacting neuroinflammation post-ICH. However, the impact of gut microbiota absence on neuroinflammation following ICH-induced brain injury remain unexplored. Here, we observed that the gut microbiota absence was associated with reduced neuroinflammation, alleviated neurological dysfunction, and mitigated gut barrier dysfunction post-ICH. In contrast, recolonization of microbiota from ICH-induced SPF mice by transplantation of fecal microbiota (FMT) exacerbated brain injury and gut impairment post-ICH. Additionally, microglia with transcriptional changes mediated the protective effects of gut microbiota absence on brain injury, with Apoe emerging as a hub gene. Subsequently, Apoe deficiency in peri-hematomal microglia was associated with improved brain injury. Finally, we revealed that gut microbiota influence brain injury and gut impairment via gut-derived short-chain fatty acids (SCFA).
Project description:The apical-basal polarity of pancreatic acinar cells is essential for maintaining tissue architecture. However, the mechanisms by which polarity proteins regulate acinar pancreas tissue homeostasis are poorly understood. Here, we evaluate the role of Par3 in acinar pancreas injury and homeostasis. While Par3 loss in the mouse pancreas disrupts tight junctions, Par3 loss is dispensable for pancreatogenesis. However, with aging, Par3 loss results in low-grade inflammation, acinar degeneration, and pancreatic lipomatosis. Par3 loss also exacerbates pancreatitis-induced acinar cell loss, resulting in pronounced pancreatic lipomatosis and failure to regenerate. Moreover, Par3 loss in mice harboring mutant Kras causes extensive pancreatic intraepithelial neoplastic (PanIN) lesions and large pancreatic cysts. We also show that Par3 loss restricts injury-induced primary ciliogenesis. Significantly, targeting BET proteins enhances primary ciliogenesis during pancreatitis-induced injury and, in mice with Par3 loss, limits pancreatitis-induced acinar loss and facilitates acinar cell regeneration. Combined, this study demonstrates how Par3 restrains pancreatitis- and Kras-induced changes in the pancreas and identifies a potential role for BET inhibitors to attenuate pancreas injury and facilitate pancreas tissue regeneration.
Project description:Objective Ulcerative colitis (UC) is a risk factor of periodontitis. This study aimed to investigate whether hematopoietic stem and progenitor cells (HSPCs) and their myeloid progeny exacerbate periodontal inflammation in UC. Design Ligature-induced periodontitis (LIP) was established in dextran sulfate sodium (DSS)-induced colitis (DIC) C57BL/6 mice. The bone resorption, intestinal and periodontal inflammation were evaluated by micro-CT and histological analyses. Inflammatory cytokines and lipopolysaccharide (LPS) in serum and gut microbiota were assessed by multiplexed flow cytometric assay, ELISA and 16S rRNA sequencing, respectively. Flow cytometry was performed to analyze HSPCs differentiation, and to sort hematopoietic stem cells for transcriptomic analysis. Berberine treatment of DIC was employed to investigate whether dampening of DIC would alleviate periodontitis. Results DIC mice exhibited disrupted intestinal barrier with dysbiotic gut microbiota, corroborating the elevated serum level of LPS and IL-1. Compared to DIC-free/LIP mice, DIC/LIP mice showed aggravated alveolar bone resorption, with enrichment of neutrophils extracellular traps (NETs) in periodontal tissues. DIC promoted myelopoiesis of HSPCs by up-regulating myeloid differentiation pathway. Intragastric administration of berberine dampened DIC and rescued the myeloid skewing of HSPCs, consequently alleviating periodontal destruction. Intriguingly, LIP induction after DIC remission still exhibited aggravated periodontal destruction and myeloid skewing of HSPCs, indicating a UC-trained immunity against periodontal infection. Conclusion Increased gut permeability and microbial dysbiosis in UC elevate the serum level of LPS and IL-1, inducing myeloid skewing of HSPCs with an immune memory. Generation of inflammatory potential myeloid cells causes NETs accumulation and aggravates periodontal destruction in the UC-related periodontitis.
Project description:Sterile tissue injury after stroke causes lymphocyte contraction in lymphoid tissues and may decrease circulating IgA-levels. Intestinal Peyer’s patches (PP) harbor large numbers of IgA+ B cell precursors and plasma cells. Whether and how tissue injury triggers PP-B cell death, thereby mediating IgA-loss, is unknown. We found decreased circulating IgA levels in stroke and myocardial infarction patients. Experimental stroke and myocardial infarction in mice phenocopied the human situation. Decreased plasma and fecal IgA were accompanied by rapid and macroscopic shrinkage of PP caused by substantial losses of PP-resident IgA+ precursors and plasma cells in mice. Tissue injury induced neutrophil activation endowed with the release of toxic neutrophil extracellular traps (NETs). Antibody-mediated or genetically- induced neutrophil loss, digestion of NETs, or inhibition of their release by the Gasdermin D blockade completely prevented lymphocyte loss and PP shrinkage. We also identified NETs in the plasma of stroke and myocardial infarction patients. Hence, tissue injury induces systemic NET-release, which might be targeted to maintain immune homeostasis at mucosal barriers.
Project description:Pancreatitis is triggered by environmental or cellular stress and is the leading contributor to pancreatic ductal adenocarcinoma. Altered gene expression in response to acinar cell stress determines the severity and duration of pancreatitis. However, it is unclear what factors contribute to this phenomenon. Here, we define a novel role for Activating Transcription Factor 3 (ATF3) during pancreatic injury. ATF3, a key mediator in the unfolded protein response, is robustly expressed in acinar cells during pancreatitis. Targeted deletion of Atf3 altered the molecular response to injury, with Atf3-/- acinar cells maintaining cell organization in response to cerulein, a well-established inducer of pancreatitis. Characterization of the mechanism using chromatin immunoprecipitation followed by Next Generation sequencing (ChIP-seq) identified 11,771 enrichment spots for ATF3, with known transcriptional start sites for >3,000 genes within 5 kb of ATF3 enrichment. Gene ontology analysis revealed a significant representation of ATF3 enrichment to genes affecting cell organization, including Mist1, a molecule required for establishing acinar cell organization. We confirmed a direct interaction of ATF3 to the Mist1 promoter during pancreatitis, and showed that ATF3 is required for altered Mist1 expression in response to injury. Finally, we demonstrate that ATF3 repression of Mist1 involves HDAC5. These findings suggest that ATF3 is a key transcriptional regulator during pancreatitis and promotes loss of the mature acinar cell phenotype in response to pancreatic injury. Two samples were produced from male mice 4 hours after CIP initiation from intraparitoneal injections of cerulein, a ChIP sample using an ATF3 antibody and an IP control.