Project description:Interleukin-10 (IL-10) is a pleiotropic anti-inflammatory cytokine produced and sensed by most hematopoietic cells. Genome wide association studies and experimental animal models point at a central role of the IL-10 axis in Inflammatory Bowel Diseases. Here we investigated the importance of intestinal macrophage production of IL-10 and their IL-10 exposure, as well as the existence of an IL-10-based autocrine regulatory loop in the gut. Specifically, we generated mice harboring IL-10 or IL-10 receptor (IL-10R?) mutations in intestinal lamina propria-resident chemokine receptor CX3CR1hi-expressingmacrophages. We found macrophage-derived IL-10 dispensable for gut homeostasis and maintenance of colonic T regulatory cells. In contrast, loss of IL-10 receptor expression impaired the critical conditioning of these monocyte-derived macrophages, but resulted in spontaneous development of severe colitis. Collectively, our results highlight IL-10 as a critical homeostatic macrophage-conditioning factor in the colon and define intestinal CX3CR1hi macrophages as a decisive factor that determines gut health or inflammation. Microarray of resident macrophages sorted from colons of Interleukin-10 deficeint mice and macrophage-restricted interleukin-10 receptor deficient mice versus colonic resident macrophages of wild type mice
Project description:Dietary n-3 polyunsaturated fatty acids can reduce inflammation via a range of mechanisms. This study tested the effect of dietary eicosapentaenoic acid (EPA) on intestinal inflammation using interleukin-10 gene-deficient (Il10-/-) mice. Methods: At 35 days of age, 12 weaned Il10-/- and 12 C57 mice were randomly assigned to one of two modified AIN-76A diets, supplemented with 3.7% purified ethyl esters of either EPA (n-3) or oleic acid (OA, control). To identify genes relevant to colon inflammation, transcription profiling (microarrays and qRT-PCR) and bioinformatic analyses were used. Results: In this study, dietary EPA reversed the decrease in colon fatty acid β-oxidation gene expression observed in OA-fed Il10-/- compared to C57 mice. Il10-/- mice fed the OA diet showed decreased expression of antioxidant enzyme genes, as well as those involved in detoxification of xenobiotics, compared to C57 mice on the same diet. In contrast, dietary EPA increased the expression of these genes in Il10-/- mice. Conclusions: These data indicate that dietary EPA induced endogenous lipid oxidation which might have a potential anti-inflammatory effect on colon tissue. This is supported by the activation of the Ppara gene that regulates the expression of pro-inflammatory and immunomodulatory genes and proteins.
Project description:Inflammatory bowel disease (IBD) is a chronic relapsing autoimmune disease of gastrointestinal tract (GI), involving in dysfunction of a variety of genes, such as Interleukin (IL)-10. Intense researches have demonstrated that IL10-deficient (IL10-/-) mice gradually exhibits features of spontaneous enterocolitis at 4-8 weeks of age and IL-10 is a significant immunomodulator in intestinal tract. Therefore, IL10-/- mice have become a classic model of enterocolitis to study the pathogenesis of IBD. The prevailing view is that IL10 deficiency leads to abnormal activation of immune cells and overproduction of a range of inflammation-inducing cytokines, which results in the persistence of intestinal inflammation in the mice. To uncover the role of the underlying molecular mechanisms involved in IL10-/--associated chronic enterocolitis, we construct IL10-deficient mice, sequence transcriptome and proteome of colon tissues from the mice with colitis and perform an integrated analysis of the two omics in this study. Mechanically, we might find out several novel signaling pathways or new therapeutic targets for IBD according to this combined analysis.
Project description:To further understand immune mechanims involved in regulating intestinal inflammation, we employed whole genome microarray expression profiling as a discovery platform to identify genes with the potential of regulating inflammation in the absence of IL-10. Whole colon tissue from IL-10-deficient and C57BL/6 (wild-type) mice was collected 2 weeks after Citrobacter rodentium infection and from uninfected controls. Consistent with the histological and cellular analysis, expression levels of many chemokines and cytokines involved in recruiting leukocytes and promoting inflammation were, on average, lower in IL-10 deficient compared to wild-type mice after infection. An exception to this general trend was IL-27, a cytokine with both pro- and anti-inflammatory properties. Two weeks after Citrobacter rodentium challenge, total RNA was extracted and analyzed from whole colon tissue of infected IL-10-deficient and wild-type mice, and compared to uninfected controls. Each sample contained equal amounts of total RNA from 4-5 female mice which were pooled and used in the experiment.
Project description:Dietary n-3 polyunsaturated fatty acids can reduce inflammation via a range of mechanisms. This study tested the effect of dietary eicosapentaenoic acid (EPA) on intestinal inflammation using interleukin-10 gene-deficient (Il10-/-) mice. Methods: At 35 days of age, 12 weaned Il10-/- and 12 C57 mice were randomly assigned to one of two modified AIN-76A diets, supplemented with 3.7% purified ethyl esters of either EPA (n-3) or oleic acid (OA, control). To identify genes relevant to colon inflammation, transcription profiling (microarrays and qRT-PCR) and bioinformatic analyses were used. Results: In this study, dietary EPA reversed the decrease in colon fatty acid β-oxidation gene expression observed in OA-fed Il10-/- compared to C57 mice. Il10-/- mice fed the OA diet showed decreased expression of antioxidant enzyme genes, as well as those involved in detoxification of xenobiotics, compared to C57 mice on the same diet. In contrast, dietary EPA increased the expression of these genes in Il10-/- mice. Conclusions: These data indicate that dietary EPA induced endogenous lipid oxidation which might have a potential anti-inflammatory effect on colon tissue. This is supported by the activation of the Ppara gene that regulates the expression of pro-inflammatory and immunomodulatory genes and proteins. Experiment Overall Design: The diet abbreviations EPA, OA, AA and CO used in the sample records Experiment Overall Design: refer to the following : Experiment Overall Design: CO : AIN-76A (control) Experiment Overall Design: OA : AIN-76A (fat-free) + 1% corn oil + 3.7% oleic acid Experiment Overall Design: EPA : AIN-76A (fat-free) + 1% corn oil + 3.7% eicosapentaenoic acid Experiment Overall Design: AA : AIN-76A (fat-free) + 1% corn oil + 3.7% arachidonic acid Experiment Overall Design: Corn oil was supplemented with purified linoleic and alpha-linolenic acid to meet the nutritional requirements of mice for these essential fatty acids. Diets fed for 6 weeks.
Project description:Background: The mechanisms underlying ozone (O3)-induced pulmonary inflammation remain unclear. Interleukin (IL)-10 is an anti-inflammatory cytokine that is known to inhibit inflammatory mediators. Objectives: The current study investigated the molecular mechanisms underlying IL-10-mediated attenuation of O3-induced pulmonary inflammation in mice. Methods: Il10-deficient (Il10-/-) and wild type (Il10+/+) mice were exposed to 0.3-ppm O3 or filtered air for 24, 48 or 72 hr. Immediately following exposure, differential cell counts, and total protein (a marker of lung permeability) were assessed from bronchoalveolar lavage fluid (BALF). mRNA and protein levels of cellular mediators were determined from lung homogenates. We also utilized global mRNA expression analyses of lung tissue with Ingenuity Pathway Analyses (IPA) to identify patterns of gene expression through which IL-10 modifies O3-induced inflammation. Results: Mean numbers of BALF polymorphonuclear leukocytes (PMNs) were significantly greater in Il10-/- mice than in Il10+/+ mice after exposure to O3 at all time points tested. O3-enhanced nuclear NF-kB translocation was elevated in the lungs of Il10-/- compared to Il10+/+ mice. Gene expression analyses revealed several key IL-10 and O3-dependent mediators, including IL-6, MIP-2, IL-1 and CD86. Conclusions: Results indicated that IL-10 protects against O3-induced pulmonary neutrophilic inflammation and cell proliferation. Moreover, gene expression analyses identified three response pathways and several novel genetic targets (e.g. Ccr1, Socs3, Il33, Hat1, and Gale) through which IL10 may modulate the innate and adaptive immune response. These novel mechanisms of protection against the pathogenesis of O3-induced pulmonary inflammation may also provide potential therapeutic targets to protect susceptible individuals. PARALLEL study design with 26 samples. Biological replicates: 2 to 3 replicates per group with wild type air exposed animals as controls for each time point (24, 48, 72 hours). Time-Course, Dose-Response, Strain comparison
Project description:Inflammatory caspases are essential effectors of inflammation and cell death. Here, we investigated their roles in colitis and colorectal cancer and report a bimodal regulation of intestinal homeostasis, inflammation and tumorigenesis by caspases-1 and -12. Casp1-/- mice exhibited defects in mucosal tissue repair and succumbed rapidly after dextran sulfate sodium (DSS) administration. This phenotype was rescued by administration of exogenous interleukin-18 and was partially reproduced in mice deficient in the inflammasome adaptor ASC. Casp12-/- mice, in which the inflammasome is derepressed, were resistant to acute colitis and showed signs of enhanced repair. Together with their increased inflammatory response, the enhanced repair response of Casp12-/- mice rendered them more susceptible to colorectal cancer induced by azoxymethane (AOM)+DSS. Taken together, our results indicate that the inflammatory caspases are critical in the induction of inflammation in the gut following injury, which is necessary for tissue repair and maintenance of immune tolerance. Total RNA obtained from isolated tumors or normal colon tissue from wild type and caspase-12 deficient mice were compared.
Project description:To further understand immune mechanims involved in regulating intestinal inflammation, we employed whole genome microarray expression profiling as a discovery platform to identify genes with the potential of regulating inflammation in the absence of IL-10. Whole colon tissue from IL-10-deficient and C57BL/6 (wild-type) mice was collected 2 weeks after Citrobacter rodentium infection and from uninfected controls. Consistent with the histological and cellular analysis, expression levels of many chemokines and cytokines involved in recruiting leukocytes and promoting inflammation were, on average, lower in IL-10 deficient compared to wild-type mice after infection. An exception to this general trend was IL-27, a cytokine with both pro- and anti-inflammatory properties.