Project description:To investigate whether loss of GPRC5B affects macrophage function, we generated myeloid-specific Gprc5b knockout mice and then did RNA-seq using resident peritoneal macrophage to analyze the gene expression profile.
Project description:To investigate whether loss of GPRC5B affects macrophage function, we generated myeloid-specific Gprc5b knockout mice and then did RNA-seq using bone marrow-derived M0 macrophages to analyze the gene expression profile.
Project description:Inflammatory bowel disease (IBD) is a condition characterized by severe intestinal inflammation and immune cell activation. The severity of the disease can be mitigated by compounds which activate peroxisome proliferator-activated receptor gamma (PPAR gamma), a receptor present widely in tissues involved in IBD pathogenesis. Our objective was to assess the affect of macrophage-specific deficiency of PPAR gamma on peripheral and colonic immune populations and colonic gene expression in experimental IBD. Macrophage-specific PPAR gamma-deficient mice (PPAR gamma flfl Lysozyme M Cre+) and control (PPAR gamma flfl Lysozyme M Cre-) littermates were treated with 2.5% dextran sodium sulfate (DSS) for 7 days. Disease activity was recorded daily and immune cell populations in the blood, spleen, mesenteric lymph nodes (MLN), and lamina propria were examined by flow cytometry. Colonic gene expression was assessed by real time PCR and microarray analyses. Our findings show that macrophage PPAR r-deficiency significantly exacerbates DSS inflammation. CD4+CD25+FoxP3+ regulatory T cells (T-regs) were significantly reduced in Cre+ mice, and MLN macrophages and CD40 expression were enhanced. There were significant differences in the number colonic macrophages between Cre+ and Cre- mice, but those from Cre+ mice expressed more CD40, Ly6C, and TLR-4. PPAR r-deficiency also increased the percent of CD8+ T cells in the lamina propria and enhanced colonic interferon gamma expression. Our findings indicate that macrophage PPAR gamma deficiency augments the severity of DSS colitis by reducing peripheral T-regs and increasing colonic macrophage activation and T cell inflammation. RNA from 3 PPAR gamma-deficient mice (PPAR gamma flfl; Lysozyme M Cre+) and 3 control (PPAR gamma flfl; Lysozyme M Cre-) littermates was processed and labeled according to the standard target labeling protocols. The samples were hybridized, stained, and scanned per standard Affymetrix protocols at the Virginia Bioinformatics Institute (VBI) core laboratory on Mouse 430 2.0 expression arrays (Affymetrix Inc., Santa Clara, CA).
Project description:Inflammatory bowel disease (IBD) is a condition characterized by severe intestinal inflammation and immune cell activation. The severity of the disease can be mitigated by compounds which activate peroxisome proliferator-activated receptor gamma (PPAR gamma), a receptor present widely in tissues involved in IBD pathogenesis. Our objective was to assess the affect of macrophage-specific deficiency of PPAR gamma on peripheral and colonic immune populations and colonic gene expression in experimental IBD. Macrophage-specific PPAR gamma-deficient mice (PPAR gamma flfl Lysozyme M Cre+) and control (PPAR gamma flfl Lysozyme M Cre-) littermates were treated with 2.5% dextran sodium sulfate (DSS) for 7 days. Disease activity was recorded daily and immune cell populations in the blood, spleen, mesenteric lymph nodes (MLN), and lamina propria were examined by flow cytometry. Colonic gene expression was assessed by real time PCR and microarray analyses. Our findings show that macrophage PPAR r-deficiency significantly exacerbates DSS inflammation. CD4+CD25+FoxP3+ regulatory T cells (T-regs) were significantly reduced in Cre+ mice, and MLN macrophages and CD40 expression were enhanced. There were significant differences in the number colonic macrophages between Cre+ and Cre- mice, but those from Cre+ mice expressed more CD40, Ly6C, and TLR-4. PPAR r-deficiency also increased the percent of CD8+ T cells in the lamina propria and enhanced colonic interferon gamma expression. Our findings indicate that macrophage PPAR gamma deficiency augments the severity of DSS colitis by reducing peripheral T-regs and increasing colonic macrophage activation and T cell inflammation.
Project description:Macrophages represent a major immune cell population in atherosclerotic plaques and play central role in the progression of this lipid-driven chronic inflammatory disease. Targeting immunometabolism is proposed as a strategy to revert aberrant macrophage activation to improve disease outcome. Here, we show ATP citrate lyase (Acly) to be activated in inflammatory macrophages and human atherosclerotic plaques. We demonstrate that myeloid Acly deficiency induces a stable plaque phenotype characterized by increased collagen deposition and fibrous cap thickness, along with a smaller necrotic core. In-depth functional, lipidomic, and transcriptional characterization indicate deregulated fatty acid and cholesterol biosynthesis and reduced liver X receptor activation within the macrophages in vitro. This results in macrophages that are more prone to undergo apoptosis, whilst maintaining their capacity to phagocytose apoptotic cells. Together, our results indicate that targeting macrophage metabolism improves atherosclerosis outcome and we reveal Acly as a promising therapeutic target to stabilize atherosclerotic plaques.