Project description:Aim of this project was to examine the global gene expression profiles of mononuclear phagocytes recruited from peripheral blood to the alveolar space following alveolar deposition of the TLR2-ligand Pam3CSK4 in transgenic CX3CR1+/GFP mice.
Project description:Muscle injury triggers inflammation in which infiltrating mononuclear phagocytes are crucial for tissue regeneration. The interaction of the CCL2/CCR2 and CX3CL1/CX3CR1 chemokine axis that guides phagocyte infiltration is incompletely understood. Here, we show that CX3CR1 deficiency promotes muscle repair and rescues Ccl2-/- mice from impaired muscle regeneration as a result of altered macrophage function, not infiltration. Transcriptomic analysis of muscle mononuclear phagocytes reveals that Apolipoprotein E (ApoE) is up-regulated in mice with efficient regeneration. ApoE treatment enhances phagocytosis by mononuclear phagocytes in vitro, and restores phagocytic activity and muscle regeneration in Ccl2-/- mice. Because CX3CR1 deficiency may compensate for defective CCL2-dependant monocyte recruitment by modulating ApoE-dependent macrophage phagocytic activity, targeting CX3CR1 expressed by macrophages might be a powerful therapeutic approach to improve muscle regeneration.
Project description:Aim of this project was to examine the global gene expression profiles of mononuclear phagocytes recruited from peripheral blood to the alveolar space following alveolar deposition of the TLR2-ligand Pam3CSK4 in transgenic CX3CR1+/GFP mice. Experiment Overall Design: Alveolar macrophages (AM) and peripheral blood monocytes (PBM) were isolated from broncho-alveolar lavages and from blood, respectively, using FACS. Expression profiles from AM and PBM of the same mice were compared on the same slides. Each labeled RNA sample contained RNA pooled from six individuals. Four pairs of RNA from corresponding AM and PBM pools were hybridized, giving a total amount of 24 individual mice analyzed. Two hybridizations were performed with AM labeled with Cy3 and PBM with Cy5, two hybridizations were performed with swaped dyes.
Project description:Inappropriate cross talk between mammals and their gut microbiota may trigger intestinal inflammation and drive extra-intestinal immune-mediated diseases. Studies with germ-free or gnotobiotic animals represent the gold standard for research on bacterial-host interaction but they are not readily accessible to the wide scientific community. We aimed at refining a protocol that in a robust manner would deplete murine intestinal microbiota and prove to have significant biologic validity. Previously published protocols for depleting mice of their intestinal microbiota by administering broad-spectrum antibiotics in drinking water were difficult to reproduce. We show that twice daily delivery of antibiotics by gavage depleted mice of their cultivable fecal microbiota and reduced the fecal bacterial DNA load by approximately 400 fold while ensuring the animals’ health. Mice subjected to the protocol for 17 days displayed enlarged ceca, reduced Peyer’s patches and small spleens. Antibiotic treatment significantly reduced the expression of antimicrobial factors and altered the expression of 517 genes in total in the colonic epithelium. Genes involved in cell cycle were significantly altered concomitant with reduced epithelial proliferative activity in situ assessed by Ki-67 expression, suggesting that commensal microbiota drives cellular proliferation in colonic epithelium. We present a robust protocol for depleting mice of their cultivatable intestinal microbiota with antibiotics by gavage and show that the biological effect of this depletion is phenotypic characteristics and epithelial gene expression profile similar to those of germ-free mice. Comparison of genome-wide gene expression of colon intestinal epithelial cells from mice subjected to microbiota depletion protocol against to control mice.
Project description:We found that low protein diet consumption resulted in decrease in the percentage of normal Paneth cell population in wild type mice, indicating that low protein diet could negatively affect Paneth cell function. We performed fecal microbiota composition profiling. Male mice were used at 4-5 weeks of age. Fecal samples were collected for microbiome analysis.