Project description:The objectives of the present studies was examined to elucidate the role of hepatic macrophages in liver repair after acute liver injury.
Project description:Purpose: The goals of this study were to identify preferential gene expression signatures that are unique to hepatic macrophages in high-fat diet -induced non-alcoholic fatty liver disease. Methods and results: Wild-type and Casp11-/- mice were treated with high fat and normal chow diet for a period of 12 weeks. Hepatic macrophages from liver were isolated to generate mRNA transcription. Conclusion: Our study represents detailed analysis of caspase-11 in regulating hepatic macrophages in high-fat diet -induced non-alcoholic fatty liver disease.
Project description:Poor wound healing due to dysregulated tissue repair responses can exacerbate and prolong disease. Successful tissue repair is critically dependent on the timely clearance of apoptotic cells by macrophages in a process termed efferocytosis. Mechanisms and factors that link these two fundamental processes are therefore of great interest. Herein, we observed that a subset of 12-lipoxygenase (ALOX12)-expressing macrophages upregulate the production of host protective autacoids termed maresin conjugates in tissue regeneration (MCTR) during efferocytosis. MCTRs in turn play autocrine and paracrine functions in enhancing the ability of both ALOX12-positive and surrounding ALOX12-negative macrophages to uptake apoptotic cells. These effects of ALOX12-positive macrophages and MCTRs in regulating apoptotic cells clearance was also observed at sites of high apoptotic cell burden in mouse and flatworm models, as the formation of these mediators was upregulated and abrogation of related ALOX activity in mice reduced the ability of macrophages to clear apoptotic cells. Furthermore, add-back of MCTRs rapidly enhanced the efferocytosis capability of macrophages in mice and planarian flatworms. Mechanistic studies in macrophages revealed that MCTRs modulated Rac1 signalling and glycolytic metabolism, two pathways crucial for effective efferocytosis, and enhanced efferocytosis-induced WNT ligand production. Inhibition of Rac1 abrogated the ability of MCTRs to enhance glucose uptake and efferocytosis in vitro, while inhibiting either Rac1, glycolysis, or WNT ligand production prevented MCTR-mediated enhancement of apoptotic cell clearance and tissue regeneration. Taken together, our findings identify a central role for ALOX12-expressing macrophages in the regulation of efferocytosis and tissue repair via the local formation of MCTRs.
Project description:The experiment was to identify gene expression changes in mouse liver macrophages upon resolution from inflammation.<br>Macrophages were isolated from mouse livers 24 hours (inflammation) and 72 hours (resolution) following injury (hepatic fibrosis).<br>RNAs were prepared and hybrised on Affymetrix Mouse Genome 1.0 ST arrays.