Project description:microRNA transcriptome data from wild type and Gata6-deficient tissue resident peritoneal macrophages. Tissue resident macrophages are notoriously heterogeneous, exhibiting discrete phenotypes as a consequence of tissue- and micro-anatomical niche-specific functions, but the molecular basis for this is not understood. Gata6 itself has been shown to be a target of multiple miR. However, microRNA transcriptome and its dependence on tissue-specific macrophage programming, such as effected by GATA6, has not been explored. We used microRNA sequencing to determine the patterns of microRNA expression in peritoneal resident macrophages at homeostasis in the absence of GATA-6 against wild type.
Project description:Tissue resident macrophages are notoriously heterogeneous, exhibiting discrete phenotypes as a consequence of tissue- and micro-anatomical niche-specific functions, but the molecular basis for this is not understood. We resolved a restricted transcriptional profile for the self-renewing population of peritoneal resident macrophages, which is expressed during homeostasis and inflammation and distinct from other MM-CM-^X. Prominent within this profile was the expression of Gata6. This study represents a characterisation of the role of Gata6 in peritoneal resident macrophage phenotype. We used microarrays to determine the patterns of gene expression in peritoneal resident MM-CM-^X in the absence of GATA-6 against wild type. Conditional 'floxed' Gata6 deficient sex-matched mice between 7 weeks old were compared against wild type
Project description:Tissue resident macrophages are notoriously heterogeneous, exhibiting discrete phenotypes as a consequence of tissue- and micro-anatomical niche-specific functions, but the molecular basis for this is not understood. We resolved a restricted transcriptional profile for the self-renewing population of peritoneal resident macrophages, which is expressed during homeostasis and inflammation and distinct from other MØ. Prominent within this profile was the expression of Gata6. This study represents a characterisation of the role of Gata6 in peritoneal resident macrophage phenotype. We used microarrays to determine the patterns of gene expression in peritoneal resident MØ in the absence of GATA-6 against wild type.
Project description:In mouse peritoneal and other serous cavities, the transcription factor Gata6 drives the identity of the major cavity resident population of macrophages, with a smaller subset of cavity-resident macrophages dependent on the transcription factor Irf4. Here we showed that GATA6+ macrophages in the human peritoneum were rare, regardless of age. Instead, more human peritoneal macrophages aligned with mouse CD206+ LYVE1+ cavity macrophages that represent a differentiation stage just preceding expression of Gata6. Low abundance of CD206+ macrophages was retained in C57BL/6J mice fed a high-fat diet or in wild-captured mice, suggesting that differences between serous cavity-resident macrophages in humans and mice were not environmental. Irf4-dependent mouse serous cavity macrophages aligned closely with human CD1c+CD14+CD64+ peritoneal cells that, in turn, resembled human peritoneal CD1c+CD14-CD64- cDC2. Thus, major populations of serous cavity-resident mononuclear phagocytes in humans and mice shared common features but the proportions of different macrophage differentiation stages greatly differ between the two species and DC2-like cells were especially prominent in humans.
Project description:Local factors produced in the tissue microenvironment play essential roles in promoting the ontogeny and phenotype of tissue resident macrophages (TRM). In the peritoneal cavity, large peritoneal macrophages (LPM) are the dominant TRMs that functionally mediate type 2 immunity, facilitate tissue repair of the mesothelium, and protect against peritoneal fibrosis. It is established that retinoic acid derived from the omentum induces transcription factor Gata6 expression in LPMs, which in turn regulates gene expression of factors that define peritoneal macrophages. It is still unclear whether retinoic acid is the sole local factor that regulates Gata6 expression in LPMs. Mesothelial cells line the entire peritoneal cavity and produce a protective, non-adhesive barrier against injury, at least in part by recruiting immune cells with secreted cytokines, such as M-CSF. We hypothesized that secreted factors from peritoneal mesothelial cells are also responsible for regulating LPM development including both ontogeny and function. Due to their immediate proximity to the peritoneal cavity, we propose that mesothelial cells can produce and secrete proteins into the peritoneum to maintain Gata6 expression by LPMs. To identify secreted factors that are highly and specifically expressed in mesothelial cells, we harvested primary mesothelial cells from 10-week-old C57BL/6 mice using FACS selection (CD45- PDPN+ GPM6a+). Total RNA was isolated from these cells and subjected to RNA-seq analysis after depletion of ribosomal RNA.
Project description:Previous work has shown conflicting roles for Tec family kinases in regulation of Toll-like receptor (TLR)-dependent signalling in myeloid cells. In the present study, we performed a detailed investigation of the role of Btk and Tec kinases in regulating TLR signalling in several types of primary murine macrophages. We demonstrate that primary resident peritoneal macrophages deficient for Btk and Tec secrete less pro-inflammatory cytokines in response to TLR stimulation than wild type cells. In contrast, we found that bone marrow-derived and thioglycollate-elicited peritoneal macrophages deficient for Btk and Tec secrete more pro-inflammatory cytokines than wild type cells. We then compared the phosphoproteome regulated by Tec kinases and lipopolysaccharide in primary peritoneal and bone marrow derived macrophages. From this analysis we determined that Tec kinases regulate different signalling programs in these cell types. In additional studies using bone marrow-derived macrophages, we find that Tec and Btk promote phosphorylation events necessary for immunoreceptor-mediated inhibition of TLR signalling. Taken together, our results are consistent with a model where Tec kinases (Btk, Tec, Bmx) are required for TLR-dependent signalling in many types of myeloid cells. However, our data also support a cell type-specific TLR-inhibitory role for Btk and Tec that is mediated by immunoreceptor activation and signalling via PI3K.
Project description:Peritoneal macrophages from control and Mac-Gata6 KO (LysM-cre;Gata6-floxed) mice were determined for genome wide gene expression. Sorted peritoneal macrophages from control and Mac-Gata6 KO mice were performed for whole genome expression analysis by Illumina microarray
Project description:Resident tissue macrophages (RTMs) are organ-specialized phagocytes responsible for the maintenance and protection of residing tissue. It is well established that tissue diversity is reflected by the heterogeneity of RTMs origin and phenotype. However, much less is known about tissue-specific phagocytic macrophage functions. Here, using quantitative proteomics approach, we identify cathepsins as key determinants of phagosome maturation in primary peritoneal, lung and brain resident macrophages. The data further uncover cathepsin K (CtsK) as a molecular marker for lung phagosomes required for intracellular protein and collagen degradation. Pharmacological blockade of CtsK activity diminished phagosomal proteolysis and collagenolysis in lung resident macrophages. Furthermore, pro-fibrotic TGF-β negatively regulated CtsK-mediated phagosomal collagen degradation independently from classical endocytic proteolytic pathways. In humans, phagosomal CtsK activity was reduced in lung COPD macrophages and lung macrophages exposed to cigarette smoke extract. Taken together, this study provides a comprehensive map of how peritoneal, lung and brain tissue environment shapes phagosomal composition of resident macrophages, revealing CtsK as a key molecular determinant of lung phagosomes contributing to phagocytic collagen clearance in lungs.