Project description:Muscle injury was elicited by cardiotoxin injection into the tibialis anterior muscle. Macrophages were isolated 2 days post-injury from the regenerating muscle. We used microarray to obtain global gene expression data of muscle-derived tissue macrophage subsets. Tissue macrophages were collected from regenerating muscle samples of three animals, Ly6C+ F4/80low and Ly6C- F4/80high macrophage subsets were sorted. The global gene expression patterns of distinct macrophage subsets were analyzed on Affymetrix microarrays.
Project description:Macrophages are a heterogeneous population of immune cells that play central roles in a broad range of biological processes, including the resolution of inflammation. Although diverse macrophage subpopulations have been identified, the characterization and functional specialization of certain macrophage subsets in inflamed tissues remain unclear. Here we uncovered a key role of specific macrophage subsets in tissue repair using proteomics, bioinformatics and functional analyses. We isolated two hepatic monocyte-derived macrophage subpopulations: Ly6ChiCX3CR1lo macrophages and Ly6CloCX3CR1hi macrophages during distinct phases of acute liver injury and employed label-free proteomics approach to profile the proteome of these cells. We found that the wound healing- and endocytosis-related proteins were specifically enriched in Ly6CloCX3CR1hi macrophages. Intriguingly, 12/15-lipoxygenase (Alox15), the most strongly up-regulated protein in Ly6CloCX3CR1hi macrophages, was identified as a specific marker for these macrophages. In co-culture systems, Ly6CloCX3CR1hi macrophages specifically induced hepatocyte proliferation. Furthermore, selective depletion of this population in CD11b-diphtheria toxin receptor mice significantly delayed liver repair. Overall, our studies shed light on the functional specialization of distinct macrophage subsets in the resolution of inflammation.
Project description:Tibialis anterior muscle was damaged by cardiotoxin injection and macrophage subsets were isolated and analyzed by gene expression analysis. We used microarray to obtain global gene expression data of muscle-derived tissue macrophage subsets. Tissue macrophages were collected from regenerating muscle samples, Gr1+/Cx3cr1low and Gr1-/Cx3cr1high macrophage subsets were sorted. The global gene expression patterns of distinct macrophage subsets were analyzed on Affymetrix microarrays.
Project description:Tibialis anterior muscle was damaged by cardiotoxin injection and macrophage subsets were isolated and analyzed by gene expression analysis. We used microarray to obtain global gene expression data of muscle-derived tissue macrophage subsets.
Project description:Muscle injury was elicited by cardiotoxin injection into the tibialis anterior muscle. Macrophages were isolated 2 days post-injury from the regenerating muscle. We used microarray to obtain global gene expression data of muscle-derived tissue macrophage subsets.
Project description:Numerous studies have shown in mouse that identity and function of macrophage populations are imprinted by their tissue of residence. By contrast, the properties of human tissue macrophages remain poorly understood. Here, we characterized human tonsil macrophages and identified 3 macrophage subsets with distinct phenotype, ontogeny and function. Using RNA-seq analysis, we found that CD36hi macrophages were transcriptionally related to monocytes, while CD36lo macrophages showed features of embryonic origin and CD36int macrophages had a mixed profile. Using scRNA-seq profiling of naïve and inflamed tonsils from non-human primates, we showed that monocyte engraftment did not pre-exist an immune challenge.
Project description:Single-cell RNA-sequencing (scRNA-seq) was applied to identify and characterise macrophage subsets that responded to larval zebrafish muscle injury. The Tg(mpeg1:mCherry) transgenic zebrafish line was utilised to isolate mCherry-expressing macrophages by FACS. Following needle-stab muscle injury of a 4 days post fertilisation (dpf) larvae, the wound site was dissected out at 1, 2, and 3 days post injury (dpi) for macrophage isolation. Macrophages isolated from 4 dpf-uninjured larvae were also included. This analysis led to the identification of 8 discrete clusters of macrophages, one of which corresponded to uninjured macrophages. The 7 wound-present macrophage subsets highlighted greater macrophage heterogeneity than previously described in an in vivo skeletal muscle injury context.