miRNA expression profiles in exosomes extracted from FAPs.

Skeletal muscle maintains remarkable regenerative ability after injury, which mainly depends on the coordination and dynamic regulation between muscle stem cells and various other cell types. Recent studies have shown that fibro/adipogenic progenitors (FAP) play an important role in skeletal muscle regeneration by coordinating the interaction between muscle stem cells and macrophages. At present, the mechanism of whether FAP cells can regulate macrophages to affect skeletal muscle regeneration remains unclear. By isolation of mouse skeletal muscle FAP cells damaged by CTX for 10 days and gathered exosomes from them called FAPD10-exos, and using the exosomes to induce macrophages in vitro, we found that they expressed high levels of M2-type factors.In summary, we believe that FAPD10-exos can promote the polarization of macrophages towards M2 phenotype by secreting exosomes, and participate in and promote the regulation and regulation of skeletal muscle regeneration to enter the stage of damage repair in the early stage of regeneration. In order to explore which molecule plays a key role in FAP exosomes, we performed sRNA sequencing on the two isolated exosomes (FAPD3-exos and FAPD10-exos) and analyzed the differential expression of miRNA among them.