Mesenchymal stem cell-derived small extracellular vesicles promoting M2 macrophage polarization through p38 MAPK inhibition

To investigate how mesenchymal stem cell-derived small extracellular vesicles (MSC-sEVs) promotes diabetic wound healing through macrophage M1-to-M2 polarization, we conducted RNA-seq to search for the signaling pathway that participates in the polarization process. MSC-sEVs was isolated from the supernatant of rat bone marrow mesenchymal stem cells, and macrophages (bone marrow-derived macrophages, BMDMs) are from Sprague-Dawley (SD) rats by stimulating the bone marrow cells with 30 ng/mL M-CSF for 7 days. The blank group was cultured for 72 hours without LPS or MSC-sEV treatment, while the LPS group received 100 ng/mL LPS for 24 hours followed by 48 hours without LPS, and the EXO group was treated with 100 ng/mL LPS for 24 hours followed by 30 μg/mL MSC-sEVs for 48 hours (n = 3/group). After treatment, the total RNA of BMDMs were collected for RNA-seq.