Conclusions
MNC-QQc cells promote wound healing by the secretion of MMP9, which induces fibroblast migration via the STAT3 signaling pathway.
Methods
After separation from a 50 mL blood sample from healthy individuals, mononuclear cells were cultured for 7 days in a serum-free ex vivo expansion system with five different cytokines (MNC-QQc method). The effects of MNC-QQc cells on human dermal fibroblast migration were observed by scratch assay. An angiogenesis array screened the MNC-QQc cell supernatant for proteins related to wound healing. Finally, fibroblast migration was confirmed by observing the intracellular signal transduction pathways via Western blot.
Results
The migration of fibroblasts co-cultured with MNC-QQc cells increased by matrix metallopeptidase-9 (MMP9) secretion, as suggested by the angiogenesis array. Furthermore, the phosphorylation of signal transducer and activator of transcription 3 (STAT3) in fibroblast/MNC-QQc cell co-culture and fibroblast culture with added recombinant human MMP9 protein increased. When fibroblasts were cultured with either an MMP9 inhibitor or a STAT3 inhibitor, both fibroblast migration and STAT3 phosphorylation were significantly suppressed. Conclusions: MNC-QQc cells promote wound healing by the secretion of MMP9, which induces fibroblast migration via the STAT3 signaling pathway.