miR-1246-overexpressing exosomes improve UVB-induced photoaging by activating autophagy via suppressing GSK3β.

Stem cell paracrine has shown potential application in skin wound repair and photoaging treatment. Our previous study demonstrated that miR-1246-overexpressing Exosomes (OE-EXs) isolated from adipose-derived stem cells (ADSCs) showed superior photo-protecting effects on UVB-induced photoaging than that of the vector, however, the underlying mechanism was unclear. The simultaneous bioinformatics analysis indicated that miR-1246 showed potential binding sites with GSK3β which acted as a negative regulator for autophagy. This study was aimed to explore whether OE-EXs ameliorate skin photoaging by activating autophagy via targeting GSK3β. The results demonstrated that OE-EXs significantly decreased GSK3β expression, enhanced autophagy flux and autophagy-related proteins like LC3II, while suppressed p62 expression. Meanwhile, OE-EXs markedly reversed the levels of intracellular ROS, MMP-1, procollagen type I and DNA damage in human skin fibroblasts caused by UVB irradiation, but the ameliorating effects were significantly inhibited when 3-Methyladenine (3-MA) was introduced to block the autophagy pathway. Further, OE-EXs could reverse UVB-induced wrinkles, epidermal hyperplasia, and collagen fibers reduction in Kunming mice, nevertheless, the therapeutical effects of OE-EXs were attenuated when it was combinative treated with 3-MA. In conclusion, OE-EXs could cure UVB induced skin photoaging by activating autophagy via targeting GSK3β.