Extracellular vesicles from adipose-derived mesenchymal stem cells promote colony formation ability and EMT of corneal limbal epithelial cells

Corneal diseases are a leading cause of visual impairment, and their treatment remains challenging. Corneal epithelial stem cells exist in the limbus, the peripheral region of the cornea, and play an important role in corneal regeneration. Here, we evaluated the effects of extracellular vesicles from human adipose-derived mesenchymal stem cells (AdMSC-EVs) on limbal epithelial cells (LECs). Colony formation assays showed that the colony-forming efficiency of LECs significantly increased in the presence of AdMSC-EVs. We next demonstrated that AdMSC-EVs accelerated the migration of LECs in a scratch assay, whereas the proliferation of LECs was decreased by AdMSC-EVs in the cell proliferation assay. RNA sequencing analysis of LECs indicated that AdMSC-EVs maintained their stem cell properties and improved epithelial-mesenchymal transition (EMT). Furthermore, after identifying the six most abundant microRNAs (miRNAs) in AdMSC-EVs, LEC transfection with miRNA mimics indicated that miR-25, miR-191, and miR-335 were the most probable miRNA factors within AdMSC-EVs at improving colony formation ability and EMT. Taken together, our findings indicated that AdMSC-EVs enhanced the colony formation ability and EMT of LECs, and the effects of AdMSC-EVs were in-part mediated by the miRNAs within the AdMSC-EVs.