Abstract
BACKGROUND: Diabetic retinopathy (DR) is a leading cause of blindness in adults, which is characterized by neurovascular dysfunction. Retinal neurodegeneration was involved in the pathogenesis of early-stage DR. This research aims to reveal the therapeutic effects and potential molecule mechanism of Mesenchymal stem cells-derived exosomes (MSCs-EXOs) in Müller cells at the early stage of DR. More specifically, we investigated in the rat retinal Müller cell line rMC-1. METHODS: We cultured rMC-1 in high glucose (HG) medium mixed with MSCs-EXOs to observe the changes in cell proliferative capacity and function. EdU assay, Immunofluorescence staining and Cell viability were used to assess cell proliferative capacity and function. Western blot and Quantitative Real-Time polymerase chain reaction (qRT-PCR) were used to assess the expression of cell proliferation-related proteins and cell cycle-related protein. Finally, dual-luciferase reporter assay, miRNA sequencing and cell transfection were used to assess the relationships between MSCs-EXOs and binding site. RESULTS: Here our results displayed that MSCs-EXOs promoted HG-induced cell proliferation in rMC-1. Furthermore, MSCs-EXOs protected HG-induced function of rMC-1. Mechanistically, MSCs-EXOs promoted the proliferation of rMC-1 by inhibiting the Hippo pathway to decrease the expression of Large tumor suppressor 1 (LATS1) and p-YAP and increase the expression of cell proliferation-related proteins Yes-associated protein (YAP), EGFR and cell cycle-related protein CYCLIN D1. In addition, LATS1 knockdown inhibited p-YAP expression and promoted HG-induced cell proliferation and YAP, EGFR and CYCLIN D1 expression in rMC-1. We subsequently performed bioinformatics sequencing analysis of MSCs-EXOs and confirmed that LATS1 was the target of miR-21a-5p. CONCLUSION: Our research proved that MSCs-EXOs containing miR-21a-5p increased the expression of YAP via targeting LATS1, and ultimately promoted the cell proliferation in rMC-1. Our current study clarified the molecular mechanism of MSCs-EXOs-regulated cell proliferation and function protection in rMC-1 and provided a novel strategy for the treatment of DR.