miR-433 protects pancreatic β cell growth in high-glucose conditions

Pancreatic β cell dysfunction is a key characteristic in the pathogenesis of diabetes mellitus (DM). MicroRNAs (miRNAs) have been identified to serve a role in DM pathogenesis, but how specific miRNAs regulate glucose‑stimulated β cell functions remain unclear. The present study aimed to explore the effects of miR‑433 on cell growth under high‑glucose culture conditions and to determine the possible mechanisms involved. Reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) analysis was performed to detect the expression levels of miRNAs in Min‑6 pancreatic β cells cultured in high‑glucose medium, which revealed that miR‑433 was significantly downregulated. Results from in vitro Cell Counting Kit‑8, colony formation and flow cytometry analyses indicated that overexpression of miR‑433 may enhance cell viability and proliferation by promoting cell cycle progression and suppressing apoptosis. Furthermore, bioinformatics prediction and luciferase analysis demonstrated that miR‑433 was able to inhibit the expression of cyclooxygenase 2 (COX2) through targeting its 3'‑UTR. Moreover, knockdown of COX2 expression alleviated the inhibition of cell growth induced by high glucose, similar to overexpression of miR‑433. In conclusion, the present results suggested that miR‑433 may protect pancreatic β cells cultured in high glucose, which suggests that miR‑433 may have beneficial effects in preventing and treating DM.