MiR-29a-5p engages in the mechanism of diabetic retinopathy by specifically targeting SIRT3

Abstract

Whether miR-29a-5p is associated with diabetic retinopathy (DR) is still a subject of ongoing discussion. The current research examines the involvement of miR-29a-5p in regulating apoptosis, oxidative stress, and inflammation of retinal ganglion cells (RGCs) generated by high glucose (HG). Additionally, we are interested in analyzing the contribution of miR-29a-5p in developing DR. We obtained peripheral blood samples from 7 people with DR and 14 individuals without DR. Subsequently, we conducted biochemical indices analyses and qRT-PCR. We randomly divided RGCs into low glucose groups, HG groups, HG + inhibitor negative control groups, and HG + miR-29a-5p inhibitor groups. SIRT3 siRNA was transfected into RGCs through lipofectamine 3000 reagent. Cell vitality was detected by MTT; qRT-PCR was applied to identify miR-29a-5p expression; Detection of ROS, SOD, and MDA levels was quantified using the DCFH-DA, WST-1, and colorimetric methods, respectively; IL-6 and TNF-α contents were analyzed utilizing ELISA; Dual-luciferase gene reporter experiment was used to examine if SIRT3 is the specific target gene of miR-29a-5p; Flow cytometry evaluated apoptosis in RGCs; The technique of Western blotting identified the expression of Caspase-3, Bax and Bcl-2 proteins. The expression of miR-29a-5p was markedly elevated in individuals with DR, and it had positive correlations with levels of total cholesterol (TC) and fasting blood glucose (FBG). The combination of miR-29a-5p, total cholesterol, and triglycerides (TG) exhibits significant diagnostic value for DR, demonstrating both high sensitivity and specificity. High glucose stimulated the expression of miR-29a-5p in RGCs and worsened cellular oxidative stress, inflammatory response, and apoptotic levels. Transfection of miR-29a-5p inhibitor protected RGCs against HG-induced oxidative injury, inflammation, and apoptosis. Furthermore, the dual-luciferase reporter experiment provided confirmation that SIRT3 was a target gene of miR-29a-5p, as it negatively regulated SIRT3 expression. Notably, SIRT3 knockdown abolished the protection of miR-29a-5p inhibition on RGCs. Suppression of the miR-29a-5p gene safeguards RGCs against injury caused by high glucose via boosting SIRT3 signaling, which might provide a new prevention and treatment strategy for DR.