MiR-20a ameliorates diabetic angiopathy in streptozotocin-induced diabetic rats by regulating intracellular antioxidant enzymes and VEGF.

OBJECTIVE: We evaluated the beneficial effect of miR-20a mimic against diabetic angiopathy (DA) in rats by regulating intracellular antioxidant enzymes and vascular endothelial growth factor (VEGF). MATERIALS AND METHODS: Diabetes was induced by intraperitoneal administration of streptozotocin (STZ; 65 mg/kg). Rats were then treated with miR-20a mimic (250 nmol/kg orally) for 8 weeks after STZ administration. The effect of miR20a mimic against DA in rats was evaluated by estimating serum glucose concentration, lipid profile, Lp-a, kidney function test, inflammatory mediators, and markers of endothelial cell function. Markers of oxidative stress in the aortic tissue were estimated in rats treated with miR-20a mimic. Western blot assay, RT-PCR, and histopathology of kidney and myocardial tissues were also performed. RESULTS: Serum levels of blood glucose and markers of renal function were significantly lower, and the lipid profile improved in the miR-20a mimic group compared to the DA group. Treatment with miR-20a mimic ameliorated the altered markers of endothelial function and oxidative stress, as well as mediators of inflammation, in the DA rats. Protein expressions of ERK1/2. JNK, and p38 MAPK. as well as mRNA expressions of TLR-4 and NF-kappa B, in aortic tissues were lower in the miR-20a mimic group than in the DA group. The miR-20a mimic group had fewer histopathological changes in kidney and myocardial tissues than the DA group. CONCLUSIONS: MiR-20a mimic can protect against DA in rats by regulating vascular endothelial function and oxidative stress.