Effects of miR-200b on the expression of inflammatory genes in thoracic aorta of type 1 diabetic rats

Abstract

Objective To investigate the expression of miR-200b and its influence on inflammatory genes in thoracic aorta of type 1 diabetic rats. Methods Rats were divided into control group and streptozotocin-induced diabetic group. The expressions of miR-200b and inflammatory genes in thoracic aorta of type 1 diabetic rats were detected by qRT-PCR, and the expression of miR-200b's target transcription inhibitor Zeb1 was measured by Western blot. Results The results of qRT-PCR showed that the expressions of miR-200b in thoracic aorta in control group and diabetic group were 1.728±0.372 and 4.587±1.261(P<0.05), respectively. The expressions of inflammatory genes such as cyclooxygenase-2, monocyte chemoattractant protein-1, tumor necrosis factor-2, and interleukin-6 in thoracic aorta of diabetic group were markedly increased in diabetic group compared with control group (3.808±1.294 vs 0.864±0.093, P<0.05; 3.203±0.402 vs 1.485±0.433, P<0.01; 2.288±0.480 vs 0.784±0.089, P<0.01; 6.334±2.683 vs 0.981±0.176, P<0.05). Western blot showed that the expressions of Zeb1 in control group and diabetic group were 0.496±0.031 and 0.264±0.012(P<0.01), exhibiting a 46.7% decrease in diabetic group. Conclusions The expression of miR-200b in thoracic aorta of type 1 diabetic rats was increased while the expression of Zeb1 was inhibited. The expression levels of downstream inflammatory genes in this pathway were also increased, which may be one of the important mechanisms of diabetic vascular complications. (Chin J Endocrinol Metab, 2015, 31: 977-981) Key words: MiR-200b; Diabetes mellitus, type 1; Thoracic aorta; Inflammatory gene