MiR-200b对1型糖尿病大鼠胸主动脉炎症基因表达的影响

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

目的 探讨1型糖尿病大鼠胸主动脉miR-200b的变化及对炎症基因表达的影响.方法 研究分为正常对照组和糖尿病组.通过对SD大鼠腹腔注射链脲佐菌素构建1型糖尿病大鼠动物模型,采用qRT-PCR和Western印迹方法测定1型糖尿病大鼠胸主动脉miR-200b、炎症基因环氧化酶-2（COX-2）、单核细胞趋化蛋白1（MCP-1）、肿瘤坏死因子α（TNF-α）和白细胞介素6（IL-6）及miR-200b靶基因转录抑制因子Zeb1的表达.结果 qRT-PCR显示糖尿病组大鼠胸主动脉miR-200b的表达较正常对照组明显上调（4.587±1.261对1.728±0.372,P＜0.05）;炎症介质COX-2、MCP-1、TNF-α和IL-6的表达量显著升高（3.808±1.294对0.864±0.093, P＜0.05;3.203 ±0.402对1.485 ±0.433, P＜0.01;2.288 ±0.480对0.784±0.089,P＜0.01;6.334±2.683对0.981 ±0.176,P＜0.05）;Western印迹显示正常对照组和糖尿病组Zeb1表达水平分别为0.496±0.031和0.264±0.012 （P＜0.01）,糖尿病组较正常对照组下降46.7％.结论 1型糖尿病时大鼠胸主动脉中miR-200b上调,并抑制靶标Zeb1表达,进而增加调控通路下游相关炎症基因的表达,这可能是糖尿病血管并发症发生发展的重要机制之一.

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＆#39;s target transcription inhibitor Zeb1 was measured by Western blot.Results The results of qRT-PCR showed that the expressins 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.