消退素D1对2型糖尿病小鼠骨骼肌TLR4影响的研究

Effect of revolvin D1 on TLR4 in skeletal muscle of type 2 diabetic mice

目的观察补充消退素D1(RvD1)对2型糖尿病小鼠骨骼肌Toll样受体4(TLR4)水平的影响。方法 35只雄性C57BL/6小鼠随机分为对照组和高糖高脂饮食组。8周后,给予高糖高脂饮食组小鼠一次性腹腔注射链脲佐菌素(STZ) 100 mg/kg造模,造模成功后,将高糖高脂饮食组的小鼠随机分为2型糖尿病组(糖尿病组)和2型糖尿病+RvD1干预组(消退素组),其中消退素组每天每只小鼠腹腔注射消退素D1 0. 2 ml,即100 ng/只。连续喂养21 d,检测各组小鼠空腹血糖、血清胰岛素、炎症因子水平,取肌肉组织通过RT-qPCR法检测TLR4的mRNA表达水平,Western blot法检测骨骼肌中TLR4的蛋白表达。结果糖尿病组小鼠的胰岛素抵抗指数、IL-6、TNF-α水平均高于对照组(P<0. 05),且消退素组小鼠的胰岛素抵抗指数、IL-6、TNF-α水平低于糖尿病组(P <0.05);糖尿病组、消退素组小鼠的TLR4蛋白表达高于对照组(P <0.05);而消退素组小鼠的TLR4表达低于糖尿病组(P <0. 05)。RT-qPCR法测小鼠TLR4的mRNA水平变化与上述结果一致。结论适量补充消退素D1可降低2型糖尿病小鼠炎症因子水平,减少2型糖尿病小鼠骨骼肌组织TLR4的表达,改善胰岛素抵抗。

Objective To observe the effect of supplemental Revolvin D1 （RvD1） on Toll-like receptor 4 （TLR4） in skeletal muscle of type 2 diabetic mice. Methods 35 male C57BL/6 mice were randomly divided into control group （NC group） and high glucose and high fat diet group. After 8 weeks, mice in high glucose and high fat diet group were given intraperitoneal injection of streptozotocin （STZ） 100 mg/ kg. Then they were randomly divided into two groups：Type 2 diabetes group （T2DM group） and type 2 diabetes ＋ RvD1 intervention group （ T2DM ＋ RvD1 group）. Mice in T2DM group mice were injected with phosphate buffer saline 0. 2 ml and T2DM ＋ RvD1 group mice were injected with Revolvin D1 100 ng/day respectively. The levels of fasting blood glucose, serum insulin and inflammatory factors were detected. The mRNA expression level of TLR4 was detected by real-time quantitative polymerase chain reaction （RT- qPCR） method, and the expression of TLR4 protein was detected by Western blot. Results The levels of insulin resistance index, interleukin （IL）-6 and tumor necrosis factor-α （TNF-α） in T2DM group and T2DM ＋ RvD1 group increased （P 〈 0.05 ）. Compared with the T2DM group, the levels of insulin resistance index, IL-6 and TNF-α in T2DM ＋ RvD1 group decreased （P 〈0. 05）. The expression of TLR4 protein in T2DM group and T2DM ＋ RvD1 group was higher than that in NC group （ P 〈 0. 05 ）. The expression of TLR4 protein in T2DM ＋ RvD1 group, was lower than that in T2DM group （P 〈0. 05）. The mRNA level of TLR4 in mice was consistent with the above results by RT-qPCR. Conclusions Moderate supplementation of RvD1 can not only decrease the level of inflammatory factors in type 2 diabetic mice, but also reduce the expression of TLR4 and insulin resistance in skeletal muscle of type 2 diabetic mice.