地黄多糖通过Wnt通路对2型糖尿病大鼠骨代谢的调节作用及机制研究

Study on Regulation Effect and Mechanism of Rehmannia Glutinosa Polysaccharides on Bone Metabolism in Type 2 Diabetic Rats Through Wnt Pathway

目的:探讨地黄多糖通过Wnt通路对2型糖尿病大鼠骨代谢的调节作用及机制。方法:65只大鼠选取10只作为空白组,其余大鼠复制2型糖尿病模型,将造模成功大鼠随机分为模型组、地黄多糖低剂量组、地黄多糖高剂量组、二甲双胍组,每组11只。各给药组大鼠给予相应药物灌胃,模型组、空白组给予等体积柠檬酸盐缓冲液灌胃,共8周。检测各组大鼠血糖、胰岛素、肝糖原含量和血清骨代谢标志物;X线测定大鼠骨密度;HE染色观察骨组织病理学变化;蛋白印迹法检测骨骼肌内Wnt通路相关蛋白表达。结果:与空白组比较,模型组大鼠血糖、碱性磷酸酶水平升高(P<0.05),胰岛素水平、肝糖原含量、骨密度、血磷水平降低(P<0.05);与模型组比较,二甲双胍组和地黄多糖低、高剂量组大鼠血糖、碱性磷酸酶水平降低(P<0.05),胰岛素水平、肝糖原含量、骨密度、血磷水平升高(P<0.05);与地黄多糖低剂量组比较,地黄多糖高剂量组和二甲双胍组大鼠血糖、碱性磷酸酶水平降低(P<0.05),胰岛素水平、肝糖原含量、骨密度、血磷水平升高(P<0.05);与地黄多糖高剂量组比较,二甲双胍组大鼠血糖、碱性磷酸酶水平降低(P<0.05),胰岛素水平、肝糖原含量、骨密度、血磷水平升高(P<0.05)。模型组大鼠胫骨骨小梁断裂,数量减少,骨皮质薄且边缘毛糙,骨皮质内有骨吸收性凹陷;与模型组比较,二甲双胍组和地黄多糖低、高剂量组大鼠骨小梁依次增粗、连续性改善,数量增加,骨皮质内吸收性凹陷减少,厚度增加。与空白组比较,模型组大鼠骨骼肌内β-连环蛋白(β-catenin)、成骨特异性转录因子抗体(Runx2)、低密度脂蛋白受体相关蛋白5(LRP5)蛋白表达水平降低(P<0.05);与模型组比较,二甲双胍组与地黄多糖低、高剂量组大鼠骨骼肌内β-catenin、Runx2、LRP5蛋白表达水平升高(P<0.05);与地黄多糖低剂量组比较,地黄多糖高剂量组和二甲双胍组大鼠骨骼肌内β-catenin、Runx2、LRP5蛋白表达水平升高(P<0.05);与地黄多糖高剂量组比较,二甲双胍组大鼠骨骼肌β-catenin、Runx2、LRP5蛋白表达水平升高(P<0.05)。结论:地黄多糖可能通过激活Wnt通路调节2型糖尿病大鼠骨代谢状态。

Objective:To investigate the regulatory effect of Rehmannia glutinosa polysaccharides(Wnt)on bone metabolism in type 2 diabetic rats and its mechanism.Methods:10 of 65 rats were selected as the blank group,and the rest were randomly divided into model group,Rehmannia glutinosa polysaccharides low-dose group,Rehmannia glutinosa polysaccharides high-dose group and metformin group,with 11 rats in each group.The rats in each administration group were given the corresponding drugs by gavage,and the model group and the blank group were given an equal volume of citrate buffer by gavage for a total of 8 weeks.The blood glucose,insulin,liver glycogen content and serum markers of bone metabolism were detected in each group of rats.The bone density of the rats was determined by X-ray.The pathological changes of bone tissue were observed by HE staining.The expression of Wnt pathway related proteins in skeletal muscle was detected by Western blotting.Results:Compared with the blank group,the levels of blood glucose and alkaline phosphatase increased,while the levels of insulin,liver glycogen,bone mineral density and blood phosphorus decreased in the model group(P<0.05).Compared with the model group,the levels of blood glucose and alkaline phosphatase decreased,and the levels of insulin,hepatic glycogen,bone mineral density and blood phosphorus increased in metformin group and Rehmannia glutinosa polysaccharide low and high-dose groups(P<0.05).Compared with the Rehmannia glutinosa polysaccharide low-dose group,the levels of blood glucose and alkaline phosphatase decreased,and the levels of insulin,liver glycogen,bone mineral density and blood phosphorus increased in Rehmannia glutinosa polysaccharide high-dose group and metformin group(P<0.05).Compared with Rehmannia glutinosa polysaccharide high-dose group,the levels of blood glucose and alkaline phosphatase decreased,and the levels of insulin,liver glycogen,bone mineral density and blood phosphorus increased in metformin group(P<0.05).In the model group,the tibia trabecula fractured,the number was reduced,the bone cortex was thin and the edges were rough,and there were bone resorption depressions in the bone cortex.Compared with the model group,the bone trabeculae of rats in metformin group and Rehmannia glutinosa polysaccharide low and high-dose groups were thickened,the continuity was improved,the number was increased,the absorptive depression in bone cortex was reduced,and the thickness was increased.Compared with the blank group,the expression levels ofβ-catenin,osteogenic-specific transcription factor antibody(Runx2),and low-density lipoprotein receptor-related protein 5(LRP5)in the skeletal muscle of the model group decreased(P<0.05).Compared with the model group,the expression levels ofβ-catenin,Runx2,and LRP5 in the skeletal muscle of rats increased in the metformin group and the Rehmannia glutinosa polysaccharide low and high-dose group(P<0.05).Compared with the Rehmannia glutinosa polysaccharide low-dose group,the skeletal muscleβ-catenin,Runx2,and LRP5 protein expression levels increased in the Rehmannia glutinosa polysaccharide high-dose group and the metformin group(P<0.05).Compared with the Rehmannia glutinosa polysaccharide high-dose group,the expression levels ofβ-catenin,Runx2,and LRP5 in the skeletal muscle of rats increased in the metformin group(P<0.05).Conclusion:Rehmannia glutinosa polysaccharides may regulate bone metabolism in type 2 diabetic rats by activating the Wnt pathway.