摘要
目的观察高糖下调微小RNA(microRNA, miR)-99a对肝窦内皮细胞功能障碍的影响及二甲双胍的干预作用, 探讨糖尿病发生脂肪肝的病理机制与二甲双胍对其可能的保护机制。方法将人肝窦内皮细胞培养后随机分为正常对照组、高糖模型组、miR-99a过表达组、miR-99a过表达阴性对照组、胰岛素样生长因子1受体(insulin-like growth factor 1 receptor, IGF-1R)抑制剂组、雷帕霉素靶蛋白(mammalian target of rapamycin, mTOR)抑制剂组、二甲双胍治疗组。采用实时荧光定量PCR(realtime quantitative PCR, RT-qPCR)法检测miR-99a mRNA的表达水平, Western印迹、免疫荧光法检测IGF-1R、磷酸化(phosphorylated, p-)mTOR、玻连蛋白(vitronectin, VN)的表达水平及定位分布, 扫描电镜观察人肝窦内皮细胞超微结构。结果与正常对照组相比, 高糖模型组miR-99a mRNA表达明显下调(P=0.008), 而IGF-1R、p-mTOR、VN蛋白表达均显著升高, 其窗孔直径变小且数量减少;与高糖模型组相比, 二甲双胍干预后miR-99a mRNA表达明显上调, 而IGF-1R、p-mTOR、VN蛋白表达均明显降低(P=0.001,P=0.016,P=0.005), miR-99a过表达组、IGF-1R抑制剂组、mTOR抑制剂组和二甲双胍治疗组其窗孔直径变大、数量增多;miR-99a过表达后, IGF-1R、p-mTOR和VN的蛋白表达明显降低(P=0.007,P=0.013,P=0.003);给予IGF-1R抑制剂后, p-mTOR和VN的蛋白表达明显降低(P=0.006,P=0.009);给予mTOR抑制剂后, VN的蛋白表达明显降低(P=0.008), 而IGF-1R表达无明显变化(P=0.553)。结论高糖下调miR-99a诱导肝窦功能障碍, 其作用机制可能与调控IGF-1R/mTOR信号通路有关;二甲双胍增加miR-99a的表达从而抑制高糖诱导的肝窦功能障碍。
Objective To observe the effect of high glucose downregulated microRNA(miR)-99a on hepatic sinus dysfunction and metformin intervention,and to explore the pathogenesis of diabetes-induced fatty liver and possible mechanism of metformin.Methods The cultured human liver sinusoidal endothelial cells were randomly divided into normal control group,high glucose model group,miR-99a overexpression group,miR-99a overexpression negative control group,insulin-like growth factor 1 receptor(IGF-1R)inhibitor group,mammalian target of rapamycin(mTOR)inhibitor group,and metformin treatment group.The mRNA expressions of miR-99a were detected with realtime quantitative PCR(RT-qPCR),and the expression levels and distribution of IGF-1R,phosphorylated(p-)mTOR and vitronectin(VN)were detected by Western blotting and immunofluorescence.The ultrastructure of human liver sinusoidal endothelial cells was observed using scanning electron microscope.Results Compared with normal control group,the mRNA expression of miR-99a was downregulated(P=0.008),while the protein expressions of IGF-1R,mTOR,and VN were significantly increased,and the diameter and number of fenestrae decreased significantly in high glucose model group.Compared with high glucose model group,after the treatment with metformin,the mRNA expression of miR-99a was upregulated,while the protein expressions of IGF-1R,mTOR,and VN were significantly decreased(P=0.001,P=0.016,P=0.005,respectively),the number of fenestras increased and the diameter became larger in miR-99a overexpression group,IGF-1R inhibitor group,mTOR inhibitor group,and metformin treatment group.After overexpression of miR-99a,the protein expressions of IGF-1R,p-mTOR,and VN were significantly reduced(P=0.007,P=0.013,P=0.003,respectively);After administration of IGF-1R inhibitors,the expressions of p-mTOR and VN significantly decreased(P=0.006,P=0.009,respectively),following treatment with the mTOR inhibitor,the expression of VN was significantly reduced(P=0.008),while the expression of IGF-1R remained unchanged(P=0.553).Conclusions Downregulating of miR-99a with high glucose induced hepatic sinus dysfunction,which may be related to the regulation of IGF-1R/mTOR pathway.Metformin increased the expression of miR-99a,thereby inhibiting high glucose-induced hepatic sinusoidal dysfunction.
作者
刘菊香
李懋
魏亚庆
常翔
刘静
权金星
Liu Juxiang;Li Mao;Wei Yaqing;Chang Xiang;Liu Jing;Quan Jinxing(Department of Endocrinology,Gansu Provincial Hospital,Key Laboratory of Endocrine and Metabolic Diseases of Gansu Province,Lanzhou 730000,China;Department of Endocrinology,Wuwei People′s Hospital,Wuwei 733000,China)
出处
《中华内分泌代谢杂志》
CAS
CSCD
北大核心
2023年第9期797-803,共7页
Chinese Journal of Endocrinology and Metabolism
基金
国家自然科学基金(81960160)
甘肃省自然科学基金项目(20JR5RA155)。
