成纤维生长因子受体1通过控制微小RNA let-7b表达调节内皮细胞线粒体生源的作用研究

目的探索成纤维生长因子受体l（fihrohlast growth factor receptor1，FGFRl）在调控内皮稳态时对上游分子N-乙酰基-丝氨酰-天冬氨酰-赖氨酰-脯氨酸（N-acetyl-seryl-aspartyl-lysyl-proline、AcSDKP）的影响和下游微小RNAlet-7（microRNA let-7、miR let-7）的诱导作用及与内皮细胞线粒体生源的关系，以期最终研究FGFR1在内皮稳态中的调控作用。方法下调FGF／FGFRl信号通路，蛋白质印迹（Western印迹．WB）法和细胞免疫荧光（Immunofluorescence staining）技术检测线粒体融合蛋白MFN2（mitofusin-2）、OPA1（optic atrophy protein1）和分裂蛋白DRP1（dynamin-related protein-1）的表达；应用线粒体染色（MitoTraker Green）检测线粒体的生成；运用实时荧光定量核酸扩增（Real-time Quantitative PCR、qPCR）检测技术检测microRNA let-7的表达。结果FGFRl通过诱导microRNA let-7b一5p的生成促进AcSDKP维持线粒体的生源；AcSDKP修复细胞因子复合物Triple（TGF-β2、IL-1β和TNF-α）所引起microRNA let-7b-5p表达抑制与线粒体的生成密切相关；抑制microRNA let-7b-5p的表达后，AcSDKP失去促进线粒体生成的作用：上调microRNA let-7b-5p的表达后，可修复内皮细胞中因FGF／FGFRl底物FRS2（fibroblast growth factor receptor substrate）沉默所致通路缺失所致的线粒体生成障碍。结论FGFRl通过上调microRNA let-7b-5p的表达，促进线粒体的生成，从而在内皮细胞的稳态中起着十分重要的作用。

Effect of Electroacupuncture on Platelet-derived Growth Factor and the Ultrastructure of Mitochondria in Rats with Diabetic Gastroparesis

Objective To observe the effect of electroacupuncture(EA)at the pressure points Zu San Li(ST36),San Yin Jiao(SP6)and Liang Men(ST21)on platelet-derived growth factor(PDGF)and the ultrastructure of mitochondria in rats with diabetic gastroparesis(DGP).Methods Sixty Sprague Dawley(SD)rats were randomly separated into a normal control group(NC,n=10)and a modeling group(n=50).Rats in the modeling group received an injection of 2%streptozotocin(STZ)and a high-fat and highglucose diet for eight weeks to establish a DGP rat model.At the same time,blood glucose and a general symptom score were recorded every week.After modeling,30 successfully modeled rats were randomly separated into the following groups:the DGP group(n=10),the EA group(n=10)and the metoclopramide(MP)group(n=10).After three weeks of intervention,the gastrointestinal propulsive rate was measured by measuring the optical density(OD).The concentration of Ca2+was determined by fluorescence immunoassay,and levels of serum insulin(INS)and PDGF were determined by ELISA.The ultrastructure of mitochondria was observed with transmission electron microscopy.Results(1)After intervention,levels of blood glucose and the general symptom score were greatly decreased in the EA group compared to the DGP group(P<0.01).Compared with the DGP group,the gastric emptying rate and the intestinal propulsive rate of the EA group was significantly improved(P<0.01),and there was no statistically significant difference between the EA and the NC groups.(2)Compared with the NC group,the levels of INS in the DGP group markedly decreased(P<0.05),but there was no significant difference of INS levels between the EA and the MP roups.(3)Compared with the DGP group,theconcentration of Ca2+in the EA and the MP groups significantly increased(P<0.01,P<0.05,respectively).(4)Compared with the NC group,the average OD of PDGF in the DGP group was significantly higher(P<0.01).Compared with the DGP group,levels of PDGF in the EA group increased significantly(P<0.01).(5)There were abundant mitochondria with a clear structure and complete cristae in the NC group.However,in the DGP group,mitochondria were severely swollen,partly vacuolated,and cristae were either fractured,absent,or shortened.In the EA group,mitochondria were slightly swollen,with clear cristae.Conclusions Electroacupuncture at the points Zu San Li(ST36),San Yin Jiao(SP6)and Liang Men(ST21)may improve gastric motility in DGP by up-regulating the amount of PDGF and improving the ultrastructure of mitochondria.