【目的】探讨黄芪甲苷对糖尿病肾病大鼠的治疗作用及机制。【方法】将27只大鼠随机分为正常组、模型组、黄芪甲苷组,每组9只。模型组、黄芪甲苷组大鼠给予高脂饲料喂养联合链脲佐菌素(STZ)40 mg/kg腹腔注射构建2型糖尿病肾病模型。造模...【目的】探讨黄芪甲苷对糖尿病肾病大鼠的治疗作用及机制。【方法】将27只大鼠随机分为正常组、模型组、黄芪甲苷组,每组9只。模型组、黄芪甲苷组大鼠给予高脂饲料喂养联合链脲佐菌素(STZ)40 mg/kg腹腔注射构建2型糖尿病肾病模型。造模成功后,黄芪甲苷组给予黄芪甲苷40 mg/kg灌胃治疗,正常组、模型组给予等体积生理盐水,每日1次,持续12周。12周后,测定大鼠空腹血糖(FBG)、尿白蛋白/尿肌酐比值(UACR)、血尿素氮(BUN)、血清肌酐(SCr)水平;苏木素-伊红(HE)染色法观察肾脏病理结构变化;过碘酸雪夫(PAS)染色、马松(Masson)染色法观察肾脏纤维化程度;定量聚合酶链反应(qPCR)、蛋白免疫印迹(Western Blot)法检测肾脏组织中腺苷酸蛋白活化激酶(AMPK)、内皮型一氧化氮合酶(e NOS)mRNA及蛋白表达水平。【结果】与模型组比较,黄芪甲苷组大鼠FBG、UACR显著降低(P<0.05),BUN、SCr含量未见明显改变;与模型组比较,黄芪甲苷组大鼠肾小球体积减小,基底膜增厚、系膜基质增生、肾小囊腔狭窄程度、胶原纤维沉积明显减轻;进一步的实验结果显示,黄芪甲苷组肾脏组织中AMPK、e NOS m RNA表达水平较模型组明显升高(P<0.05),AMPK的磷酸化水平及eNOS蛋白表达水平较模型组明显上调(P<0.05)。【结论】黄芪甲苷可改善大鼠糖尿病肾损害,其机制可能与激活AMPK/eNOS信号通路有关。展开更多
Endothelial nitric oxide synthase (eNOS) is a key enzyme responsible for the regu-lation of vascular homeostasis. Many humor factors and mechanical forces can affect eNOS ac-tivity via phosphorylation modification but...Endothelial nitric oxide synthase (eNOS) is a key enzyme responsible for the regu-lation of vascular homeostasis. Many humor factors and mechanical forces can affect eNOS ac-tivity via phosphorylation modification but the mechanisms involved vary with stimuli applied. We have demonstrated that cytochrome P450 (CYP) epoxygenase-dependent metabolites of ara-chidonic acid, epoxyeicosatrienoic acids (EETs), can robustly up-regulate eNOS expression and its activity, however the relevant signaling pathways responsible for activity regulation are not well known. In this study, we explored the role of PI3 kinase (PI3K)/protein kinase B (Akt) sig-naling pathway in eNOS expression and its phosphorylation in response to EETs via direct addi-tion of EETs into cultured bovine aorta endothelial cells (BAECs) and recombinant adeno- asso-ciated virus-mediated transfection of CYP epoxygenase genes CYPF87V and CYP2C11 to pro-duce endogenous EETs followed by co-treatment with PI3K or Akt inhibitor. Results show that both exogenous and endogenous EETs could remarkably enhance eNOS expression and its phosphorylation at Ser1179 and Thr497 residues; PI3K inhibitor LY294002 could inhibit EETs-induced increase in eNOS-Ser(P)1179 but had no effect on the change of eNOS-Thr(P)497, while Akt inhibitor could attenuate the increase in phosphor-eNOS at both residues; both of the two inhibitors could block EETs-enhanced eNOS expression. These results lead to conclusions: (i) EETs-mediated regulation of eNOS activity may be related with the changes of phosphoryla-tion level at eNOS-Ser1179 via PI3K/Akt and eNOS-Thr497 via Akt; (ii) PI3K/Akt signaling pathway is involved in the up-regulation of eNOS expression by EETs.展开更多
Objective: To assess the effects of traditional Chinese medicine YiQiFuMai on cardiac function during the progression of ischemic heart failure. Methods: Rabbits were divided into sham, heart failure, and YiQiFuMai gr...Objective: To assess the effects of traditional Chinese medicine YiQiFuMai on cardiac function during the progression of ischemic heart failure. Methods: Rabbits were divided into sham, heart failure, and YiQiFuMai groups. The ischemic heart failure model was established in New Zealand white rabbits, which were intraperitoneally injected with YiQiFuMai injection and 0.9% sodium chloride after the operation. After six weeks, cardiac function was examined by ultrasound;serum BNP levels were measured by ELISA;p-AKT, eNOS, ICAM-1 and VEGF levels were evaluated by real-time PCR and Western-Blot;pathological changes of the myocardial tissue were observed by H&E staining;CD31 expression in tissue samples was analyzed by immunohistochemistry. The ultrastructure and microcirculation of myocardial tissue specimens from the three groups were assessed by transmission electron microscopy. Results: YiQiFuMai decreased serum BNP levels, and increased LVEF and reduced LVEDD at 6 weeks postoperatively. In addition, YiQiFuMai can improve myocardial damage and microcirculation structure, as assessed by histology and transmission electron microscope. At the molecular level, treatment with YiQiFuMai resulted in increased eNOS, VEGF and p-AKT levels but reduced ICAM-1 amounts compared with the heart failure group. Conclusion: Ischemic heart failure damages the microvascular structure and functions of the myocardium. Treatment with YiQiFuMai potentially ameliorates microcirculatory damage and alleviates cardiac failure by improving endothelial function and angiogenesis, and inhibiting inflammatory cell adhesion.展开更多
文摘【目的】探讨黄芪甲苷对糖尿病肾病大鼠的治疗作用及机制。【方法】将27只大鼠随机分为正常组、模型组、黄芪甲苷组,每组9只。模型组、黄芪甲苷组大鼠给予高脂饲料喂养联合链脲佐菌素(STZ)40 mg/kg腹腔注射构建2型糖尿病肾病模型。造模成功后,黄芪甲苷组给予黄芪甲苷40 mg/kg灌胃治疗,正常组、模型组给予等体积生理盐水,每日1次,持续12周。12周后,测定大鼠空腹血糖(FBG)、尿白蛋白/尿肌酐比值(UACR)、血尿素氮(BUN)、血清肌酐(SCr)水平;苏木素-伊红(HE)染色法观察肾脏病理结构变化;过碘酸雪夫(PAS)染色、马松(Masson)染色法观察肾脏纤维化程度;定量聚合酶链反应(qPCR)、蛋白免疫印迹(Western Blot)法检测肾脏组织中腺苷酸蛋白活化激酶(AMPK)、内皮型一氧化氮合酶(e NOS)mRNA及蛋白表达水平。【结果】与模型组比较,黄芪甲苷组大鼠FBG、UACR显著降低(P<0.05),BUN、SCr含量未见明显改变;与模型组比较,黄芪甲苷组大鼠肾小球体积减小,基底膜增厚、系膜基质增生、肾小囊腔狭窄程度、胶原纤维沉积明显减轻;进一步的实验结果显示,黄芪甲苷组肾脏组织中AMPK、e NOS m RNA表达水平较模型组明显升高(P<0.05),AMPK的磷酸化水平及eNOS蛋白表达水平较模型组明显上调(P<0.05)。【结论】黄芪甲苷可改善大鼠糖尿病肾损害,其机制可能与激活AMPK/eNOS信号通路有关。
基金This work was supported by the National Natural Science Foundation(Grant Nos.39870307,30270561&30430320).
文摘Endothelial nitric oxide synthase (eNOS) is a key enzyme responsible for the regu-lation of vascular homeostasis. Many humor factors and mechanical forces can affect eNOS ac-tivity via phosphorylation modification but the mechanisms involved vary with stimuli applied. We have demonstrated that cytochrome P450 (CYP) epoxygenase-dependent metabolites of ara-chidonic acid, epoxyeicosatrienoic acids (EETs), can robustly up-regulate eNOS expression and its activity, however the relevant signaling pathways responsible for activity regulation are not well known. In this study, we explored the role of PI3 kinase (PI3K)/protein kinase B (Akt) sig-naling pathway in eNOS expression and its phosphorylation in response to EETs via direct addi-tion of EETs into cultured bovine aorta endothelial cells (BAECs) and recombinant adeno- asso-ciated virus-mediated transfection of CYP epoxygenase genes CYPF87V and CYP2C11 to pro-duce endogenous EETs followed by co-treatment with PI3K or Akt inhibitor. Results show that both exogenous and endogenous EETs could remarkably enhance eNOS expression and its phosphorylation at Ser1179 and Thr497 residues; PI3K inhibitor LY294002 could inhibit EETs-induced increase in eNOS-Ser(P)1179 but had no effect on the change of eNOS-Thr(P)497, while Akt inhibitor could attenuate the increase in phosphor-eNOS at both residues; both of the two inhibitors could block EETs-enhanced eNOS expression. These results lead to conclusions: (i) EETs-mediated regulation of eNOS activity may be related with the changes of phosphoryla-tion level at eNOS-Ser1179 via PI3K/Akt and eNOS-Thr497 via Akt; (ii) PI3K/Akt signaling pathway is involved in the up-regulation of eNOS expression by EETs.
文摘Objective: To assess the effects of traditional Chinese medicine YiQiFuMai on cardiac function during the progression of ischemic heart failure. Methods: Rabbits were divided into sham, heart failure, and YiQiFuMai groups. The ischemic heart failure model was established in New Zealand white rabbits, which were intraperitoneally injected with YiQiFuMai injection and 0.9% sodium chloride after the operation. After six weeks, cardiac function was examined by ultrasound;serum BNP levels were measured by ELISA;p-AKT, eNOS, ICAM-1 and VEGF levels were evaluated by real-time PCR and Western-Blot;pathological changes of the myocardial tissue were observed by H&E staining;CD31 expression in tissue samples was analyzed by immunohistochemistry. The ultrastructure and microcirculation of myocardial tissue specimens from the three groups were assessed by transmission electron microscopy. Results: YiQiFuMai decreased serum BNP levels, and increased LVEF and reduced LVEDD at 6 weeks postoperatively. In addition, YiQiFuMai can improve myocardial damage and microcirculation structure, as assessed by histology and transmission electron microscope. At the molecular level, treatment with YiQiFuMai resulted in increased eNOS, VEGF and p-AKT levels but reduced ICAM-1 amounts compared with the heart failure group. Conclusion: Ischemic heart failure damages the microvascular structure and functions of the myocardium. Treatment with YiQiFuMai potentially ameliorates microcirculatory damage and alleviates cardiac failure by improving endothelial function and angiogenesis, and inhibiting inflammatory cell adhesion.
