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
目的基于CYP2J3/EETs介导脂肪酸代谢探讨化瘀祛痰方防治血脂异常的机制。方法32只SPF级SD大鼠分为空白对照组、模型组、化瘀祛痰方组、辛伐他汀组,每组8只。除空白对照组外,其他各组给予高脂饲料喂饲,建立高脂血症模型。于第13周开始,...目的基于CYP2J3/EETs介导脂肪酸代谢探讨化瘀祛痰方防治血脂异常的机制。方法32只SPF级SD大鼠分为空白对照组、模型组、化瘀祛痰方组、辛伐他汀组,每组8只。除空白对照组外,其他各组给予高脂饲料喂饲,建立高脂血症模型。于第13周开始,化瘀祛痰方组给予化瘀祛痰方灌胃,辛伐他汀组给予辛伐他汀灌胃,空白对照组、模型组给予相应体积的生理盐水灌胃,每日1次,灌胃4周。采用全自动生化分析仪检测各组大鼠血清中总胆固醇(Total cholesterol,TC)、甘油三酯(Triglyceride,TG)、低密度脂蛋白胆固醇(Low density lipoprotein cholesterol,LDL-C)及高密度脂蛋白胆固醇(High density lipoprotein cholesterol,HDL-C)水平;HE染色观察肝脏组织病理变化;Elisa检测各组大鼠肝脏14,15-环氧二十碳三烯酸(14,15-epoxyeicosatrienoic acid,14,15-EET)水平;Real time RT-PCR检测肝脏组织细胞色素P450表氧化酶2J3(Cytochrome P450 oxidase 2J3,CYP2J3)、肉毒碱棕榈酰转移酶1(Carnitine palmitoyltransferase-1,CPT-1)mRNA水平;Western blot法检测肝脏组织CYP2J3、腺苷酸活化蛋白激酶(AMP-actived protein kinase,AMPK)、磷酸化腺苷酸活化蛋白激酶(p-AMPK)、乙酰辅酶A羧化酶(Acetyl CoA Carboxylase,ACC)、磷酸化乙酰辅酶A羧化酶(p-ACC)、CPT-1蛋白水平。结果与空白对照组比较,模型组大鼠血清TC、TG和LDL-C水平显著升高(P<0.01),HDL-C水平显著降低(P<0.05);肝脏脂质沉积显著,可见大量脂滴;肝脏组织内14,15-EET含量显著降低(P<0.01);肝脏CYP2J3、CPT-1 mRNA和蛋白表达水平显著降低(P<0.01),p-AMPK/AMPK、p-ACC/ACC显著降低(P<0.01)。与模型组比较,经化瘀祛痰方及辛伐他汀干预后,大鼠血清TC、TG和LDL-C水平显著降低(P<0.05或P<0.01),HDL-C水平显著升高(P<0.05);肝脏脂质沉积情况明显改善,脂滴数明显减少;肝脏组织内14,15-EET水平显著升高(P<0.01);肝脏CYP2J3、CPT-1 mRNA和蛋白表达水平显著升高(P<0.05或P<0.01),p-AMPK/AMPK展开更多
The cardiovascular effects of vitamin C (VitC) could be mediated by epoxyeicosatrienoic acids (EETs). We aimed to study the mechanism of VitC-dependent microsomal formation of cis- and trans-EETs and the regulation of...The cardiovascular effects of vitamin C (VitC) could be mediated by epoxyeicosatrienoic acids (EETs). We aimed to study the mechanism of VitC-dependent microsomal formation of cis- and trans-EETs and the regulation of EET levels in rat isolated perfused kidneys and in vivo. VitC biphasically stimulated rat kidney microsomal cis- and trans-EET formation in a ratio of 1:2, involving the participation of lipid hydroperoxides (LOOHs), Fe2+ , and cytochrome P450 (CYP). Levels of LOOHs correlated with microsomal EET production. LOOH stimulation of CYP isoforms resulted in preferred trans- over cis-EET formation from arachidonic acid and was associated with the cleavage of LOOHs, which indicated a CYP peroxy-genase activity. EETs contributed to VitC-induced vasodilator responses in rat isolated perfused kidneys. VitC (1 mg/ml) given in the drinking water for 9 days doubled rat urinary EET excretion, increased plasma levels of EETs, mostly trans-EETs, by 40%, and reduced plasma levels of 20-hydroxyeicosatetraenoic acid. Depletion of VitC in brain cortex and kidney tissues by more than 20- and 50-fold, respectively, in gulonolactone oxidase-knockout mice was associated with mild increases in tissue EETs. These data suggest that LOOHs are a determinant factor for EET formation in vivo in which VitC exerts a key regulatory effect. VitC-activated CYP peroxygenase activity may represent a CYP interaction with lipoxygenases and cyclooxygenases to mediate the cardiovascular effects of VitC via formation of EETs.展开更多
In addition to its role as a barrier between blood and tissues, the vascular endothelium is responsible for the synthesis and released of a number of vasodilators including prostaglandins, nitric oxide and endothelium...In addition to its role as a barrier between blood and tissues, the vascular endothelium is responsible for the synthesis and released of a number of vasodilators including prostaglandins, nitric oxide and endotheliumderived hyperpolarizing factor (EDHF). As one of these vasodilators, the specific nature of EDHF has not been fully elucidated, although a number of roles have been proposed. Importantly, many conditions, such as hypertension, hyperlipidemia, heart failure, ischemiareperfusion and diabetes mellitus comprise vascular endothelial dysfunction with EDHF dysregulation. This article reviews reports on the role of EDHF in diabetesrelated endothelial dysfunction.展开更多
目的:观察11,12-EET延迟性保护作用对缺血再灌注大鼠心肌ERK活性及磷酸化ERK表达的影响,探讨其在11,12-EET延迟性保护中的作用。方法:复制大鼠心肌缺血/再灌注模型;观察缺血/再灌注期间心脏收缩期左心室内压上升的最大变化速率(+dp/dtm ...目的:观察11,12-EET延迟性保护作用对缺血再灌注大鼠心肌ERK活性及磷酸化ERK表达的影响,探讨其在11,12-EET延迟性保护中的作用。方法:复制大鼠心肌缺血/再灌注模型;观察缺血/再灌注期间心脏收缩期左心室内压上升的最大变化速率(+dp/dtm ax)及舒张期左心室内压下降的最大变化速率(-dp/dtm ax);采用免疫共沉淀法测定大鼠心肌组织中细胞外调节激酶(ERK)的活性,采用W estern b lotting法测定大鼠心肌组织中磷酸化ERK的表达。结果:I/R组缺血60 m in及再灌注30 m in两个时段±dp/dtm ax均低于sham组(P<0.05),24 hE-ET+I/R组缺血60 m in及再灌注30 m in两个时段±dp/dtm ax明显高于I/R组(P<0.05),而24hEET+PD+I/R组缺血60 m in及再灌注30 m in两个时段±dp/dtm ax明显低于24hEET+I/R组(P<0.05)。ERK的活性24hEET+I/R高于norm al组,24hEET+I/R组低于24hEET+PD+I/R组。磷酸化ERK的表达I/R组高于norm al组和sham组,24hEET+I/R高于I/R组,24 hEET+I/R组低于24hEET+PD+I/R组。结论:外源性11,12-EET具有延迟性心脏保护作用,大量激活磷酸化的ERK参与这种保护作用。展开更多
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.
文摘目的基于CYP2J3/EETs介导脂肪酸代谢探讨化瘀祛痰方防治血脂异常的机制。方法32只SPF级SD大鼠分为空白对照组、模型组、化瘀祛痰方组、辛伐他汀组,每组8只。除空白对照组外,其他各组给予高脂饲料喂饲,建立高脂血症模型。于第13周开始,化瘀祛痰方组给予化瘀祛痰方灌胃,辛伐他汀组给予辛伐他汀灌胃,空白对照组、模型组给予相应体积的生理盐水灌胃,每日1次,灌胃4周。采用全自动生化分析仪检测各组大鼠血清中总胆固醇(Total cholesterol,TC)、甘油三酯(Triglyceride,TG)、低密度脂蛋白胆固醇(Low density lipoprotein cholesterol,LDL-C)及高密度脂蛋白胆固醇(High density lipoprotein cholesterol,HDL-C)水平;HE染色观察肝脏组织病理变化;Elisa检测各组大鼠肝脏14,15-环氧二十碳三烯酸(14,15-epoxyeicosatrienoic acid,14,15-EET)水平;Real time RT-PCR检测肝脏组织细胞色素P450表氧化酶2J3(Cytochrome P450 oxidase 2J3,CYP2J3)、肉毒碱棕榈酰转移酶1(Carnitine palmitoyltransferase-1,CPT-1)mRNA水平;Western blot法检测肝脏组织CYP2J3、腺苷酸活化蛋白激酶(AMP-actived protein kinase,AMPK)、磷酸化腺苷酸活化蛋白激酶(p-AMPK)、乙酰辅酶A羧化酶(Acetyl CoA Carboxylase,ACC)、磷酸化乙酰辅酶A羧化酶(p-ACC)、CPT-1蛋白水平。结果与空白对照组比较,模型组大鼠血清TC、TG和LDL-C水平显著升高(P<0.01),HDL-C水平显著降低(P<0.05);肝脏脂质沉积显著,可见大量脂滴;肝脏组织内14,15-EET含量显著降低(P<0.01);肝脏CYP2J3、CPT-1 mRNA和蛋白表达水平显著降低(P<0.01),p-AMPK/AMPK、p-ACC/ACC显著降低(P<0.01)。与模型组比较,经化瘀祛痰方及辛伐他汀干预后,大鼠血清TC、TG和LDL-C水平显著降低(P<0.05或P<0.01),HDL-C水平显著升高(P<0.05);肝脏脂质沉积情况明显改善,脂滴数明显减少;肝脏组织内14,15-EET水平显著升高(P<0.01);肝脏CYP2J3、CPT-1 mRNA和蛋白表达水平显著升高(P<0.05或P<0.01),p-AMPK/AMPK
基金supported by the Natrural Science Foundation of Hunan Province (2019JJ50975)Science and Technology Planning Project of Yunnan Provincial Science and Technology Department (2019FE001),China
基金supported by grants from the National Natural Science Foundation of China(No.81790624,81630010 and 81900341)the Tongji Hospital(HUST)Foundation for Excellent Young Scientist(No.2020YQ10)。
文摘The cardiovascular effects of vitamin C (VitC) could be mediated by epoxyeicosatrienoic acids (EETs). We aimed to study the mechanism of VitC-dependent microsomal formation of cis- and trans-EETs and the regulation of EET levels in rat isolated perfused kidneys and in vivo. VitC biphasically stimulated rat kidney microsomal cis- and trans-EET formation in a ratio of 1:2, involving the participation of lipid hydroperoxides (LOOHs), Fe2+ , and cytochrome P450 (CYP). Levels of LOOHs correlated with microsomal EET production. LOOH stimulation of CYP isoforms resulted in preferred trans- over cis-EET formation from arachidonic acid and was associated with the cleavage of LOOHs, which indicated a CYP peroxy-genase activity. EETs contributed to VitC-induced vasodilator responses in rat isolated perfused kidneys. VitC (1 mg/ml) given in the drinking water for 9 days doubled rat urinary EET excretion, increased plasma levels of EETs, mostly trans-EETs, by 40%, and reduced plasma levels of 20-hydroxyeicosatetraenoic acid. Depletion of VitC in brain cortex and kidney tissues by more than 20- and 50-fold, respectively, in gulonolactone oxidase-knockout mice was associated with mild increases in tissue EETs. These data suggest that LOOHs are a determinant factor for EET formation in vivo in which VitC exerts a key regulatory effect. VitC-activated CYP peroxygenase activity may represent a CYP interaction with lipoxygenases and cyclooxygenases to mediate the cardiovascular effects of VitC via formation of EETs.
文摘In addition to its role as a barrier between blood and tissues, the vascular endothelium is responsible for the synthesis and released of a number of vasodilators including prostaglandins, nitric oxide and endotheliumderived hyperpolarizing factor (EDHF). As one of these vasodilators, the specific nature of EDHF has not been fully elucidated, although a number of roles have been proposed. Importantly, many conditions, such as hypertension, hyperlipidemia, heart failure, ischemiareperfusion and diabetes mellitus comprise vascular endothelial dysfunction with EDHF dysregulation. This article reviews reports on the role of EDHF in diabetesrelated endothelial dysfunction.
文摘目的:观察11,12-EET延迟性保护作用对缺血再灌注大鼠心肌ERK活性及磷酸化ERK表达的影响,探讨其在11,12-EET延迟性保护中的作用。方法:复制大鼠心肌缺血/再灌注模型;观察缺血/再灌注期间心脏收缩期左心室内压上升的最大变化速率(+dp/dtm ax)及舒张期左心室内压下降的最大变化速率(-dp/dtm ax);采用免疫共沉淀法测定大鼠心肌组织中细胞外调节激酶(ERK)的活性,采用W estern b lotting法测定大鼠心肌组织中磷酸化ERK的表达。结果:I/R组缺血60 m in及再灌注30 m in两个时段±dp/dtm ax均低于sham组(P<0.05),24 hE-ET+I/R组缺血60 m in及再灌注30 m in两个时段±dp/dtm ax明显高于I/R组(P<0.05),而24hEET+PD+I/R组缺血60 m in及再灌注30 m in两个时段±dp/dtm ax明显低于24hEET+I/R组(P<0.05)。ERK的活性24hEET+I/R高于norm al组,24hEET+I/R组低于24hEET+PD+I/R组。磷酸化ERK的表达I/R组高于norm al组和sham组,24hEET+I/R高于I/R组,24 hEET+I/R组低于24hEET+PD+I/R组。结论:外源性11,12-EET具有延迟性心脏保护作用,大量激活磷酸化的ERK参与这种保护作用。
