AIM: To investigate the redox dependency and promotion of downstream targets in thyroid hormone (T<sub>3</sub>)-induced AMP-activated protein kinase (AMPK) signaling as cellular energy sensor to limit meta...AIM: To investigate the redox dependency and promotion of downstream targets in thyroid hormone (T<sub>3</sub>)-induced AMP-activated protein kinase (AMPK) signaling as cellular energy sensor to limit metabolic stresses in the liver.展开更多
多囊卵巢综合征(Polycystic ovary syndrome,PCOS)是一组生殖内分泌代谢紊乱的综合征,临床以稀发排卵、高雄激素体征、胰岛素抵抗为主要特征,其中育龄期发病率高,对女性生育力造成严重不良影响。PCOS的发生发展涉及多种信号通路,腺苷酸...多囊卵巢综合征(Polycystic ovary syndrome,PCOS)是一组生殖内分泌代谢紊乱的综合征,临床以稀发排卵、高雄激素体征、胰岛素抵抗为主要特征,其中育龄期发病率高,对女性生育力造成严重不良影响。PCOS的发生发展涉及多种信号通路,腺苷酸活化蛋白激酶(AMP-activated protein kinase,AMPK)及哺乳动物雷帕霉素靶蛋白(Mammalian target of rapamycin,mTOR)作为细胞能量感受器是其中两个关键靶点。二者在PCOS各个发病部位包括下丘脑-垂体-卵巢轴、子宫内膜、脂肪与骨骼肌中发挥重要的调节作用,通过影响细胞自噬、氧化应激、炎症、线粒体功能、葡萄糖摄取等,促进卵泡的发育和成熟,改善胰岛素抵抗。近年来,中医药因其成分多样、靶点众多等优势广泛应用于临床,研究人员已对PCOS的发病以及中药治疗及改善PCOS的机制进行了大量研究,结果提示AMPK与mTOR相关通路在其中发挥关键作用。通过总结中药干预AMPK与mTOR及其相关通路治疗PCOS的研究结果,为临床治疗及基础研究提供参考。展开更多
Epidemiological studies indicate that treatment with metformin, an AMP-activated protein kinase (AMPK) activator, reduces the incidence of cancers. Activation of AMPK has also been reported to oppose tumor progression...Epidemiological studies indicate that treatment with metformin, an AMP-activated protein kinase (AMPK) activator, reduces the incidence of cancers. Activation of AMPK has also been reported to oppose tumor progression in diverse types of cancers and offers promising cancer therapy. Furthermore, AMPK is a primary regulator of energy metabolism and has also been implicated in cell cycle progression, angiogenesis, cell transformation, migration, and cancer. We have recently synthesized novel flavonoids, namely, triphenylmethanol derivatives (TPMs), but the effectiveness of the TPMs on the activity of AMPK remains unclear. We hypothesized that the novel TPMs would inhibit cancer cell proliferation through the activation of AMPK isoforms in cells. The effects of TPMs on prostate cells (PC-3) were investigated. Cells were exposed to TPMs for either 12 or 24 hr. at the respective doses of 0, 25, 50 100, and 200 µM based on the cell viability studies by the (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, a tetrazole) (MTT) assay. The results indicate that cells exposed to the respective doses of TPMs increased both phospho- and total-AMPKα1 in a dose- and time-dependent manner. The effects of the increases for the phospho- and total-AMPKα in cells were greater for the 24-hr than the 12-hr. incubation. Further studies are currently going on to elucidate the specificities of the said insults in increasing the phospho- and total-AMPKα activities and for the other respective isoforms.展开更多
Background:Metabolic stress has been proposed to contribute to neuronal damage in glaucoma,but the mechanism driving this response is not understood.The adenosine monophosphate-activated protein kinase(AMPK)is a maste...Background:Metabolic stress has been proposed to contribute to neuronal damage in glaucoma,but the mechanism driving this response is not understood.The adenosine monophosphate-activated protein kinase(AMPK)is a master regulator of energy homeostasis that becomes active at the onset of energy stress.AMPK is a potent inhibitor of the mammalian target of rapamycin complex 1(mTORC1),which we showed is essential for the maintenance of retinal ganglion cell(RGC)dendrites,synapses,and survival.Here,we tested the hypothesis that AMPK is an early mediator of metabolic stress in glaucoma.Methods:Unilateral elevation of intraocular pressure was induced by injection of magnetic microbeads into the anterior chamber of mice expressing yellow fluorescent protein in RGCs.Inhibition of AMPK was achieved by administration of siRNA or compound C.RGC dendritic trees were 3D-reconstructed and analyzed with Imaris(Bitplane),and survival was assessed by counting Brn3a or RBPMS-labeled soma and axons in the optic nerve.RGC function was examined by quantification of anterograde axonal transport after intraocular administration of cholera toxinβ-subunit.Retinas from glaucoma patients were analyzed for expression of active AMPK.Results:Ocular hypertension triggered rapid upregulation of AMPK activity in RGCs concomitant with loss of mTORC1 function.AMPK inhibition with compound C or siRNA effectively restored mTORC1 activity and promoted an increase in total dendritic length,surface and complexity relative to control retinas.Attenuation of AMPK activity led to robust RGC soma and axon survival.For example,95%of RGCs(2,983±258 RGCs/mm2,mean±S.E.M.)survived with compound C compared to 77%in vehicle-treated eyes(2,430±233 RGCs/mm2)(ANOVA,P<0.001)at three weeks after glaucoma induction(n=8-10/group).Importantly,blockade of AMPK activity effectively restored anterograde axonal transport.Lastly,RGC-specific upregulation of AMPK activity was detected in human glaucomatous retinas relative to age-matched controls(n=10/group).Conclusions:Metabolic stress in glaucoma involves AMPK activation and mTORC1 inhibition promoting early RGC dendritic pathology,dysfunction and neurodegeneration.展开更多
Obesity is a worldwide epidemic. Promoting browning of white adipose tissue(WAT)contributes to increased energy expenditure and hence counteracts obesity. Here we show that cordycepin(Cpn), a natural derivative of ade...Obesity is a worldwide epidemic. Promoting browning of white adipose tissue(WAT)contributes to increased energy expenditure and hence counteracts obesity. Here we show that cordycepin(Cpn), a natural derivative of adenosine, increases energy expenditure, inhibits weight gain, improves metabolic profile and glucose tolerance, decreases WAT mass and adipocyte size, and enhances cold tolerance in normal and high-fat diet-fed mice. Cpn markedly increases the surface temperature around the inguinal WAT and turns the inguinal fat browner. Further investigations show that Cpn induces the development of brown-like adipocytes in inguinal and, to a less degree, epididymal WAT depots. Cpn also increases the expression of uncoupling protein 1(UCP1) and other thermogenic genes in WAT and3T3-L1 differentiated adipocytes, in which AMP-activated protein kinase(AMPK) plays an important role. Our results provide novel insights into the function of Cpn in regulating energy balance, and suggest a potential utility of Cpn in the treatment of obesity.展开更多
【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
基金Supported by National Commission for Scientific and Technological Research Grant No.1120034
文摘AIM: To investigate the redox dependency and promotion of downstream targets in thyroid hormone (T<sub>3</sub>)-induced AMP-activated protein kinase (AMPK) signaling as cellular energy sensor to limit metabolic stresses in the liver.
文摘多囊卵巢综合征(Polycystic ovary syndrome,PCOS)是一组生殖内分泌代谢紊乱的综合征,临床以稀发排卵、高雄激素体征、胰岛素抵抗为主要特征,其中育龄期发病率高,对女性生育力造成严重不良影响。PCOS的发生发展涉及多种信号通路,腺苷酸活化蛋白激酶(AMP-activated protein kinase,AMPK)及哺乳动物雷帕霉素靶蛋白(Mammalian target of rapamycin,mTOR)作为细胞能量感受器是其中两个关键靶点。二者在PCOS各个发病部位包括下丘脑-垂体-卵巢轴、子宫内膜、脂肪与骨骼肌中发挥重要的调节作用,通过影响细胞自噬、氧化应激、炎症、线粒体功能、葡萄糖摄取等,促进卵泡的发育和成熟,改善胰岛素抵抗。近年来,中医药因其成分多样、靶点众多等优势广泛应用于临床,研究人员已对PCOS的发病以及中药治疗及改善PCOS的机制进行了大量研究,结果提示AMPK与mTOR相关通路在其中发挥关键作用。通过总结中药干预AMPK与mTOR及其相关通路治疗PCOS的研究结果,为临床治疗及基础研究提供参考。
文摘Epidemiological studies indicate that treatment with metformin, an AMP-activated protein kinase (AMPK) activator, reduces the incidence of cancers. Activation of AMPK has also been reported to oppose tumor progression in diverse types of cancers and offers promising cancer therapy. Furthermore, AMPK is a primary regulator of energy metabolism and has also been implicated in cell cycle progression, angiogenesis, cell transformation, migration, and cancer. We have recently synthesized novel flavonoids, namely, triphenylmethanol derivatives (TPMs), but the effectiveness of the TPMs on the activity of AMPK remains unclear. We hypothesized that the novel TPMs would inhibit cancer cell proliferation through the activation of AMPK isoforms in cells. The effects of TPMs on prostate cells (PC-3) were investigated. Cells were exposed to TPMs for either 12 or 24 hr. at the respective doses of 0, 25, 50 100, and 200 µM based on the cell viability studies by the (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, a tetrazole) (MTT) assay. The results indicate that cells exposed to the respective doses of TPMs increased both phospho- and total-AMPKα1 in a dose- and time-dependent manner. The effects of the increases for the phospho- and total-AMPKα in cells were greater for the 24-hr than the 12-hr. incubation. Further studies are currently going on to elucidate the specificities of the said insults in increasing the phospho- and total-AMPKα activities and for the other respective isoforms.
文摘Background:Metabolic stress has been proposed to contribute to neuronal damage in glaucoma,but the mechanism driving this response is not understood.The adenosine monophosphate-activated protein kinase(AMPK)is a master regulator of energy homeostasis that becomes active at the onset of energy stress.AMPK is a potent inhibitor of the mammalian target of rapamycin complex 1(mTORC1),which we showed is essential for the maintenance of retinal ganglion cell(RGC)dendrites,synapses,and survival.Here,we tested the hypothesis that AMPK is an early mediator of metabolic stress in glaucoma.Methods:Unilateral elevation of intraocular pressure was induced by injection of magnetic microbeads into the anterior chamber of mice expressing yellow fluorescent protein in RGCs.Inhibition of AMPK was achieved by administration of siRNA or compound C.RGC dendritic trees were 3D-reconstructed and analyzed with Imaris(Bitplane),and survival was assessed by counting Brn3a or RBPMS-labeled soma and axons in the optic nerve.RGC function was examined by quantification of anterograde axonal transport after intraocular administration of cholera toxinβ-subunit.Retinas from glaucoma patients were analyzed for expression of active AMPK.Results:Ocular hypertension triggered rapid upregulation of AMPK activity in RGCs concomitant with loss of mTORC1 function.AMPK inhibition with compound C or siRNA effectively restored mTORC1 activity and promoted an increase in total dendritic length,surface and complexity relative to control retinas.Attenuation of AMPK activity led to robust RGC soma and axon survival.For example,95%of RGCs(2,983±258 RGCs/mm2,mean±S.E.M.)survived with compound C compared to 77%in vehicle-treated eyes(2,430±233 RGCs/mm2)(ANOVA,P<0.001)at three weeks after glaucoma induction(n=8-10/group).Importantly,blockade of AMPK activity effectively restored anterograde axonal transport.Lastly,RGC-specific upregulation of AMPK activity was detected in human glaucomatous retinas relative to age-matched controls(n=10/group).Conclusions:Metabolic stress in glaucoma involves AMPK activation and mTORC1 inhibition promoting early RGC dendritic pathology,dysfunction and neurodegeneration.
基金supported financially by the National Natural Science Foundation of China (81402983, 81573436)CAMS Innovation Fund for Medical Sciences (CIFMS) 2016-I2M-3–015the National Major Scientific and Technological Special Project for "Significant New Drugs Development" (2015ZX09501005, China)
文摘Obesity is a worldwide epidemic. Promoting browning of white adipose tissue(WAT)contributes to increased energy expenditure and hence counteracts obesity. Here we show that cordycepin(Cpn), a natural derivative of adenosine, increases energy expenditure, inhibits weight gain, improves metabolic profile and glucose tolerance, decreases WAT mass and adipocyte size, and enhances cold tolerance in normal and high-fat diet-fed mice. Cpn markedly increases the surface temperature around the inguinal WAT and turns the inguinal fat browner. Further investigations show that Cpn induces the development of brown-like adipocytes in inguinal and, to a less degree, epididymal WAT depots. Cpn also increases the expression of uncoupling protein 1(UCP1) and other thermogenic genes in WAT and3T3-L1 differentiated adipocytes, in which AMP-activated protein kinase(AMPK) plays an important role. Our results provide novel insights into the function of Cpn in regulating energy balance, and suggest a potential utility of Cpn in the treatment of obesity.
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。
