BACKGROUND It is well known that nonalcoholic fatty liver disease(NAFLD)is associated with insulin resistance(IR).LB100,a serine/threonine protein phosphatase 2A(PP2A)inhibitor,is closely related to IR.However,there i...BACKGROUND It is well known that nonalcoholic fatty liver disease(NAFLD)is associated with insulin resistance(IR).LB100,a serine/threonine protein phosphatase 2A(PP2A)inhibitor,is closely related to IR.However,there is little data regarding its direct influence on NAFLD.AIM To elucidate the effect and underlying mechanism of LB100 in NAFLD.METHODS After 10 wk of high fat diet(HFD)feeding,male C57BL/6 mice were injected intraperitoneally with vehicle or LB100 for an additional 6 wk(three times a week).The L02 cell line was treated with LB100 and free fatty acids(FFAs)for 24 h.Hematoxylin and eosin and oil red O staining were performed for histological examination.Western blot analysis was used to detect the protein expression of Sirtuin 1(Sirt1),total and phosphorylated AMP-activated protein kinaseα(AMPKα),and the proteins involved in lipogenesis and fatty acid oxidation.The mRNA levels were determined by qPCR.Pharmacological inhibition of AMPK was performed to further examine the exact mechanism of LB100 in NAFLD.RESULTS LB100 significantly ameliorated HFD-induced obesity,hepatic lipid accumulation and hepatic injury in mice.In addition,LB100 significantly downregulated the protein levels of acetyl-CoA carboxylase,sterol regulatory element-binding protein 1 and its lipogenesis target genes,including stearoyl-CoA desaturase-1 and fatty acid synthase,and upregulated the levels of proteins involved in fatty acidβ-oxidation,such as peroxisome proliferator-activated receptorα(PPARα),peroxisome proliferator-activated receptor gamma coactivator-1α(PGC-1α),carnitine palmitoyltransferase 1α,acyl-CoA oxidase 1 and uncoupling protein 2,as well as the upstream mediators Sirt1 and AMPKαin the livers of HFD-fed mice.In vitro,LB100 alleviated FFA-induced lipid accumulation in L02 cells through the AMPK/Sirt1 signaling pathway.Further studies showed that the curative effect of LB100 on lipid accumulation was abolished by inhibiting AMPKαin L02 cells.CONCLUSION PP2A inhibition by LB100 significantly ameliorates hepatic 展开更多
目的:探讨和厚朴酚通过调节自噬对帕金森病模型小鼠多巴胺能神经元及AMP活化蛋白激酶(AMP-activated protein kinase,AMPK)/沉默信息调节因子1(silent information regulator 1,SIRT1)通路的影响。方法:构建帕金森病模型小鼠,分为模型...目的:探讨和厚朴酚通过调节自噬对帕金森病模型小鼠多巴胺能神经元及AMP活化蛋白激酶(AMP-activated protein kinase,AMPK)/沉默信息调节因子1(silent information regulator 1,SIRT1)通路的影响。方法:构建帕金森病模型小鼠,分为模型组、和厚朴酚低、高剂量组和自噬抑制组,4组小鼠分别灌胃生理盐水、20 mg/kg和厚朴酚、60 mg/kg和厚朴酚及60 mg/kg和厚朴酚,自噬抑制组同时灌胃20 mg/kg氯喹,另设未造模小鼠为对照组,每组16只,灌胃14 d。转棒实验及爬杆实验测试小鼠的行为学功能,TUNEL染色检测黑质神经元凋亡率,免疫组化染色检测黑质中beclin-1阳性细胞数,Western blot实验检测黑质中p-AMPK/AMPK、SIRT1、微管相关蛋白1轻链3(microtubule-associated protein 1 light chain 3,LC3)-II/LC3-I、beclin-1、Bcl-2相关X蛋白(Bcl-2 related X protein,Bax)、胱天蛋白酶3(caspase-3)蛋白表达。结果:与对照组相比,模型组小鼠的跌落潜伏期显著缩短,爬杆时间显著延长(P<0.05),黑质神经元凋亡率及Bax和caspase-3蛋白表达水平显著升高(P<0.05),黑质中beclin-1阳性细胞数及p-AMPK/AMPK、SIRT1、LC3-II/LC3-I和beclin-1蛋白表达水平显著降低(P<0.05)。与模型组相比,和厚朴酚低、高剂量组小鼠上述指标呈相反趋势,且呈现剂量依赖性(P<0.05)。自噬抑制组处理后逆转了和厚朴酚的作用(P<0.05)。结论:和厚朴酚能激活自噬,活化AMPK/SIRT1通路,提高帕金森病模型小鼠黑质多巴胺能神经元的自噬水平,减少细胞凋亡,改善其行为学功能。展开更多
腺苷酸活化蛋白激酶(AMP-activated protein kinase,AMPK)是一种进化保守的丝氨酸/苏氨酸蛋白激酶,被称为"细胞能量调节器",是维持细胞和机体能量平衡的关键分子。近年来的研究显示,AMPK与炎症反应密切相关,其抗炎机制主要是...腺苷酸活化蛋白激酶(AMP-activated protein kinase,AMPK)是一种进化保守的丝氨酸/苏氨酸蛋白激酶,被称为"细胞能量调节器",是维持细胞和机体能量平衡的关键分子。近年来的研究显示,AMPK与炎症反应密切相关,其抗炎机制主要是通过激活SIRT1、PGC-1α、p53、FoxO3a和p300等途径,下调NF-κB、AP-1等多种炎性相关蛋白的活性来发挥作用。本文通过对AMPK发挥抗炎作用的分子机制进行综述,为以AMPK为靶点治疗炎症及相关疾病提供参考。展开更多
目的:研究丹酚酸A对棕榈酸诱导的AML12肝细胞脂毒性的保护作用并初步探究其分子机制。方法:采用棕榈酸诱导AML12细胞建立脂毒性模型并给予丹酚酸A进行干预,采用乳酸脱氢酶(LDH)法检测细胞损伤,采用酶法检测细胞内甘油三酯含量,采用Bodip...目的:研究丹酚酸A对棕榈酸诱导的AML12肝细胞脂毒性的保护作用并初步探究其分子机制。方法:采用棕榈酸诱导AML12细胞建立脂毒性模型并给予丹酚酸A进行干预,采用乳酸脱氢酶(LDH)法检测细胞损伤,采用酶法检测细胞内甘油三酯含量,采用Bodipy染色法观察胞内的脂滴,采用甲基偶氮唑盐微量酶反应比色法(MTT)检测细胞存活率,采用荧光细胞通透性染料罗丹明123和荧光显微镜检测线粒体膜电位。采用2',7'-二氯荧光黄双乙酸盐(DCFH-DA)和荧光显微镜检测细胞内活性氧(ROS)水平。采用Western blot技术检测沉默信息调节因子相关酶Ⅰ(silent information regulator 1,SIRT1)及腺苷酸活化蛋白激酶(AMP-activated protein kinase,AMPK)蛋白表达。结果:棕榈酸作为肝细胞脂毒性诱导剂可显著降低AML12细胞存活率,加重细胞内脂质沉积,而丹酚酸A干预可改善棕榈酸诱导的肝细胞脂毒性损伤(P<0.05)。其次,丹酚酸A干预可改善棕榈酸诱导的细胞线粒体膜电位降低(P<0.01)及细胞内ROS水平升高(P<0.01)。此外,Western blot结果显示棕榈酸可显著抑制AMPK及SIRT1蛋白表达(P<0.05),而经过丹酚酸A处理可显著升高棕榈酸抑制的SIRT1及AMPK磷酸化水平(P<0.05)。结论:丹酚酸A可有效改善脂毒性诱导的肝细胞损伤,该保护作用可能与其激活AMPK及SIRT1蛋白有关。展开更多
瘦蛋白(leptin)介导的腺苷酸激活蛋白激酶(AMP-activated protein kinase,AMPK)信号转导途径在脂肪代谢的调节中起重要作用。瘦蛋白与其受体结合使AMPK信号转导途径激活,最终激活肉碱脂酰转移酶-1,通过促进脂肪酸氧化而参与脂肪代谢的...瘦蛋白(leptin)介导的腺苷酸激活蛋白激酶(AMP-activated protein kinase,AMPK)信号转导途径在脂肪代谢的调节中起重要作用。瘦蛋白与其受体结合使AMPK信号转导途径激活,最终激活肉碱脂酰转移酶-1,通过促进脂肪酸氧化而参与脂肪代谢的调节。本文主要介绍近年来关于瘦蛋白介导的AMPK信号转导途径的组成、活性调节及其作用机制的最新研究进展。展开更多
文摘BACKGROUND It is well known that nonalcoholic fatty liver disease(NAFLD)is associated with insulin resistance(IR).LB100,a serine/threonine protein phosphatase 2A(PP2A)inhibitor,is closely related to IR.However,there is little data regarding its direct influence on NAFLD.AIM To elucidate the effect and underlying mechanism of LB100 in NAFLD.METHODS After 10 wk of high fat diet(HFD)feeding,male C57BL/6 mice were injected intraperitoneally with vehicle or LB100 for an additional 6 wk(three times a week).The L02 cell line was treated with LB100 and free fatty acids(FFAs)for 24 h.Hematoxylin and eosin and oil red O staining were performed for histological examination.Western blot analysis was used to detect the protein expression of Sirtuin 1(Sirt1),total and phosphorylated AMP-activated protein kinaseα(AMPKα),and the proteins involved in lipogenesis and fatty acid oxidation.The mRNA levels were determined by qPCR.Pharmacological inhibition of AMPK was performed to further examine the exact mechanism of LB100 in NAFLD.RESULTS LB100 significantly ameliorated HFD-induced obesity,hepatic lipid accumulation and hepatic injury in mice.In addition,LB100 significantly downregulated the protein levels of acetyl-CoA carboxylase,sterol regulatory element-binding protein 1 and its lipogenesis target genes,including stearoyl-CoA desaturase-1 and fatty acid synthase,and upregulated the levels of proteins involved in fatty acidβ-oxidation,such as peroxisome proliferator-activated receptorα(PPARα),peroxisome proliferator-activated receptor gamma coactivator-1α(PGC-1α),carnitine palmitoyltransferase 1α,acyl-CoA oxidase 1 and uncoupling protein 2,as well as the upstream mediators Sirt1 and AMPKαin the livers of HFD-fed mice.In vitro,LB100 alleviated FFA-induced lipid accumulation in L02 cells through the AMPK/Sirt1 signaling pathway.Further studies showed that the curative effect of LB100 on lipid accumulation was abolished by inhibiting AMPKαin L02 cells.CONCLUSION PP2A inhibition by LB100 significantly ameliorates hepatic
文摘目的:探讨和厚朴酚通过调节自噬对帕金森病模型小鼠多巴胺能神经元及AMP活化蛋白激酶(AMP-activated protein kinase,AMPK)/沉默信息调节因子1(silent information regulator 1,SIRT1)通路的影响。方法:构建帕金森病模型小鼠,分为模型组、和厚朴酚低、高剂量组和自噬抑制组,4组小鼠分别灌胃生理盐水、20 mg/kg和厚朴酚、60 mg/kg和厚朴酚及60 mg/kg和厚朴酚,自噬抑制组同时灌胃20 mg/kg氯喹,另设未造模小鼠为对照组,每组16只,灌胃14 d。转棒实验及爬杆实验测试小鼠的行为学功能,TUNEL染色检测黑质神经元凋亡率,免疫组化染色检测黑质中beclin-1阳性细胞数,Western blot实验检测黑质中p-AMPK/AMPK、SIRT1、微管相关蛋白1轻链3(microtubule-associated protein 1 light chain 3,LC3)-II/LC3-I、beclin-1、Bcl-2相关X蛋白(Bcl-2 related X protein,Bax)、胱天蛋白酶3(caspase-3)蛋白表达。结果:与对照组相比,模型组小鼠的跌落潜伏期显著缩短,爬杆时间显著延长(P<0.05),黑质神经元凋亡率及Bax和caspase-3蛋白表达水平显著升高(P<0.05),黑质中beclin-1阳性细胞数及p-AMPK/AMPK、SIRT1、LC3-II/LC3-I和beclin-1蛋白表达水平显著降低(P<0.05)。与模型组相比,和厚朴酚低、高剂量组小鼠上述指标呈相反趋势,且呈现剂量依赖性(P<0.05)。自噬抑制组处理后逆转了和厚朴酚的作用(P<0.05)。结论:和厚朴酚能激活自噬,活化AMPK/SIRT1通路,提高帕金森病模型小鼠黑质多巴胺能神经元的自噬水平,减少细胞凋亡,改善其行为学功能。
文摘腺苷酸活化蛋白激酶(AMP-activated protein kinase,AMPK)是一种进化保守的丝氨酸/苏氨酸蛋白激酶,被称为"细胞能量调节器",是维持细胞和机体能量平衡的关键分子。近年来的研究显示,AMPK与炎症反应密切相关,其抗炎机制主要是通过激活SIRT1、PGC-1α、p53、FoxO3a和p300等途径,下调NF-κB、AP-1等多种炎性相关蛋白的活性来发挥作用。本文通过对AMPK发挥抗炎作用的分子机制进行综述,为以AMPK为靶点治疗炎症及相关疾病提供参考。
文摘目的:研究丹酚酸A对棕榈酸诱导的AML12肝细胞脂毒性的保护作用并初步探究其分子机制。方法:采用棕榈酸诱导AML12细胞建立脂毒性模型并给予丹酚酸A进行干预,采用乳酸脱氢酶(LDH)法检测细胞损伤,采用酶法检测细胞内甘油三酯含量,采用Bodipy染色法观察胞内的脂滴,采用甲基偶氮唑盐微量酶反应比色法(MTT)检测细胞存活率,采用荧光细胞通透性染料罗丹明123和荧光显微镜检测线粒体膜电位。采用2',7'-二氯荧光黄双乙酸盐(DCFH-DA)和荧光显微镜检测细胞内活性氧(ROS)水平。采用Western blot技术检测沉默信息调节因子相关酶Ⅰ(silent information regulator 1,SIRT1)及腺苷酸活化蛋白激酶(AMP-activated protein kinase,AMPK)蛋白表达。结果:棕榈酸作为肝细胞脂毒性诱导剂可显著降低AML12细胞存活率,加重细胞内脂质沉积,而丹酚酸A干预可改善棕榈酸诱导的肝细胞脂毒性损伤(P<0.05)。其次,丹酚酸A干预可改善棕榈酸诱导的细胞线粒体膜电位降低(P<0.01)及细胞内ROS水平升高(P<0.01)。此外,Western blot结果显示棕榈酸可显著抑制AMPK及SIRT1蛋白表达(P<0.05),而经过丹酚酸A处理可显著升高棕榈酸抑制的SIRT1及AMPK磷酸化水平(P<0.05)。结论:丹酚酸A可有效改善脂毒性诱导的肝细胞损伤,该保护作用可能与其激活AMPK及SIRT1蛋白有关。
文摘瘦蛋白(leptin)介导的腺苷酸激活蛋白激酶(AMP-activated protein kinase,AMPK)信号转导途径在脂肪代谢的调节中起重要作用。瘦蛋白与其受体结合使AMPK信号转导途径激活,最终激活肉碱脂酰转移酶-1,通过促进脂肪酸氧化而参与脂肪代谢的调节。本文主要介绍近年来关于瘦蛋白介导的AMPK信号转导途径的组成、活性调节及其作用机制的最新研究进展。
