Aim In diabetic patients, metformin appears to provide cardiovascular protection that cannot be attribu- ted only to its antihyperglycemic effects. Metformin is also known as the AMP-activated protein kinase （AMPK） ...Aim In diabetic patients, metformin appears to provide cardiovascular protection that cannot be attribu- ted only to its antihyperglycemic effects. Metformin is also known as the AMP-activated protein kinase （AMPK） ac- tivator. Our previous study suggested that metformin inhibits transforming growth factor-β1 （TGF-β1） production in a mouse heart failure model of pressure overload. TGF-β1 is a key factor in cardiac fibrosis and is usually induced by Angiotensin Ⅱ （Ang Ⅱ ） in the pressure overload mouse models. This study investigated the effect of metformin on cardiac fibrosis and TGF-β production induced by AngII and the underlying mechanisms. Methods C57/BL6 wild-type and AMPKα2 knockout mice were used. AngII （3 mg · kg-1 · d-1） was infused subcutaneously into mice for 7 days. Adult mouse cardiac fibroblasts were isolated and treated with AngII （ 1 μmol · L-1） and/or met- formin （1 mmol · L-l）. Results In C57/BL6 mice, metformin inhibits AngII-induced cardiac fibrosis. In cardi-ac fibroblasts, metformin inhibits TGF-β1 expression and production induced by AngII. AMPK inhibitor, com- pound C, reversed the effects of metformin. In vivo, AMPKα2 deficiency further increases AngII-induced TGF-β1 production. In cardiac fibroblasts, metformin inhibited AngII induced hepatocyte nuclear factor4 （HNF4ot protein level increase and HNF4α binding with TGF-β1 promoter using chromatin immunoprecipitation assay. In vivo, AMPKα2 deficiency further increased AngII-induced HNF4α protein level. Using HNF4α adenovirus, overexpress- ing HNF4α led to a 1.5-fold increase in TGF-β1 mRNA expression. HNF4a siRNA blocked AngII induced TGF- β1 production. Luciferase reporter with deleted HNF4a binding sites showed decreased TGFbl transcriptional activ- ity induced by AngII. In AMPK or2-/- heart, the inhibition of metformin on HNF4a protein was attenuated. Con- clusion Metformin inhibits AngII induced cardiac fibrosis and TGF-β1 production through AMPK activation. The underlying mechanism is that AMPK activation inhibits AngII induced HNF4α and then decreases TGF-β1 expres- sion.展开更多
目的检测活化的蛋白激酶C受体1(RACK1)、低氧诱导因子1α(HIF-1α)、血管内皮生长因子(VEGF)在宫颈癌组织中的表达并探讨其病理学意义。方法选取2014年6月至2018年6月于本院行手术切除并经病理确诊的85例宫颈癌组织样本及其对应的癌旁组...目的检测活化的蛋白激酶C受体1(RACK1)、低氧诱导因子1α(HIF-1α)、血管内皮生长因子(VEGF)在宫颈癌组织中的表达并探讨其病理学意义。方法选取2014年6月至2018年6月于本院行手术切除并经病理确诊的85例宫颈癌组织样本及其对应的癌旁组织,通过免疫组织化学染色ABC法分别检测RACK1、HIF-1α、VEGF蛋白在宫颈癌组织及其癌旁组织中的表达。结合患者的临床病理资料,分析宫颈癌组织中RACK1、HIF-1α和VEGF蛋白表达与患者年龄及肿瘤直径、浸润深度、病理分级、淋巴结转移之间的关系,并分析三者表达之间的相关性。结果RACK1、HIF-1α、VEGF蛋白在宫颈癌组织中的表达均高于癌旁组织(P均<0.05),阳性表达率分别为81.2%(69/85)、63.5%(54/85)、89.4%(76/85)。RACK1表达与肿瘤浸润深度、病理分级和淋巴结是否转移有关(P均<0.05),HIF-1α和VEGF表达均与肿瘤直径、浸润深度、病理分级及淋巴结是否转移有关(P均<0.05)。RACK1、HIF-1α、VEGF蛋白的表达两两之间呈正相关(RACK1 vs HIF-1α:r=0.523,P=0.0439;RACK1 vs VEGF:r=0.428,P=0.0337;HIF-1αvs VEGF:r=0.689,P=0.0245)。结论RACK1、HIF-1、VEGF蛋白在宫颈癌组织中高表达且三者之间的表达呈正相关,提示其可能在肿瘤的发生、发展过程中起协同作用,可作为判断肿瘤侵袭、转移及预后的重要指标。展开更多
文摘Aim In diabetic patients, metformin appears to provide cardiovascular protection that cannot be attribu- ted only to its antihyperglycemic effects. Metformin is also known as the AMP-activated protein kinase （AMPK） ac- tivator. Our previous study suggested that metformin inhibits transforming growth factor-β1 （TGF-β1） production in a mouse heart failure model of pressure overload. TGF-β1 is a key factor in cardiac fibrosis and is usually induced by Angiotensin Ⅱ （Ang Ⅱ ） in the pressure overload mouse models. This study investigated the effect of metformin on cardiac fibrosis and TGF-β production induced by AngII and the underlying mechanisms. Methods C57/BL6 wild-type and AMPKα2 knockout mice were used. AngII （3 mg · kg-1 · d-1） was infused subcutaneously into mice for 7 days. Adult mouse cardiac fibroblasts were isolated and treated with AngII （ 1 μmol · L-1） and/or met- formin （1 mmol · L-l）. Results In C57/BL6 mice, metformin inhibits AngII-induced cardiac fibrosis. In cardi-ac fibroblasts, metformin inhibits TGF-β1 expression and production induced by AngII. AMPK inhibitor, com- pound C, reversed the effects of metformin. In vivo, AMPKα2 deficiency further increases AngII-induced TGF-β1 production. In cardiac fibroblasts, metformin inhibited AngII induced hepatocyte nuclear factor4 （HNF4ot protein level increase and HNF4α binding with TGF-β1 promoter using chromatin immunoprecipitation assay. In vivo, AMPKα2 deficiency further increased AngII-induced HNF4α protein level. Using HNF4α adenovirus, overexpress- ing HNF4α led to a 1.5-fold increase in TGF-β1 mRNA expression. HNF4a siRNA blocked AngII induced TGF- β1 production. Luciferase reporter with deleted HNF4a binding sites showed decreased TGFbl transcriptional activ- ity induced by AngII. In AMPK or2-/- heart, the inhibition of metformin on HNF4a protein was attenuated. Con- clusion Metformin inhibits AngII induced cardiac fibrosis and TGF-β1 production through AMPK activation. The underlying mechanism is that AMPK activation inhibits AngII induced HNF4α and then decreases TGF-β1 expres- sion.
文摘目的检测活化的蛋白激酶C受体1(RACK1)、低氧诱导因子1α(HIF-1α)、血管内皮生长因子(VEGF)在宫颈癌组织中的表达并探讨其病理学意义。方法选取2014年6月至2018年6月于本院行手术切除并经病理确诊的85例宫颈癌组织样本及其对应的癌旁组织,通过免疫组织化学染色ABC法分别检测RACK1、HIF-1α、VEGF蛋白在宫颈癌组织及其癌旁组织中的表达。结合患者的临床病理资料,分析宫颈癌组织中RACK1、HIF-1α和VEGF蛋白表达与患者年龄及肿瘤直径、浸润深度、病理分级、淋巴结转移之间的关系,并分析三者表达之间的相关性。结果RACK1、HIF-1α、VEGF蛋白在宫颈癌组织中的表达均高于癌旁组织(P均<0.05),阳性表达率分别为81.2%(69/85)、63.5%(54/85)、89.4%(76/85)。RACK1表达与肿瘤浸润深度、病理分级和淋巴结是否转移有关(P均<0.05),HIF-1α和VEGF表达均与肿瘤直径、浸润深度、病理分级及淋巴结是否转移有关(P均<0.05)。RACK1、HIF-1α、VEGF蛋白的表达两两之间呈正相关(RACK1 vs HIF-1α:r=0.523,P=0.0439;RACK1 vs VEGF:r=0.428,P=0.0337;HIF-1αvs VEGF:r=0.689,P=0.0245)。结论RACK1、HIF-1、VEGF蛋白在宫颈癌组织中高表达且三者之间的表达呈正相关,提示其可能在肿瘤的发生、发展过程中起协同作用,可作为判断肿瘤侵袭、转移及预后的重要指标。
