Aim： To determine the mechanisms of glucocorticoids in inhibiting advanced prostate cancer growth. Methods： The cell proliferation and cell cycle of prostate cancer DU145 cells following dexamethasone treatment were...Aim： To determine the mechanisms of glucocorticoids in inhibiting advanced prostate cancer growth. Methods： The cell proliferation and cell cycle of prostate cancer DU145 cells following dexamethasone treatment were determined by proliferation assay and fluorescence-activated cell sorter. Western blot analysis was carried out to evaluate the effects of dexamethasone on phosphorylation of extracellular signal-regulated kinase （ERK）1/2 and expression of cyclin D1 in DU145 cells with or without glucocorticoid receptor （GR） antagonist RU486. Reverse transcription- polymerase chain reaction verified the expression of GR mRNA in DU145 cells. Results： Dexamethasone significantly inhibited DU 145 cell proliferation at the G0/G1 phase. Westem blot analysis showed a dramatic reduction of ERK1/2 activity and cyclin D1 expression in dexamethasone-treated cells. The decreased phosphorylation of ERK1/2 in dexamethasone-treated cells was attenuated by GR blockade. Additionally, the effects of dexamethasone in inhibiting cyclin D1 expression were altered by GR blockade. Conclusion： Dexamethasone suppresses DU145 cell proliferation and cell cycle, and the underlying mechanisms are through the inhibition of phosphorylation of ERK1/2 and cyclin D1 expression. The inhibition of ERK1/2 phosphorylation and cyclin D1 expression is attenuated by GR blockade, suggesting that GR regulates ERK1/2 and cyclin D1 pathways. These observations suggest that dexamethasone has a potential clinical application in prostate cancer therapy.展开更多
Aim： To assess the spatiotemporal changes in the expression of extracellular signal-regulated kinases 1 and 2 （ERK1/ 2）, c-Jun N-terminal kinases （JNK） and p38 mitogen-activated protein kinases （MAPK） in respon...Aim： To assess the spatiotemporal changes in the expression of extracellular signal-regulated kinases 1 and 2 （ERK1/ 2）, c-Jun N-terminal kinases （JNK） and p38 mitogen-activated protein kinases （MAPK） in response to heat stress in the cryptorchid testis, and to investigate a possible relation to Sertoli cell dedifferentiation. Methods： Immunohistochemistry and western blot were used to examine the expression and activation of ERK1/2, p38 and JNK in the cryptorchid testis at various stages after experimental cryptorchidism. Results： The abdominal temperature did not obviously change the total ERK1/2 expression but significantly activated phospho-ERK1/2 in the Sertoli cells of the cryptorchid testis. Heat stress increased total JNK expression in the Sertoli cells of the cryptorchid testis but did not activate phospho-JNK. Neither total p38 nor phospho-p38 was induced by heat stress in the Sertoli cells of the cryptorchid testis. Changes in the spatiotemporal expression of cytokeratin 18 （CK18）, a marker of immature or undifferentiated Sertoli cells, were induced in the cryptorchid testis in a pattern similar to the activation of ERK1/2. Condusion： The activation of ERK1/2 in the testis may be related to dedifferentiation of Sertoli cells under heat stress induced by experimental cryptorchidism.展开更多
Objective:Cardiac remodeling is a common pathological change in various cardiovascular diseases and can ultimately result in heart failure.Thus,there is an urgent need for more effective strategies to aid in cardiac p...Objective:Cardiac remodeling is a common pathological change in various cardiovascular diseases and can ultimately result in heart failure.Thus,there is an urgent need for more effective strategies to aid in cardiac protection.Our previous work found that sphingosine-1-phosphate(S1P)could ameliorate cardiac hypertrophy.In this study,we aimed to investigate whether S1P could prevent cardiac fibrosis and the associated mechanisms in cardiac remodeling.Methods:Eight-week-old male C57BL/6 mice were randomly divided into a sham,transverse aortic constriction(TAC)or a TAC+S1P treatment group.Results:We found that S1P treatment improved cardiac function in TAC mice and that the cardiac fibrosis ratio in the TAC+S1P group was significantly lower and was accompanied by a decrease inα-smooth muscle actin(α-SMA)and collagen type I(COL I)expression compared with the TAC group.We also found that one of the key S1P enzymes,sphingosine kinase 2(SphK2),which was mainly distributed in cytoblasts,was downregulated in the cardiac remodeling case and recovered after S1P treatment in vivo and in vitro.In addition,our in vitro results showed that S1P treatment activated extracellular regulated protein kinases(ERK)phosphorylation mainly through the S1P receptor 2(S1PR2)and spurred p-ERK transposition from the cytoplasm to cytoblast in H9c2 cells exposed to phenylephrine.Conclusion:These findings suggest that SphK2 and the S1PR2/ERK pathway may participate in the anti-remodeling effect of S1P on the heart.This work therefore uncovers a novel potential therapy for the prevention of cardiac remodeling.展开更多
Aim:To assess the spatiotemporal changes in the expression of extracellular signal-regulated kinases 1 and 2(ERK1/ 2),c-Jun N-terminal kinases(JNK)and p38 mitogen-activated protein kinases(MAPK)in response to heat str...Aim:To assess the spatiotemporal changes in the expression of extracellular signal-regulated kinases 1 and 2(ERK1/ 2),c-Jun N-terminal kinases(JNK)and p38 mitogen-activated protein kinases(MAPK)in response to heat stress in the cryptorchid testis,and to investigate a possible relation to Sertoli cell dedifferentiation.Methods:Immunohis- tochemistry and western blot were used to examine the expression and activation of ERK1/2,p38 and JNK in the cryptorchid testis at various stages after experimental cryptorchidism.Results:The abdominal temperature did not obviously change the total ERK1/2 expression but significantly activated phospho-ERK1/2 in the Sertoli cells of the cryptorchid testis.Heat stress increased total JNK expression in the Sertoli cells of the cryptorchid testis but did not activate phospho-JNK.Neither total p38 nor phospho-p38 was induced by heat stress in the Sertoli cells of the cryptorchid testis.Changes in the spatiotemporal expression of cytokeratin 18(CK18),a marker of immature or undifferentiated Sertoli cells,were induced in the cryptorchid testis in a pattern similar to the activation of ERK1/2. Conclusion:The activation of ERK1/2 in the testis may be related to dedifferentiation of Sertoli cells under heat stress induced by experimental cryptorchidism.展开更多
目的探索莓茶提取物对2型糖尿病(type 2 diabetes mellitus,T2DM)大鼠糖脂代谢及肝脏沉默信息调节因子1(silence information regulator 1,SIRT1)、AMP活化蛋白激酶(AMP activated protein kinase,AMPK)、过氧化物酶体增殖物激活受体γ...目的探索莓茶提取物对2型糖尿病(type 2 diabetes mellitus,T2DM)大鼠糖脂代谢及肝脏沉默信息调节因子1(silence information regulator 1,SIRT1)、AMP活化蛋白激酶(AMP activated protein kinase,AMPK)、过氧化物酶体增殖物激活受体γ辅助活化因子1α(peroxisome proliferator-activated receptor-γcoactivator-1α,PGC-1α)蛋白表达的影响。方法高脂高糖喂养联合链脲佐菌素(35 mg/kg)腹腔注射建立T2DM大鼠模型,建模成功后随机分为模型组、莓茶低剂量组(0.4 g/kg)、莓茶高剂量组(0.8 g/kg),另设普通饲料喂养大鼠为正常组,每组8只。各组灌胃给药6周后,行口服葡萄糖耐量试验计算血糖-时间曲线下面积(area under the curve,AUC),ELISA法检测空腹血胰岛素(fasting insulin,FINS)水平,计算稳态模型以评估胰岛素抵抗指数(homeostatic model assessment for insulin resistance,HOMA-IR),全自动生化分析仪测定血清总胆固醇(total cholesterol,TC)、甘油三酯(triglycerides,TG)、高密度脂蛋白胆固醇(high density lipoprotein cholesterol,HDL-C)、低密度脂蛋白胆固醇(low density lipoprotein cholesterol,LDL-C)、超氧化物歧化酶(superoxide dismutase,SOD)、丙二醇(malondialdehyde,MDA)水平,HE染色观察肝脏组织形态学变化,Western blot检测肝脏SIRT1、AMPK、PGC-1α蛋白表达。结果与正常组比较,模型组FBG、AUC、FINS、HOMA-IR、TC、TG、LDL-C、MDA均明显升高(P<0.01),HDL-C、SOD和SIRT1、AMPK、PGC-1α蛋白表达均明显降低(P<0.01),肝脏组织肝索排列紊乱,肝细胞间隙不清晰,呈脂肪变性改变。与模型组比较,莓茶低剂量组、莓茶高剂量组FBG、FINS、HOMA-IR、TG、MDA均明显降低(P<0.05,P<0.01),SOD和SIRT1、AMPK、PGC-1α蛋白表达均明显升高(P<0.05,P<0.01),肝脏组织肝索排列相对整齐,脂肪变性得到改善;莓茶高剂量组AUC、TC均明显降低(P<0.05),HDL-C明显升高(P<0.05)。与莓茶低剂量组比较,莓茶高剂量组FBG、AUC、FINS、TC、MDA均明显降低(P<0.05),SIRT1、AMPK、PGC-1α蛋白表达均明显升高(P<0.05)。结论莓茶提取物能在一定程度上改善T2DM大鼠糖脂代谢,减轻胰岛素抵抗,其机制可能与改善氧化应激,调节肝脏SIRT1、AMPK、PGC-1α蛋白表达有关。展开更多
文摘Aim： To determine the mechanisms of glucocorticoids in inhibiting advanced prostate cancer growth. Methods： The cell proliferation and cell cycle of prostate cancer DU145 cells following dexamethasone treatment were determined by proliferation assay and fluorescence-activated cell sorter. Western blot analysis was carried out to evaluate the effects of dexamethasone on phosphorylation of extracellular signal-regulated kinase （ERK）1/2 and expression of cyclin D1 in DU145 cells with or without glucocorticoid receptor （GR） antagonist RU486. Reverse transcription- polymerase chain reaction verified the expression of GR mRNA in DU145 cells. Results： Dexamethasone significantly inhibited DU 145 cell proliferation at the G0/G1 phase. Westem blot analysis showed a dramatic reduction of ERK1/2 activity and cyclin D1 expression in dexamethasone-treated cells. The decreased phosphorylation of ERK1/2 in dexamethasone-treated cells was attenuated by GR blockade. Additionally, the effects of dexamethasone in inhibiting cyclin D1 expression were altered by GR blockade. Conclusion： Dexamethasone suppresses DU145 cell proliferation and cell cycle, and the underlying mechanisms are through the inhibition of phosphorylation of ERK1/2 and cyclin D1 expression. The inhibition of ERK1/2 phosphorylation and cyclin D1 expression is attenuated by GR blockade, suggesting that GR regulates ERK1/2 and cyclin D1 pathways. These observations suggest that dexamethasone has a potential clinical application in prostate cancer therapy.
基金Acknowledgment This study was supported by the National Natural Science Foundation of China （30230190）, the National Basic Science Research and Development Project （973） （G1999055901） and the Chinese Academy of Sciences （CAS） Knowledge Innovation Program （KSCX-2-SW-201）.
文摘Aim： To assess the spatiotemporal changes in the expression of extracellular signal-regulated kinases 1 and 2 （ERK1/ 2）, c-Jun N-terminal kinases （JNK） and p38 mitogen-activated protein kinases （MAPK） in response to heat stress in the cryptorchid testis, and to investigate a possible relation to Sertoli cell dedifferentiation. Methods： Immunohistochemistry and western blot were used to examine the expression and activation of ERK1/2, p38 and JNK in the cryptorchid testis at various stages after experimental cryptorchidism. Results： The abdominal temperature did not obviously change the total ERK1/2 expression but significantly activated phospho-ERK1/2 in the Sertoli cells of the cryptorchid testis. Heat stress increased total JNK expression in the Sertoli cells of the cryptorchid testis but did not activate phospho-JNK. Neither total p38 nor phospho-p38 was induced by heat stress in the Sertoli cells of the cryptorchid testis. Changes in the spatiotemporal expression of cytokeratin 18 （CK18）, a marker of immature or undifferentiated Sertoli cells, were induced in the cryptorchid testis in a pattern similar to the activation of ERK1/2. Condusion： The activation of ERK1/2 in the testis may be related to dedifferentiation of Sertoli cells under heat stress induced by experimental cryptorchidism.
基金supported by the National Natural Science Foundation of China(No.81873505).
文摘Objective:Cardiac remodeling is a common pathological change in various cardiovascular diseases and can ultimately result in heart failure.Thus,there is an urgent need for more effective strategies to aid in cardiac protection.Our previous work found that sphingosine-1-phosphate(S1P)could ameliorate cardiac hypertrophy.In this study,we aimed to investigate whether S1P could prevent cardiac fibrosis and the associated mechanisms in cardiac remodeling.Methods:Eight-week-old male C57BL/6 mice were randomly divided into a sham,transverse aortic constriction(TAC)or a TAC+S1P treatment group.Results:We found that S1P treatment improved cardiac function in TAC mice and that the cardiac fibrosis ratio in the TAC+S1P group was significantly lower and was accompanied by a decrease inα-smooth muscle actin(α-SMA)and collagen type I(COL I)expression compared with the TAC group.We also found that one of the key S1P enzymes,sphingosine kinase 2(SphK2),which was mainly distributed in cytoblasts,was downregulated in the cardiac remodeling case and recovered after S1P treatment in vivo and in vitro.In addition,our in vitro results showed that S1P treatment activated extracellular regulated protein kinases(ERK)phosphorylation mainly through the S1P receptor 2(S1PR2)and spurred p-ERK transposition from the cytoplasm to cytoblast in H9c2 cells exposed to phenylephrine.Conclusion:These findings suggest that SphK2 and the S1PR2/ERK pathway may participate in the anti-remodeling effect of S1P on the heart.This work therefore uncovers a novel potential therapy for the prevention of cardiac remodeling.
文摘Aim:To assess the spatiotemporal changes in the expression of extracellular signal-regulated kinases 1 and 2(ERK1/ 2),c-Jun N-terminal kinases(JNK)and p38 mitogen-activated protein kinases(MAPK)in response to heat stress in the cryptorchid testis,and to investigate a possible relation to Sertoli cell dedifferentiation.Methods:Immunohis- tochemistry and western blot were used to examine the expression and activation of ERK1/2,p38 and JNK in the cryptorchid testis at various stages after experimental cryptorchidism.Results:The abdominal temperature did not obviously change the total ERK1/2 expression but significantly activated phospho-ERK1/2 in the Sertoli cells of the cryptorchid testis.Heat stress increased total JNK expression in the Sertoli cells of the cryptorchid testis but did not activate phospho-JNK.Neither total p38 nor phospho-p38 was induced by heat stress in the Sertoli cells of the cryptorchid testis.Changes in the spatiotemporal expression of cytokeratin 18(CK18),a marker of immature or undifferentiated Sertoli cells,were induced in the cryptorchid testis in a pattern similar to the activation of ERK1/2. Conclusion:The activation of ERK1/2 in the testis may be related to dedifferentiation of Sertoli cells under heat stress induced by experimental cryptorchidism.
文摘目的探索莓茶提取物对2型糖尿病(type 2 diabetes mellitus,T2DM)大鼠糖脂代谢及肝脏沉默信息调节因子1(silence information regulator 1,SIRT1)、AMP活化蛋白激酶(AMP activated protein kinase,AMPK)、过氧化物酶体增殖物激活受体γ辅助活化因子1α(peroxisome proliferator-activated receptor-γcoactivator-1α,PGC-1α)蛋白表达的影响。方法高脂高糖喂养联合链脲佐菌素(35 mg/kg)腹腔注射建立T2DM大鼠模型,建模成功后随机分为模型组、莓茶低剂量组(0.4 g/kg)、莓茶高剂量组(0.8 g/kg),另设普通饲料喂养大鼠为正常组,每组8只。各组灌胃给药6周后,行口服葡萄糖耐量试验计算血糖-时间曲线下面积(area under the curve,AUC),ELISA法检测空腹血胰岛素(fasting insulin,FINS)水平,计算稳态模型以评估胰岛素抵抗指数(homeostatic model assessment for insulin resistance,HOMA-IR),全自动生化分析仪测定血清总胆固醇(total cholesterol,TC)、甘油三酯(triglycerides,TG)、高密度脂蛋白胆固醇(high density lipoprotein cholesterol,HDL-C)、低密度脂蛋白胆固醇(low density lipoprotein cholesterol,LDL-C)、超氧化物歧化酶(superoxide dismutase,SOD)、丙二醇(malondialdehyde,MDA)水平,HE染色观察肝脏组织形态学变化,Western blot检测肝脏SIRT1、AMPK、PGC-1α蛋白表达。结果与正常组比较,模型组FBG、AUC、FINS、HOMA-IR、TC、TG、LDL-C、MDA均明显升高(P<0.01),HDL-C、SOD和SIRT1、AMPK、PGC-1α蛋白表达均明显降低(P<0.01),肝脏组织肝索排列紊乱,肝细胞间隙不清晰,呈脂肪变性改变。与模型组比较,莓茶低剂量组、莓茶高剂量组FBG、FINS、HOMA-IR、TG、MDA均明显降低(P<0.05,P<0.01),SOD和SIRT1、AMPK、PGC-1α蛋白表达均明显升高(P<0.05,P<0.01),肝脏组织肝索排列相对整齐,脂肪变性得到改善;莓茶高剂量组AUC、TC均明显降低(P<0.05),HDL-C明显升高(P<0.05)。与莓茶低剂量组比较,莓茶高剂量组FBG、AUC、FINS、TC、MDA均明显降低(P<0.05),SIRT1、AMPK、PGC-1α蛋白表达均明显升高(P<0.05)。结论莓茶提取物能在一定程度上改善T2DM大鼠糖脂代谢,减轻胰岛素抵抗,其机制可能与改善氧化应激,调节肝脏SIRT1、AMPK、PGC-1α蛋白表达有关。
