Rho-associated protein kinase is an essential regulator of cytoskeletal dynamics during the process of neurite extension. However, whether Rho kinase regulates microtubule remodeling or the distri- bution of adhesive ...Rho-associated protein kinase is an essential regulator of cytoskeletal dynamics during the process of neurite extension. However, whether Rho kinase regulates microtubule remodeling or the distri- bution of adhesive proteins to mediate neurite outgrowth remains unclear. By specifically modulat- ing Rho kinase activity with pharmacological agents, we studied the morpho-dynamics of neurite outgrowth. We found that lysophosphatidic acid, an activator of Rho kinase, inhibited neurite out- growth, which could be reversed by Y-27632, an inhibitor of Rho kinase. Meanwhile, reorganization of microtubules was noticed during these processes, as indicated by their significant changes in the soma and growth cone. In addition, exposure to lysophosphatidic acid led to a decreased mem- brane distribution of vinculin, a focal adhesion protein in neurons, whereas Y-27632 recruited vin- culin to the membrane. Taken together, our data suggest that Rho kinase regulates rat hippocampal neurite growth and microtubule formation via a mechanism associated with the redistribution of vinculin.展开更多
AIM: To investigate the roles and interactions of rhoassociatedprotein kinase (ROCK)1 and miR-124 inhuman colorectal cancer (CRC).METHODS: Expression of ROCK1 protein wasexamined by Western blotting, and quantitativer...AIM: To investigate the roles and interactions of rhoassociatedprotein kinase (ROCK)1 and miR-124 inhuman colorectal cancer (CRC).METHODS: Expression of ROCK1 protein wasexamined by Western blotting, and quantitativereverse transcriptase PCR was performed to measureexpression of ROCK1 mRNA and miR-124. Two cancercell lines were transfected with pre-miR-124 (mimic)and anti-miR-124 (inhibitor) and the effects onROCK1 protein and mRNA expression were observed.In addition, cell proliferation was assessed via a5-ethynyl-2′ deoxyuridine assay. Soft agar formationassay, and cell migration and invasion assays wereused to determine the effect of survivin on thetransformation and invasion activity of CRC cells.RESULTS: miR-124 was significantly downregulated inCRC compared to normal specimens (0.603 ± 0.092 vs1.147 ± 0.286, P = 0.016) and in metastatic comparedto nonmetastatic CRC specimens (0.416 ± 0.047 vs0.696 ± 0.089, P = 0.020). Expression of miR-124 wassignificantly associated with CRC metastasis, tumor Tand N stages, and tumor grade (all P < 0.05). ROCK1protein was significantly increased in CRC comparedto normal tissues (1.896 ± 0.258 vs 0.866 ± 0.136,P = 0.026), whereas ROCK1 mRNA expression wasunaltered (2.613 ± 0.251 vs 2.325 ± 0.246). miR-124and ROCK1 were inversely expressed in CRC tissuesand cell lines. ROCK1 mRNA was unaltered in cellstransfected with miR-124 mimic and miR-124 inhibitor,compared to normal controls. There was a significantreduction in ROCK1 protein in cells transfected withmiR-124 mimic and a significant increase in cells transfected with miR-124 inhibitor (P s < 0.05).Transformation and invasion of cells transfectedwith miR-124 inhibitor were significantly increasedcompared to those in normal controls (P < 0.05). Cellstransfected with miR-124 inhibitor showed increasedcell proliferation.CONCLUSION: miR-124 promotes hyperplasia andcontributes to invasion of CRC cells, but downregulatesROCK1. ROCK1 and miR-124 may play important rolesin CRC.展开更多
BACKGROUND: The increased β-arrestin-2 and its combination with G-protein-coupled receptors (GPCRs) lead to GPCRs desensitization. The latter may be responsible for decreased contractile reactivity in the mesenteric ...BACKGROUND: The increased β-arrestin-2 and its combination with G-protein-coupled receptors (GPCRs) lead to GPCRs desensitization. The latter may be responsible for decreased contractile reactivity in the mesenteric arteries of cirrhotic patients and rats. The present study is to investigate the machinery changes of α-adrenergic receptors and G proteins and their roles in the contractility of mesenteric arteries of cirrhotic patients and animal models. METHODS: Patients with cirrhosis due to hepatitis B and cirrhotic rats induced by CCl 4 were studied. Mesenteric artery contractility in response to norepinephrine was determined by a vessel perfusion system. The contractile effect of G protein-coupled receptor kinase-2 (GRK-2) inhibitor on the mesenteric artery was evaluated. The protein expression of the α 1 adrenergic receptor, G proteins, β-arrestin-2, GRK-2 as well as the activity of Rho associated coiled-coil forming protein kinase-1 (ROCK-1) were measured by Western blot. In addition, the interaction of α 1 adrenergic receptor with β-arrestin-2 was assessed by co-immunoprecipitation. RESULTS: The portal vein pressure of cirrhotic patients and rats was significantly higher than that of controls. The doseresponse curve to norepinephrine in mesenteric arteriole was shifted to the right, and EC 50 was significantly increased in cirrhotic patients and rats. There were no significant differences in the expressions of the α 1 adrenergic receptor and G proteins in the cirrhotic group compared with the controls. However, the protein expressions of GRK-2 and β-arrestin-2 were significantly elevated in cirrhotic patients and rats compared with those of the controls. The interaction of the α 1 adrenergic receptor and β-arrestin-2 was significantly aggravated. This interaction was significantly reversed by GRK-2 inhibitor. Both the protein expression and activity of ROCK-1 were significantly decreased in the mesenteric artery in patients with cirrhosis compared with those of the controls, and this phenomenon was not shown in the cirrhotic rats. Norepinephrine significantly increased the activity of ROCK-1 in normal rats but not in cirrhotic ones. Norepinephrine significantly increased ROCK-1 activity in cirrhotic rats when GRK-2 inhibitor was used. CONCLUSIONS: β-arrestin-2 expression and its interaction with GPCRs are significantly upregulated in the mesenteric arteries in patients and rats with cirrhosis. These upregulations result in GPCR desensitization, G-protein dysfunction and ROCK inhibition. These may explain the decreased contractility of the mesenteric artery in response to vasoconstrictors.展开更多
目的研究Rho相关卷曲螺旋蛋白激酶1(ROCK1)在动脉粥样硬化血管壁中的表达及其与基质金属蛋白酶2(MMP2)、转化生长因子1(TGF-β1)的相关性。方法选择30只载脂蛋白E基因敲除小鼠为实验组,高脂饲料喂养,另选30只C57BL/6小鼠为对照组,普通...目的研究Rho相关卷曲螺旋蛋白激酶1(ROCK1)在动脉粥样硬化血管壁中的表达及其与基质金属蛋白酶2(MMP2)、转化生长因子1(TGF-β1)的相关性。方法选择30只载脂蛋白E基因敲除小鼠为实验组,高脂饲料喂养,另选30只C57BL/6小鼠为对照组,普通饲料喂养。在喂养的第10、16、22、28及34周,取眼球血监测小鼠血脂水平;取小鼠腹主动脉作为标本,包埋切片并进行苏木精-伊红染色观察血管壁形态;应用免疫组化染色观察血管壁中ROCK1、MMP2、TGF-β1的表达;使用Image Pro Plus 6.0软件测量切片中血管壁厚度、斑块面积、血管壁中ROCK1、MMP2及TGF-β1的表达量。采用SPSS 27.0统计软件进行数据分析。采用单因素方差分析进行组间比较,两两比较采用Tukey检验。采用Pearson相关与线性回归分析ROCK1与血管壁厚度及斑块面积、MMP2、TGF-β1的关系。结果成功建立动脉粥样硬化小鼠模型。在喂养第10、16、22、28及34周,实验组血脂水平明显高于对照组,差异有统计学意义(P<0.05)。自喂养第16周起,实验组小鼠血管内均有斑块形成,随着喂养时间的延长,斑块面积和血管壁厚度不断增加,差异有统计学意义(P<0.05);血管壁内ROCK1的表达逐步增高,其表达与斑块面积及血管壁厚度呈正相关(r=0.821,0.730;P<0.05)。线性相关分析及回归分析显示,ROCK1与MMP2、TGF-β1表达均呈正相关(r=0.801,0.906;P<0.05)。结论在动脉粥样硬化血管壁中存在ROCK1蛋白的表达,且表达量随着血管壁厚度增加而增高,ROCK1的表达与MMP2、TGF-β1呈显著正相关性。鉴于ROCK1蛋白的致血管痉挛作用,提示动脉粥样硬化血管壁可能易于痉挛,具体机制需进一步研究。展开更多
基金supported by the National Natural Science Foundation of China,No.31170941the Fundamental Research Funds for the Central Universities,No.21612424the Science and Technology Planning Project of Guangdong Province,No.2010B031600102
文摘Rho-associated protein kinase is an essential regulator of cytoskeletal dynamics during the process of neurite extension. However, whether Rho kinase regulates microtubule remodeling or the distri- bution of adhesive proteins to mediate neurite outgrowth remains unclear. By specifically modulat- ing Rho kinase activity with pharmacological agents, we studied the morpho-dynamics of neurite outgrowth. We found that lysophosphatidic acid, an activator of Rho kinase, inhibited neurite out- growth, which could be reversed by Y-27632, an inhibitor of Rho kinase. Meanwhile, reorganization of microtubules was noticed during these processes, as indicated by their significant changes in the soma and growth cone. In addition, exposure to lysophosphatidic acid led to a decreased mem- brane distribution of vinculin, a focal adhesion protein in neurons, whereas Y-27632 recruited vin- culin to the membrane. Taken together, our data suggest that Rho kinase regulates rat hippocampal neurite growth and microtubule formation via a mechanism associated with the redistribution of vinculin.
文摘AIM: To investigate the roles and interactions of rhoassociatedprotein kinase (ROCK)1 and miR-124 inhuman colorectal cancer (CRC).METHODS: Expression of ROCK1 protein wasexamined by Western blotting, and quantitativereverse transcriptase PCR was performed to measureexpression of ROCK1 mRNA and miR-124. Two cancercell lines were transfected with pre-miR-124 (mimic)and anti-miR-124 (inhibitor) and the effects onROCK1 protein and mRNA expression were observed.In addition, cell proliferation was assessed via a5-ethynyl-2′ deoxyuridine assay. Soft agar formationassay, and cell migration and invasion assays wereused to determine the effect of survivin on thetransformation and invasion activity of CRC cells.RESULTS: miR-124 was significantly downregulated inCRC compared to normal specimens (0.603 ± 0.092 vs1.147 ± 0.286, P = 0.016) and in metastatic comparedto nonmetastatic CRC specimens (0.416 ± 0.047 vs0.696 ± 0.089, P = 0.020). Expression of miR-124 wassignificantly associated with CRC metastasis, tumor Tand N stages, and tumor grade (all P < 0.05). ROCK1protein was significantly increased in CRC comparedto normal tissues (1.896 ± 0.258 vs 0.866 ± 0.136,P = 0.026), whereas ROCK1 mRNA expression wasunaltered (2.613 ± 0.251 vs 2.325 ± 0.246). miR-124and ROCK1 were inversely expressed in CRC tissuesand cell lines. ROCK1 mRNA was unaltered in cellstransfected with miR-124 mimic and miR-124 inhibitor,compared to normal controls. There was a significantreduction in ROCK1 protein in cells transfected withmiR-124 mimic and a significant increase in cells transfected with miR-124 inhibitor (P s < 0.05).Transformation and invasion of cells transfectedwith miR-124 inhibitor were significantly increasedcompared to those in normal controls (P < 0.05). Cellstransfected with miR-124 inhibitor showed increasedcell proliferation.CONCLUSION: miR-124 promotes hyperplasia andcontributes to invasion of CRC cells, but downregulatesROCK1. ROCK1 and miR-124 may play important rolesin CRC.
基金supported by a grant from the National Natural Science Foundation of China (30972920)
文摘BACKGROUND: The increased β-arrestin-2 and its combination with G-protein-coupled receptors (GPCRs) lead to GPCRs desensitization. The latter may be responsible for decreased contractile reactivity in the mesenteric arteries of cirrhotic patients and rats. The present study is to investigate the machinery changes of α-adrenergic receptors and G proteins and their roles in the contractility of mesenteric arteries of cirrhotic patients and animal models. METHODS: Patients with cirrhosis due to hepatitis B and cirrhotic rats induced by CCl 4 were studied. Mesenteric artery contractility in response to norepinephrine was determined by a vessel perfusion system. The contractile effect of G protein-coupled receptor kinase-2 (GRK-2) inhibitor on the mesenteric artery was evaluated. The protein expression of the α 1 adrenergic receptor, G proteins, β-arrestin-2, GRK-2 as well as the activity of Rho associated coiled-coil forming protein kinase-1 (ROCK-1) were measured by Western blot. In addition, the interaction of α 1 adrenergic receptor with β-arrestin-2 was assessed by co-immunoprecipitation. RESULTS: The portal vein pressure of cirrhotic patients and rats was significantly higher than that of controls. The doseresponse curve to norepinephrine in mesenteric arteriole was shifted to the right, and EC 50 was significantly increased in cirrhotic patients and rats. There were no significant differences in the expressions of the α 1 adrenergic receptor and G proteins in the cirrhotic group compared with the controls. However, the protein expressions of GRK-2 and β-arrestin-2 were significantly elevated in cirrhotic patients and rats compared with those of the controls. The interaction of the α 1 adrenergic receptor and β-arrestin-2 was significantly aggravated. This interaction was significantly reversed by GRK-2 inhibitor. Both the protein expression and activity of ROCK-1 were significantly decreased in the mesenteric artery in patients with cirrhosis compared with those of the controls, and this phenomenon was not shown in the cirrhotic rats. Norepinephrine significantly increased the activity of ROCK-1 in normal rats but not in cirrhotic ones. Norepinephrine significantly increased ROCK-1 activity in cirrhotic rats when GRK-2 inhibitor was used. CONCLUSIONS: β-arrestin-2 expression and its interaction with GPCRs are significantly upregulated in the mesenteric arteries in patients and rats with cirrhosis. These upregulations result in GPCR desensitization, G-protein dysfunction and ROCK inhibition. These may explain the decreased contractility of the mesenteric artery in response to vasoconstrictors.
文摘目的研究Rho相关卷曲螺旋蛋白激酶1(ROCK1)在动脉粥样硬化血管壁中的表达及其与基质金属蛋白酶2(MMP2)、转化生长因子1(TGF-β1)的相关性。方法选择30只载脂蛋白E基因敲除小鼠为实验组,高脂饲料喂养,另选30只C57BL/6小鼠为对照组,普通饲料喂养。在喂养的第10、16、22、28及34周,取眼球血监测小鼠血脂水平;取小鼠腹主动脉作为标本,包埋切片并进行苏木精-伊红染色观察血管壁形态;应用免疫组化染色观察血管壁中ROCK1、MMP2、TGF-β1的表达;使用Image Pro Plus 6.0软件测量切片中血管壁厚度、斑块面积、血管壁中ROCK1、MMP2及TGF-β1的表达量。采用SPSS 27.0统计软件进行数据分析。采用单因素方差分析进行组间比较,两两比较采用Tukey检验。采用Pearson相关与线性回归分析ROCK1与血管壁厚度及斑块面积、MMP2、TGF-β1的关系。结果成功建立动脉粥样硬化小鼠模型。在喂养第10、16、22、28及34周,实验组血脂水平明显高于对照组,差异有统计学意义(P<0.05)。自喂养第16周起,实验组小鼠血管内均有斑块形成,随着喂养时间的延长,斑块面积和血管壁厚度不断增加,差异有统计学意义(P<0.05);血管壁内ROCK1的表达逐步增高,其表达与斑块面积及血管壁厚度呈正相关(r=0.821,0.730;P<0.05)。线性相关分析及回归分析显示,ROCK1与MMP2、TGF-β1表达均呈正相关(r=0.801,0.906;P<0.05)。结论在动脉粥样硬化血管壁中存在ROCK1蛋白的表达,且表达量随着血管壁厚度增加而增高,ROCK1的表达与MMP2、TGF-β1呈显著正相关性。鉴于ROCK1蛋白的致血管痉挛作用,提示动脉粥样硬化血管壁可能易于痉挛,具体机制需进一步研究。
