Aim Angiotensin II （AngII） induces vascular smooth muscle cell （VSMC） migration and growth, which is responsible for vascular remodeling during some cardiovascular diseases. It has been demonstrated to activate a ...Aim Angiotensin II （AngII） induces vascular smooth muscle cell （VSMC） migration and growth, which is responsible for vascular remodeling during some cardiovascular diseases. It has been demonstrated to activate a C1 current, but the underlying mechanism is not clear. Methods Whole-cell patch clamp, co-immunoprecipitation （co-IP）, site-specific mutagenesis, angiotensinII-infusion hypertensive mice model were used. Results In VSMCs, AngII could induce a C1C-3-dependent C1- current that was abolished in C1C-3 null mice. The activation mechanism of this AngII-induced C1- current was ascribed to the interaction between C1C-3 and Rho-kinase 2 （ROCIL2）, as re- vealed by N-terminal or C-terminal truncation of C1C-3, ROCIC2 siRNA and Co-IP experiments. Then we searched for and identified the phosphorylation site of C1C-3 at threonine 532 is critical for AngII-induced C1- current and VSMC migration through ROCK. The C1C-3 T532D mutant （mutation of threonine 532 to aspartate）, mimicking the phos- phorylation state of C1C-3, significantly potentiated AngII-induced C1- current and VSMC migration; while C1C-3 T532A （mutation of threonine 532 to alanine） had the opposite effects. Furthermore, we found a remarkably de- creased AngII-induced VSMC migration in C1C-3 null mice that is insensitive to Y27632, an inhibitor of ROCIL2. In addition, AngII-induced cerebrovascular remodeling was ameliorated in C1C-3 null mice, possibly by ROCIL2 path- way. Conclusions C1C-3 protein phosphorylation at threonine 532 by ROCIL2 is required for AngII-induced C1- cur- rent and VSMC migration that are involved in AngII-induced hypertensive vascular remodeling.展开更多
基金This work was supported by grants from the Wellcome Trust UK (056909/299/Z) the Education Ministry of China (GJ9901) and the Health Department of Guangdong Province (A2001474).
文摘Aim Angiotensin II （AngII） induces vascular smooth muscle cell （VSMC） migration and growth, which is responsible for vascular remodeling during some cardiovascular diseases. It has been demonstrated to activate a C1 current, but the underlying mechanism is not clear. Methods Whole-cell patch clamp, co-immunoprecipitation （co-IP）, site-specific mutagenesis, angiotensinII-infusion hypertensive mice model were used. Results In VSMCs, AngII could induce a C1C-3-dependent C1- current that was abolished in C1C-3 null mice. The activation mechanism of this AngII-induced C1- current was ascribed to the interaction between C1C-3 and Rho-kinase 2 （ROCIL2）, as re- vealed by N-terminal or C-terminal truncation of C1C-3, ROCIC2 siRNA and Co-IP experiments. Then we searched for and identified the phosphorylation site of C1C-3 at threonine 532 is critical for AngII-induced C1- current and VSMC migration through ROCK. The C1C-3 T532D mutant （mutation of threonine 532 to aspartate）, mimicking the phos- phorylation state of C1C-3, significantly potentiated AngII-induced C1- current and VSMC migration; while C1C-3 T532A （mutation of threonine 532 to alanine） had the opposite effects. Furthermore, we found a remarkably de- creased AngII-induced VSMC migration in C1C-3 null mice that is insensitive to Y27632, an inhibitor of ROCIL2. In addition, AngII-induced cerebrovascular remodeling was ameliorated in C1C-3 null mice, possibly by ROCIL2 path- way. Conclusions C1C-3 protein phosphorylation at threonine 532 by ROCIL2 is required for AngII-induced C1- cur- rent and VSMC migration that are involved in AngII-induced hypertensive vascular remodeling.
