Adrenomedullin up-regulates osteopontin and attenuates vascular calcification via the cAMP/PKA signaling pathway  

作　　者：Yan CAI Xu TENG Chun-shui PAN Xiao-hui DUAN Chao-shu TANG Yong-fen QI 

机构地区：[1]Laboratory of Cardiovascular Bioactive Molecules, School of Basic Medical Sciences, Peking University, Beijing 100191, China [2]Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing 100191, China [3]Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, China

出　　处：《Acta Pharmacologica Sinica》2010年第10期1359-1366,共8页中国药理学报（英文版）

基　　金：Acknowledgments This work was supported by the National Natural Science Foundation of China （No 30470693, 30871013 to Yong-fen QI）, the State Major Basic Research Development Program of the People＇s Republic of China （No 2006CB503807 to Yong-fen QI）, and the Beijing Natural Science Foundation of the People＇s Republic of China （No 7052041 to Yong-fen QI）.

摘　　要：Aim： To determine whether adrenomedullin （ADM） attenuates vascular calcification （VC） by inducing osteopontin （OPN） expression. Methods： A VC model of rat aorta was induced with vitamin D3 plus nicotine （VDN）, and vascular smooth muscle cell （VSMC） calcification was induced with beta-glycerophosphate. Von Kossa staining and alizarin red staining were assessed. Alkaline phosphatase （ALP） activity was measured. Immunohistochemical analysis was used to detect alpha-actin, while RT-PCR and Western blot analysis were used to quantify OPN expression. Results： Administration of ADM greatly reduced VC in VDN-treated aortas compared with controls, which was confirmed in calcified VSMCs. The decrease in alpha-actin expression was ameliorated by ADM both in vivo and in vitro. Moreover, mRNA and protein expression levels of OPN were significantly up-regulated in calcified aortas, and ADM increased OPN expression in calcified aortas. Furthermore, ADM up-regulated OPN expression in normal aortas and VSMCs. The ADM-mediated effects were similar to that of forskolin, which activates adenylyl cyclase; additionally, while the PKA inhibitor H89 and Ca2＋ chelator Fura-2 blocked the effect of ADM. However, the MEK/ERK inhibitor PD98509 had no effect on ADM induction of OPN mRNA expression. An OPN polyclonal antibody inhibited ADM-mediated attenuation of VC. Conclusion： ADM up-regulates OPN expression and thus attenuates VC via PKA. ADM appears to be an endogenous cardiovascular protective peptide and may represent a new therapeutic target for VC treatment.Aim： To determine whether adrenomedullin （ADM） attenuates vascular calcification （VC） by inducing osteopontin （OPN） expression. Methods： A VC model of rat aorta was induced with vitamin D3 plus nicotine （VDN）, and vascular smooth muscle cell （VSMC） calcification was induced with beta-glycerophosphate. Von Kossa staining and alizarin red staining were assessed. Alkaline phosphatase （ALP） activity was measured. Immunohistochemical analysis was used to detect alpha-actin, while RT-PCR and Western blot analysis were used to quantify OPN expression. Results： Administration of ADM greatly reduced VC in VDN-treated aortas compared with controls, which was confirmed in calcified VSMCs. The decrease in alpha-actin expression was ameliorated by ADM both in vivo and in vitro. Moreover, mRNA and protein expression levels of OPN were significantly up-regulated in calcified aortas, and ADM increased OPN expression in calcified aortas. Furthermore, ADM up-regulated OPN expression in normal aortas and VSMCs. The ADM-mediated effects were similar to that of forskolin, which activates adenylyl cyclase; additionally, while the PKA inhibitor H89 and Ca2＋ chelator Fura-2 blocked the effect of ADM. However, the MEK/ERK inhibitor PD98509 had no effect on ADM induction of OPN mRNA expression. An OPN polyclonal antibody inhibited ADM-mediated attenuation of VC. Conclusion： ADM up-regulates OPN expression and thus attenuates VC via PKA. ADM appears to be an endogenous cardiovascular protective peptide and may represent a new therapeutic target for VC treatment.

关 键 词：ADRENOMEDULLIN OSTEOPONTIN vascular calcification cell signaling protein kinase A vascular smooth muscle cells vitamin D3： nicotine 

分 类 号：Q463[生物学—生理学] Q51