Li-Min Cheng1, Yue-Jiao Li1, Xing-Feng Chen1, Xiao-Long Li1, Xiao-Shan Chen1, Yan-Hua Du2. 1. Department of Pharmacology, Cardiac and Cerebral Vascular Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, People's Republic of China. 2. Department of Pharmacology, Cardiac and Cerebral Vascular Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, People's Republic of China. Electronic address: duyanhua@mail.sysu.edu.cn.
Abstract
BACKGROUND: Endothelial progenitor cell (EPC) therapy has been suggested as a major breakthrough in the treatment of ischemic diseases. However, the molecular mechanism that underlies EPC functional regulation is still unclear. METHODS: We examined the angiogenic capacity of EPCs in a hindlimb ischemia model of wild-type and ClC-3 knockout mice. RESULTS: Mice lacking of ClC-3 exhibited reduced blood flow recovery and neovascularization in ischemic muscles 7 and 14 days after hind limb ischemia. Moreover, compared with wild-type EPCs, the hindlimb blood reperfusion in mice receiving ClC-3 knockout EPCs was significantly impaired, accompanied by reduced EPC homing and retention. In vitro, EPCs derived from ClC-3 knockout mice displayed impaired migratory, adhesive, and angiogenic activity. CXC chemokine receptor 4 (CXCR4) expression was significantly reduced in EPC from ClC-3 knockout mice compared with wild-type. Moreover, the expression and phosphorylation of Janus kinase 2 (JAK-2), a downstream signalling of CXCR4, was also reduced in ClC-3 knockout EPC, indicating that CXCR4/JAK-2 signalling is dysregulated by ClC-3 deficiency. Consistent with this assumption, the migratory capacity of wild-type EPCs was attenuated by either CXCR4 antagonist AMD3100 or JAK-2 inhibitor AG490. More importantly, the impaired migratory capacity of ClC-3 knockout EPCs was rescued by overexpression of CXCR4. CONCLUSIONS: ClC-3 plays a critical role in the angiogenic capacity of EPCs and EPC-mediated neovascularization of ischemic tissues. Disturbance of CXCR4/JAK-2 signalling may contribute to the functional impairment of ClC-3 deficient EPCs. Thus, ClC-3 may be a potential therapeutic target for modulating neovascularization in ischemic diseases.
BACKGROUND: Endothelial progenitor cell (EPC) therapy has been suggested as a major breakthrough in the treatment of ischemic diseases. However, the molecular mechanism that underlies EPC functional regulation is still unclear. METHODS: We examined the angiogenic capacity of EPCs in a hindlimb ischemia model of wild-type and ClC-3 knockout mice. RESULTS:Mice lacking of ClC-3 exhibited reduced blood flow recovery and neovascularization in ischemic muscles 7 and 14 days after hind limb ischemia. Moreover, compared with wild-type EPCs, the hindlimb blood reperfusion in mice receiving ClC-3 knockout EPCs was significantly impaired, accompanied by reduced EPC homing and retention. In vitro, EPCs derived from ClC-3 knockout mice displayed impaired migratory, adhesive, and angiogenic activity. CXC chemokine receptor 4 (CXCR4) expression was significantly reduced in EPC from ClC-3 knockout mice compared with wild-type. Moreover, the expression and phosphorylation of Janus kinase 2 (JAK-2), a downstream signalling of CXCR4, was also reduced in ClC-3 knockout EPC, indicating that CXCR4/JAK-2 signalling is dysregulated by ClC-3 deficiency. Consistent with this assumption, the migratory capacity of wild-type EPCs was attenuated by either CXCR4 antagonist AMD3100 or JAK-2 inhibitor AG490. More importantly, the impaired migratory capacity of ClC-3 knockout EPCs was rescued by overexpression of CXCR4. CONCLUSIONS:ClC-3 plays a critical role in the angiogenic capacity of EPCs and EPC-mediated neovascularization of ischemic tissues. Disturbance of CXCR4/JAK-2 signalling may contribute to the functional impairment of ClC-3 deficient EPCs. Thus, ClC-3 may be a potential therapeutic target for modulating neovascularization in ischemic diseases.