SDF-1α Induction in Mature Smooth Muscle Cells by Inactivation of PTEN Is a Critical Mediator of Exacerbated Injury-Induced Neointima Formation

作者：Raphael A. Nemenoff, Henrick Horita, Allison C. Ostriker, Seth B. Furgeson, Peter Simpson, Vicki VanPutten, Joseph T. Crossno, Stefan Offermanns, Mary C.M. Weiser‐Evans · 发表于：Arteriosclerosis Thrombosis and Vascular Biology · 年份：2011 · DOI：10.1161/atvbaha.111.223701 · 被引用次数：137 · 研究领域：PI3K/AKT/mTOR signaling in cancer、Inflammatory mediators and NSAID effects、Lymphatic System and Diseases

OBJECTIVE: PTEN inactivation selectively in smooth muscle cells (SMC) initiates multiple downstream events driving neointima formation, including SMC cytokine/chemokine production, in particular stromal cell-derived factor-1α (SDF-1α). We investigated the effects of SDF-1α on resident SMC and bone marrow-derived cells and in mediating neointima formation. METHODS AND RESULTS: Inducible, SMC-specific PTEN knockout mice (PTEN iKO) were bred to floxed-stop ROSA26-β-galactosidase (βGal) mice to fate-map mature SMC in response to injury; mice received wild-type green fluorescent protein-labeled bone marrow to track recruitment. Following wire-induced femoral artery injury, βGal(+) SMC accumulated in the intima and adventitia. Compared with wild-type, PTEN iKO mice exhibited massive neointima formation, increased replicating intimal and medial βGal(+)SMC, and enhanced vascular recruitment of bone marrow cells following injury. Inhibiting SDF-1α blocked these events and reversed enhanced neointima formation observed in PTEN iKO mice. Most recruited green fluorescent protein(+) cells stained positive for macrophage markers but not SMC markers. SMC-macrophage interactions resulted in a persistent SMC inflammatory phenotype that was dependent on SMC PTEN and SDF-1α expression. CONCLUSION: Resident SMC play a multifaceted role in neointima formation by contributing the majority of neointimal cells, regulating recruitment of inflammatory cells, and contributing to adventitial remodeling....