From the Section of Molecular Medicine, Department of Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK (P.S., Y.Z., K.A.C., X.D., H.X., M.-H.Z.); College of Medicine, Hubei, Province Key Laboratory on Cardiovascular, Cerebrovascular, and Metabolic Disorders, Hubei University of Science and Technology, Xianning, Hubei, China (Y.Z.); College of Medicine, Yangzhou University, Yangzhou, Jiangsu, China (H.X.); Institut Cochin, Université Paris Descartes, CNRS (UMR 8104), Paris, France (B.V.); and INSERM, U1016, Paris, France (B.V.).
Arterioscler Thromb Vasc Biol. 2013 Dec;33(12):2800-9. doi: 10.1161/ATVBAHA.113.301869. Epub 2013 Oct 10.
Abnormal proliferation and migration of vascular smooth muscle cells (VSMCs) are critical events in the progression of several vasculopathologies. Adenosine monophosphate-activated protein kinase (AMPK) has been shown to play a pivotal role in cellular proliferation and migration. However, the roles of AMPK in VSMC migration and its underlying molecular mechanisms remain elusive.
VSMC migration and the neointima formation were studied in cultured mouse VSMCs or in carotid artery ligation of wild-type C57BL/6J mice, AMPKα2, AMPKα1 homozygous-deficient (AMPKα2(-/-), AMPKα1(-/-)) mice. Deletion of AMPKα2, but not AMPKα1, led to increased phosphorylation of both IкB kinase α and its downstream target nuclear factor кB2/p100 at serine 866/870. Consequently, phosphor-p100 at S866/870 bound with E3 ubiquitin ligase β-transducin repeat-containing protein resulting in the proteolytic processing of the p100 precursor and nuclear factor кB2/p52 induction. Interestingly, acetylation of histone H3 at lysine 56 mediated by histone deacetylase-3 reduction was enhanced significantly in AMPKα2(-/-) VSMCs compared with wild-type or AMPKα1(-/-) VSMCs. Moreover, the augmented association of p52/acetylation of histone H3 at lysine 56 with the promoter of ubiquitin E3 ligase, S-phase kinase-associated protein 2, was shown in AMPKα2(-/-) VSMCs by chromatin immunoprecipitation assay. Furthermore, AMPKα2 deletion caused S-phase kinase-associated protein 2-mediated E-cadherin downregulation. S-Phase kinase-associated protein 2 siRNA abolished the increased migration of AMPKα2(-/-) VSMCs via E-cadherin upregulation. Finally, neointima formation after ligation of carotid artery was increased in AMPKα2(-/-), but not AMPKα1(-/-), mice.
We conclude that deletion of AMPKα2 causes aberrant VSMC migration with accelerated neointima formation in vivo.
血管平滑肌细胞（VSMCs）的异常增殖和迁移是多种血管病变进展的关键事件。腺苷单磷酸激活蛋白激酶（AMPK）已被证明在细胞增殖和迁移中发挥关键作用。然而，AMPK 在 VSMC 迁移及其潜在的分子机制中的作用仍不清楚。
在培养的小鼠 VSMCs 或 C57BL/6J 野生型小鼠颈动脉结扎中研究了 VSMC 迁移和新生内膜形成，AMPKα2、AMPKα1 纯合缺失（AMPKα2(-/-)、AMPKα1(-/-)）小鼠。AMPKα2 的缺失而非 AMPKα1 的缺失导致 IкB 激酶 α 及其下游靶标核因子 кB2/p100 在丝氨酸 866/870 处的磷酸化增加。结果，磷酸化的 p100 在 S866/870 处与 E3 泛素连接酶 β-转导重复蛋白结合，导致 p100 前体的蛋白水解处理和核因子 кB2/p52 的诱导。有趣的是，与野生型或 AMPKα1(-/-) VSMCs 相比，AMPKα2(-/-) VSMCs 中组蛋白 H3 在赖氨酸 56 处的乙酰化明显增强，由组蛋白脱乙酰酶-3 的减少介导。此外，通过染色质免疫沉淀分析显示，在 AMPKα2(-/-) VSMCs 中，p52/组蛋白 H3 在赖氨酸 56 处的乙酰化与泛素 E3 连接酶 S 期激酶相关蛋白 2 的启动子的增强结合。此外，AMPKα2 的缺失导致 S 期激酶相关蛋白 2 介导的 E-钙黏蛋白下调。S 期激酶相关蛋白 2 siRNA 通过 E-钙黏蛋白上调消除了 AMPKα2(-/-) VSMCs 迁移的增加。最后，在 AMPKα2(-/-)但不是 AMPKα1(-/-)小鼠中，颈动脉结扎后新生内膜形成增加。
我们得出结论，AMPKα2 的缺失导致体内 VSMC 迁移异常，新生内膜形成加速。
