Poldip2 controls vascular smooth muscle cell migration by regulating focal adhesion turnover and force polarization
Poldip2 controls vascular smooth muscle cell migration by regulating focal adhesion turnover and force polarization
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DOI：
10.1152/ajpheart.00918.2013
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发表时间：
2014-10-01
影响因子：
4.8
通讯作者：
Griendling, Kathy K.
中科院分区：
文献类型：
--
作者：
Datla, Srinivasa Raju;McGrail, Daniel J.;Griendling, Kathy K.
聚合酶- δ相互作用蛋白2 （Poldip2）与NADPH氧化酶4 （Nox4）相互作用并调节迁移；然而，确切的潜在机制尚不清楚。在这里，我们研究了Poldip2在局灶粘连翻转、牵引力产生和极化中的作用。血管平滑肌细胞（VSMCs）中Poldip2过表达（AdPoldip2）会损害pdgf诱导的迁移，并诱导长细胞质延伸的特征性表型。AdPoldip2还可以防止PDGF反应中观察到的扩散减少和宽高比增加，并轻微损害细胞收缩。此外，AdPoldip2阻断局灶黏附溶解并维持局灶黏附中的H2O2水平，而敲低Poldip2 （siPoldip2）可显著减少局灶黏附的数量。在对照细胞中，刺激局灶黏附溶解时，RhoA活性不变，但在adpoldip2处理的细胞中，RhoA活性增加。RhoA的抑制阻断了Poldip2介导的局灶黏附溶解的衰减，而RhoA或局灶黏附激酶（focal adhesion kinase， FAK）的过表达逆转了siPoldip2诱导的局灶黏附的丧失，表明RhoA和FAK介导了Poldip2对局灶黏附的影响。Nox4沉默可阻止AdPoldip2稳定局灶粘附，并诱导类似于siPoldip2的表型，这表明Nox4在poldip2诱导的局灶粘附稳定性中起作用。由于局灶黏附转换受损，pdgf处理的AdPoldip2细胞无法减少和极化牵引力，这是迁移的必要第一步。这些结果表明，Poldip2通过以Nox4/RhoA/ fak依赖的方式调节焦点粘附转换和牵引力产生，从而参与VSMC迁移。
Polymerase-delta-interacting protein 2 (Poldip2) interacts with NADPH oxidase 4 (Nox4) and regulates migration; however, the precise underlying mechanisms are unclear. Here, we investigated the role of Poldip2 in focal adhesion turnover, as well as traction force generation and polarization. Poldip2 overexpression (AdPoldip2) in vascular smooth muscle cells (VSMCs) impairs PDGF-induced migration and induces a characteristic phenotype of long cytoplasmic extensions. AdPoldip2 also prevents the decrease in spreading and increased aspect ratio observed in response to PDGF and slightly impairs cell contraction. Moreover, AdPoldip2 blocks focal adhesion dissolution and sustains H2O2 levels in focal adhesions, whereas Poldip2 knockdown (siPoldip2) significantly decreases the number of focal adhesions. RhoA activity is unchanged when focal adhesion dissolution is stimulated in control cells but increases in AdPoldip2-treated cells. Inhibition of RhoA blocks Poldip2-mediated attenuation of focal adhesion dissolution, and overexpression of RhoA or focal adhesion kinase (FAK) reverses the loss of focal adhesions induced by siPoldip2, indicating that RhoA and FAK mediate the effect of Poldip2 on focal adhesions. Nox4 silencing prevents focal adhesion stabilization by AdPoldip2 and induces a phenotype similar to siPoldip2, suggesting a role for Nox4 in Poldip2-induced focal adhesion stability. As a consequence of impaired focal adhesion turnover, PDGF-treated AdPoldip2 cells are unable to reduce and polarize traction forces, a necessary first step in migration. These results implicate Poldip2 in VSMC migration via regulation of focal adhesion turnover and traction force generation in a Nox4/RhoA/FAK-dependent manner.