Poldip2, a novel regulator of Nox4 and cytoskeletal integrity in vascular smooth muscle cells.
Poldip2, a novel regulator of Nox4 and cytoskeletal integrity in vascular smooth muscle cells.
复制标题
DOI：
10.1161/circresaha.109.193722
复制
发表时间：
2009-07-31
影响因子：
20.1
通讯作者：
Griendling KK
中科院分区：
文献类型：
--
作者：
Lyle AN;Deshpande NN;Taniyama Y;Seidel-Rogol B;Pounkova L;Du P;Papaharalambus C;Lassègue B;Griendling KK
NADPH氧化酶（Nox）调节血管生理并参与血管疾病的发病机制。在血管平滑肌细胞（VSMCs）中，单个Nox同源物与调节蛋白的相互作用还不清楚。本研究的目的是确定新的NADPH氧化酶调节蛋白。使用酵母双杂交筛选，我们确定了一种新的结合伙伴，Poldip 2，并证明它与p22 phox，Nox 1和Nox 4和共定位与p22 phox在Nox 4定位的网站。Poldip 2使Nox 4酶活性增加3倍，并正向调节VSMC中基础活性氧（ROS）的产生（O2·−：增加86.3±15.6%; H2 O2：增加40.7±4.5%）。Poldip 2的过表达激活Rho（增加180.2±24.8%），加强局灶性粘连并增加应力纤维形成。这些表型变化被显性负性Rho阻断。相反，Poldip 2或Nox 4的耗尽导致这些结构的损失，这通过添加回活性Rho来挽救。需要动态细胞骨架重塑的细胞迁移受到Poldip 2过量（减少70.1±14.7%）或不足（减少63.5±5.9%）的损害。这些结果表明，Poldip 2与p22 phox激活Nox 4，导致局灶性粘附周转和VSMC迁移的调节，从而连接ROS的产生和细胞骨架重塑。Poldip 2可能是一种新的治疗靶点，用于具有显著VSMC迁移组分的血管病变，如再狭窄和动脉粥样硬化。
NADPH oxidases (Nox) regulate vascular physiology and contribute to the pathogenesis of vascular disease. In vascular smooth muscle cells (VSMCs), the interactions of individual Nox homologues with regulatory proteins are poorly defined. The objective of this study was to identify novel NADPH oxidase regulatory proteins. Using a yeast 2 hybrid screen, we identified a novel binding partner, Poldip2, and demonstrate that it associates with p22phox, Nox1 and Nox4 and co-localizes with p22phox at sites of Nox4 localization. Poldip2 increases Nox4 enzymatic activity by 3-fold and positively regulates basal reactive oxygen species (ROS) production in VSMCs (O2•−: 86.3±15.6% increase; H2O2: 40.7±4.5% increase). Overexpression of Poldip2 activates Rho (180.2±24.8% increase), strengthens focal adhesions and increases stress fiber formation. These phenotypic changes are blocked by dominant negative Rho. In contrast, depletion of either Poldip2 or Nox4 results in a loss of these structures, which is rescued by adding back active Rho. Cell migration, which requires dynamic cytoskeletal remodeling, is impaired by either excess (70.1±14.7% decrease) or insufficient Poldip2 (63.5±5.9% decrease). These results suggest that Poldip2 associates with p22phox to activate Nox4, leading to regulation of focal adhesion turnover and VSMC migration, thus linking ROS production and cytoskeletal remodeling. Poldip2 may be a novel therapeutic target for vascular pathologies with a significant VSMC migratory component, such as restenosis and atherosclerosis.