作者:Philip Vitorino、Stacey Yeung、Ailey Crow、Jesse Bakke、Tanya Smyczek、Kristina West、Erin McNamara、Jeffrey Eastham-Anderson、Stephen Gould、Seth F. Harris、Chudi Ndubaku、Weilan Ye
DOI:10.1038/nature14323
日期:2015.3
Cell migration is a stepwise process that coordinates multiple molecular machineries. Using in vitro angiogenesis screens with short interfering RNA and chemical inhibitors, we define here a MAP4K4âmoesinâtalinâβ1-integrin molecular pathway that promotes efficient plasma membrane retraction during endothelial cell migration. Loss of MAP4K4 decreased membrane dynamics, slowed endothelial cell migration, and impaired angiogenesis in vitro and in vivo. In migrating endothelial cells, MAP4K4 phosphorylates moesin in retracting membranes at sites of focal adhesion disassembly. Epistasis analyses indicated that moesin functions downstream of MAP4K4 to inactivate integrin by competing with talin for binding to β1-integrin intracellular domain. Consequently, loss of moesin (encoded by the MSN gene) or MAP4K4 reduced adhesion disassembly rate in endothelial cells. Additionally, α5β1-integrin blockade reversed the membrane retraction defects associated with loss of Map4k4 in vitro and in vivo. Our study uncovers a novel aspect of endothelial cell migration. Finally, loss of MAP4K4 function suppressed pathological angiogenesis in disease models, identifying MAP4K4 as a potential therapeutic target. A new MAP4K4âmoesinâtalinâβ1-integrin pathway regulating endothelial cell motility was discovered through chemical and siRNA screens; loss of Map4k4 or inhibition of MAP4K4 kinase activity altered the sprout morphology of endothelial cells during angiogenesis by blocking moesin phosphorylation, which regulates the disassembly of focal adhesions, demonstrating that this pathway is involved in both normal and pathological angiogenesis. Cell migration is crucial in important biological processes such as embryogenesis, inflammation and angiogenesis, but many aspects of the cell motility machinery remain to be defined at the molecular level. Here Weilan Ye and colleagues identify a previously unknown pathway regulating endothelial cell motility. Using chemical and RNA screens, they found that a selective inhibitor of MAP4K4 altered the sprout morphology of endothelial cells during angiogenesis. The inhibitor caused endothelial cells to accumulate long, thin subcellular protrusions, suggesting a failure to retract these protrusions. The authors show that MAP4K4 phosphorylates moesin, which regulates the disassembly of focal adhesions by inactivating β1-integrin, and they demonstrate that this MAP4K4âmoesinâtalinâβ1-integrin pathway plays a role in both normal and pathological angiogenesis.
细胞迁移是一个逐步的过程,协调多个分子机制。通过使用短干扰RNA和化学抑制剂的体外血管生成筛选,我们在此定义了一个MAP4K4–moesin–talin–β1-整合素的分子途径,该途径促进内皮细胞迁移过程中有效的质膜收缩。MAP4K4的丧失降低了膜动力学,减缓了内皮细胞迁移,并在体内外损害了血管生成。在迁移的内皮细胞中,MAP4K4在收缩膜的粘附斑解体部位磷酸化moesin。表观遗传分析表明,moesin在MAP4K4下游起作用,通过与talin竞争结合β1-整合素的细胞内结构域来使整合素失活。因此,moesin(由MSN基因编码)或MAP4K4的丧失降低了内皮细胞的粘附解体速率。此外,α5β1-整合素的阻断逆转了体内外与Map4k4丧失相关的膜收缩缺陷。我们的研究揭示了内皮细胞迁移的一个新方面。最后,MAP4K4功能的丧失抑制了疾病模型中的病理性血管生成,识别MAP4K4作为潜在的治疗靶点。通过化学和siRNA筛选,发现了一个新的MAP4K4–moesin–talin–β1-整合素途径,该途径调节内皮细胞的运动性;Map4k4的丧失或MAP4K4激酶活性的抑制改变了内皮细胞在血管生成过程中的芽形态,通过阻止moesin磷酸化,从而调节粘附斑的解体,表明该途径在正常和病理性血管生成中均发挥作用。细胞迁移在胚胎发生、炎症和血管生成等重要生物过程中至关重要,但细胞运动机制的许多方面仍需在分子水平上加以定义。在这里,韦兰·叶及其同事确定了一个以前未知的调节内皮细胞运动性的途径。通过化学和RNA筛选,他们发现MAP4K4的选择性抑制剂改变了内皮细胞在血管生成过程中的芽形态。该抑制剂导致内皮细胞累积长而细的亚细胞突出物,表明未能收缩这些突出物。作者表明,MAP4K4磷酸化moesin,后者通过使β1-整合素失活来调节粘附斑的解体,并证明该MAP4K4–moesin–talin–β1-整合素途径在正常和病理性血管生成中均发挥作用。