RhoA and Rac1 are both required for efficient wound closure of airway epithelial cells
RhoA and Rac1 are both required for efficient wound closure of airway epithelial cells
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DOI：
10.1152/ajplung.00022.2004
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发表时间：
2004-12-01
影响因子：
4.9
通讯作者：
Waters, CM
中科院分区：
文献类型：
--
作者：
Desai, LP;Aryal, AM;Waters, CM
损伤后气道上皮的修复对于恢复正常的肺部至关重要。再上皮化过程涉及扩散和迁移，随后是细胞增殖。 Rho-GTP 酶是许多不同类型组织中伤口愈合过程的关键成分，但 RhoA 和 Rac1 的具体作用各不相同，并且在肺上皮细胞中尚未确定。我们研究了 RhoA 和 Rac1 是否调节支气管上皮细胞的伤口闭合。通过基于腺病毒的基因转移，RhoA 和 Rac1 蛋白在人支气管上皮细胞 (16HBE) 细胞系中有效表达。我们发现组成型活性 RhoA 和显性失活 RhoA 都会抑制伤口愈合，这表明 RhoA 的激活和抑制都会干扰正常的伤口愈合。野生型 Rac1 的过度表达诱导 RhoA 上调，破坏细胞间连接并抑制伤口闭合。显性阴性 Rac1 也抑制伤口闭合。用 Y-27632 抑制 RhoA 下游效应器 Rho 激酶，抑制肌动蛋白应力纤维和粘着斑形成，增加 Rac1 活性，并刺激伤口闭合。 RhoA和Rac1的活性均受到微管聚合状态的影响，细胞迁移涉及肌动蛋白和微管的协调作用。诺考达唑治疗后的微管解聚导致粘着斑增加和伤口闭合减少。我们得出的结论是，RhoA 和 Rac1 活性的协调有助于体外支气管上皮伤口修复机制，抑制 Rho 激酶可加速伤口闭合，并且有效修复涉及完整的微管。
Repair of the airway epithelium after injury is critical for restoring normal lung. The reepithelialization process involves spreading and migration followed later by cell proliferation. Rho-GTPases are key components of the wound healing process in many different types of tissues, but the specific roles for RhoA and Rac1 vary and have not been identified in lung epithelial cells. We investigated whether RhoA and Rac1 regulate wound closure of bronchial epithelial cells. RhoA and Rac1 proteins were efficiently expressed in a cell line of human bronchial epithelial cells (16HBE) by adenovirus-based gene transfer. We found that both constitutively active RhoA and dominant negative RhoA inhibited wound healing, suggesting that both activation and inhibition of RhoA interfere with normal wound healing. Overexpression of wild-type Rac1 induced upregulation of RhoA, disrupted intercellular junctions, and inhibited wound closure. Dominant negative Rac1 also inhibited wound closure. Inhibition of the downstream effector of RhoA, Rho-kinase, with Y-27632 suppressed actin stress fibers and focal adhesion formation, increased Rac1 activity, and stimulated wound closure. The activity of both RhoA and Rac1 are influenced by the polymerization state of microtubules, and cell migration involves coordinated action of actin and microtubules. Microtubule depolymerization upon nocodazole treatment led to an increase in focal adhesions and decreased wound closure. We conclude that coordination of both RhoA and Rac1 activity contributes to bronchial epithelial wound repair mechanisms in vitro, that inhibition of Rho-kinase accelerates wound closure, and that efficient repair involves intact microtubules.