Autotaxin induces lung epithelial cell migration through lysoPLD activity-dependent and -independent pathways.
Autotaxin induces lung epithelial cell migration through lysoPLD activity-dependent and -independent pathways.
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DOI：
10.1042/bj20110274
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发表时间：
2011-10-01
期刊：
影响因子：
--
通讯作者：
Zhao Y
中科院分区：
文献类型：
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作者：
Zhao J;He D;Berdyshev E;Zhong M;Salgia R;Morris AJ;Smyth SS;Natarajan V;Zhao Y
肺细胞迁移是上皮化的关键步骤，而上皮化又对于肺损伤后的重塑和修复至关重要。我们假设具有溶血磷脂酶 D (lysoPLD) 活性的分泌型自分泌运动因子 (ATX) 通过溶血磷脂酸 (LPA) 生成依赖性和非依赖性途径刺激肺上皮细胞迁移。在肺上皮细胞培养基中检测内源性ATX蛋白的释放和活性。与对照培养基相比，带有 V5 标签的 ATX (ATX-V5) 过表达条件培养基具有更高的 LPA 水平，并通过 Gαi 偶联 LPA 受体刺激细胞迁移、细胞骨架重排、迁移细胞前缘的 PKCδ 和皮质蛋白磷酸化。抑制 PKCδ 可减弱 ATX-V5 过度表达的条件培养基介导的皮质素磷酸化。此外，缺乏lysoPLD活性的重组ATX突变体或热灭活的ATX也诱导肺上皮细胞迁移。细胞外 ATX 与 A549 细胞表面的 LPA 受体和整合素 β4 复合物结合。最后，气管内将脂多糖注入小鼠气道，诱导支气管肺泡灌洗液中 ATX 释放和 LPA 产生。这些结果表明，ATX 通过诱导 LPA 产生介导的 PKCδ 和 Cortactin 磷酸化，在肺上皮细胞迁移和重塑中发挥重要作用。此外，我们还证明了ATX与上皮细胞表面LPA受体和整合素β4的关联。
Lung cell migration is a crucial step for re-epithelialization that in turn is essential for remodeling and repair after lung injury. We hypothesize that secreted autotaxin (ATX), which exhibits lysophospholipase D (lysoPLD) activity, stimulates lung epithelial cell migration through lysophosphatidic acid (LPA) generation-dependent and -independent pathways. Release of endogenous ATX protein and activity was detected in lung epithelial cell culture medium. ATX with V5 tag (ATX-V5) overexpressed conditional medium had higher LPA levels compared to control medium and stimulated cell migration through Gαi-coupled LPA receptors, cytoskeleton rearrangement, phosphorylation of PKCδ and cortactin at the leading edge of migrating cells. Inhibition of PKCδ attenuated ATX-V5 overexpressed conditional medium-mediated phosphorylation of cortactin. In addition, a recombinant ATX mutant, lacking lysoPLD activity, or heat-inactived ATX also induced lung epithelial cell migration. Extracelluar ATX bound to LPA receptor and integrin β4 complex on A549 cell surface. Finally, intratracheal administration of lipopolysaccharide into mouse airway induced ATX release and LPA production in bronchoalveolar lavage fluid. These results suggested a significant role for ATX in lung epithelial cell migration and remodeling through its ability to induce LPA production-mediated phosphorylation of PKCδ and cortactin. In addition we also demonstrated assocation of ATX with epithelial cell surface LPA receptor and integrin β4.