Protein kinase A inhibits lysophosphatidic acid-induced migration of airway smooth muscle cells
Protein kinase A inhibits lysophosphatidic acid-induced migration of airway smooth muscle cells
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DOI：
10.1124/jpet.106.118042
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发表时间：
2007-06-01
影响因子：
3.5
通讯作者：
Oike, Masahiro
中科院分区：
文献类型：
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作者：
Hirakawa, Masakazu;Karashima, Yuji;Oike, Masahiro
溶血磷脂酸（LPA）是一种生物活性磷脂，由活化的血小板释放，影响气道平滑肌细胞的收缩特性。然而，LPA对细胞迁移（气道重塑的初始事件之一）的可能作用尚不清楚。本研究旨在观察LPA对牛气管平滑肌细胞（BTSMCs）迁移和肌动蛋白纤维形成的影响。随机和定向细胞迁移分别用伤口试验和Boyden室试验进行检查。用罗丹明鬼笔环肽染色细胞质肌动蛋白纤维。RhoA的膜易位，RhoA活化的标志，通过蛋白质印迹法进行评估。LPA可促进BTSMCs从创伤融合单层迁移，但不促进BTSMCs向LPA的趋化迁移。LPA还诱导瞬时肌动蛋白重组和RhoA激活。密集的肌动蛋白纤维主要在伤口边缘，但没有在迁移的细胞，从而表明肌动蛋白重组的作用，在启动细胞迁移。Rho激酶抑制剂Y27632 [R-（+）-trans-N-（4-pyridyl）-4-（1-aminoethyl）-hexane carboxamide]可阻断LPA诱导的肌动蛋白纤维形成。LPA对迁移和肌动蛋白纤维形成的影响也被cAMP升高剂抑制，即，二丁酰cAMP、毛喉素、异丙肾上腺素和茶碱。KT5720（9 S，10 S，12 R）-2，3，9，10，11，12-六氢-10-羟基-9-甲基-1-氧代-9，12-环氧-1H-二吲哚并[1，2，3-fg：3 '，2 '，1 '-kl]吡咯并[3，4-i][1，6]苯并二氮杂环辛四烯-10-羧酸己酯]，蛋白激酶A（PKA）抑制剂，逆转cAMP对LPA诱导的反应的抑制作用。这些结果表明，LPA诱导cAMP/PKA敏感的，RhoA介导的BTSMCs的随机迁移。调节这种机制将有利于控制气道重塑。
Lysophosphatidic acid (LPA) is a bioactive phospholipid that is released from activated platelets and affects contractile properties of airway smooth muscle cells. However, possible roles of LPA on cell migration, one of the initial events of airway remodeling, are not clarified. This study aimed to examine the effects of LPA on migration and actin fiber formation in bovine tracheal smooth muscle cells (BTSMCs). Random and oriented cell migrations were examined with wound assay and Boyden chamber assay, respectively. Cytosolic actin fibers were stained with rhodamine-phalloidin. Membrane translocation of RhoA, a hallmark of RhoA activation, was assessed by Western blotting. LPA augmented the migration of BTSMCs from wounded confluent monolayer but did not accelerate the chemotactic migration toward LPA. LPA also induced a transient actin reorganization and RhoA activation. Dense actin fibers were observed mainly in the wound edge but not in migrated cells, thereby suggesting the role of actin reorganization in the initiation of cell migration. LPA-induced actin fiber formation was blocked by Y27632 [R-(+)-trans-N-(4-pyridyl)-4-(1-aminoethyl)-cyclohexane carboxamide], an inhibitor of Rho kinase. Effects of LPA on migration and actin fiber formation were also inhibited by cAMP-elevating agents, i.e., dibutyryl cAMP, forskolin, isoproterenol, and theophylline. KT5720 (9S, 10S, 12R)-2,3,9,10,11,12-hexahydro-10-hydroxy-9-methyl-1-oxo-9,12-epoxy- 1H-diindolo[ 1,2,3-fg: 3 ', 2 ', 1 '-kl] pyrrolo[3,4-i][1,6]benzodiazocine-10- carboxylic acid hexyl ester], a protein kinase A (PKA) inhibitor, reversed the inhibitory actins of cAMP on LPA-induced responses. These results indicate that LPA induces cAMP/PKA-sensitive, RhoA-mediated random migration of BTSMCs. Regulation of this mechanism would be beneficial for the control of airway remodeling.