Mast cell tryptase activates extracellular-regulated kinases (p44/p42) in airway smooth-muscle cells: importance of proteolytic events, time course, and role in mediating mitogenesis.
Mast cell tryptase activates extracellular-regulated kinases (p44/p42) in airway smooth-muscle cells: importance of proteolytic events, time course, and role in mediating mitogenesis.
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肥大细胞类胰蛋白酶激活气道平滑肌细胞中的细胞外调节激酶 (p44/p42)：蛋白水解事件的重要性、时间进程以及在介导有丝分裂中的作用。
DOI：
10.1165/ajrcmb.24.2.4165
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发表时间：
2001
影响因子：
6.4
通讯作者：
Caughey,GH
中科院分区：
文献类型：
--
作者：
Brown,JK;Jones,CA;Rooney,LA;Caughey,GH
我们以前曾报道肥大细胞类胰蛋白酶是一种有效的有丝分裂原培养的气道平滑肌细胞，但早期的细胞内信号介导这种反应是未知的。 在许多细胞中，增殖效应由涉及Raf-1、MAP激酶激酶（MEK）和细胞外信号调节蛋白激酶（ERK）1和2的促分裂原活化蛋白激酶信号通路介导。因此，我们在培养的狗气管平滑肌细胞中检测类胰蛋白酶诱导的ERK 1和2激活。类胰蛋白酶，在纳摩尔浓度，有力地刺激DNA合成，增加双重磷酸化的细胞裂解物中的ERK以及ERK 2激酶活性的免疫沉淀。用MEK抑制剂PD 098059预处理细胞，可以消除类胰蛋白酶诱导的DNA合成增加，并减弱ERK 2活性的增加。 不可逆抑制类胰蛋白酶的蛋白水解活性，使用p-amidino phenylmethanesulfonyl fluoride，衰减类胰蛋白酶诱导的DNA合成增加和ERK的双重磷酸化分别增加76%和40 - 60%。 类胰蛋白酶也增加了c-fos转录定量聚合酶链反应。在浓度，导致类似的DNA合成增加，类胰蛋白酶和血小板衍生生长因子（PDGF-BB）增加ERK活性（和c-fos转录）与显着不同的动力学，类胰蛋白酶诱导的反应是在发病较慢，更持久。我们的结论是类胰蛋白酶诱导的有丝分裂在气道平滑肌细胞需要激活ERK 1和2，这些反应部分依赖于，但不完全，类胰蛋白酶的性质作为蛋白酶，而且它们是缓慢的发病和更持久的比PDGF-BB诱导的。
We previously reported that mast cell tryptase is a potent mitogen for cultured airway smooth-muscle cells, but the early intracellular signals mediating this response are not known. In many cells, proliferative effects are mediated by a mitogen-activated protein kinase signaling pathway involving Raf-1, MAP kinase kinases (MEKs), and extracellular signal-regulated protein kinases (ERKs) 1 and 2. Therefore, we tested for tryptase-induced activation of ERK1 and 2 in cultured dog tracheal smooth-muscle cells. Tryptase, in nanomolar concentrations which potently stimulated DNA synthesis, increased dual phosphorylation of ERKs in cellular lysates as well as ERK2 kinase activity in immunoprecipitates. Pretreatment of cells with the MEK inhibitor PD098059 abolished tryptase-induced increases in DNA synthesis and attenuated increases in ERK2 activity. Irreversible inhibition of tryptase's proteolytic activity, usingp-amidino phenylmethanesulfonyl fluoride, attenuated tryptase-induced increases in DNA synthesis and dual phosphorylation of ERKs by 76% and 40 to 60%, respectively. Tryptase also increased c-fos transcription as quantified in polymerase chain reactions. In concentrations that caused similar increases in DNA synthesis, tryptase and platelet-derived growth factor (PDGF-BB) increased ERK activity (and c-fos transcription) with markedly different kinetics, the tryptase-induced responses being slower in onset and more sustained. We conclude that tryptase-induced mitogenesis in airway smooth-muscle cells requires activation of ERK1 and 2; that these responses depend partially, but not completely, upon tryptase's properties as a protease; and that they are slower in onset and more sustained than those induced by PDGF-BB.