Contribution of the p38MAPK signalling pathway to proliferation in human cultured airway smooth muscle cells is mitogen-specific
Contribution of the p38MAPK signalling pathway to proliferation in human cultured airway smooth muscle cells is mitogen-specific
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DOI：
10.1038/sj.bjp.0705809
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发表时间：
2004-08-01
影响因子：
7.3
通讯作者：
Stewart, AG
中科院分区：
文献类型：
--
作者：
Fernandes, DJ;Ravenhall, CE;Stewart, AG
1我们研究了p38（MAPK）在凝血酶和bFGF诱导的人气道平滑肌（HASM）增殖中的作用。还检测了细胞周期蛋白D1 mRNA、细胞周期蛋白D1、细胞周期蛋白E和p21（Cip 1）蛋白水平的调节，以及视网膜母细胞瘤蛋白（pRb）磷酸化对p38（MAPK）激活的响应程度。2两种不同的p38（MAPK）抑制剂，SB 203580（10 μ M）和SB 202190（10 μ M），抑制bFGF（0.3-3 nM）刺激的细胞增殖，但对凝血酶（0.3-3 U ml（-1））的反应没有影响。3在与凝血酶或bFGF孵育20 h的细胞中，bFGF引起p38（MAPK）磷酸化增加，但凝血酶不引起。凝血酶和bFGF刺激的ERK磷酸化和细胞周期蛋白D1 mRNA和蛋白水平的增加不受SB 203580预处理的影响。同样，细胞周期蛋白E和p21（Cip 1）蛋白水平，与有丝分裂原孵育20小时后测量，似乎没有被SB 203580（10 μ M）调节。4虽然凝血酶和bFGF显着增加pRb磷酸化的水平，SB 203580（10 μ M）只抑制bFGF刺激的pRb磷酸化。此外，SB 203580（10 μ M）选择性抑制bFGF刺激的DNA合成，表明SB 203580对pRb磷酸化的抗有丝分裂作用导致细胞周期停滞在G1期晚期。5总之，这些结果表明p38（MAPK）参与bFGF刺激的HASM增殖，但不参与凝血酶刺激的HASM增殖。bFGF激活p38（MAPK）通路，而不是凝血酶，调节pRb的磷酸化，而不影响细胞周期蛋白D1的表达。
1 We have investigated the role of p38(MAPK) in human airway smooth muscle (HASM) proliferation in response to thrombin and bFGF. The regulation of cyclin D1 mRNA, cyclin D1, cyclin E and p21(Cip1) protein levels, and the extent of retinoblastoma protein (pRb) phosphorylation in response to activation of p38(MAPK) have also been examined.2 Two distinct inhibitors of p38(MAPK), SB 203580 (10 muM) and SB 202190 (10 muM), prevented bFGF (0.3-3 nM)-stimulated cell proliferation, but had no effect on the response to thrombin (0.3-3 U ml(-1)).3 In cells incubated with thrombin or bFGF for 20 h, there was an increase in p38(MAPK) phosphorylation in response to bFGF, but not to thrombin. Thrombin and bFGF-stimulated increases in ERK phosphorylation and cyclin D1 mRNA and protein levels were not influenced by SB 203580 pre-treatment. Similarly, cyclin E and p21(Cip1) protein levels, measured after 20 h incubation with mitogen, did not appear to be regulated by SB 203580 (10 muM).4 Although both thrombin and bFGF significantly increased levels of pRb phosphorylation, SB 203580 (10 muM) inhibited only bFGF-stimulated pRb phosphorylation. In addition, SB 203580 (10 muM) selectively inhibited bFGF-stimulated DNA synthesis, suggesting that the antimitogenic actions of SB 203580 on pRb phosphorylation cause cell cycle arrest at late G1 phase.5 In conclusion, these results indicate that p38(MAPK) is involved in bFGF-, but not in thrombin-stimulated HASM proliferation. The activation of the p38(MAPK) pathway by bFGF, but not by thrombin, regulates the phosphorylation of pRb without influencing cyclin D1 expression.