Tsuda Yuki, Okazaki Masahiro, Uezono Yasuhito, Osajima Akihiko, Kato Hiroaki, Okuda Haruhito, Oishi Yosuke, Yashiro Akira, Nakashima Yasuhide
The Second Department of Internal Medicine, University of Occupational and Environmental Health, School of Medicine, 1-1 Iseigaoka, Yahatanishi, Kitakyushu, 807-8555, Japan.
Eur J Pharmacol. 2002 Jun 20;446(1-3):15-24. doi: 10.1016/s0014-2999(02)01811-3.
In hypertension, increased transmural pressure directly influences vascular smooth muscle cells and causes cell proliferation. However, the mechanisms of transmural pressure-induced proliferation of vascular smooth muscle cells are unknown. We investigated the role of various protein kinases in pressure-induced proliferation of vascular smooth muscle cells. Pressure was applied to quiescent rat vascular smooth muscle cells in culture by compressed helium gas in a loading apparatus. Pressure application increased [3H]thymidine incorporation in a time- and pressure-dependent manner and significantly increased the cell number. The pressor response was significantly suppressed by various protein kinase inhibitors for protein kinase C (bisindolylmaleimide I), tyrosine kinase (genistein), extracellular signal-regulated kinase kinase (PD98059; 2'-amino-3'-methoxyflavone) and p38 mitogen-activated protein kinases (MAPK) (SB203580; 4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H-imidazole). Pressure rapidly increased the phosphorylation and activity of extracellular signal-regulated kinases (ERK). Pressure also caused increment of phosphorylation level of p38 MAPK but not that of c-JUN N-terminal protein kinase (JNK). In ERK-deficient cells prepared by transfection of an antisense oligonucleotide for ERK, pressure-induced DNA synthesis was almost abolished. Our results suggest that activation of ERK is essential for pressure-induced DNA synthesis in rat vascular smooth muscle cells, in addition to activation of protein kinase C, tyrosine kinase and p38 MAPK. These processes could be involved in the pathogenesis of hypertension-related atherosclerosis.
在高血压中，跨壁压力升高直接影响血管平滑肌细胞并导致细胞增殖。然而，跨壁压力诱导血管平滑肌细胞增殖的机制尚不清楚。我们研究了各种蛋白激酶在压力诱导的血管平滑肌细胞增殖中的作用。通过加载装置中的压缩氦气对培养的静止大鼠血管平滑肌细胞施加压力。施加压力以时间和压力依赖性方式增加了[3H]胸苷掺入，并显著增加了细胞数量。蛋白激酶C（双吲哚基马来酰亚胺I）、酪氨酸激酶（染料木黄酮）、细胞外信号调节激酶激酶（PD98059；2'-氨基-3'-甲氧基黄酮）和p38丝裂原活化蛋白激酶（MAPK）（SB203580；4-(4-氟苯基)-2-(4-甲基亚磺酰基苯基)-5-(4-吡啶基)1H-咪唑）的各种蛋白激酶抑制剂显著抑制了升压反应。压力迅速增加了细胞外信号调节激酶（ERK）的磷酸化和活性。压力还导致p38 MAPK磷酸化水平升高，但c-JUN N端蛋白激酶（JNK）的磷酸化水平未升高。在用ERK反义寡核苷酸转染制备的ERK缺陷细胞中，压力诱导的DNA合成几乎被消除。我们的结果表明，除了蛋白激酶C、酪氨酸激酶和p38 MAPK的激活外，ERK的激活对于大鼠血管平滑肌细胞压力诱导的DNA合成至关重要。这些过程可能参与高血压相关动脉粥样硬化的发病机制。
