Protein kinase C delta inhibits the proliferation of vascular smooth muscle cells by suppressing G(1) cyclin expression
Protein kinase C delta inhibits the proliferation of vascular smooth muscle cells by suppressing G(1) cyclin expression
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DOI：
10.1074/jbc.272.21.13816
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发表时间：
1997-05-23
影响因子：
4.8
通讯作者：
Morii, H
中科院分区：
文献类型：
--
作者：
Fukumoto, S;Nishizawa, Y;Morii, H
为了阐明蛋白激酶C（PKC）δ的生理作用，PKC δ是在血管平滑肌细胞（VSMC）中广泛表达的亚型，PKC δ在大鼠克隆VSMC A7 r5细胞中稳定过表达。PKC δ（DV）过表达的A7 r5中的[H-3]胸苷掺入被抑制至37.1 +/- 16.3%（平均值+/- S.D.）。对照或单独用载体转染的A7 r5（EV）中的水平。[H-3]胸苷掺入的减少与过表达的PKC水平密切相关。此外，瞬时转染的显性负性突变体的PKC δ恢复DVs的增殖减少。流式细胞仪分析表明DVs被阻滞在细胞周期的G（0）/G（1）期。与EV相比，DV中细胞周期蛋白D1和E的表达以及视网膜母细胞瘤蛋白磷酸化水平降低，而p27蛋白水平升高。c-fos、c-jun、c-myc、cyclin D2、D3、cyclin dependent kinase 2、cyclin dependent kinase 4和p21的表达在各克隆间无显著差异。结论：PKC δ主要通过抑制细胞周期蛋白D1和E的表达，将细胞阻滞于G（1）期，从而抑制VSMC的增殖。
To elucidate the physiological role of protein kinase C (PKC) delta, a ubiquitously expressed isoform in vascular smooth muscle cells (VSMC), PKC delta was stably overexpressed in A7r5 cells, rat clonal VSMC. The [H-3]thymidine incorporation in A7r5 overexpressed with PKC delta (DVs) was suppressed to 37.1 +/- 16.3% (mean +/- S.D.) of the level in control or A7r5 transfected with vector alone (EVs). The reduction of [H-3]thymidine incorporation was strongly correlated with overexpressed PKC levels. Moreover, transient transfection of a dominant negative mutant of PKC delta restored the reduced proliferation in DVs. Flow cytometry analysis demonstrated that DVs were arrested in the G(0)/G(1), phase of the cell cycle. Expression of cyclins D1 and E and retinoblastoma protein phosphorylation were reduced, while the protein levels of p27 were elevated in DVs as compared with EVs. There were no significant differences in the expression of c-fos, c-jun, c-myc, cyclin D2, D3, cyclin dependent kinase 2, cyclin-dependent kinase 4, and p21 among the clones. We conclude that PKC delta inhibits the proliferation of VSMC by arresting cells in G(1) via mainly inhibiting the expression of cyclin D1 and cyclin E.