Downregulation of Dicer expression by serum withdrawal sensitizes human endothelial cells to apoptosis
Downregulation of Dicer expression by serum withdrawal sensitizes human endothelial cells to apoptosis
复制标题
DOI：
10.1152/ajpheart.00233.2008
复制
发表时间：
2008-12-01
影响因子：
4.8
通讯作者：
Oh, Hidemasa
中科院分区：
文献类型：
--
作者：
Asada, Satoshi;Takahashi, Tomosaburo;Oh, Hidemasa
血清剥夺下调Dicer表达使人内皮细胞对凋亡敏感。《美国生理学杂志 - 心脏和循环生理学》295卷：H2512 - H2521，2008年。首次发表于2008年10月31日；doi:10.1152/ajpheart.00233.2008。 - 尽管在肿瘤转化时Dicer表达的调节已有记载，但对于环境刺激对Dicer表达的调节及其在原代细胞细胞功能调节中的作用知之甚少。在本研究中，我们发现人脐静脉内皮细胞（HUVECs）在血清剥夺时Dicer表达下调。血清剥夺诱导Dicer表达呈时间依赖性抑制，血管内皮细胞生长因子或1 - 磷酸鞘氨醇可特异性逆转这种抑制。当用针对Dicer的短发夹RNA使Dicer表达沉默时，细胞在血清剥夺条件下更易发生凋亡，而在含血清条件下凋亡率与对照细胞相当。基于实时PCR的基因表达谱分析鉴定出几个基因，其表达受Dicer沉默调节，包括黏附及基质相关分子、半胱天冬酶 - 3和一氧化氮合酶3（NOS3）。Dicer沉默显著损害迁移功能，但不影响细胞黏附，并抑制贴壁HUVECs中黏着斑激酶和富含脯氨酸的酪氨酸激酶2的磷酸化。Dicer敲低上调半胱天冬酶 - 3并下调NOS3表达，且血清剥夺确实增加半胱天冬酶 - 3并降低NOS3表达。此外，在HUVECs中过表达Dicer导致血清剥夺时凋亡显著减少，半胱天冬酶 - 3降低且NOS3表达增加。N - ω - 硝基 - L - 精氨酸甲酯对NOS活性的抑制消除了Dicer过表达使细胞从血清剥夺诱导的凋亡中恢复的作用。这些结果表明血清剥夺降低Dicer表达，通过调节半胱天冬酶 - 3和NOS3表达导致对凋亡的敏感性增加。
Downregulation of Dicer expression by serum withdrawal sensitizes human endothelial cells to apoptosis. Am J Physiol Heart Circ Physiol 295: H2512-H2521, 2008. First published October 31, 2008; doi:10.1152/ajpheart.00233.2008.-Although the modulated expression of Dicer is documented upon neoplastic transformation, little is known of the regulation of Dicer expression by environmental stimuli and its roles in the regulation of cellular functions in primary cells. In this study, we found that Dicer expression was downregulated upon serum withdrawal in human umbilical vein endothelial cells (HUVECs). Serum withdrawal induced a time-dependent repression of Dicer expression, which was specifically rescued by vascular endothelial cell growth factor or sphingosine-1-phosphate. When Dicer expression was silenced by short-hairpin RNA against Dicer, the cells were more prone to apoptosis under serum withdrawal, whereas the rate of apoptosis was comparable with control cells in the serum-containing condition. Real-time PCR-based gene expression profiling identified several genes, the expression of which was modulated by Dicer silencing, including adhesion and matrix-related molecules, caspase-3, and nitric oxide synthase 3 (NOS3). Dicer silencing markedly impaired migratory functions without affecting cell adhesion and repressed phosphorylation of focal adhesion kinase and proline-rich tyrosine kinase 2 in adherent HUVECs. Dicer knockdown upregulated caspase-3 and downregulated NOS3 expression, and serum withdrawal indeed increased caspase-3 and decreased NOS3 expression. Furthermore, the overexpression of Dicer in HUVECs resulted in a marked reduction in apoptosis upon serum withdrawal and a decreased caspase-3 and increased NOS3 expression. The inhibition of NOS activity by N-omega-nitro-L-arginine methyl ester abrogated the effect of Dicer overexpression to rescue the cells from serum withdrawal-induced apoptosis. These results indicated that serum withdrawal decreases Dicer expression, leading to an increased susceptibility to apoptosis through the regulation of caspase-3 and NOS3 expression.