Key Laboratory of Molecular Cardiovascular Science, Peking University Health Science Center, Beijing 100191, China.
Proc Natl Acad Sci U S A. 2010 Feb 16;107(7):3240-4. doi: 10.1073/pnas.0914882107. Epub 2010 Jan 27.
Endothelial cells (ECs) respond to changes in mechanical forces, leading to the modulation of signaling networks and cell function; an example is the inhibition of EC proliferation by steady laminar flow. MicroRNAs (miRs) are short noncoding 20-22 nucleotide RNAs that negatively regulate the expression of target genes at the posttranscriptional level. This study demonstrates that miRs are involved in the flow regulation of gene expression in ECs. With the use of microRNA chip array, we found that laminar shear stress (12 dyn/cm(2), 12 h) regulated the EC expression of many miRs, including miR-19a. We further showed that stable transfection of miR-19a significantly decreased the expression of a reporter gene controlled by a conserved 3'-untranslated region of the cyclinD1 gene and also the protein level of cyclin D1, leading to an arrest of cell cycle at G1/S transition. Laminar flow suppressed cyclin D1 protein level, and this suppressive effect was diminished when the endogenous miR-19a was inhibited. In conclusion, we demonstrated that miR-19a plays an important role in the flow regulation of cyclin D1 expression. These results revealed a mechanism by which mechanical forces modulate endothelial gene expression.
内皮细胞(ECs)对机械力的变化做出反应,导致信号转导网络和细胞功能的调节;例如,层流抑制 EC 的增殖。微 RNA(miRs)是短的非编码 20-22 个核苷酸的 RNA,在转录后水平上负调控靶基因的表达。本研究表明,miRs 参与了 EC 中基因表达的流动调节。通过使用 microRNA 芯片阵列,我们发现层流剪切力(12 dyn/cm(2),12 h)调节许多 miRs 的 EC 表达,包括 miR-19a。我们进一步表明,miR-19a 的稳定转染显著降低了受细胞周期蛋白 D1 基因保守 3'-非翻译区控制的报告基因的表达,并且细胞周期蛋白 D1 的蛋白水平也降低,导致细胞周期在 G1/S 转换时停滞。层流抑制细胞周期蛋白 D1 蛋白水平,而当抑制内源性 miR-19a 时,这种抑制作用减弱。总之,我们证明了 miR-19a 在细胞周期蛋白 D1 表达的流动调节中起着重要作用。这些结果揭示了机械力调节内皮基因表达的一种机制。