Department of Ophthalmology, Duke University, Durham, NC 27710, USA.
Mech Ageing Dev. 2009 Nov-Dec;130(11-12):731-41. doi: 10.1016/j.mad.2009.09.002.
We investigated miRNA expression changes associated with stress-induced premature senescence (SIPS) in primary cultures of human diploid fibroblast (HDF) and human trabecular meshwork (HTM) cells. Twenty-five miRNAs were identified by miRNA microarray analysis and their changes in expression were validated by TaqMan real-time RT-PCR in three independent cell lines of HTM and HDF. SIPS in both HTM and HDF cell types was associated with significant down-regulation of four members of the miR-15 family and five miRNAs of the miR-106b family located in the oncogenic clusters miR-17-92, miR-106a-363, and miR-106b-25. SIPS was also associated with up-regulation of two miRNAs (182 and 183) from the miR-183-96-182 cluster. Transfection with miR-106a agomir inhibited the up-regulation of p21(CDKN1A) associated with SIPS while transfection with miR-106a antagomir led to increased p21(CDKN1A) expression in senescent cells. In addition, we identified retinoic acid receptor gamma (RARG) as a target of miR-182 and showed that this protein was down-regulated during SIPS in HDF and HTM cells. These results suggest that changes in miRNA expression might contribute to phenotypic alterations of senescent cells by modulating the expression of key regulatory proteins such as p21(CDKN1A) as well as by targeting genes that are down-regulated in senescent cells such as RARG.
我们研究了与压力诱导的早衰（SIPS）相关的 miRNA 表达变化，这些变化发生在原代培养的人类二倍体成纤维细胞（HDF）和人眼小梁网（HTM）细胞中。通过 miRNA 微阵列分析鉴定了 25 个 miRNA，并通过 TaqMan 实时 RT-PCR 在三个独立的 HTM 和 HDF 细胞系中验证了它们的表达变化。HTM 和 HDF 细胞类型中的 SIPS 与 miR-15 家族的四个成员和位于致癌簇 miR-17-92、miR-106a-363 和 miR-106b-25 中的五个 miRNA 的表达显著下调有关。SIPS 还与 miR-183-96-182 簇中的两个 miRNA（182 和 183）的上调有关。miR-106a 激动剂的转染抑制了与 SIPS 相关的 p21（CDKN1A）的上调，而 miR-106a 拮抗剂的转染导致衰老细胞中 p21（CDKN1A）的表达增加。此外，我们鉴定了视黄酸受体γ（RARG）是 miR-182 的靶标，并表明该蛋白在 HDF 和 HTM 细胞的 SIPS 期间下调。这些结果表明，miRNA 表达的变化可能通过调节关键调节蛋白（如 p21（CDKN1A））的表达以及通过靶向衰老细胞中下调的基因（如 RARG）来促进衰老细胞的表型改变。
