Alterations in microRNA expression in stress-induced cellular senescence

Abstract

Summary We investigated miRNA expression changes associated with stress-induced premature senescence (SIPS) in primary cultures of human diploid fibroblasts (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 realtime 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 p21CDKN1A associated with SIPS while transfection with miR-106a antagomir led to increased p21CDKN1A 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 p21CDKN1A as well as by targeting genes that are down-regulated in senescent cells such as RARG.

MiR-146a as marker of senescence-associated pro-inflammatory status in cells involved in vascular remodelling

“…However, our findings clearly show that miR-146a is not involved in oxidative stress response in neither younger nor senescent HUVECs. These results are in accordance with previous data showing that robust expression of miR-146a is not associated with growth arrest or stress-induced stasis (Bhaumik et al 2009;Magenta et al 2011;Li et al 2009). We also confirmed that miR-200c and miR-141 were up-regulated in younger and senescent HUVECs in response to oxidative stress (Magenta et al 2011;Li et al 2009).…”

“…Interestingly, there was an almost 2-fold increase in up-regulated miRs compared to down-regulated ones in senescent cells. This finding is in accordance with data reported regarding in vitro cultured cells and tissues of aged animals and humans, suggesting that an over-expression of miRs might counteract the age-related increase in the expression of protein-encoding genes (Maes et al 2009;Bates et al 2010;Li et al 2009). Among the 367 profiled miRs, miR-146a, miR-9, miR-204 and miR-367 were significantly up-regulated in senescent vs. young cells with miR-146a showing the highest expression.…”

“…Several independent lines of evidence have indicated a critical role for miRs, as biomarkers of cellular senescence, in both replicative and stress-induced modulation of in vitro cellular senescence (Lafferty-Whyte et al 2009;Poliseno et al 2008;Wagner et al 2008;Li et al 2009Li et al , 2010Olivieri et al 2009). Human umbilical vein endothelial cells (HUVECs) have been extensively used as an in vitro endothelial model representing common functional and morphological features of the in vivo endothelial cells (Unterluggauer et al 2007).…”

miR-200c is upregulated by oxidative stress and induces endothelial cell apoptosis and senescence via ZEB1 inhibition

“…32 Finally, we focused on the mechanism of miR-200c induction by H 2 O 2 . We found that, miR The results of the present work and of previous studies indicate that in EC, H 2 O 2 causes pRb dephosphorylation by different mechanisms: PP2A activity, p53 and p21 increase, and also by a miR-200c-dependent mechanism involving a ZEB1-mediated upregulation of p21.…”

Targeting of Integrin β1 and Kinesin 2α by MicroRNA 183

“…We have recently found that, although miR-183 is normally expressed only at low levels in human trabecular meshwork (HTM) cells and human diploid fibroblasts (HDF), its expression increased significantly after the induction of cellular senescence by exposure to H 2 O 2 in these two different cell types (7). Because cellular senescence is recognized as an anticancer mechanism (8), this observation has led us to hypothesize that miR-183 could play a role in the phenotypic changes characteristic of senescent cells, and, in particular, those involved in preventing malignant transformation of aging cells.…”