Unità di Biologia Vascolare e Medicina Rigenerativa, Centro Cardiologico Monzino (CCM), IRCCS, Milano, Italy.
Unità di Cardio-Oncologia Sperimentale e Invecchiamento Cardiovascolare, Centro Cardiologico Monzino (CCM), IRCCS, Milano, Italy.
J Mol Cell Cardiol. 2015 Apr;81:62-70. doi: 10.1016/j.yjmcc.2015.01.012. Epub 2015 Jan 29.
Age-associated cardiovascular diseases are at least partially ascribable to vascular cell senescence. Replicative senescence (RS) and stress-induced premature senescence (SIPS) are provoked respectively by endogenous (telomere erosion) and exogenous (H2O2, UV) stimuli resulting in cell cycle arrest in G1 and G2 phases. In both scenarios, mitochondria-derived ROS are important players in senescence initiation. We aimed to define whether a mtDNA-transcribed long-non-coding-RNA (lncRNA), ASncmtRNA-2, has a role in vascular aging and senescence. Aortas of old mice, characterized by increased senescence, showed an increment in ASncmtRNA-2 expression. In vitro analysis of Endothelial Cells (EC) and Vascular Smooth Muscle Cells (VSMC) established that ASncmtRNA-2 is induced in EC, but not in VSMC, during RS. Surprisingly, ASncmtRNA-2 is not upregulated in two different EC SIPS scenarios, treated with H2O2 and UV. The p16 gene displayed similar ASncmtRNA-2 expression patterns, suggesting a possible co-regulation of the two genes. Interestingly, the expression of two miRNAs, hsa-miR-4485 and hsa-miR-1973, with perfect homology to the double strand region of ASncmtRNA-2 and originating at least in part from a mitochondrial transcript, was induced in RS, opening to the possibility that this lncRNA functions as a non-canonical precursor of these miRNAs. Cell cycle analysis of EC transiently over-expressing ASncmtRNA-2 revealed an accumulation of EC in the G2/M phase, but not in the G1 phase. We propose that ASncmtRNA-2 in EC might be involved in the RS establishment by participating in the cell cycle arrest in G2/M phase, possibly through the production of hsa-miR-4485 and hsa-miR-1973. This article is part of a Special Issue entitled: Mitochondria.
与年龄相关的心血管疾病至少部分归因于血管细胞衰老。复制性衰老(RS)和应激诱导的早衰(SIPS)分别由内源性(端粒磨损)和外源性(H2O2、UV)刺激引起,导致细胞周期停滞在 G1 和 G2 期。在这两种情况下,线粒体来源的 ROS 是衰老起始的重要参与者。我们旨在确定是否有一种 mtDNA 转录的长非编码 RNA(lncRNA),ASncmtRNA-2,在血管衰老和衰老中起作用。具有增加的衰老特征的老年小鼠的主动脉显示出 ASncmtRNA-2 表达的增加。体外分析内皮细胞(EC)和血管平滑肌细胞(VSMC)表明,ASncmtRNA-2 在 RS 期间在 EC 中诱导,但不在 VSMC 中诱导。令人惊讶的是,在两种不同的 EC SIPS 情况下,用 H2O2 和 UV 处理,ASncmtRNA-2 没有上调。p16 基因显示出类似的 ASncmtRNA-2 表达模式,表明这两个基因可能存在共同调节。有趣的是,两个 miRNA,hsa-miR-4485 和 hsa-miR-1973 的表达与 ASncmtRNA-2 的双链区具有完美的同源性,并且至少部分来源于线粒体转录物,在 RS 中被诱导,这为该 lncRNA 作为这些 miRNA 的非典型前体发挥作用的可能性打开了大门。瞬时过表达 ASncmtRNA-2 的 EC 的细胞周期分析显示,EC 积累在 G2/M 期,但不在 G1 期。我们提出,EC 中的 ASncmtRNA-2 可能通过参与 G2/M 期的细胞周期阻滞而参与 RS 的建立,可能通过产生 hsa-miR-4485 和 hsa-miR-1973 来实现。本文是题为“线粒体”的特刊的一部分。