ABSTRACT

The role of epigenetics in endothelial cell senescence is a cutting-edge topic in ageing research. However, little is known of the relative contribution to pro-senescence signal propagation provided by microRNAs shuttled by extracellular vesicles (EVs) released from senescent cells. Analysis of microRNA and DNA methylation profiles in non-senescent (control) and senescent (SEN) human umbilical vein endothelial cells (HUVECs), and microRNA profiling of their cognate small EVs (sEVs) and large EVs demonstrated that SEN cells released a significantly greater sEV number than control cells. sEVs were enriched in miR-21-5p and miR-217, which target DNMT1 and SIRT1. Treatment of control cells with SEN sEVs induced a miR-21/miR-217-related impairment of DNMT1-SIRT1 expression, the reduction of proliferation markers, the acquisition of a senescent phenotype and a partial demethylation of the locus encoding for miR-21. MicroRNA profiling of sEVs from plasma of healthy subjects aged 40–100 years showed an inverse U-shaped age-related trend for miR-21-5p, consistent with senescence-associated biomarker profiles. Our findings suggest that miR-21-5p/miR-217 carried by SEN sEVs spread pro-senescence signals, affecting DNA methylation and cell replication.

摘要

表观遗传学在内皮细胞衰老中的作用是衰老研究的前沿课题。然而，关于由衰老细胞释放的细胞外小泡（EV）穿梭的微小RNA对促衰老信号传播的相对贡献知之甚少。分析非衰老（对照）和衰老（SEN）人脐静脉内皮细胞（HUVEC）中的microRNA和DNA甲基化谱，并对它们的同类小型EV（sEV）和大型EV进行microRNA分析，结果表明SEN细胞释放出明显更高的sEV数比对照电池多。sEV富含针对DNMT1和SIRT1的miR-21-5p和miR-217。用SEN sEV处理对照细胞会诱导DNMT1-SIRT1表达的miR-21 / miR-217相关损伤，增殖标志物的减少，衰老表型的获得和编码miR-21的基因座的部分去甲基化。来自40-100岁健康受试者血浆中sEV的MicroRNA分析显示，miR-21-5p与年龄相关的趋势呈倒U型，与衰老相关的生物标志物特征一致。我们的发现表明，SEN sEV携带的miR-21-5p / miR-217会传播衰老前信号，从而影响DNA甲基化和细胞复制。