miR-377 induces senescence in human skin fibroblasts by targeting DNA methyltransferase 1.
miR-377 induces senescence in human skin fibroblasts by targeting DNA methyltransferase 1.
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miR-377 通过靶向 DNA 甲基转移酶 1 诱导人皮肤成纤维细胞衰老
DOI：
10.1038/cddis.2017.75
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发表时间：
2017-03-09
影响因子：
9
通讯作者：
Li J
中科院分区：
文献类型：
--
作者：
Xie HF;Liu YZ;Du R;Wang B;Chen MT;Zhang YY;Deng ZL;Li J
皮肤老化是一个复杂的生理过程，表观遗传特征，包括微rna介导的调控和DNA甲基化，已被证明有助于这一过程。DNA甲基化是由DNA甲基转移酶调控的，其中DNA甲基转移酶1 （DNMT1）最为人所知。但支持其在皮肤衰老中的作用的证据仍然很少，迄今为止还没有报道涉及其在皮肤衰老过程中具体的上游调节分子。在这里，我们发现DNMT1在年轻的人皮肤成纤维细胞（hsf）中的表达明显高于传代衰老的hsf，并且DNMT1敲低显著诱导年轻hsf的衰老表型。我们利用miRNA数据库预测了能够调控DNMT1的上游miRNA，发现miR-377与人类DNMT1 mRNA的3′-UTR序列具有高度同源性。我们通过荧光素酶报告基因检测证实了miR-377是DNMT1的潜在调节因子。miR-377在传代老龄hsf中的表达明显高于年轻hsf。miR-377过表达可促进年轻hsf的衰老，抑制miR-377可降低传代老化hsf的衰老。此外，这些功能是通过靶向DNMT1介导的。对24个衰老相关基因启动子的微流控PCR和下一代亚硫酸盐测序显示，在miR-377模拟物或抑制剂处理的hsf中，FoxD3、p53和UTF1的启动子甲基化水平发生了变化。我们还验证了mir -377介导的p53表达变化可以通过调节hsf中的DNMT1来逆转。同样，在年轻和光老化的hsf、hsf或来自不同年龄供体的未暴露紫外线区域的皮肤组织中，miR-377和DNMT1表达呈负相关。我们的研究结果强调了miR-377-DNMT1-p53轴在HSF衰老中的新作用。这些发现揭示了皮肤老化的机制，并确定了未来的治疗预防机会。
Skin aging is a complicated physiological process and epigenetic feature, including microRNA-mediated regulation and DNA methylation, have been shown to contribute to this process. DNA methylation is regulated by DNA methyltransferase, of which DNA methyltransferase 1 (DNMT1) is the most abundantly known. But evidence supporting its role in skin aging remains scarce, and no report regards its specifical upstream-regulating molecules in the process of skin aging so far. Here, we found that DNMT1 expression was markedly higher in young human skin fibroblasts (HSFs) than that in passage-aged HSFs, and DNMT1 knockdown significantly induced the senescence phenotype in young HSFs. We predicted the upstream miRNAs which could regulate DNMT1 with miRNA databases and found miR-377 had high homology with a sequence in the 3′-UTR of human DNMT1 mRNA. We confirmed that miR-377 was a potential regulator of DNMT1 by luciferase reporter assays. miR-377 expression in passage-aged HSFs was markedly higher than that in the young HSFs. miR-377 overexpression promoted senescence in young HSFs, and inhibition of miR-377 reduced senescence in passage-aged HSFs. Moreover, these functions were mediated by targeting DNMT1. Microfluidic PCR and next-generation bisulfite sequencing of 24 senescent-associated genes’ promoters revealed alterations of the promoter methylation levels of FoxD3, p53, and UTF1 in HSFs treated with miR-377 mimics or inhibitors. We also verified that the miR-377-mediated changes in p53 expression could be reversed by regulation of DNMT1 in HSFs. Similarly, there was a negative correlation between miR-377 and DNMT1 expression in young and photoaged HSFs, HSFs, or skin tissues from UV-unexposed areas of different aged donors. Our results highlight a novel role for miR-377-DNMT1-p53 axis in HSF senescence. These findings shed new light on the mechanisms of skin aging and identify future opportunities for its therapeutic prevention.