HOTAIR与DNMT1相互作用在皮肤细胞衰老中的机制研究

已有研究表明衰老的发生可能受到了长链非编码RNA的调节。我们的预实验发现HOTAIR在自然衰老和传代衰老的皮肤角质形成细胞和成纤维细胞中表达均上升，抑制HOTAIR能减轻细胞的衰老表型；同时，发现HOTAIR能负向调控DNA甲基转移酶1（DNMT1）的表达，且DNMT1沉默后能明显促进HOTAIR的表达。本研究中，我们将先明确HOTAIR在皮肤细胞衰老中的作用，再利用RNA沉降技术及DNA甲基化谱等技术探讨HOTAIR通过DNMT1在细胞衰老过程中的作用机制；再通过重亚硫酸氢盐测序等方法了解DNMT1对HOTAIR表达量及基因启动子甲基化水平的调节，以明确DNMT1对HOTAIR的作用机制；最后利用HOTAIR基因敲除鼠和表皮条件性DNMT1基因敲除鼠，在体内验证上述现象。本研究的最终目的在于明确HOTAIR在皮肤细胞衰老中的作用和机制，为探索皮肤衰老的机制和治疗方法提供新的方向。

Several studies have demonstrated that long non-coding RNA could regulate aging. Our preliminary experiments showed that expression of lncRNA-HOTAIR increased in the senescent keratinocytes and skin fibroblasts. Senescence phenotype was alleviated dramaticlly after HOTAIR inhibition in cells. At the same time, we also found that HOTAIR repressed DNMT1 expression and interestingly, expression of HOTAIR increased after silence of DNMT1. In our present study, we will firstly explore the role of HOTAIR in the senescence of skin cells. Then, we will investigate the mechanism of how HOTAIR effect on DNMT1 expression and cellular senescence by using RNA pull-down, DNA methylation profiling, et al. Moreover, the regulation of DNMT1 in expression level and methylated level of HOTAIR promoter are to be further studied by bisulfite sequencing. Finally, we will verify the phenomenon above in vivo by establishing transgenic mice. Our study aims to explore the mechanism of HOTAIR-DNMT1 interaction on the senescence of skin cells and provide a new direction and target gene in the research field and therapeutic field of skin aging.