MiR-185 targets POT1 to induce telomere dysfunction and cellular senescence
MiR-185 targets POT1 to induce telomere dysfunction and cellular senescence
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MiR-185 靶向 POT1 诱导端粒功能障碍和细胞衰老。
DOI：
10.18632/aging.103541
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发表时间：
2020-07-31
期刊：
影响因子：
5.2
通讯作者：
Huang, Yan
中科院分区：
文献类型：
--
作者：
Li, Tingting;Luo, Zhenhua;Huang, Yan
端粒1 （POT1）是庇护蛋白复合体中端粒单链DNA （ssDNA）结合蛋白，其保护作用与DNA损伤反应、肿瘤发生和衰老有关。端粒脱保护引起的端粒功能障碍可加速人原代细胞的衰老。虽然先前的研究表明了POT1在衰老和癌症中的生物学机制，但POT1是如何被转录后调节的，在很大程度上仍然未知。为了更好地了解POT1调控轴，我们进行了生物信息学预测，并通过双荧光素酶报告基因实验进一步确认了选择的候选基因。总之，我们的研究结果表明，miR-185可以通过直接靶向POT1 3 ' -非翻译区（3 ' -UTR）显著降低POT1 mRNA和蛋白水平。在癌细胞和原代人成纤维细胞中，miR-185的过表达增加了端粒功能障碍诱导的病灶（TIF）信号。在端粒酶阳性细胞系HTC75中，miR-185升高导致端粒延长，这在表型上与POT1敲低一致。此外，miR-185以pot1依赖的方式加速了原代人成纤维细胞的复制衰老过程。有趣的是，升高的血清miR-185可能代表一种潜在的与衰老相关的生物标志物。综上所述，我们的研究结果揭示了miR-185是一种针对POT1的新型衰老相关miRNA，并为细胞内和细胞外水平的端粒和衰老调节网络提供了见解。
Protection of telomere 1 (POT1), the telomeric single-stranded DNA (ssDNA)-binding protein in the shelterin complex, has been implicated in the DNA damage response, tumorigenesis and aging. Telomere dysfunction induced by telomere deprotection could accelerate cellular senescence in primary human cells. While previous work demonstrated the biological mechanism of POT1 in aging and cancer, how POT1 is posttranscriptionally regulated remains largely unknown. To better understand the POT1 regulatory axis, we performed bioinformatic prediction, and selected candidates were further confirmed by dual-luciferase reporter assay. Collectively, our results revealed that miR-185 can significantly reduce POT1 mRNA and protein levels by directly targeting the POT1 3’-untranslated region (3’-UTR). Overexpression of miR-185 increased telomere dysfunction-induced foci (TIF) signals in both cancer cells and primary human fibroblasts. Elevated miR-185 led to telomere elongation in the telomerase-positive cell line HTC75, which was phenotypically consistent with POT1 knocking down. Moreover, miR-185 accelerated the replicative senescence process in primary human fibroblasts in a POT1-dependent manner. Interestingly, increased serum miR-185 could represent a potential aging-related biomarker. Taken together, our findings reveal miR-185 as a novel aging-related miRNA that targets POT1 and provide insight into the telomere and senescence regulatory network at both the intracellular and extracellular levels.