Ultraviolet radiation (UVR) can play two roles: induce cellular senescence and convert skin melanocytes into melanoma. To assess whether this conversion might rely on melanocytes having to first acquire a senescent phenotype, we studied the effects of physiological doses of UVR (UVA + UVB) on quiescent melanocytes in vitro. Repeated doses of UVR induced these melanocytes into a senescent‐like state. Additionally, these cells secrete exosomes with specific miRNAs that differ in quantity from those of the un‐irradiated melanocytes. Many of the exosomal miRNAs that were differentially enriched regulated genes comprising a “senescence core signature” and encoding factors of the senescence‐messaging secretome (SASP), while a subset of the differentially reduced miRNAs targeted DNA repair genes that have been experimentally shown to be repressed in senescent melanocytes. Thus, the selection of specific miRNAs by exosomes and their release from melanocytes after exposure to UVR have activities in inducing these cells into premature senescence.

中文翻译：

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暴露于太阳UVR后人类黑素细胞的过早衰老：一种外来体与UV-miRNA的连接。

紫外线（UVR）可以发挥两个作用：诱导细胞衰老并将皮肤黑素细胞转化为黑色素瘤。为了评估这种转化是否可能依赖于必须先获得衰老表型的黑素细胞，我们研究了生理剂量的UVR（UVA + UVB）对体外静止黑素细胞的影响。重复剂量的UVR诱导这些黑素细胞进入衰老状。此外，这些细胞分泌具有特定miRNA的外泌体，其数量与未照射的黑素细胞不同。许多外泌体miRNA是差异富集的调控基因，包括“衰老核心特征”和衰老信息传递分泌蛋白（SASP）的编码因子，而差异减少的miRNA的一个子集则以DNA修复基因为靶标，该基因已通过实验证明在衰老的黑素细胞中受到抑制。因此，外泌体对特定miRNA的选择及其在暴露于UVR后从黑素细胞中释放具有诱导这些细胞过早衰老的活性。