Department of Biology, Kyung Hee University, Seoul 02447, Korea.
Cells. 2021 Oct 22;10(11):2848. doi: 10.3390/cells10112848.
Exosomes participate in intercellular communication by transferring molecules from donor to recipient cells. Exosomes are found in various body fluids, including blood, urine, cerebrospinal fluid and milk. Milk exosomes contain many endogenous microRNA molecules. MicroRNAs are small noncoding RNAs and have important roles in biological processes. The specific biological functions of milk exosomes are not well understood. In this study, we investigated the effects of milk exosomes on melanin production in melanoma cells and melanocytes. We found that milk exosomes decreased melanin contents, tyrosinase activity and the expression of melanogenesis-related genes in melanoma cells and melanocytes. Bovine-specific miR-2478 in exosomes inhibited melanin production. We found that Rap1a is a direct target gene of miR-2478 in melanoma cells and melanocytes. MiR-2478 overexpression decreased Rap1a expression, which led to downregulated melanin production and expression of melanogenesis-related genes. Inhibition of Rap1a expression decreased melanogenesis through the Akt-GSK3β signal pathway. These results support the role of miR-2478 derived from milk exosomes as a regulator of melanogenesis through direct targeting of Rap1a. These results show that milk exosomes could be useful cosmeceutical ingredients to improve whitening.
外泌体通过将分子从供体细胞转移到受体细胞来参与细胞间通讯。外泌体存在于各种体液中，包括血液、尿液、脑脊液和乳汁。乳泌体中含有许多内源性 microRNA 分子。miRNA 是小的非编码 RNA，在生物过程中具有重要作用。乳泌体的具体生物学功能尚不清楚。在这项研究中，我们研究了乳泌体对黑色素瘤细胞和黑素细胞中黑色素生成的影响。我们发现乳泌体减少了黑色素瘤细胞和黑素细胞中的黑色素含量、酪氨酸酶活性和黑色素生成相关基因的表达。乳泌体中的牛特异性 miR-2478 抑制黑色素生成。我们发现 Rap1a 是黑色素瘤细胞和黑素细胞中 miR-2478 的直接靶基因。miR-2478 的过表达降低了 Rap1a 的表达，导致黑色素生成和黑色素生成相关基因的表达下调。Rap1a 表达的抑制通过 Akt-GSK3β 信号通路减少了黑色素生成。这些结果支持了源自乳泌体的 miR-2478 通过直接靶向 Rap1a 作为黑色素生成调节剂的作用。这些结果表明，乳泌体可以作为一种有用的化妆品成分，通过改善美白来提高美白效果。
