CHU de Québec Research Center and Department of Obstetrics and Gynecology, Laval University School of Medicine, Quebec, Canada.
Biol Reprod. 2013 Aug 15;89(2):30. doi: 10.1095/biolreprod.113.110486. Print 2013 Aug.
Epididymosomes are small membrane vesicles that are secreted by epididymal epithelial cells and are involved in posttesticular sperm maturation. Although their role in protein transfer to the sperm membrane is well documented, we report their capacity to transport microRNAs (miRNAs), which are potent regulators of posttranscriptional gene expression. Using a microperfusion technique combined with a global microarray approach, we demonstrated that epididymosomes from two discrete bovine epididymal regions (caput and cauda) possess distinct miRNA signatures. In addition, we also established that miRNA repertoires contained within epididymosomes differ from those of their parent epithelial cells, suggesting that miRNA populations released from the cells may be selectively sorted. Binding of DilC12-labeled epididymosomes to primary cultured epididymal cells was measured by flow cytometry, and the results indicated that epididymosomes from the median caput and their miRNA content may be incorporated into distal caput epithelial cells. Overall, these findings reveal that distinct miRNA repertoires are released into the intraluminal fluid in a region-specific manner and could be involved in a novel mechanism of intercellular communication throughout the epididymis via epididymosomes.
附睾小体是由附睾上皮细胞分泌的小膜泡，参与精子的后熟过程。尽管它们在蛋白质向精子膜转移中的作用已得到充分证实，但我们也报告了它们运输 microRNAs（miRNAs）的能力，miRNAs 是转录后基因表达的有效调节剂。我们使用微灌注技术结合全局微阵列方法，证明了来自两个不同牛附睾区域（头段和尾段）的附睾小体具有不同的 miRNA 特征。此外，我们还发现附睾小体内含有的 miRNA 谱与它们的亲代上皮细胞不同，这表明从细胞释放的 miRNA 群体可能被选择性分拣。通过流式细胞术测量 DilC12 标记的附睾小体与原代培养的附睾细胞的结合，结果表明，来自中间头段的附睾小体及其 miRNA 含量可能被整合到远端头段上皮细胞中。总的来说，这些发现表明，不同的 miRNA 谱以区域特异性的方式释放到腔液中，并可能通过附睾小体参与到整个附睾中一种新的细胞间通讯机制中。
