Department of Medicine and Animal Surgery, Veterinary Science, University of Murcia, Murcia, Spain.
Exosomes Laboratory, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Derio, Vizcaya, Spain.
Sci Rep. 2024 Jul 13;14(1):16175. doi: 10.1038/s41598-024-67229-w.
Seminal plasma (SP) is rich in extracellular vesicles (EVs), which are still poorly studied, especially in livestock species. To better understand their functional role in both spermatozoa and endometrial epithelial cells, proper characterization of EVs is an essential step. The objective was to phenotypically characterize porcine seminal EVs (sEVs) using cryogenic electron microscopy (cryo-EM), which allows visualization of EVs in their native state. Porcine ejaculates are released in fractions, each containing SP from different source. This allows characterization sEVs released from various male reproductive tissues. Two experiments were performed, the first with SP from the entire ejaculate (n:6) and the second with SP from three ejaculate fractions (n:15): the first 10 mL of the sperm-rich ejaculate fraction (SRF-P1) with SP mainly from the epididymis, the remainder of the SRF (SRF-P2) with SP mainly from the prostate, and the post-SRF with SP mainly from the seminal vesicles. The sEVs were isolated by size exclusion chromatography and 1840 cryo-EM sEV images were acquired using a Jeol-JEM-2200FS/CR-EM. The size, electron density, complexity, and peripheral corona layer were measured in each sEV using the ImageJ software. The first experiment showed that sEVs were structurally and morphologically heterogeneous, although most (83.1%) were small (less than 200 nm), rounded, and poorly electrodense, and some have a peripheral coronal layer. There were also larger sEVs (16.9%) that were irregularly shaped, more electrodense, and few with a peripheral coronal layer. The second experiment showed that small sEVs were more common in SRF-P1 and SRF-P2, indicating that they originated mainly from the epididymis and prostate. Large sEVs were more abundant in post-SRF, indicating that they originated mainly from seminal vesicles. Porcine sEVs are structurally and morphologically heterogeneous. This would be explained by the diversity of reproductive organs of origin.
精浆 (SP) 富含细胞外囊泡 (EVs),但对其研究甚少,尤其是在牲畜物种中。为了更好地了解它们在精子和子宫内膜上皮细胞中的功能作用,对 EVs 进行适当的表征是至关重要的一步。本研究的目的是使用低温电子显微镜 (cryo-EM) 对猪精液 EVs (sEVs) 进行表型特征分析,cryo-EM 允许在其天然状态下观察 EVs。猪精液被释放为不同的部分,每个部分都含有来自不同来源的 SP。这允许对来自不同雄性生殖组织的 sEVs 进行特征分析。进行了两项实验,第一项是使用整个精液的 SP (n:6),第二项是使用三个精液部分的 SP (n:15):富含精子的精液部分的前 10 毫升 (SRF-P1),其 SP 主要来自附睾,其余的 SRF (SRF-P2) 主要来自前列腺,以及剩余的 SRF (post-SRF),其 SP 主要来自精囊。通过大小排阻色谱法分离 sEVs,使用 Jeol-JEM-2200FS/CR-EM 获得 1840 个 cryo-EM sEV 图像。使用 ImageJ 软件在每个 sEV 中测量其大小、电子密度、复杂性和外周冠状层。第一项实验表明,sEVs 在结构和形态上是异质的,尽管大多数 (83.1%) 是小的 (小于 200nm)、圆形的和电子密度低的,并且一些具有外周冠状层。也有一些较大的 sEVs (16.9%) 形状不规则,电子密度更高,很少有外周冠状层。第二项实验表明,小 sEVs 在 SRF-P1 和 SRF-P2 中更为常见,表明它们主要来源于附睾和前列腺。大 sEVs 在 post-SRF 中更为丰富,表明它们主要来源于精囊。猪 sEVs 在结构和形态上是异质的。这可以解释为起源于不同生殖器官的多样性。