School of Environmental and Life Sciences, College of Engineering, Science and Environment, The University of Newcastle, University Drive, Callaghan, New South Wales, Australia.
Infertility and Reproduction Research Program, Hunter Medical Research Institute, New Lambton Heights, New South Wales, Australia.
Reprod Fertil. 2024 Oct 4;5(4). doi: 10.1530/RAF-23-0088. Print 2024 Oct 1.
Seminal fluid extracellular vesicles (SFEVs) have previously been shown to interact with spermatozoa and influence their fertilisation capacity. Here, we sought to extend these studies by exploring the functional consequences of SFEV interactions with human spermatozoa. SFEVs were isolated from the seminal fluid of normozoospermic donors prior to assessing the kinetics of sperm-SFEV binding in vitro, as well as the effects of these interactions on sperm capacitation, acrosomal exocytosis, and motility profile. Biotin-labelled SFEV proteins were transferred primarily to the flagellum of spermatozoa within minutes of co-incubation, although additional foci of SFEV biotinylated proteins also labelled the mid-piece and head domain. Functional analyses of high-quality spermatozoa collected following liquefaction revealed that SFEVs did not influence sperm motility during incubation at pH 5, yet SFEVs induced subtle increases in total and progressive motility in sperm incubated with SFEVs at pH 7. Additional investigation of sperm motility kinematic parameters revealed that SFEVs significantly decreased beat cross frequency and increased distance straight line, linearity, straightness, straight line velocity, and wobble. SFEVs did not influence sperm capacitation status or the ability of sperm to undergo acrosomal exocytosis. Functional assessment of both high- and low-quality spermatozoa collected prior to liquefaction showed limited SFEV influence, with these vesicles inducing only subtle decreases in beat cross frequency in spermatozoa of both groups. These findings raise the prospect that, aside from subtle effects on sperm motility, the encapsulated SFEV cargo may be destined for physiological targets other than the male germline, notably the female reproductive tract.
A male's influence over the biological processes of pregnancy extends beyond the provision of sperm. Molecular signals present in the ejaculate can influence the likelihood of pregnancy and healthy pregnancy progression, but the identity and function of these signals remain unclear. In this study, we wanted to understand if nano-sized particles present in the male ejaculate, called seminal fluid extracellular vesicles, can assist sperm in traversing the female reproductive tract to access the egg. To explore this, we isolated seminal fluid extracellular vesicles from human semen and incubated them with sperm. Our data showed that seminal fluid extracellular vesicles act to transfer molecular information to sperm, but this resulted in only subtle changes to the movement of sperm.
先前的研究表明，精液细胞外囊泡（SFEV）与精子相互作用，并影响其受精能力。在这里，我们试图通过探索 SFEV 与人类精子相互作用的功能后果来扩展这些研究。在体外评估精子-SFEV 结合的动力学以及这些相互作用对精子获能、顶体反应和运动特征的影响之前，从正常精子供体的精液中分离 SFEV。SFEV 蛋白在孵育的几分钟内主要转移到精子的鞭毛上，尽管 SFEV 生物素化蛋白的其他焦点也标记了中段和头部区域。对液化后收集的高质量精子进行的功能分析表明，SFEV 在 pH5 下孵育时不会影响精子运动，但 SFEV 在 pH7 下孵育时会轻微增加总运动和渐进运动。对精子运动运动学参数的进一步研究表明，SFEV 显著降低了鞭打交叉频率，增加了直线距离、直线性、直线度、直线速度和摆动。SFEV 不影响精子获能状态或精子发生顶体反应的能力。对液化前收集的高、低质量精子的功能评估表明，SFEV 的影响有限，这些囊泡仅在两组精子中轻微降低了鞭打交叉频率。这些发现表明，除了对精子运动的细微影响外，包裹的 SFEV 货物可能会被运送到除了男性生殖细胞以外的其他生理靶标，特别是女性生殖道。
男性对妊娠生物学过程的影响不仅限于提供精子。精液中存在的分子信号可以影响妊娠和健康妊娠进展的可能性，但这些信号的身份和功能仍不清楚。在这项研究中，我们想了解男性精液中存在的纳米大小的颗粒，称为精液细胞外囊泡，是否可以帮助精子穿越女性生殖道到达卵子。为了探索这一点，我们从人类精液中分离出精液细胞外囊泡，并将其与精子一起孵育。我们的数据表明，精液细胞外囊泡作用于将分子信息传递给精子，但这仅导致精子运动的细微变化。
