Laboratory of Regulatory Biology, Department of Life Sciences, School of Agriculture, Meiji University, Kanagawa 214-8571, Japan.
Department of Reproductive Biology, National Research Institute for Child Health and Development, Tokyo 157-8535, Japan.
Int J Mol Sci. 2020 May 31;21(11):3961. doi: 10.3390/ijms21113961.
Semenogelin 1 (SEMG1), a main component of human seminal plasma, is a multi-functional protein involved in the regulation of sperm motility and fertility. SEMG1 is orthologous to mouse seminal vesicle secretion 2 (SVS2), required for sperm survival in the female reproductive tract after copulation; however, its in vivo function remains unclear. In this study, we addressed this issue by examining the effect of recombinant SEMG1 on intrauterine mouse sperm survival. SEMG1 caused a dose-dependent decrease in mouse sperm motility, similar to its effect on human sperm, but SVS2 had no effect on mouse sperm motility. Mouse epididymal sperm in the presence of 100 µM SEMG1, a concentration that does not affect mouse sperm motility, were injected into the mouse uterus (intrauterine insemination, IUI). IUI combined with SEMG1 significantly increased the survival rate of intrauterine mouse sperm. The effect of SEMG1 on intrauterine sperm survival was comparable with that of SVS2. For clinical applications, three potentially sperm-protecting polypeptides that are easy to handle were designed from SEMG1, but their individual use was unable to mimic the ability of SEMG1. Our results indicate that SEMG1 has potential clinical applications for effective IUI and thereby for safe, simple, and effective internal fertilization.
精浆蛋白 1（SEMG1）是人类精液中的主要成分之一，是一种多功能蛋白，参与精子运动和生育能力的调节。SEMG1 与小鼠的附囊分泌蛋白 2（SVS2）同源，后者是交配后精子在雌性生殖道中存活所必需的；然而，其体内功能尚不清楚。在这项研究中，我们通过检查重组 SEMG1 对宫内小鼠精子存活的影响来解决这个问题。SEMG1 导致小鼠精子运动呈剂量依赖性下降，这与其对人精子的影响相似，但 SVS2 对小鼠精子运动没有影响。在 100µM SEMG1 存在下，将浓度不影响小鼠精子运动的小鼠附睾精子注入小鼠子宫（宫内授精，IUI）。IUI 结合 SEMG1 显著增加了宫内小鼠精子的存活率。SEMG1 对宫内精子存活的影响可与 SVS2 相媲美。对于临床应用，从 SEMG1 设计了三个易于处理的潜在精子保护多肽，但它们各自的使用都无法模拟 SEMG1 的能力。我们的结果表明，SEMG1 具有有效的 IUI 的潜在临床应用，从而为安全、简单和有效的内部受精提供了可能。
