National Engineering Research Center for Breeding Swine Industry, Guangdong Provincial Key Lab of Agro-animal Genomics and Molecular Breeding, College of Animal Science of South China Agricultural University, Guangzhou, 510642, China.
National Engineering Research Center for Breeding Swine Industry, Guangdong Provincial Key Lab of Agro-animal Genomics and Molecular Breeding, College of Animal Science of South China Agricultural University, Guangzhou, 510642, China; Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Maoming, 525000, China.
Theriogenology. 2022 Oct 15;192:28-37. doi: 10.1016/j.theriogenology.2022.08.017. Epub 2022 Aug 24.
Mammalian spermatozoa acquire their fertilizing ability in the epididymis, which is important for sperm maturation and capacitation. Carboxypeptidase E (CPE) is a prohormone-processing enzyme and sorting receptor that functions intracellularly. Recently, CPE was identified to exist in the seminal plasma. However, little is known about the effects of CPE on reproductive function. This study focused on the effects of CPE on sperm function and fertilization. Herein, CPE was identified to be localized in the boar sperm, testis, epididymis, accessory gonad and seminal plasma, with high expression found in the bulbourethral glands and cauda epididymis. Furthermore, compared with high motility spermatozoa, a decrease in CPE abundance was observed in low motile spermatozoa by Western blot analysis. The use of specific antibody to inhibit the CPE in spermatozoa led to a decrease in sperm motility, followed by an expected decrease in acrosome exocytosis and tyrosine phosphorylation in the capacitation process. These changes were accompanied by a decrease in intracellular Ca ([Ca]) influx, which resulted in a significant decrease in the cleavage rate during in vitro fertilization (IVF). Based on these observations, we suggest that CPE might affect porcine sperm Ca influx to participate in the regulation of sperm function during capacitation.
哺乳动物精子在附睾中获得受精能力，这对于精子成熟和获能非常重要。羧肽酶 E (CPE) 是一种激素前体加工酶和分选受体，在细胞内发挥作用。最近，CPE 被鉴定存在于精液中。然而，关于 CPE 对生殖功能的影响知之甚少。本研究集中于 CPE 对精子功能和受精的影响。本文鉴定到 CPE 定位于公猪精子、睾丸、附睾、附性腺和精液中，在尿道球腺和附睾尾部表达量较高。此外，与高活力精子相比，Western blot 分析显示低活力精子中 CPE 丰度降低。使用特异性抗体抑制精子中的 CPE 导致精子运动能力下降，随后在获能过程中顶体反应和酪氨酸磷酸化预期下降。这些变化伴随着细胞内 Ca([Ca])内流减少，导致体外受精 (IVF) 过程中的卵裂率显著下降。基于这些观察结果，我们认为 CPE 可能通过影响猪精子 Ca 内流来参与调节获能过程中的精子功能。
