Influence of human sperm motility and cryopreservation on the oocyte activating factor phospholipase C zeta

Abstract

OBJECTIVE:Phospholipase C zeta (PLCz) is considered to be the sperm-borne factor responsible for successful mammalian oocyte activation. Absence, abnormal expression or defective functional forms of PLCz have been linked to oocyte activation deficiency and failed fertilization. As such, PLCz could be used as a biomarker of human male infertility. DESIGN:This study was implemented to determine the proportion and specific pattern of PLCz localization in sperm and to examine the effect of motile sperm selection (experiment A) and sperm cryopreservation (experiment B). MATERIALS & METHODS:Fresh semen samples of proven oocyte activation capacity were obtained from 17 patients with informed written consent. For experiment A, processed sperm from 14 patients was either used directly for PLCz immunofluorescence or after selecting exclusively motile sperm by a swim-out procedure. For experiment B, selected motile sperm from 3 patients was stained either fresh or after freezing-thawing of the native sample. A new affinity purified polyclonal antibody was used which specifically recognizes the full-length PLCz. Only acrosome-intact sperm were analyzed by laser scanning confocal microscopy. Group comparisons were performed with the Wilcoxon rank test and a P-value of 0.05 was considered statistically significant.

PLCζ, WBP2NL and TNF-α expression in spermatozoa is associated with stallion fertility and seminal quality?

“…PLCζ was already observed in the soluble fractions of sperm from mice ( Saunders et al, 2002 ), humans ( Heindryck et al, 2012 ) pigs ( Kaewmala et al, 2012 ), cats ( Villaverde, 2010 ), and horses ( Bedford-Guaus et al, 2011 ). In equine species, this gene is expressed over the acrosome, equatorial segment, head-midpiece junction, and the principal piece of the flagellum ( Bedford-Guaus et al, 2011 ).…”

“…Based on this observation, it was hypothesized that PLCζ might play a role in processes other than oocyte activation, such as hyperactivation ( Bedford-Guaus et al, 2012 ). Hyperactivation is a possible explanation to the positive correlation of PLCζ expression with TM; PLCζ expression correlates with sperm motility in men ( Heindryck et al, 2012 ). No correlation was observed between PLCζ expression and velocity parameters (VAP, VSL, VCL) and ALH; these results agree with the observed previously ( Barrier Battut et al, 2016 ), which detected no correlation between the same parameters and fertility.…”