Proteins from human oviductal tissue-conditioned medium modulate sperm capacitation
Authors: Zumoffen, C.M.; Caille, A.M.; Munuce, M.J.; Cabada, M.O.; Ghersevich, S.A.
Source: Human Reproduction, Volume 25, Number 6, 8 June 2010 , pp. 1504-1512(9)
Publisher: Oxford University Press
Abstract:BACKGROUNDSpermatozoa acquire the ability to fertilize an oocyte when they become capacitated. Capacitation takes place when sperm pass through the female reproductive tract, interacting with female fluids. Both tyrosine phosphorylation of sperm proteins and the ability to respond to acrosome reaction (AR) inducers have been associated with sperm capacitation. Recent data indicate that conditioned media (CM) from human oviductal tissue culture decrease sperm affinity for the zona pellucida in vitro. Since capacitation enables the spermoocyte interaction, the aim of the present study was to investigate the effect of CM on events related to sperm capacitation and to assess whether these effects were permanent.METHODSOviductal tissue was obtained from premenopausal patients (scheduled for hysterectomies because of uterine fibromyoma). The tissues were cultured as explants and CM were collected. Explant viability was assessed as tissue DNA integrity. Normozoospermic semen samples were obtained from healthy donors. Motile spermatozoa were incubated under capacitating conditions with or without increasing protein concentrations of CM for 6 or 22 h. Human follicular fluid-induced AR was detected by the Pisum sativum technique. Tyrosine phosphorylated proteins were detected with a monoclonal anti-phosphotyrosine antibody.RESULTSThe incubation of spermatozoa in the presence of increasing concentrations of conditioned medium (CM) proteins caused a dose-dependent decrease in both tyrosine phosphorylation of sperm proteins and in the level of AR induction. When CM was removed from the sperm incubation media, the effects were reversed. Heat-inactivated CM did not affect either tyrosine phosphorylation or the induction of AR.CONCLUSIONSThe present data suggest that proteins secreted from human oviductal tissue are able to inhibit events associated with sperm capacitation in vitro.
Document Type: Research article
Publication date: 2010-06-08
- Human Reproduction features full-length, peer-reviewed papers reporting original research, clinical case histories, as well as opinions and debates on topical issues. Papers published cover the scientific and medical aspects of reproductive physiology and pathology, endocrinology, andrology, gonad function, gametogenesis, fertilization, embryo development, implantation, pregnancy, genetics, genetic diagnosis, oncology, infectious disease, surgery, contraception, infertility treatment, psychology, ethics and social issues. The highest scientific and editorial standard is maintained throughout the journal along with a rapid rate of publication.