The Expression Of Attractin In Infertile Men And The Possible Mechanisms

Objective: To explore the correlation between Attractin and male infertility by thereasearch on the distribution and expression of Attractin in testes of infertile men.Methods: To observe the distribution of Attractin, testicular tissues of fertile and infertilemen were fixed and prepared separately for HE stain, immunohistochemical andimmunofluorescent assay. Q-PCR was adopted to detect Atrractin mRNA and itshomologen Attractin likel mRNA in testicular tissues. The expression of Attractin weremeasured in fertile and infertile male groups by western blotting.Results: Immunohistochemical and immunofluorescent assay showed that Attractin wasdiffusely expressed in testis, mainly on cell membrane and in cytoplasm, with a higherintensity on the membrane. Leydig cells, Sertoli cells, spermatogonia, spermatocytes andspermatozoa were all Attractin positive. Q-PCR revealed that the level of Attractin mRNAand Attractin likel mRNA was positively correlated with male fertility--highest in fertilegroup while lowest in primary non-obstructive azoospermia group(P<0.05).The same resultwas also observed in western blotting that Attractin was strongly expressed in fertile groupbut weakly in primary non-obstructive azoospermia group.Conclusions: Attractin was widely expressed in human testis and closely related to maleinfertility, but the mechanism is yet to be further studied. Objective: To further explore the relationship between Attractin and male fertility bycomparing with its level in semen among normal、oligo/asthenospermia and azoospermiagroups.Methods: Seminal plasma（SP) and sperm extraction(SE) were obtained by centrifugationfrom semen. Attractin protein level was assessed using Western blotting，while AttractinmRNA and Attractin likel mRNA expression was measured by Q-PCR in different groups.Results: The existence of Attractin protein was proved in human’s semen，both in seminalfluid and sperm extraction by Western blotting, the level of Attractin was higher in seminalfluid and lower in sperm extraction. In the seminal plasma of three group, the level ofAttractin is highest in normalspermia group while lowest in azoospermia group. It wasproved by Western blotting that in sperm extractin the level of Attractin protein is higherin normalspermia group than in oligo/asthenospermia group and the difference issignificant. Q-PCR revealed that Attractin mRNA and Attractin likel mRNA was expressedhigher in normalspermia group than in oligo/asthenospermia group in sperm extraction.Conclusions: Attractin was exist both in seminal fluid and in sperm extraction, which iscorrelated with the semen quality. Objective: To test if Attractin interferes with cell apoptosis and cytokines, and if it wasconsistent with animal research.Methods：Apoptosis level was assessed by TUNNEL and detecting apotosis associatedprotein Caspase2,3,6, Bcl-2,FAS and SOD1in testicular tissues obtained from maleinfertility groups. Attractin level in seminal plasma was assesed by Western bltting whileIL-2,IL6,TNF-α in seminal plasma were measured by ELISA. The relationship betweenAttractin and the above molecules was studied.Results： Apoptosis level in infertile males is obviously high by TUNNEL.Apoptosis-related factors Caspase2,3,6and FAS were lowest in azoospermia group, highestin normalspermia group which have oppsite trend with Attractin, apoptosis inhibitorsBcl-2,SOD2were highest in azoospermia group, lowest in normalspermia group whichhave same trend with Attractin; IL-2,IL-6,TNF-α were slightly expressed in fertileseminal plasma but strongly expressed in infertile group, which were not accordance withAttractin.Conclusions：Above results led us to speculate that Attractin not related to changes ofcytokines in seminal plasma, maybe it interferes with male fertility mainly throughregulating cell apoptosis and oxidative stress in male gonad-testis.