Fas/FasL基因和蛋白表达对精子浓度和活力的影响

Impacts of the expressions of Fas and FasL mRNA and proteins on sperm concentration and motility

目的:探讨精液中细胞凋亡Fas/FasL基因和蛋白的表达对精子浓度和活力的影响。方法:将精液标本根据精子浓度和前向运动精子百分率分为4组:正常精子组、弱精子症组、少精子症组和少弱精子症组,每组20例。分别检测各组精液常规参数、Fas/FasL蛋白浓度、Fas/FasL基因表达水平。结果:(1)4组精子的浓度(×10^(6)/ml)分别为68.11±35.49、92.21±60.96、8.55±2.82、5.96±3.80;4组精子的前向运动精子百分率(%)为:49.40±13.86、22.12±7.13、40.77±8.41、14.53±9.74;(2)ELISA法检测4组精子Fas蛋白水平(pg/ml)分别为:381.07±52.37、425.03±50.56、442.32±84.88、448.42±84.79,与正常组比较均偏高,有统计学差异(P<0.05),与精子浓度呈负相关关系(r=-0.377,P<0.01),与前向运动精子呈负相关关系(r=-0.350,P<0.01);Fasl蛋白水平(pg/ml)分别为:167.49±29.91、166.98±27.39、169.51±32.62、171.46±32.61,与正常组比较无统计学差异(P>0.05);(3)RT-PCR方法检测4组的Fas基因的相对定量结果分别是:1、0.88±1.17、2.55±2.11、0.69±0.90,与正常组比较,弱精子症组和少弱精子症组的Fas基因表达下调,精子活力较低的样本中Fas基因表达较低;FasL基因的结果分别是:1、1.99±1.81、2.08±2.06、2.03±2.23,与正常组比较,少精子症组和少弱精子症组FasL基因表达上调,精子浓度较低的样本FasL基因表达较高;与正常组比较,弱精子症组Fas、FasL表达均下调,少精子症组Fas、FasL表达均上调,而少弱精子症组Fas表达下调,FasL表达上调。前向运动精子(PR%)与Fas mRNA基因呈正相关关系(r=0.355,P=0.01);精子总活力(PR+NR%)与Fas mRNA基因呈正相关关系(r=0.358,P<0.01);精子浓度与FasL mRNA基因表达呈负相关关系(r=-0.305,P<0.05);其余指标无明显相关关系。结论:Fas/FasL在正常、弱精子、少精子和少弱精子症组的表达水平有差异,Fas/FasL表达上调可能促进了生精细胞和精子细胞的凋亡,这可能是少精子症的发生的原因之一,而Fas/FasL表达下调可能是生长异常的生精细胞和精子细胞没有即时执行程序性死亡,这可能是弱精子症发生的原因之一。

Objective:To investigate the influence of the expressions of apoptosis-related Fas and FasL mRNA and proteins on sperm concentration and motility.Methods:We collected semen samples from 80 adult males and divided them into four groups of an equal number according to sperm concentration and the percentage of progressively motile sperm(PMS):normal,asthenospermia(AS),oligozoospermia(OS)and oligoasthenospermia(OAS).We examined the routine semen parameters,the levels of Fas and FasL proteins and the expressions of Fas and FasL genes in different groups.Results:The sperm concentrations in the normal,AS,OS and OAS groups were(68.11±35.49),(92.21±60.96),(8.55±2.82)and(5.96±3.80)×10^(6)/ml,respectively,and the percentages of PMS were(49.40±13.86)%,(22.12±7.13)%,(40.77±8.41)%and(14.53±9.74),respectively.The Fas protein level was significantly higher in the AS,OS and OAS than in the normal group([425.03±50.56],[442.32±84.88]and[448.42±84.79]vs[381.07±52.37]pg/ml,P<0.05),correlated negatively with sperm concentration(r=-0.377,P<0.01)and PMS(r=-0.350,P<0.01),but exhibited no statistically significant differences between the former three and latter group([166.98±27.39],[169.51±32.62]and[171.46±32.61]vs[167.49±29.91]pg/ml,P>0.05).The relative levels of the Fas gene in the normal,AS,OS and OAS groups were 1,(0.88±1.17),(2.55±2.11)and(0.69±0.90)respectively,lower in the AS and OAS than in the normal group,and positively correlated with sperm motility;those of the FasL gene were 1,(1.99±1.81),(2.08±2.06)and(2.03±2.23)respectively,higher in the OS and OAS than in the normal group,and negatively correlated with sperm motility.Compared with the normal group,the expressions of Fas and FasL were down-regulated in the AS but up-regulated in the OS group;the expression of Fas,however,was down-regulated and that of FasL up-regulated in the OAS group.The expression of Fas mRNA was positively correlated with the percentage of PMS(r=0.355,P=0.01)and total sperm motility(r=0.358,P<0.01),while sperm concentration negatively correlated with the expression FasL mRNA(r=-0.305,P<0.05).There was no significant correlation between the other parameters.Conclusion:Fas and FasL are differentially expressed in normal,asthenospermia,oligozoospermia and oligoasthenospermia males.Their up-regulated expressions may promote the apoptosis of spermatogenic and sperm cells and induce oligozoospermia,while their down-regulated expressions may indicate the failure of abnormal spermatogenic and sperm cells to immediately undergo programmed death,which can be one of the causes of asthenospermia.