Chk1基因在人类精子中的表达及其意义

Expression of Chk1 in human sperm and its significance

目的:探讨Chk1基因在人精子中的表达及其临床意义。方法:收集正常组、少精子组、弱精子组和少弱精子组的标本各20份,分别采用Western印迹和RT-PCR方法检测各组精子中Chk1的表达,并计算其相对表达量;采用DNA梯度法检测4组精子中DNA的损伤和梯度变化,用Annexin V/PI双染色法检测各组精子的凋亡情况。结果:Chk1基因在正常组和其他3组的精子中均有表达,Chk1在各组中表达有差异,在正常组、少精子组、弱精子组和少弱精子组的Chk1 mRNA的相对表达量分别为1.00±0.22、0.76±0.10、0.45±0.08、0.37±0.07,各组间比较差异有显著性(P<0.01)。CHK1蛋白的相对表达量与mRNA类似。DNA梯度检测显示弱精子组和少弱精子组中DNA呈现梯状条带;Annexin V/PI双染色法检测发现,与正常组相比,少精子组、弱精子组、少弱精子组和100%d级精子组中精子凋亡率明显增加[分别为(7.6±0.34)%、(8.3±0.60)%、(11.6±0.92)%、(12.5±1.43)%和(17.0±1.98)%,各组间比较P<0.05]。结论:实验证实Chk1在人类精子中有表达,且在不同患者中的表达显著不同,Chk1的表达与DNA损伤和精子凋亡之间存在相关性。即Chk1表达的减少可能导致精子DNA损伤修复功能的下降,精子凋亡增加,从而影响精液质量。

Objective：To investigate the expression of the Chk1 gene in human sperm and its clinical significance.Methods：We collected 80 semen samples and divided them into 4 groups of equal number：normal,oligospermia,asthenozoospermia and oligoasthenozoospermia.The Chk1 expression and its relative level were detected by Western blot and RT-PCR,sperm DNA damage and gradient changes assessed by DNA ladder analysis,and sperm apoptosis determined by Annexin V / PI double staining in each group.Results：The Chk1 gene was expressed in all the four groups,but with significant differences（P〈0.01）;the relative levels of CHK1 protein were similar to those of Chk1 mRNA in the normal,oligospermia,asthenozoospermia and oligoasthenozoospermia groups,which were 1.00 ± 0.22,0.76 ± 0.10,0.45 ± 0.08 and 0.37 ± 0.07,respectively.DNA ladder analysis showed a marked DNA ladder in the asthenozoospermia and oligoasthenozoospermia groups.Sperm apoptosis was markedly increased in the oligospermia,asthenozoospermia,oligoasthenozoospermia and 100% grade d sperm groups（[8.3 ± 0.60]%,[11.6 ± 0.92]%,[12.5 ± 1.43]% and [17.0 ± 1.98]%）,as compared with the normal group（[7.6 ± 0.34]%）（P〈0.05）.Conclusion：Chk1 is expressed in human sperm,but differently in different semen quality groups.And its expression is correlated with sperm DNA damage and apoptosis;its reduction may lead to declined sperm repair and increased sperm apoptosis and thus affect semen quality.