大肠埃希菌体外感染对人精子运动参数、超微结构和细胞凋亡的影响

Effects of Escherichia coli infection on the motility,ultrastructure,and apoptosis of human sperm in vitro

目的研究体外大肠埃希菌感染对人精子运动功能、超微结构和细胞凋亡的影响,寻找男性不育原因,为诊断和治疗病原微生物感染所致男性不育提供依据。方法取30名健康青年男性精液,制备精子悬液,分为A、B、C、D 4组:未处理的精子悬液作为A组(空白对照),大肠埃希菌悬液与精子悬液混合液为B组,中药清利生精丸处理的大肠埃希菌与精子混合液为C组,呋喃坦啶处理的大肠埃希菌与精子混合液为D组,分别在0、2、4h用CASA系统分析各组精子参数,用透射电镜观察精子超微结构,用FITC-AnnenixV/PI双色荧光染色结合流式细胞技术检测精子凋亡情况。结果 B组在4h时精子前向运动百分率、VSL、VCL、VAP、ALH等运动参数均显著下降,与其他各组比较差异有统计学意义(P<0.01);电镜下观察对照组和用药物处理组精子超微结构无明显改变,B组精子超微结构出现明显改变;B组精子细胞凋亡增加,凋亡率与其他各组比较差异有统计学意义(P<0.01)。结论大肠埃希菌体外感染可显著抑制精子运动,导致细胞超微结构异常、细胞凋亡率增高。推测大肠埃希菌感染可能是导致男性不育的原因之一。

Objective The effects of Escherichia coli on the motility, ultrastructure, and apoptosis of human sperm in vitro were studied in order to identify the cause of male infertility and facilitate diagnosis and therapy for male infertility caused by pathogenic infections. Methods Semen samples were obtained from 30 healthy volunteers. Four groups of sperm suspensions were prepared： a normal sperm suspension serving as negative control （Group A）, a sperm suspension mixed with suspended E. coli （Group B）, a sperm suspension mixed with suspended E. coli treated with traditional Chi- nese medicine （Group C）, and a sperm suspension mixed with suspended E. coli treated with furadantin （Group D）. These samples were collected at 0, 2, and 4 h. Motility parameters were analyzed using a computer-aided semen analysis （CASA） system. Changes in the ultrastructure of human sperm were observed with transmission electron microscopy. The rate of apoptosis of semen sperm was detected with flow cytometry combined with FITC-Annexin V/PI dual color fluorescence staining. Results Group 13 had significantly lower motility parameters, including straight line velocity （VSL）, curve velocity （VCL）, average path velocity （VAP）, amplitude of lateral head displacement （ALH）, and pro- gressive motility, in comparison to the other groups at 4h （P〈0.01）. There were no significant differences in the ultra- structure of sperm in the control group （A） and groups treated with medicine （C and D）, while there were significant changes in the ultrastructure of sperm in Group B. In addition, the rate of sperm apoptosis increased significantly （P〈 0.01） in Group B. Conclusion E. coli significantly inhibited sperm motility, changed the ultrastructure of sperm, and increased the rate of apoptosis of sperm in vitro. Therefore, E. coli infection may be one cause of male infertility.