酞酸酯类暴露和Fas/FasL基因遗传变异与男性生殖损害的相关性研究

Reproductive toxicology studies have suggested that phthalates and their metabolites can cause reproductive and developmental toxicity such as injury of germ cell, interference with the endocrine systems, reduction in semen quality as well as induction of spermatogenic cell apoptosis by changes in Fas and FasL expression. However, the findings from epidemiological studies whether human exposure to phthalates cause male reproductive harm are not consistent. In the present study, a cross-sectional epidemiological study will be conducted to investigate the effect of human exposure to phthalates on male reproductive harm. Phthalates metabolites in urine and semen are measured as biomarkers of internal exposure and target exposure, respectively. Semen quality, sperm DNA damage, reproductive hormones and sperm apoptosis are detected as effect biomarkers. The genetic polymorphisms of Fas/FasL which are mediator of spermatogenic cell apoptosis are analyzed as biomarkers of susceptibility. The effect of phthalates exposure in environmental levels on male reproductive harm will be investigated by using these biomarkers. The study may lead to clarify the associations of phthalates exposure and Fas/FasL genetic variants with male reproductive harm on the basis of "exposure - effects - gene" and to give basic research data of PAEs exposure and male reproductive harm, and finally to provide scientific basis for reproductive hazard assessment of phthalates exposure.

生殖毒理学研究表明酞酸酯类（PAEs）及其代谢产物对雄性动物具有损伤生殖细胞、干扰内分泌系统、降低精液质量，改变Fas/FasL基因表达水平进而诱导生精细胞凋亡等生殖毒性，但PAEs暴露致男性生殖损害的人群流行病学研究结论尚不一致。本课题拟采用横断面研究开展PAEs暴露致男性生殖损害的人群流行病学调查，通过测定研究对象精液和尿液中PAEs代谢产物含量精确评估个体生殖靶器官暴露水平和内暴露水平，以精液质量、精子DNA损伤、生殖功能相关激素和精子凋亡为效应指标，以生精细胞凋亡调节密切相关的Fas/FasL基因多态性为易感标志，研究环境水平的PAEs暴露对男性生殖健康的危害，在"暴露-效应-基因"的基础上揭示PAEs暴露和Fas/FasL遗传变异与育龄男性生殖损害的关系，提供基于我国男性人群的PAEs暴露致生殖损害的基础研究资料，为PAEs暴露的生殖危害和风险评估提供科学依据。

生殖毒理学研究表明酞酸酯类（Phthalate esters, PAEs）对雄性动物具有生殖毒性，但PAEs暴露致男性生殖损害的人群流行病学研究结论尚不一致。本项目以来武汉市同济医院生殖医学中心寻求精液分析的育龄期男性为研究对象，以个体不同时点双次尿PAEs代谢产物浓度为内暴露标志，探讨了尿PAEs代谢产物水平与男性精液质量参数、血清生殖激素水平、DNA损伤指标和精子细胞凋亡参数之间的关系，结果提示邻苯二甲酸酯正丁酯（di-n-butyl phthalate, DBP）暴露与降低的精子密度和总数有关；邻苯二甲酸二（2-乙基己基）酯（di（2-ethylhexyl） phthalate , DEHP）暴露与增加的精子畸形率、精子DNA损伤以及精子细胞凋亡有关，而与降低的血清睾酮和雌二醇水平有关。我们以个体精浆液PAEs代谢产物浓度为生殖靶器官暴露标志，进一步分析了精浆PAEs代谢产物水平与男性生殖健康指标之间的关联，结果提示DBP暴露与降低的精液量有关，DEHP暴露与降低的精子运动参数、精子细胞凋亡有关；邻苯二甲酸酯丁苄酯（butyl benzyl phthalate, BBzP）暴露与降低的精子运动参数、增加的精子畸形率有关；邻苯二甲酸二甲酯（Dimethyl phthalate，DMP）和邻苯二甲酸二乙酯（Diethyl phthalate，DEP）暴露与精子DNA损伤有关。最后，我们测定了3种Fas/FasL基因多态性（Fas-rs223476、FasL-rs763110 和 CASP3-rs12108497），并分析了PAEs 暴露和 Fas/FasL 遗传变异与育龄男性生殖损害的关系，结果提示DBP暴露可改变FasL-rs763110基因的表达，导致精子活力降低；DMP与DEHP暴露分别可改变FasL-rs763110和CASP-rs12108497基因的表达，促进精子细胞凋亡。本项目在"暴露-效应-基因"的基础上揭示 PAEs 暴露和 Fas/FasL 遗传变异与育龄男性生殖损害之间存在关联，为 PAEs 暴露的生殖危害和风险评估提供科学依据。