亚慢性苯吸入暴露抑制小鼠单倍体精子核蛋白基因的表达  

Expressions inhibition of haploid sperm nucleoprotein genes in mice sub-chronically exposed to benzene via inhalation

作　　者：张亚亚[1] 覃琼玉[1] 林冲[1] 孙书强[1] 朱华[2] 杨新军[1] 闫洪涛[1] 

机构地区：[1]温州医科大学环境与公共卫生学院预防医学系,浙江温州325035 [2]温州医科大学基础医学院,浙江温州325035

出　　处：《温州医科大学学报》2016年第4期249-253,共5页Journal of Wenzhou Medical University

基　　金：国家自然科学基金资助项目(30972510);浙江省自然科学基金资助项目(LY13H260003)

摘　　要：目的：探讨苯对小鼠精子生成损伤的主要阶段。方法：6~8周龄C57BL/6J雄性小鼠,按体质量随机分为3组,对照组、1 ppm和100 ppm苯暴露组,模拟职业暴露情况,实施每天8 h,每周5 d,共13周的亚慢性动式吸入染毒。HE染色观察睾丸组织病理学改变。选取精子发生中阶段特异性表达基因作为不同阶段精子的marker,选定的marker基因有代表未分化型精原细胞的Plzf,分化型精原细胞的Stra8,初级精母细胞的Sycp3,圆形精子的过渡蛋白Tnp1、Tnp2,长形精子的Akap4,以及鱼精蛋白Prm1、Prm2,采用实时荧光定量PCR（RT-PCR）检测marker基因m RNA表达。结果：苯暴露组小鼠睾丸组织呈现嗜酸性染色增强,1 ppm组出现少量核溶解、细胞脱落等改变;100 ppm组小鼠睾丸生殖细胞变性、坏死明显增多,管腔中心无（或少）细胞的曲细精管数量明显增多,表明亚慢性苯暴露可引起小鼠睾丸的病理改变。苯暴露组Plzf、Stra8、Sycp3、Akap4的m RNA表达均未显示统计学差别,而1 ppm组鱼精蛋白Prm2的m RNA表达显著降低（P〈0.01）;100 ppm组过渡蛋白Tnp1、Tnp2,鱼精蛋白Prm1、Prm2的m RNA表达均显著降低（P〈0.05）。结论：亚慢性苯吸入暴露可导致小鼠睾丸组织的病理改变,下调Tnps和Prms m RNA表达,主要影响单倍体精子细胞核内组蛋白被鱼精蛋白取代的过程。Objective： To explore the major damage stage of spermatogenesis in mice submitted to subchronic inhalation of benzene. Methods： C57BL/6J mice were randomly divided into control, 1 ppm and 100 ppm benzene exposure group. Simulated occupational exposure condition, a subchronic inhalation exposure test was carried out using the dynamic control equipment. The pathological change of testicular tissue was observed with HE staining. The m RNA expression of marker genes of spermatogenesis was quantitatively tested with real-time polymerase chain reaction, the selected marker genes included Plzf of undifferentiated spermatogonia, Stra8 of differentiated spermatogonia, Sycp3 of primary spermatocyte, Tnp1 and Tnp2 of round spermatid, Akap4 of elongating spermatid, as well as Prm1 and Prm2. Results： Enhanced eosinophilic staining were observed in mice testicular tissue section of benzene exposure groups, a few karyolysis and exfoliative cells were found in 1 ppm exposure group, the phenomenon of mice testis germ cell degeneration and necrosis were more obvious in 100 ppm exposure group, the number of seminiferous tubules with no or few germ cells were increased obviously. It suggested that subchronic benzene exposure could induce pathological change in mice testis. The m RNA expression of Plzf, Stra8, Sycp3, Akap4 did not show statistical difference in all groups, Prm2 expression was signifi cantly reduced in 1 ppm group than that of control group（P〈0.01）. The m RNA expression of transition protein Tnp1 and Tnp2, protamine Prm1 and Prm2 were signifi cantly reduced in 100 ppm exposure group than that of the control and 1 ppm group. Conclusion： Subchronic benzene exposure can induce the pathological change in mice testis, down-regulate the m RNA expression of Tnps and Prms, mainly infl uence the process of histone replaced by protamine in round spermatid nuclei.

关 键 词：苯 精子 精子生成 过渡蛋白 鱼精蛋白 小鼠 

分 类 号：R114[医药卫生—卫生毒理学]