Expressions inhibition of haploid sperm nucleoprotein genes in mice sub-chronically exposed to benzene via inhalation
ZHANG Yaya1, QIN Qiongyu1, LIN Chong1, SUN Shuqiang1, ZHU Hua2, YANG Xinjun1, YAN hongtao1
1.Department of Preventive Medicine, Environmental Science and Public Health College, Wenzhou Medical University, Wenzhou, 325035; 2.Basic Medicine College, Wenzhou Medical University, Wenzhou, 325035
ZHANG Yaya,QIN Qiongyu,LIN Chong, et al. Expressions inhibition of haploid sperm nucleoprotein genes in mice sub-chronically exposed to benzene via inhalation[J]. JOURNAL OF WEZHOU MEDICAL UNIVERSITY, 2016, 46(4): 249-253.
Abstract：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 mRNA 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 mRNA expression of Plzf, Stra8, Sycp3, Akap4 did not show statistical difference in all groups, Prm2 expression was significantly reduced in 1 ppm group than that of control group (P<0.01). The mRNA expression of transition protein Tnp1 and Tnp2, protamine Prm1 and Prm2 were significantly 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 mRNA expression of Tnps and Prms, mainly influence the process of histone replaced by protamine in round spermatid nuclei.
[1] 林冲, 刘政, 于秀远, 等. 亚慢性苯吸入小鼠凋亡相关基因Survivin、Bcl2L13的表达与甲基化状态分析[J]. 温州医科大学学报, 2014, 44(7): 480-484.
[2] KATUKAM V, KULAKARNI M, SYED R, et al. Effect of benzene exposure on fertility of male workers employed in bulk drug industries[J]. Genet Test Mol Biomarkers, 2012, 16(6): 592-597.
[3] XING C, MARCHETTI F, LI G, et al. Benzene exposure near the U.S. permissible limit is associated with sperm aneuploidy[J]. Environ Health Perspect, 2010, 118(6): 833-839.
[4] MACHETTI F, ESKENAZI B, WELDON R H, et al. Occupational exposure to benzene and chromosomal structural aberrations in the sperm of Chinese men[J]. Environ Health Perspect, 2012, 120(2): 229-234.
[5] 刘政, 刘子巍, 林冲, 等. 亚慢性低浓度苯暴露对小鼠精子活力的影响[J]. 毒理学杂志, 2013, 27(3): 207-209.
[6] WARD C O, KUNA R A, SNYDER N K, et al. Subchronic inhalation toxicity of benzene in rats and mice[J]. Am J Ind Med, 1985, 7(5-6): 457-473.
[7] 江俊康, 翁诗君. 苯对雄性小鼠生殖系统的影响[J]. 中国工业医学杂志, 2004, 17(2): 94-96.
[8] COSTOYA J A, HOBBS R M, BARNA M, et al. Essential role of Plzf in maintenance of spermatogonial stem cells[J].Nat Genet, 2004, 36(6): 653-659.
[9] SADATE-NGATCHOU P I, PAYNE C J, DEARTH A T, et al. Cre recombinase activity specific to postnatal, premeiotic male germ cells in transgenic mice[J]. Genesis, 2008, 46(12): 738-742.
[10] SCHALK J A, DIETRICH A J, VINK A C, et al. Localization of SCP2 and SCP3 protein molecules within synaptonemal complexes of the rat[J]. Chromosoma, 1998, 107(8): 540-548.
[11] BROWN P R, MIKI K, HARPER D B, et al. A-kinase anchoring protein 4 binding proteins in the fibrous sheath of flagellum[J]. Biol Reprod, 2003, 68(6): 2241-2248.
[12] ULLAS K S, RAO M R. Phosphorylation of rat sperma-
tidal protein TP2 by sperm-specific protein kinase A and modulation of its transport into the haploid nucleus[J]. J Biol Chem, 2003, 278(52): 52673-52680.
[13] BRAUN R E. Packaging paternal chromosomes with protamine[J]. Nat Genet, 2001, 28(1): 10-12.
[14] EVENSON D P, LARSON K L, JOST L K. Sperm chromatin structure assay: Its clinical use for detecting sperm DNA fragmentation in male infertility and comparisons with other techniques[J]. J Androl, 2002, 23(1): 25-43.
[15] 黄学锋, 金建远, 费前进, 等. 精子DNA损伤: 独立的精子质量评价指标[J]. 温州医学院学报, 2010, 40(3): 239-242.
[16] 陈康, 周宇林, 余波澜, 等. 精子核蛋白组型异常及DNA损伤与精子活动力的相关性研究[J]. 中华临床医师杂志(电子版), 2013, 7(2): 575-578.
[17] UTSUNO H, MIYAMOTO T, OKA K, et al. Morphological alterations in protamine-deficient spermatozoa[J]. Hum Reprod, 2014, 29(11): 2374-2381.
