title: Nicotine induces Nme2-mediated apoptosis in mouse testes.
abstract: In mouse testes, germ cell apoptosis can be caused by cigarette smoke and lead to declining quality of semen, but the exact molecular mechanisms remain unclear. To evaluate the effects of nicotine exposure on apoptosis during spermatogenesis, we first constructed a nicotine-treated mouse model and detected germ cell apoptosis activity in the testes using the TUNEL method. Then we analyzed the variation of telomere length and telomerase activity by real-time PCR and TRAP-real-time PCR, respectively. Further, we investigated a highly expressed gene, Nme2, in mouse testes after nicotine treatment from our previous results, which has close correlation with the apoptosis activity predicted by bioinformatics. We performed NME2 overexpression in Hela cells to confirm whether telomere length and telomerase activity were regulated by the Nme2 gene. Finally, we examined methylation of CpG islands in the Nme2 promoter with the Bisulfite Sequencing (BSP) method. The results showed that apoptosis had increased significantly, and then telomerase activity became weak. Further, telomere length was shortened in the germ cells among the nicotine-treated group. In Hela cells, both overexpression of the Nme2 gene and nicotine exposure can suppress the activity of telomerase activity and shorten telomere length. BSP results revealed that the Nme2 promoter appeared with low methylation in mouse testes after nicotine treatment. We assume that nicotine-induced apoptosis may be caused by telomerase activity decline, which is inhibited by the up expression of Nme2 because of its hypomethylation in mouse germ cells.
authors.affiliation: School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, PR China.
authors.forename: Yunqi
authors.initials: Y
authors.lastname: Gu
authors.affiliation: School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, PR China.
authors.forename: Wangjie
authors.initials: W
authors.lastname: Xu
authors.affiliation: School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, PR China.
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Nie
authors.affiliation: School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, PR China.
authors.forename: Dong
authors.initials: D
authors.lastname: Zhang
authors.affiliation: School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, PR China.
authors.forename: Jingbo
authors.initials: J
authors.lastname: Dai
authors.affiliation: School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, PR China.
authors.forename: Xianglong
authors.initials: X
authors.lastname: Zhao
authors.affiliation: School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, PR China.
authors.forename: Meixing
authors.initials: M
authors.lastname: Zhang
authors.affiliation: School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, PR China.
authors.forename: Zhaoxia
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Urology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, PR China. Electronic address: chenzhongchina@hotmail.com.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Chen
authors.affiliation: School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, PR China. Electronic address: zdqiao@sjtu.edu.cn.
authors.forename: Zhongdong
authors.initials: Z
authors.lastname: Qiao
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D019175:DNA Methylation / Q000187:drug effects; D006367:HeLa Cells; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D054778:NM23 Nucleoside Diphosphate Kinases / Q000235:genetics / Q000378:metabolism*; D009538:Nicotine / Q000633:toxicity*; D018722:Nicotinic Agonists / Q000494:pharmacology*; D013091:Spermatogenesis / Q000187:drug effects; D019098:Telomerase / Q000378:metabolism; D059505:Telomere Homeostasis / Q000187:drug effects*; D013737:Testis / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism
chemical_list: D054778:NM23 Nucleoside Diphosphate Kinases; D018722:Nicotinic Agonists; D009538:Nicotine; C517941:Nme2 protein, mouse; D019098:Telomerase
keywords: Apoptosis; DNA methylation; Male reproduction; Nicotine; Nme2; Telomere