title: Cigarette smoking exposure alters pebp1 DNA methylation and protein profile involved in MAPK signaling pathway in mice testis.
abstract: Many studies have addressed the role of cigarette smoking on semen quality, but the exact mechanisms remain inconclusive. To evaluate the detrimental effects of smoking on the spermatogenesis process, we initially screened and investigated 31 differentially expressed proteins extracted from the testes of mice exposed daily to cigarette smoke using matrix-assisted laser desorption/ionization-time of flight-mass spectrometry analysis. Data mining analysis showed that these 31 proteins were categorized into five functional clustering groups: metabolic process, cell growth and/or maintenance, RNA and protein processing, stress response, and spermatogenesis. Additionally, 23 of 31 proteins were involved in a main pathway network, including Pkc (s), ERK1/2, Akt, and NF-kappaB, which are known to be involved in cell communication, proliferation, and differentiation. Interestingly, among the 31 proteins, a spermatogenesis-associated protein, phosphatidylethanolamine-binding protein 1 (PEBP1), was especially expressed in serial sections of spermatids of spermiogenesis and interacted with ERKs. The bisulfite sequencing result showed four CpGs near the Pebp1 transcriptional start site were largely methylated in the treated group. A 5-aza-2'-deoxycytidine treatment on GC-1 spg cells reversed the hypermethylation status and elevated both Pebp1 mRNA and protein expression levels. ERK1/2 phosphorylation levels were also increased with upregulation of Pebp1 expression in GC-1 spg cells. In conclusion, protein profile in testes could be altered by cigarette smoking. Moreover, we also suggest that epigenetic Pebp1 inactivation may affect activation of ERK, and it could impair spermatogenesis of mice. Our data could provide further insight into the mechanisms of spermatogenesis.
authors.affiliation: School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, People's Republic of China.
authors.forename: Wangjie
authors.initials: W
authors.lastname: Xu
authors.forename: Peng
authors.initials: P
authors.lastname: Fang
authors.forename: Zijue
authors.initials: Z
authors.lastname: Zhu
authors.forename: Jingbo
authors.initials: J
authors.lastname: Dai
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Nie
authors.forename: Zhong
authors.initials: Z
authors.lastname: Chen
authors.forename: Qiaojing
authors.initials: Q
authors.lastname: Qin
authors.forename: Lianyun
authors.initials: L
authors.lastname: Wang
authors.forename: Zhaoxia
authors.initials: Z
authors.lastname: Wang
authors.forename: Zhongdong
authors.initials: Z
authors.lastname: Qiao
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D019175:DNA Methylation; D015180:Electrophoresis, Gel, Two-Dimensional; D053263:Gene Regulatory Networks; D020935:MAP Kinase Signaling System / Q000235:genetics; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D049488:Phosphatidylethanolamine Binding Protein / Q000235:genetics* / Q000378:metabolism*; D055101:Semen Analysis; D012907:Smoking / Q000235:genetics / Q000378:metabolism; D013091:Spermatogenesis / Q000235:genetics; D013737:Testis / Q000378:metabolism*
chemical_list: D049488:Phosphatidylethanolamine Binding Protein; C539308:Raf kinase inhibitory protein, mouse
keywords: DNA methylation; MALDI-TOF-MS; MAPK; PEBP1; cigarette smoking; male infertility; proteomics; spermatogenesis, testis