Nicotine induces Nme2-mediated apoptosis in mouse testes

Area of Science:

• Reproductive biology
• Molecular toxicology
• Genetics

Background:

• Cigarette smoke induces germ cell apoptosis in mouse testes, impacting semen quality.
• The precise molecular mechanisms underlying nicotine-induced germ cell apoptosis are not fully understood.

Purpose of the Study:

• To investigate the effects of nicotine exposure on apoptosis during spermatogenesis.
• To elucidate the role of the Nme2 gene in nicotine-induced testicular damage.

Main Methods:

• Nicotine-treated mouse model, TUNEL assay for apoptosis detection.
• Real-time PCR and TRAP-real-time PCR for telomere length and telomerase activity.
• NME2 gene overexpression in Hela cells.
• Bisulfite Sequencing (BSP) for Nme2 promoter methylation analysis.

Main Results:

• Nicotine exposure significantly increased germ cell apoptosis, decreased telomerase activity, and shortened telomere length in mouse testes.
• NME2 gene overexpression and nicotine exposure suppressed telomerase activity and shortened telomeres in Hela cells.
• Nicotine treatment led to hypomethylation of the Nme2 promoter in mouse testes.

Conclusions:

• Nicotine-induced germ cell apoptosis may result from decreased telomerase activity.
• Upregulation of Nme2, due to promoter hypomethylation, appears to inhibit telomerase activity, contributing to apoptosis.