Impact of Heavy Smoking on the Expression Levels of PGAM5, PTPRN2 and TYRO3 and Its Correlation to Male Infertility

Smoking have been linked to male infertility by affecting the sperm epigenome and genome. In this study, we aimed to determine possible changes in the transcript levels of the PTPRN2, PGAM5, and TYRO3 genes in heavy smokers compared with non-smokers; and to investigate their association with fundamental sperm parameters. One hundred eighteen sperm samples (63 heavy-smokers (G1) and 55 non-smokers (G2) were included in this study. Semen analysis was performed according to WHO guidelines. After total RNA extraction, RT-PCR was used to quantify the transcript levels of studied genes. In G1 a significant decrease in standard semen parameters in comparison to non-smokers has been shown (p<0.05). Moreover, PGAM5 and PTPRN2 were differentially expressed (P≤0.03 and P≤0.01, respectively), and downregulated in spermatozoa of G1 compared to G2. In contrast, no difference was observed for TYRO3 (p≤0.3). In G1, mRNA expression level of studied genes correlated negatively with motility, sperm count, normal form, vitality, and sperm membrane integrity (p<0.05). Therefore, smoking may affect gene expression and male fertility by altering DNA methylation patterns in genes associated with fertility and sperm quality, including PGAM5, PTPRN2, and TYRO3.