Potential effect of smoking on semen quality through DNA damage and the downregulation of Chk1 in sperm
Open Access
- 20 May 2016
- journal article
- Published by Spandidos Publications in Molecular Medicine Reports
- Vol. 14 (1), 753-761
- https://doi.org/10.3892/mmr.2016.5318
Abstract
Previous studies have found that smoking is associated with decreased male fertility via altering the quality of semen. However, the mechanism by which cigarette smoking affects semen quality remains to be fully elucidated. Heavy smoking-induced DNA damage has been reported to correlate with abnormal spermatozoa and male infertility. It has been reported that, in response to DNA damage, activation of the checkpoint kinase 1 (Chk1) facilitates S and G2 checkpoint arrest. The aim of the present study was to investigate the expression levels of Chk1 in sperm cells of smoking and non‑smoking men, and to further examine the correlation between DNA fragmentation rates and the expression levels of Chk1 with smoking. The present study was performed on a cohort of 841 smoking men and 287 non‑smoking men. In the investigation, sperm concentration, motility, viability, seminal plasma zinc concentration, acrosin activity and sperm DNA fragmentation were examined. The gene and protein expression levels of Chk1 were detected using reverse transcription-quantitative polymerase chain reaction and western blot analyses, respectively. It was observed that the progressive motility of the sperm was significantly decreased in the moderate and heavy smoking groups, whereas no significant changes were observed in the mild smoking group. The sperm in the medium‑term smoking group had significantly decreased progressive motility, and the semen concentration, sperm count and progressive motility vitality were markedly decreased in the long‑term smoking group. Compared with the non‑smoking group, the abnormal head rates in the heavy smoking group and long‑term smoking group were significantly increased. The sperm viability and seminal plasma zinc concentration were markedly increased in the smoking group. Increased DNA fragmentation rates were found in the smoking group. The expression of Chk1 was significantly decreased in the smoking group, compared with the non‑smoking group. Progressive motility and sperm concentration showed a nonlinear association with the relative mRNA expression of Chk1. However, an inverse association was found between DNA fragmentation rates and the progressive motility and sperm concentration. These data suggested that the decrease of semen quality caused by cigarette smoking was not only correlated with sperm DNA fragmentation rates, but was also correlated with a decline in the expressive level of Chk1. The expression of Chk1 was associated with DNA damage and apoptosis, the reduction of which may lead to decreased sperm repair and increased sperm apoptosis, with a subsequent effect on semen quality.Keywords
This publication has 33 references indexed in Scilit:
- Inhibition of the checkpoint kinase Chk1 induces DNA damage and cell death in human Leukemia and Lymphoma cellsMolecular Cancer, 2014
- DNA replication stress in CHK1-depleted tumour cells triggers premature (S-phase) mitosis through inappropriate activation of Aurora kinase BCell Death & Disease, 2014
- Chk1 as a new therapeutic target in triple-negative breast cancerThe Breast, 2014
- Effect of smoking on the functional aspects of sperm and seminal plasma protein profiles in patients with varicoceleHuman Reproduction, 2012
- Apoptosis spermatogenesis and male infertilityFrontiers in Bioscience-Elite, 2012
- Apoptosis, spermatogenesis and male infertilityFrontiers in Bioscience, 2012
- Cigarette smoking is related to a decrease in semen volume in a population of fertile menBJU International, 2006
- Effect of Antioxidant Intake on Sperm Chromatin Stability in Healthy Nonsmoking MenJournal of Andrology, 2005
- Impact négatif du tabac sur la fertilité masculine : des spermatozoïdes à la descendanceJournal de Gynécologie Obstétrique et Biologie de la Reproduction, 2004
- Role of the MAPK cascade in mammalian germ cellsReproduction, Fertility and Development, 1999