Sperm as a Carrier of Genome Instability in Relation to Paternal Lifestyle and Nutritional Conditions

Abstract

Endogenous and exogenous factors can severely affect the integrity of genetic information by inducing DNA damage and impairing genome stability. The extent to which men with and without subfertility are exposed to several adverse lifestyle factors and the impact on sperm DNA fragmentation (SDF), sperm chromatin maturity (condensation and decondensation), stability (hypo- and hypercondensation) and sperm aneuploidy are assessed in this study. Standardized assays employing flow cytometry were used to detect genome instability in 556 samples. Semen parameters deteriorated with age, BMI, increased physical activity and smoking. Age and BMI were associated with increased SDF. Increased BMI was associated with increased hypocondensed chromatin and decreased decondensed chromatin. Increase in age also caused an increase in sex chromosome aneuploidy in sperms. Surprisingly, alcohol abuse reduced chromatin hypercondensation and drug abuse reduced SDF. Although genome instability was more pronounced in the subfertile population as compared to the fertile group, the proportion of men with at least one lifestyle risk factor was the same in both the fertile and subfertile groups. While one in three benefited from nutritional supplementation, one in five showed an increase in SDF after supplementation. Whilst the message of ‘no smoking, no alcohol, no drugs, but a healthy diet’ should be offered as good health advice, we are a long way from concluding that nutritional supplementation would be beneficial for male fertility.

Factors affecting to neonatal thyroid hormone deficiency in the era of the COVID-19 pandemic, Akat Amnuai district, Sakon Nakhon Province

“…10,11 And affecting the sperm, the cell after fertilization has a cell division disorder which involves iodine in the cell further developing into the thyroid gland. 12 Smoking causes changes in thyroid function.…”

Epidemiology of sperm DNA fragmentation in a retrospective cohort of 1191 men

“…One possible and rather logical explanation is that there is a progressive increase in systemic oxidative stress during aging which may enhance post-testicular sperm nuclear condensation via an increase in sperm protamine disulfide bridges, 24 resulting in a decrease in HDS.…”

“…[29][30][31][32][33] However, many other reports instead suggest that high BMI is associated with higher risks of sperm DNA damage. 18,[34][35][36][37][38][39][40][41][42][43] Given that high BMI may have several causative factors, its relationship with SDF will need to be further investigated.…”

“…This may seem surprising, as one would expect aging males with higher SDF status to also exhibit nuclear decondensation, which HDS appreciates. One possible and rather logical explanation is that there is a progressive increase in systemic oxidative stress during aging which may enhance post‐testicular sperm nuclear condensation via an increase in sperm protamine disulfide bridges, 24 resulting in a decrease in HDS. This phenomenon has been clearly demonstrated in animal models 25 .…”

Male reproductive ageing: a radical road to ruin

“…The male is responsible for creating pre-mutational lesions in the paternal DNA, while the female is responsible for the effective repair of this damage following fertilization. Importantly, advanced age will impact both sides of this equation, promoting DNA damage in the spermatozoa on the one hand while impairing the DNA repair capacity of the oocyte on the other ( Evenson et al , 2020 ; Horta et al , 2020 ; Punjabi et al , 2022 ; Aitken, 2022c ). As a consequence of these associations, there is an additive effect on pregnancy and live birth rates when both partners are of an advanced age in ART cycles ( McPherson et al , 2018 ; Setti et al , 2021 ).…”