SYSTEMS BIOLOGY REPRODUCTIVE MEDICINE RESEARCH ARTICLE

Histone retention, protein carbonylation, and lipid peroxidation in spermatozoa: Possible role in recurrent pregnancy loss

Contribution from a defective paternal genome has been attributed to be an important cause for spontaneous recurrent pregnancy loss (RPL). Increased oxidative stress results in decreased detoxification and is a cause for damage to chromatin, proteins, and membrane lipids. The present study aimed to explore if there is a significant relationship between retained histones due to defective packaging of DNA in spermatozoa and oxidative stress. RPL patients (n=16) with a history of ≥2 embryo losses before the 20th week of gestation and no female factor abnormality, and fertile healthy volunteers (n=20) as controls were included in the study. A significant difference in the levels of protein carbonylation and lipid peroxidation together with an increased retention of histones in the experimental groups was noticed. Histone carrying sites for oxidative modification such as arginine and lysine might be responsible for disturbing the paternal epigenomic control during early stages of embryonic differentiation leading to abortion.

Results and discussion

The semen was viscous and had a pH within the range of 7.0-8.0 in both the control and RPL groups. Routinely analyzed sperm attributes except sperm count and leukocyte concentration showed a distinct significant change in the RPL group (Table 1). The percentage of motile spermatozoa drastically dropped in the RPL group but it was still possible to achieve pregnancy as it is above the lower reference limit of 40% [WHO 2010]. However, the oxidative stress parameters of semen showed a significant increment in the RPL patient group

Gatatri Mohanty^a,*, Nirlipta Swain^a,b,*, Chandan Goswami^b, Sujata Kar^c , and Luna Samanta^a