Improvement of Rat Sperm Chromatin Integrity and Spermatogenesis with Omega 3 following Bleomycin, Etoposide and Cisplatin Treatment

Sperm chromatin: Evaluation, epigenetic signatures and relevance for embryo development and assisted reproductive technology outcomes

Sperm chromatin is distinct from somatic cell chromatin, as a result of extensive remodeling during the final stages of spermatogenesis. In this process, the majority of histones is replaced with protamines. The chromatin is consequently highly condensed and inert, which facilitates protection of the DNA. The sperm epigenomic landscape is shaped by histone retention, histone and protamine modification, DNA methylation, and RNAs. In recent years, sperm chromatin integrity and its epigenetic marks have been increasingly studied, and the constitution of sperm chromatin is steadily being uncovered. This growing body of research prompts assessment of the frequently overlooked involvement of sperm in fertility and embryonic development. Moreover, numerous endogenous and exogenous factors are known to affect sperm chromatin, which may in turn impact the reproductive success. Concerns have been raised about the effects of assisted reproductive technology (ART) on the sperm epigenome, embryonic development and offspring health. This review examines the structure and epigenetic signatures of sperm chromatin in the context of fertility and early embryonic development. Additionally, sperm chromatin evaluation and causes of aberrant integrity are outlined. Building on the knowledge discussed in the current review, future research should aim to elucidate the intricate relationship between all aspects of sperm chromatin and embryo development. This could lead to the uncovering of new targets for treating infertility, as well as the acquisition of much needed insights into the possible reciprocal association between ART and sperm chromatin integrity.

Sperm HSP70: may not be an age-dependent gene but is associated with field fertility in Bali bulls (Bos sondaicus)

This study aimed to analyze the characteristics of the HSP70 gene and protein in spermatozoa of Bali bulls of different age groups and to examine its potential as a biomarker determining bull fertility. This study used frozen semen produced from six Bali bulls divided into two groups based on age (≤ 9 years and ≥ 12 years). Parameters of frozen semen quality analyzed included sperm motility and kinetics using computer-assisted semen analysis, sperm morphological defects using Diff-Quick staining, acrosome integrity using FITC-PNA staining, and DNA fragmentation using acridine orange staining. HSP70 gene expression characterization was analyzed using qRT-PCR, and HSP70 protein abundance was analyzed using enzyme immunoassays. Fertility field data were obtained by analyzing the percentage conception rate for each bull based on the artificial insemination service data contained in the Indonesian-integrated system of the National Animal Health Information System (iSIKHNAS). The results showed significant differences (P<0.05) in total and progressive motility, morphological defects of the neck and midpiece, and tail of sperm, and acrosome integrity between the age groups of Bali bulls. HSP70 gene expression and protein abundance showed no significant differences (P>0.05) in different age groups. HSP70 gene expression correlated with fertility rate (P<0.05). Age affected several semen quality parameters but did not affect HSP70 gene expression and protein abundance. The HSP70 gene molecule could be a biomarker that determines the fertility of Bali bulls.

Omega 6/Omega 3 Ratio Is High in Individuals with Increased Sperm DNA fragmentation

An imbalance between omega-6 and omega-3 fatty acids in sperm has been linked with lipid peroxidation and DNA damage in sperm, indicating a possible correlation to fertility potential. This cross-sectional study involved 56 infertile men (aged 25-45), and assessed the relationship between the omega-6 to omega-3 fatty acid ratio in sperm and seminal plasma with sperm DNA fragmentation. Individuals were categorized based on high or low levels of sperm DNA fragmentation according to two tests (TUNEL and SCSA assay less or greater than 10 and 30%, respectively), and their fatty acid composition, as well as sperm functional tests, were analyzed. Results showed that men with high DNA fragmentation exhibited higher percentages of total saturated, monounsaturated, and omega-6 to omega-3 fatty acid ratios in both sperm (P < 0.001) and seminal plasma (P < 0.001) compared to men with low DNA fragmentation. The percentage of sperm lipid peroxidation, and residual histone (P < 0.05) were higher, while the percentage of sperm motility (P < 0.001) was lower in the former compared to the latter group. Moreover, Pearson's correlation revealed positive associations between the omega-6 to omega-3 fatty acid ratio with sperm lipid peroxidation, DNA fragmentation, and residual histones in both sperm and seminal plasma. Overall, these observations suggest that consumption of omega-3 fatty acids may be related to male fertility potential, as it appears that individuals with a high percentage of omega-3 fatty acids have better sperm quality compared to men with a lower omega-3 fatty acid.

Cisplatin-Induced Reproductive Toxicity and Oxidative Stress: Ameliorative Effect of Kinetin

Cisplatin is a commonly used chemotherapeutic agent; however, its potential side effects, including gonadotoxicity and infertility, are a critical problem. Oxidative stress has been implicated in the pathogenesis of cisplatin-induced testicular dysfunction. We investigated whether kinetin use at different concentrations could alleviate gonadal injury associated with cisplatin treatment, with an exploration of the involvement of its antioxidant capacity. Kinetin was administered in different doses of 0.25, 0.5, and 1 mg/kg, alone or along with cisplatin for 10 days. Cisplatin toxicity was induced via a single IP dose of 7 mg/kg on day four. In a dose-dependent manner, concomitant administration of kinetin with cisplatin significantly restored testicular oxidative stress parameters, corrected the distorted sperm quality parameters and histopathological changes, enhanced levels of serum testosterone and testicular StAR protein expression, as well as reduced the up-regulation of testicular TNF-α, IL-1β, Il-6, and caspase-3, caused by cisplatin. It is worth noting that the testicular protective effect of the highest kinetin dose was comparable/more potent and significantly higher than the effects of vitamin C and the lowest kinetin dose, respectively. Overall, these data indicate that kinetin may offer a promising approach for alleviating cisplatin-induced reproductive toxicity and organ damage, via ameliorating oxidative stress and reducing inflammation and apoptosis.

Effects of chemotherapeutic agents on male germ cells and possible ameliorating impact of antioxidants

Treatment of cancer in young adults is associated with several side effects, particularly in the reproductive system. Detrimental effects of chemotherapy on the germ cells depend on many factors including primary semen parameters, the way of drug administration, the kind and dose of chemotherapeutic regimens, and the phase of spermatogenesis during the time of drug administration. Lack of appropriate fertility preservation treatments particularly in the affected children necessitates the introduction of methods to amend the harmful effects of chemotherapeutic agents on male germ cells. Several studies have assessed the toxic effects of chemotherapeutic agents in rodent models and tested a number of antioxidants to evaluate their possible impact on the preservation of sperm cells. In the present manuscript, we describe the effects of the mostly investigated chemotherapeutic drugs in this regard i.e., cisplatin, doxorubicin, paclitaxel, 5-fluorouracil, and cyclophosphamide. As several in vivo and in vitro studies have shown the impact of antioxidants on chemotherapy-induced damage of sperms, we also describe the protective effects of antioxidants in this regard.

A Bayesian analysis of boar spermatozoa kinematics and head morphometrics and their relationship with litter size fertility variables

The semen movement and sperm head size patterns of boar ejaculates were analysed using computer-assisted semen analysis (CASA)-Mot and -Morph systems. The aim of the present study was to compare morphometric and kinematics variables from boars and to determine the relationship with sow fertility variables related to litter size. The females were from maternal crossing schemes such as the continuous 3-generation cross between York (Y), Landrace (L), and Pietrain (P) hybrid sows and Pietrain boars. Semen samples were collected from 11 sexually mature boars from two sire lines. Samples were analysed using the ISAS^® v1 system to evaluate eight kinematic variables of sperm velocity, progressiveness and undulations. Four morphometric parameters of sperm head size (length, width, area and perimeter) were analysed. Bayesian analysis revealed relevant differences in four kinematic variables (VSL, LIN, STR and WOB) between sire lines, with a probability of relevance (P_R ) of 0.79-0.91, and Pietrain boars were associated with higher progressive motility compared with Duroc x Pietrain boars. Moreover, there were relevant differences in all morphometric variables (P_R  = 0.82-0.85) between sire lines. The dam line Y-L-50 (½ Y × ½ L) had higher total born per litter and piglets born alive, and YLP-75 (¹ /₈ Y × ¹ /₈ L × ³ /₄ P) was associated with higher values of litter weight at birth (highest posterior density region at 95% = 9.92, 16.41 kg). There are relevant differences in kinematic variables between the assessed sire lines and the differences in morphometric and litter size variables were also relevant. The York-Landrace hybrid sows had higher total born per litter and piglets born alive, and there were relevant differences when compared with YLP-50 (¼ York × ¼ Landrace × ½ Pietrain). Differences in kinematic and morphometric variables between sire and dam lines related to fertility need to be further studied.