Glutathione S-transferase P1 Ile105Val Polymorphism and Male Infertility Risk: An Updated Meta-analysis

Reduction of SLC7A11 and GPX4 Contributing to Ferroptosis in Sperm from Asthenozoospermia Individuals

Ferroptosis is a newly defined form of regulated cell death, which is involved in various pathophysiological conditions. However, the role of ferroptosis in male infertility remains unclear. In this study, 42 asthenozoospermic and 45 normozoospermic individuals participated. To investigate the ferroptosis level in the two groups, the levels of reactive oxygen species (ROS), malondialdehyde (MDA), and iron were measured, and mitochondrial membrane potential (MMP) was detected as an indicator of mitochondrial injuries. Compared with the normozoospermic group, ROS (p < 0.05), MDA (p < 0.001), and iron (p < 0.001) of the asthenozoospermic group were significantly increased. However, the asthenozoospermia group had a decreased MMP level (p < 0.05). In addition, the expression levels of GSH-dependent peroxidase 4 (GPX4) (p < 0.001) and solute carrier family 7 member 11 (SLC7A11) (p < 0.05) were also reduced in asthenozoospermic individuals. In asthenozoospermic samples, a significantly high positive correlation was observed between GPX4 mRNA levels and progressive motility (r = 0.397, p = 0.009) and total motility (r = 0.389, p = 0.011), while a negative correlation was observed between GPX4 and iron concentration (r =  - 0.276, p = 0.077). The function of ferroptosis in asthenozoospermic males has never been studied before. In our study, we concluded that GPX4 and SLC7A11 expression levels in asthenozoospermia patients were related to increased ferroptosis and impaired sperm function, revealing novel molecular insights into the complex systems involved in male infertility.

Genetic variations as molecular diagnostic factors for idiopathic male infertility: current knowledge and future perspectives

INTRODUCTION

Infertility is a major health problem, worldwide, which affects 10-15% of couples. About half a percent of infertility cases are related to male-related factors. Male infertility is a complex disease that is the result of various insults as lifestyle issues, genetics, and epigenetic factors. Idiopathic infertility is responsible for 30% of total cases. The genetic factors responsible for male infertility include chromosomal abnormalities, deletions of chromosome Y, and mutations and genetic variations of key genes.

AREAS COVERED

In this review article, we aim to narrate performed studies on polymorphisms of essential genes involved in male infertility including folate metabolizing genes, oxidative stress-related genes, inflammation, and cellular pathways related to spermatogenesis. Moreover, possible pathophysiologic mechanisms responsible for genetic polymorphisms are discussed.

EXPERT OPINION

Analysis and assessment of these genetic variations could help in screening, diagnosis, and treatment of idiopathic male infertility.

Association of Herpes simplex virus I&II infections with rs187084 SNP of TLR9 and male infertility

Since TLR9 recognises unmethylated CpG motifs in viral DNA, its polymorphisms may contribute to the susceptibility to Herpes simplex virus I&II infection. In the present study, to evaluate the role of rs187084 SNP (single nucleotide polymorphism) of TLR9 in Herpes simplex virus I&II infection and male infertility, 103 infertile and 27 fertile blood and semen samples were analysed. We assessed the micro and macro properties of semen specimens and the presence of HSV immunoglobulins. Tetra-primer ARMS PCR was used to detect SNP and to investigate the genotype distribution of TLR9-rs187084 SNPs, and the correlation between polymorphisms of TLR9 gene and male infertility. Moreover, the odds ratio (OR) and 95% confidence intervals were used to estimate the strength of the association. Based on our finding, a significant correlation was observed between HSV infection, agglutination and polymorphism (TT) under dominant (OR = 1.28, 95% CI = 0.94-1.75) and recessive (OR = 0.44, 95% CI = 0.21-0.94) models for the data, which was complied with Hardy-Weinberg equilibrium (HWE) (OR = 2.91, 95% CI = 1.02-8.30). The result showed a significant association between HSV IgM and agglutination in HSV infection (p < .001), and in addition, there were associations between alleles so that rs187084 SNP might be considered as a risk factor for the incidence of HSV infection.

SNP's in xenobiotic metabolism and male infertility

1. Glutathione S-transferases (GST) and cytochrome P450s (CYPs) are xenobiotic metabolizing enzymes participating in the protection of cell. The present study aimed to investigate the relationship between polymorphisms of glutathione S-transferase M1 (GSTM1) null, glutathione S-transferase T1 (GSTT1) null, glutathione S-transferase P1 (GSTP1) Ile105Val, cytochrome P450 1A2 (CYP1A2) 734 C→A, cytochrome P450 2D6 (CYP2D6) 1934 G→A and male infertility.2. A total of 306 azoospermic or oligozoospermic infertile men and 129 normozoospermic or fertile controls were enrolled in the study. Multiplex polymerase chain reaction (PCR) or PCR-restriction fragment length polymorphism methods were used for genotyping. There was a significant relationship between male infertility and CYP2D6 GG genotype (p < 0.001). CYP1A2 AA genotype was slightly higher in the infertile group (p = 0.056).3. There was no association between GSTT1 null polymorphisms and male infertility (p = 0.068), GSTM1 null (p = 0.843) and GSTP1 Ile105Val (p = 0.192) genes. GSTM1 null genotype frequency was higher in azoospermic men (p = 0.009). Men carrying CYP1A2 AA genotype had higher risk of infertility risk (OR = 3.14; %95 CI = 1.16-8.54) in the smoker group.4. Our results demonstrated that polymorphisms of CYP2D6 and CYP1A2 may play a role in idiopathic male infertility in our sample population.

Glutathione S-transferase π: a potential role in antitumor therapy

Glutathione S-transferase π (GSTπ) is a Phase II metabolic enzyme that is an important facilitator of cellular detoxification. Traditional dogma asserts that GSTπ functions to catalyze glutathione (GSH)-substrate conjunction to preserve the macromolecule upon exposure to oxidative stress, thus defending cells against various toxic compounds. Over the past 20 years, abnormal GSTπ expression has been linked to the occurrence of tumor resistance to chemotherapy drugs, demonstrating that this enzyme possesses functions beyond metabolism. This revelation reveals exciting possibilities in the realm of drug discovery, as GSTπ inhibitors and its prodrugs offer a feasible strategy in designing anticancer drugs with the primary purpose of reversing tumor resistance. In connection with the authors' current research, we provide a review on the biological function of GSTπ and current developments in GSTπ-targeting drugs, as well as the prospects of future strategies.