Synergism between the N-acetyltransferase 2 gene and oxidant exposure increases the risk of idiopathic male infertility

Impact of Tobacco and Marijuana on Infertility and Early Reproductive Wastage

Reducing exposure to tobacco and marijuana during preconception and early pregnancy is a critical area of intervention for obstetricians, gynecologists, and other reproductive health care professionals. Beyond the deleterious personal health effects, both substances have been extensively associated with short-term and long-term detrimental effects to gametogenesis, fecundity, as well as tissue level effects in the reproductive tracts. When tobacco and marijuana do not impair the ability to achieve pregnancy, an increasing body of literature suggests either may be associated with increased risk of early pregnancy loss and reproductive wastage. In this review, we will discuss what is known about how tobacco and marijuana affect the male and female reproductive systems and highlight how these consequences may impair attempts at successful conception and pregnancy continuation beyond the first trimester.

Characterisation and preliminary functional analysis of N-acetyltransferase 13 from Schistosoma japonicum

Background

N-acetyltransferase 13 (NAT13) is a probable catalytic component of the ARD1A-NARG1 complex possessing alpha (N-terminal) acetyltransferase activity.

Results

In this study, a full-length complementary DNA (cDNA) encoding Schistosoma japonicum NAT13 (SjNAT13) was isolated from schistosome cDNAs. The 621 bp open reading frame of SjNAT13 encodes a polypeptide of 206 amino acids. Real-time PCR analysis revealed SjNAT13 expression in all tested developmental stages. Transcript levels were highest in cercariae and 21-day-old worms, and higher in male adult worms than female adult worms. The rSjNAT13 protein induced high levels of anti-rSjNAT13 IgG antibodies. In two independent immunoprotection trials, rSjNAT13 induced 24.23% and 24.47% reductions in the numbers of eggs in liver. RNA interference (RNAi) results showed that small interfering RNA (siRNA) Sj-514 significantly reduced SjNAT13 transcript levels in worms and decreased egg production in vitro.

Conclusions

Thus, rSjNAT13 might play an important role in the development and reproduction of schistosomes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-021-03045-y.

Relationship between functional Nrf2 gene promoter polymorphism and sperm DNA damage in male infertility

This study examines the association of the -617 C > A polymorphism in the Nrf2 gene (rs6721961) with male infertility in a Turkish population and determines its functional role in spermatogenesis in correlation with the impact of different levels of DNA damage on the genotypes. A total of 100 infertile men and 100 healthy fertile men were included in the study. Nrf2 genotyping was performed with the PCR-based restriction fragment length gene polymorphism (RFLP-PCR) analysis. According to our results, the Nrf2 CC, CA, and AA genotype distribution frequencies were 58.6%, 38.4%, and 3% in the control group, respectively, and 38%, 48%, and 14% in the infertile men, respectively. The AA genotype was significantly higher in the patient group. In smokers, a significant difference was found in progressive motility values between the genotypes (p = 0.001). Also, sperm progressive motility and concentration decreased significantly in those smokers with the AA genotype; smokers carrying this genotype were also 5.75 times more likely to have oligoasthenozoospermia than those with CC (p < 0.05). There was a significant relationship between the number of cases with high sperm-DNA damage when comparing the frequency of Nrf2 AA genotype carriers with the CC genotype 16.3% vs. 6.9%, respectively (p < 0.001). These results suggest the importance of the Nrf2 gene C > A (rs 6,721,961) polymorphism in the etiology of sperm DNA damage as a risk factor for male infertility. Smokers carrying the AA genotype are more likely to impair seminal parameters through antioxidant mechanisms.Abbreviations: Polymerase chain reaction (PCR)-based restriction fragment length gene polymorphism (RFLP-PCR); reactive oxygen species (ROS); deoxyribonucleic acid (DNA); catalases (CATs); superoxide dismutase (SOD); glutathione peroxidase (GPX); glutathione-S-transferase (GST); Nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2); basic leucine zipper (bZIP); antioxidant response element (ARE); World Health Organization (WHO);normospermia(NS);asthenozoospermia(AS);oligozoospermia(OS);oligoasthenozoospermia (OAS); follicle stimulating hormone (FSH); ultraviolet (UV); low-melting-point agarose (LMA); normal-melting-point agarose (NMA); arbitrary units (AU); total comet score (TCS); A one-way analysis of variance (ANOVA); standard deviation (SD); N-acetyltransferase (NAT2); small non-coding RNAs (ncRNAs); microRNAs (miRNA).

Genetic polymorphisms of NAT2 and risk of acute myeloid leukemia: A case-control study

Our purpose was to investigate the possible associations between N-acetyltransferase-2 (NAT2) gene polymorphisms and the risk of acute myeloid leukemia (AML) in Chinese Han population.A case-control study was conducted including 98 AML cases and 112 healthy controls. NAT2 gene 2 polymorphisms rs1799930 and rs1799931 were genotyped using direct sequencing. Chi-square test was performed to compare the genotype and allele distribution differences between groups. Odds ratio (OR) with 95% confidence interval (CI) was calculated to estimate the association between NAT2 gene polymorphisms and AML onset.A remarkable decrease trend of rs1799931 GA genotype was detected in AML patients compared with controls, whereas the ancestral GG genotype frequency increased in cases (P < .05). And the mutant A allele of rs1799931 significantly reduced the risk of AML by 0.585-fold versus the ancestral G allele carriers (OR = 0.585, 95% CI = 0.361-0.950). But the distributions of rs1799930 genotype and allele were similar between groups (P > .05).Our findings suggested that NAT2 gene polymorphism rs1799931 was associated with decreased risk of AML and was likely to be a protective factor against AML development.

Impact of CAG repeat length in the androgen receptor gene on male infertility - a meta-analysis

CAG repeats are polymorphic nucleotide repeats present in the androgen receptor gene. Many studies have estimated the association between CAG repeat length and male infertility, but the conclusions are controversial. Previous meta-analyses have come to different conclusions; however, new studies have been published. An updated meta-analysis was conducted. PubMed, CBM, CNKI and Web of Science databases were systematically searched for studies published from 1 January 2000 to 1 October 2015. Case-control studies on the association between CAG repeat length and male infertility using appropriate methodology were included. Forty studies were selected, including 3858 cases and 3161 controls. Results showed statistically significantly longer CAG repeat length among cases compared with controls (SMD = 0.14; 95% CI, 0.02-0.26). Shorter repeat length was associated with a lower risk of male infertility compared with a longer repeat length in the overall analysis (OR = 0.79, 95% CI: 0.66-0.95). Moreover, CAG repeat length was associated with male infertility in Caucasian populations, but not Asian or Egyptian populations. Subgroup analysis revealed no significant difference in German populations, but CAG repeat length was associated with male infertility in China and the USA. There were no significant differences between cases and controls in azoospermia and severe oligozoospermia.

Smoking and Male Infertility: An Evidence-Based Review

Many studies have reported that the contents of cigarette smoke negatively affect sperm parameters, seminal plasma, and various other fertility factors. Nevertheless, the actual effect of smoking on male fertility is not clear. The effect of smoking on semen parameters is based on the well-established biological finding that smoking increases the presence of reactive oxygen species, thereby resulting in oxidative stress (OS). OS has devastating effects on sperm parameters, such as viability and morphology, and impairs sperm function, hence reducing male fertility. However, not all studies have come to the same conclusions. This review sheds light upon the arguable association between smoking and male fertility and also assesses the impact of non-smoking routes of tobacco consumption on male infertility. It also highlights the evidence that links smoking with male infertility, including newly emerging genetic and epigenetic data, and discusses the clinical implications thereof.

Joint effect of glutathione S-transferase genotypes and cigarette smoking on idiopathic male infertility

Inconsistent results of association studies investigated the role of glutathione S-transferase genes in idiopathic male infertility may be explained by ethnical differences in gene-gene and gene-environment interactions. In this study, we investigated a joint contribution of GSTM1, GSTT1 and GSTP1 gene polymorphisms and cigarette smoking to the risk of idiopathic infertility in Russian men. DNA samples from 203 infertile and 227 fertile men were genotyped by a multiplex polymerase chain reaction (GSTM1 and GSTT1 deletions) and PCR-restriction fragment length polymorphism (GSTP1 I105V) methods. The GSTP1 genotype 105IV was associated with increased risk of male infertility (OR = 1.50 95% CI 1.02-2.20 P = 0.04). Genotype combinations GSTP1 105II/GSTT1 del (G1), GSTM1 del/GSTT1 del (G2) and GSTM1 + /GSTT1 del (G3) were associated with decreased risk of male infertility (P ≤ 0.003), whereas a genotype combination GSTP1 105IV/GSTT1 + (G4) was associated with increased disease risk (P = 0.001). The genotype combinations G3 and G4 showed a significant association with infertility in smokers; however, nonsmokers carriers did show the disease risk. In conclusion, GSTM1, GSTT1 and GSTP1 genes are collectively involved in the development of idiopathic male infertility and their phenotypic effects on the disease risk are potentiated by cigarette smoking.