Association of polymorphisms in tektin-t gene with idiopathic asthenozoospermia in Sichuan, China

Structural specializations of the sperm tail

Sperm motility is crucial to reproductive success in sexually reproducing organisms. Impaired sperm movement causes male infertility, which is increasing globally. Sperm are powered by a microtubule-based molecular machine-the axoneme-but it is unclear how axonemal microtubules are ornamented to support motility in diverse fertilization environments. Here, we present high-resolution structures of native axonemal doublet microtubules (DMTs) from sea urchin and bovine sperm, representing external and internal fertilizers. We identify >60 proteins decorating sperm DMTs; at least 15 are sperm associated and 16 are linked to infertility. By comparing DMTs across species and cell types, we define core microtubule inner proteins (MIPs) and analyze evolution of the tektin bundle. We identify conserved axonemal microtubule-associated proteins (MAPs) with unique tubulin-binding modes. Additionally, we identify a testis-specific serine/threonine kinase that links DMTs to outer dense fibers in mammalian sperm. Our study provides structural foundations for understanding sperm evolution, motility, and dysfunction at a molecular level.

Investigation of the association of endothelial nitric oxide synthase (eNOS)-T786C gene polymorphism with the risk of male infertility in an Iranian population

Recent studies have demonstrated that making the sorts of oxygen reactive, such as nitric oxide, can cause oxidative lipid damage, protein damage, and damage to the DNA of cells. Sperm DNA damage effect on the reduction of sperm mobility and damage of acrosome membrane lead to the inability of sperm to fertilize the oocyte. Increasing expression of endothelial nitric oxide synthase (eNOS) gene is seen in various diseases such as cardiovascular and infertility diseases. This study aimed to assess the association between eNOS gene single nucleotide polymorphism/SNP (rs2070744, T786C) and risk of male infertility and the quality of sperm parameters in an Iranian population. In this case-control study, 100 infertile men were enrolled as a patient group. Control groups consisted of 100 fertile men. T786C genotypes were determined using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Results showed that T786C SNP, contained frequent genotype TC (p = 0.000; OR = 0.000; 95% CI = 0.000-0.015), TC + CC genotypes (p = 0.000; OR = 0.000; 95% CI = 0.000-0.015), and C allele (p = 0.000; OR = 0.00; 95% CI = 0.000-0.007), revealed a significant with male infertility. Based on the findings of this study suggested that although T786C SNP could not be applied as an appropriate genetic risk factor for male infertility, it probably may be considered a protective marker for other researchers. However, more comprehensive studies in different populations are required to confirm our data.

Genetic aspects of idiopathic asthenozoospermia as a cause of male infertility

Infertility is a worldwide problem affecting about 15% of couples trying to conceive. Asthenozoospermia (AZS) is one of the major causes of male infertility, diagnosed by reduced sperm motility, and has no effective therapeutic treatment. To date, a few genes have been found to be associated with AZS in humans and mice, but in most of cases its molecular aetiology remains unknown. Genetic causes of AZS may include chromosomal abnormalities, specific mutations of nuclear and mitochondrial genes. However recently, epigenetic factors, altered microRNAs expression signature, and proteomics have shed light on the pathophysiological basis of AZS. This review article summarises the reported genetic causes of AZS.

Curcumin improves asthenozoospermia by inhibiting reactive oxygen species reproduction through nuclear factor erythroid 2-related factor 2 activation

We conducted this study for the purpose of evaluating the protective mechanisms of curcumin against oxidative stress in asthenozoospermic individuals. Asthenozoospermic individuals were grouped into AS group, curcumin treatment group and brusatol + curcumin treatment group. The sperm motility was measured by computer-aided sperm analysis. We conducted flow cytometry and spectrophotometry to assess the levels of reactive oxygen species (ROS) and malondialdehyde (MDA). Chlortetracycline (CTC) was used to examine the acrosomal reaction of spermatozoa. Also, Western blotting was carried to measure antioxidant gene Nrf2 (nuclear factor erythroid 2-related factor) expression level. As our results shown, treatment with curcumin significantly decreased ROS formation and MDA production, compared with spermatozoa of AS group; however, Nrf2 inhibitor, Brusatol, inhibited Nrf2 expression and sperm function. Our results have shown that curcumin might protect spermatozoa by regulating Nrf2 level.

Association of DNAH11 gene polymorphisms with asthenozoospermia in Northeast Chinese patients

Reduced or no progressive sperm motility in the fresh ejaculate defines asthenozoospermia as one of the major causes of male infertility. The axonemal heavy chain dynein type 11 (DNAH11) gene encodes for one of the axonemal dynein heavy chain (DHC) family members and participates in assembling respiratory cilia and sperm flagella. Given the high degree of conservation of DNAH11, mutations could give rise to primary ciliary dyskinesia (PCD) and asthenozoospermia. To date, few studies have reported on the association between variants in DNAH11 and asthenozoospermia. In the present study, 87 patients with idiopathic asthenozoospermia for variants in DNAH11 were screened by using high-throughput targeted gene sequencing technology. Bioinformatics analysis was further assessed. We found compound heterozygous variants (c.9484-1 G>T, c.12428 T>C) of DNAH11 detected in 1 of 87 patients. The variant c.9484-1 G>T was confirmed as a novel virulence variant which was predicted to affect splicing by Human Splicing Finder 3.1. And c.12428 T>C was predicted to be mildly pathogenic in silico analysis. We found that DNAH11 polymorphisms display strong associations with asthenozoospermia, and may contribute to an increased risk of male infertility in Chinese patients.

Association of GRP78 promoter polymorphisms and serum GRP78 level with risk of asthenozoospermia

PURPOSE

The aim of this study was undertaken to investigate the association of 78-kDa glucose-regulated protein (GRP78) gene promoter polymorphisms with risk of asthenozoospermia (AZS) men. In addition, we performed association analysis between GRP78 promoter mutations and serum GRP78 level in asthenozoospermia.

METHODS

The study population comprised 400 subjects with AZS patients and 400 healthy controls. We assessed GRP78 rs3216733, rs17840761, and rs17840762 polymorphisms by using Snapshot SNP genotyping assays; serum GRP78 level was measured by enzyme-linked immunosorbent assay (ELISA). Semen quality was assessed by computer-assisted semen analysis.

RESULTS

We found that rs3216733 was associated with increased risk of AZS (Gd vs. dd: adjusted OR = 1.42, 95% CI, 1.06-1.93, P = 0.020; Gd/GG vs. dd: adjusted OR = 1.43, 95% CI, 1.08-1.91, P = 0.013; G vs. d adjusted OR = 1.26, 95% CI, 1.03-1.56, P = 0.027). The haplotype analyses showed the frequency of G-C-C haplotype was significantly higher in AZS (P = 0.026). The percentage of progressive motility sperm was lower in the asthenozoospermic men with Gd and Gd/GG genotypes than dd genotype (P = 0.003). Moreover, the serum GRP78 levels were significantly lower in rs3216733 Gd/GG genotypes compared with the dd genotype (P < 0.001).

CONCLUSION

Our findings suggest that rs3216733 Gd/GG genotypes contribute to poor sperm motility, probably by decreasing the level of GRP78.

Association of polymorphisms in PATE1 gene with idiopathic asthenozoospermia in Sichuan, China

PURPOSE

Idiopathic Asthenozoospermia (AZS) is a common symptom of male infertility described as reduced forward motility or absence of sperm motility. The PATE1 is generally expressed in male genital tract and related to sperm development, maturation and fertilization. However, the single nucleotide polymorphisms (SNPs) of the PATE1 gene which contribute to AZS were still unknown. For this reason, the possible association between the single nucleotide polymorphisms of the PATE1 gene and idiopathic asthenozoospermia was investigated in this research.

METHODS

108 idiopathic asthenozoospermia were screened by karyotype analysis, detection of Y microdeletions and mutations in 5 other genes from 140 clinical AZS. The sequence analyses of the PATE1 gene were conducted in 108 idiopathic asthenozoospermia and 106 fertile men with normospermic parameters in Sichuan, China.

RESULTS

In this study, a total 108 patients without chromosomal abnormalities, Y microdeletions and selected genes mutation were confirmed. The 1423G (odds ratio [OR] 1.939, 95% confidence interval [CI] 1.320-2.848, P=0.001) was found to be increased significantly in idiopathic asthenozoospermic patients compared with their fertile counterparts. This mutation substitutes a highly conserved glutamic to arginine at the position of the 47th amino acid which was shown to be located on the flank of the pleated sheet domain in PATE1 protein by the 3D model given by the Protein Model Portal (PMP). Moreover, PolyPhen-2 analysis predicted that this variant was "probably damaging".

CONCLUSIONS

These results suggested that PATE1 variant (A1423G) was probably one of the high risk genetic factors for idiopathic asthenozoospermia among males in Sichuan, China.