Analysis of the correlation of CATSPER single nucleotide polymorphisms (SNPs) with idiopathic asthenospermia

Characteristics of gut microbiota in patients with asthenozoospermia: a Chinese pilot study

BACKGROUND

Identification of intestinal flora composition is significant for exploring the cause and pathogenic mechanisms of the gut-testis axis and clarifying the relationship between microbiota and infertility. Our study aimed to examine the alternation in gut microbiota composition and identify potential microbes associated with development of Asthenozoospermia (AS).

METHOD

A total of 580 males were recruited in the outpatient department of Tianjin Medical University General Hospital between September 2021 and March 2023. Sperm parameters were analyzed according to the WHO laboratory manual. The 16 S rRNA gene high-throughput sequencing was performed to detect the gut microbiota composition in fecal samples. LEfSe analysis was used to screen key microbiota. PICRUSt2 software was utilized to predict relevant pathways.

RESULTS

After rigorous screening, 60 isolated AS patients (AS group) and 48 healthy men (NC group) were enrolled. No significant differences were observed in demographic characteristics (p > 0.05), semen volume (p = 0.718), sperm concentration (p = 0.109), or total sperm count (p = 0.200). Sperm total motility and progressive motility were significantly decreased in the AS group (p < 0.001). AS patients had significantly lower alpha diversity indices (Chao1, observed OTUs, and PD Whole-tree; p < 0.05). The beta-diversity of gut microbiota in AS patients significantly differed from NC men (PCoA analysis, p = 0.001). Firmicutes, Bacteroidota, Proteobacteria, and Actinobacteria were the primary phyla, with the dominant genera including Bacteroides, Prevotella, and Blautia. Eleven key genera such as Escherichia_Shigella and Prevotellaceae_UCG_001 were identified by LEfSe analysis. Most of these genera were negatively correlated with sperm mobility. Eighty-eight KEGG pathways, including steroid biosynthesis and meiosis, were significantly enriched between the two groups.

CONCLUSIONS

It appears that gut microbiota composition in AS patients significantly differed from that in healthy men, and the development of AS might be associated with intestinal flora dysbiosis.

Impaired fertility in 4930590J08Rik mutant male mice is associated with defective sperm energy metabolism

Testis-specifically expressed genes are important for male reproduction according to their unique expression patterns. However, the functions of most of these genes in reproduction are unclear. Here, we showed that mouse 4930590J08Rik was a testis-specifically expressed gene. 4930590J08Rik knockout mice exhibited a delay in the first wave of spermatogenesis and a reduction of cauda epididymal sperm. Furthermore, knockout spermatozoa exhibited defective acrosome reactions and decreased progressive motility, which led to impaired in vivo fertilization. Transcriptome analysis of testes revealed that most of the differentially expressed genes in knockout testes were associated with metabolic processes. 4930590J08Rik knockout sperm exhibited oxidative phosphorylation deficiency and were highly dependent on increased anaerobic glycolysis to compensate for ATP demands. Taken together, the 4930590J08Rik-disrupted mouse partially mimics the phenotypes of human asthenospermia and oligozoospermia, which provides a new model for further understanding the pathogenesis of idiopathic male infertility.

Paternal factors in recurrent pregnancy loss: an insight through analysis of non-synonymous single-nucleotide polymorphism in human testis-specific chaperone HSPA2 gene

Heat shock protein A2 (HSPA2) is a testis-specific molecular chaperone of the 70 kDa heat shock protein (HSP70) family and reported to play a key role in spermatogenesis as well as in the remodelling of the sperm surface during capacitation. It is established that mice lacking HSPA2 gene are infertile and spermatozoa that fail to interact with the zona pellucida of the oocyte consistently lack HSPA2 protein expression. However, its role in post fertilization events is not fully understood. Owing to the importance of HSPA2 in male reproduction, the present study is undertaken to reveal the association between genetic mutation and phenotypic variation in recurrent pregnancy loss (RPL) patients through an in silico prediction analysis. In this study, we used different computational tools and servers such as SIFT, PolyPhen2, PROVEAN, nsSNPAnalyzer, and SNPs & GO to analyse the functional consequences of the nsSNPs in human HSPA2 gene. The most damaging amino acid variants generated were subjected to I-Mutant 2.0 and ConSurf. Post-translational modifications such as phosphorylation mediated by these deleterious nsSNPs were analysed using NetPhos 2.0, and gene-gene interaction study was conducted using GeneMANIA. Finally, in-depth studies of the nsSNPs were studied through Project HOPE. The findings of the study revealed 18 nsSNPs to be deleterious using a combinatorial bioinformatic approach. Further functional analysis suggests that screening of nsSNP variants of HSPA2 that tend to be conserved and has potential to undergo phosphorylation at critical positions (rs764410231, rs200951589, rs756852956) may be useful for predicting outcome in altered reproductive outcome. The physicochemical alterations and its impact on the structural and functional conformity were determined by Project HOPE. Gene-gene interaction depicts its close association with antioxidant enzyme (SOD1) strongly supporting an inefficient oxidative scavenging regulatory mechanism in the spermatozoa of RPL patients as reported earlier. The present study has thus identified high-risk deleterious nsSNPs of HSPA2 gene and would be beneficial in the diagnosis and prognosis of the paternal effects in RPL patients.

Discovery and Characterization of Multiple Classes of Human CatSper Blockers

The cation channel of sperm (CatSper) is a validated target for nonhormonal male contraception, but it lacks selective blockers, hindering studies to establish its role in both motility and capacitation. Via an innovative calcium uptake assay utilizing human sperm we discovered novel inhibitors of CatSper function from a high-throughput screening campaign of 72,000 compounds. Preliminary SAR was established for seven hit series. HTS hits or their more potent analogs blocked potassium-induced depolarization and noncompetitively inhibited progesterone-induced CatSper activation. CatSper channel blockade was confirmed by patch clamp electrophysiology and these compounds inhibited progesterone- and prostaglandin E1-induced hyperactivated sperm motility. One of the hit compounds is a potent CatSper inhibitor with high selectivity for CatSper over hCav1.2, hNav1.5, moderate selectivity over hSlo3 and hERG, and low cytotoxicity and is therefore the most promising inhibitor identified in this study. These new CatSper blockers serve as useful starting points for chemical probe development and drug discovery efforts.

Association of CATSPER1, SPATA16 and TEX11 genes polymorphism with idiopathic azoospermia and oligospermia risk in Iranian population

Background

Male infertility is a heterogeneous disease which can occur due to spermatogenesis defects. The idiopathic azoospermia and oligospermia are the common cause of male infertility with unknown underlying molecular mechanisms. The aim of this study was to investigate association of idiopathic azoospermia and oligospermia with single-nucleotide polymorphisms of CATSPER1, SPATA16 and TEX11 genes in Iranian-Azeri men.

Methods

In this case–control study, we recruited 100 infertile men (case group) and 100 fertile men (control group) from Azeri population in north western provinces, Iran, population. The genomic DNA was extracted using a proteinase K method from peripheral blood leukocytes. The genotypes analysis was conducted using tetra-primer amplification refractory mutation system-polymerase chain reaction method. The obtained data were analyzed by statistical software.

Results

We found a significant difference in the frequencies of heterozygote AB and mutant homozygote BB genotypes in the CATSPER1 (rs2845570) gene polymorphism between patients and healthy controls (p < 0.05). Moreover, we observed a significant difference in the frequencies of heterozygote BA genotype in the SPATA16 (rs1515442) gene polymorphism between patients and healthy controls (p < 0.05). However, no significant difference was found in genotypes distribution of case and control groups in the TEX11 (rs143246552) gene polymorphism.

Conclusion

Our finding showed that the CATSPER1 (rs2845570) and SPATA16 (rs1515442) genes polymorphism may play an important role in idiopathic azoospermia and oligospermia in Iranian Azeri population. However, more extensive studies with larger sample sizes from different ethnic origins are essential for access more accurate results.

Steroidal Antagonists of Progesterone- and Prostaglandin E1-Induced Activation of the Cation Channel of Sperm

The cation channel of sperm (CatSper) is the principal entry point for calcium in human spermatozoa and its proper function is essential for successful fertilization. As CatSper is potently activated by progesterone, we evaluated a range of steroids to define the structure-activity relationships for channel activation and found that CatSper is activated by a broad range of steroids with diverse structural modifications. By testing steroids that failed to elicit calcium influx as inhibitors of channel activation, we discovered that medroxyprogesterone acetate, levonorgestrel, and aldosterone inhibited calcium influx produced by progesterone, prostaglandin E₁, and the fungal natural product l-sirenin, but these steroidal inhibitors failed to prevent calcium influx in response to elevated K⁺ and pH. In contrast to these steroid antagonists, we demonstrated for the first time that the T-type calcium channel blocker ML218 acts similarly to mibefradil, blocking CatSper channels activated by both ligands and alkalinization/depolarization. These T-type calcium channel blockers produced an insurmountable blockade of CatSper, whereas the three steroids produced antagonism that was surmountable by increasing concentrations of each activator, indicating that the steroids selectively antagonize ligand-induced activation of CatSper rather than blocking channel function. Both the channel blockers and the steroid antagonists markedly reduced hyperactivated motility of human sperm assessed by computer-aided sperm analysis, consistent with inhibition of CatSper activation. Unlike the channel blockers mibefradil and ML218, which reduced total and progressive motility, medroxyprogesterone acetate, levonorgestrel, and aldosterone had little effect on these motility parameters, indicating that these steroids are selective inhibitors of hyperactivated sperm motility. SIGNIFICANCE STATEMENT: The steroids medroxyprogesterone acetate, levonorgestrel, and aldosterone selectively antagonize progesterone- and prostaglandin E₁-induced calcium influx through the CatSper cation channel in human sperm. In contrast to T-type calcium channel blockers that prevent all modes of CatSper activation, these steroid CatSper antagonists preferentially reduce hyperactivated sperm motility, which is required for fertilization. The discovery of competitive antagonists of ligand-induced CatSper activation provides starting points for future discovery of male contraceptive agents acting by this unique mechanism.

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.

Metabolic and transcriptional changes in seminal plasma of asthenozoospermia patients

This study was designed to investigate the metabolic and transcriptional alterations in seminal fluid caused by asthenozoospermia (AS). To address these issues, a method of metabonomics based on ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and real-time quantitative PCR (RT-qPCR) was performed to identify some crucial biomarkers and transcription levels of the enzymes in seminal fluid. Seminal fluid samples were collected from 87 AS patients and 73 healthy males with normozoospermia. The quantitative analysis by UPLC-MS/MS showed that 19 metabolites in seminal plasma were associated with AS, and they were involved in several metabolic pathways, such as energy metabolism, purine metabolism, methionine cycle, and branched chain amino acid metabolism. Among these metabolites, the levels of citric acid, malic acid, succinic acid, and pyruvic acid, which are related to energy metabolism, were collectively reduced in the AS group, whereas the lactic acid level was enhanced. These results indicated that lesser energy source (adenosine triphosphate) was produced through the anaerobic glycolysis pathway rather than via aerobic catabolism of suger and tricarboxylic acid cycle, resulting in reduced power of sperms. Meanwhile, partial least squares discriminant analysis showed significant differences in metabolic profiles between the AS and control groups. In addition, RT-qPCR results revealed that the expression levels of four genes encoding fructokinase citrate synthase, succinate dehydrogenase, and spermine synthase, which were related to energy metabolism, were decreased in the AS group. The 23 descriptors with differential expression in AS may be valuable for the diagnosis and sequential study on AS. These results will help highlight the role of sperm inactivity in AS pathogenesis.

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.

Expression Analysis of the CRISP2, CATSPER1, PATE1 and SEMG1 in the Sperm of Men with Idiopathic Asthenozoospermia

BACKGROUND

The purpose of this study was to analyze the expression level of CRISP2, CATSPER1, PATE1 and SEMG1 genes in the sperm of men with asthenozoospermia (AZS). AZS is a cause of infertility in men in which the motility of the sperm is reduced. So far, a few genes have been associated with AZS; however, in most of the cases, its molecular etiology is unclear.

METHODS

A total of 35 subjects with idiopathic AZS and 35 fertile and healthy men as control were included. In study after total RNA extraction and cDNA synthesis, relative quantification was performed. B2M was used as the normalizer gene and fold change was calculated by 2^-ΔΔCt method. Mann-Whitney test was used to compare the expression levels between the case and control groups with significance level of p<0.05.

RESULTS

Our results showed that CRISP2 (p=0.03) and SEMG1 (p=0.03) were significantly down-and up-regulated in AZS men respectively compared to the controls. But CATSPER1 and PATE1 did not show significant changes.

CONCLUSION

Down-regulation of CRISP2 and up-regulation of SEMG1 were associated with AZS, which could be suggested as the potential candidate genes for the development of a diagnostic marker or potentially for more studies for treatment of AZS.

Associations between DNAH1 gene polymorphisms and male infertility: A retrospective study

Genetic abnormalities could account for 10% to 15% of male infertility cases, so increasing attention is being paid to gene mutations in this context. DNAH1 gene polymorphisms are highly correlated with astheno-teratozoospermia, but limited information has been reported on pathogenic variations in DNAH1 in the Chinese population. We explored 4 novel variations of the DNAH1 gene in Chinese infertile patients. Mutation screening of the DNAH1 gene was performed on 87 cases of asthenozoospermia with targeted high-throughput sequencing technology; another 200 nonobstructive azoospermia cases were further analyzed to investigate the prevalence of DNAH1 variations. The effects of the variations on protein function were further assessed by bioinformatic prediction. For carriers of DNAH1 variations, genetic counseling should be considered. Assisted reproductive technologies should be performed for these individuals and microsurgery should be considered for patients with azoospermia. DNAH1 variations were identified in 6 of 287 patients. These included 8 heterozygous variations in exons and a splicing site. Among these, 4 variations (g.52400764G>C, g.52409336C>T, g.52430999_52431000del, g.52412624C>A) had already been registered in the 1000 Genomes and Exome Aggregation Consortium databases. The other 4 novel variations (g.52418050del, g.52404762T>G, g.52430536del, g.52412620del) were all predicted to be pathogenic by in silico analysis. The variations g.52418050del and g.52430999_52431000del were detected in 1 patient who was more severe than another patient with the variation g.52430999_52431000del. Physicians should be aware of genetic variants in male infertility patients and DNAH1 mutations should be considered in patients with asthenospermia or azoospermia.

Ion channel gene expressions in infertile men: A case-control study

BACKGROUND

Infertility is described as not receiving pregnancy despite unprotected and regular sexual intercourse in a 1 yr period. It is detected by 15% of the couples. Male and female factor in the etiology may be detected in similar rates.

OBJECTIVE

The present study aims to investigate ion channel gene expression in semen samples of infertile male compared with fertile men.

MATERIALS AND METHODS

A total of 150 men who applied to the urology clinic due to infertility were divided into five equal groups: asthenozoospermia, oligozoospermia, oligoasthenoteratozoospermia, teratozoospermia, and normozoospermia (control). All paticipants were evaluated with Cation Channel Spermia (CatSper) 1, 2, 3, 4, Proton Voltage Gated Ion Channel1 (Hv1), Potassium Channel Subfamily U1 (KCNU1), and transmembrane protein (TMEM16A) gene expression in semen samples.

RESULTS

"CatSper1, 4, HV1, KCNU1, and TMEM16A gene expression were detected higher in the oligozoospermia group compared to the controls. CatSper1, 2, 3, 4, KCNU1, and TMEM16A gene expression in the asthenozoospermia group and CatSper1, 2, 3, 4, KCNU1, and TMEM16A gene expression in the teratozoospermia group were detected lower compared to the controls. CatSper1, 4, HV1, and TMEM16A gen expression were higher in the oligoasthenoteratozoospermia men than the controls while CatSper3 gen expression was detected as lower."

CONCLUSION

It was detected that these ion channels have an effect on sperm progressive motility and morphology. It may be considered that mutations in these ion channels may result in infertility.