Androgen receptor (AR)-CAG trinucleotide repeat length and idiopathic male infertility: a case-control trial and a meta-analysis

The relationship between common mutations in CFTR, AR genes, Y chromosome microdeletions and karyotyping abnormalities with very severe oligozoospermia in Iranian men

BACKGROUND

Male infertility due to very severe oligozoospermia has been associated with some genetic risk factors.

OBJECTIVE

To investigate the distribution of the mutations in the CFTR gene, the CAG-repeat expansion of the AR gene, also Y chromosome microdeletions and karyotyping abnormalities in very severe oligozoospermia patients.

METHODS

In the present case-control study, 200 patients and 200 fertile males were enrolled. All patients and control group were karyotyped. Microdeletions were evaluated using multiplex PCR. Five common CFTR mutations were genotyped using the ARMS-PCR technique. The CAG-repeat expansion in the AR gene was evaluated for each individual using sequencing.

RESULTS

Overall 4% of cases shows a numerical and structural abnormality. 7.5% of patients had a deletion in one of the AZF regions on Yq, and 3.5% had a deletion in two regions. F508del was the most common (4.5%) CFTR gene mutation; G542X, and W1282X were detected with 1.5% and 1% respectively. One patient was found to have AZFa microdeletion and F508del in heterozygote form; one patient had AZFb microdeletion with F508del. F508del was seen as compound heterozygous with G542X in one patient and with W1282X in the other patient. The difference in the mean of the CAG-repeats in the AR gene in patients and control groups was statistically significant (P = 0.04).

CONCLUSION

Our study shows the genetic mutations in men with severe oligozoospermia and given the possibility of transmission of these disorders to the next generation by fertilization, counseling and genetic testing are suggested for these couples before considering ICSI.

Association Analysis of GSTP1-rs1695 Polymorphism with the Risk of Oral Cancer: A Literature Review, an Updated Meta- Analysis, and a Structural Assessment

BACKGROUND

This study aimed to investigate the association of rs1695 polymorphism in glutathione S-transferase P1 (GSTP1) with risk of oral cancer in a meta-analysis which was followed by a bioinformatics approach.

MATERIALS AND METHODS

Related articles were collected through a systematic search in PubMed, Google Scholar, and EMBASE databases up to June 2022 and then screened. Finally, seven studies, including 1249 cases of oral cancer and 1861 healthy individuals, were included in our meta-analysis. Seven different genetic models including G vs. A, GG+GA vs. AA, GG vs. GA+AA, GA vs. GG+AA, GG vs. GA, GG vs. AA, and GA vs. AA were used for the calculation of odds ratio and 95% confidence interval in order to assess the association between GSTP1-rs1695 polymorphism and oral cancer risk. Also, the ethnicity-based stratified analyses were performed using the seven mentioned models. Some bioinformatics software was used to investigate the effect of rs1695 polymorphism on the primary, secondary, and three-dimensional structure of GSTP1.

RESULTS

Our results showed that rs1695 polymorphism was not associated with the risk of oral cancer in any seven genetic models (G vs. A: OR= 0.9331, 95%CI= 0.6339-1.3737, P= 0.726; GG vs. GA+AA: OR= 0.9112 , 95%CI= 0.6865-1.2093, P= 0.520; GG+GA vs. AA: OR= 0.9006, 95%CI= 0.5522-1.4690, P= 0.675; GA vs. GG+AA: OR= 0.8732, 95%CI= 0.5763-1.3230, P= 0.522; GG vs. AA: OR= 0.9516, 95%CI= 0.5503-1.6456, P= 0.859; GG vs. GA: OR= 1.0645, 95%CI= 0.7891-1.4359, P= 0.683; GA vs. AA: OR= 0.8825, 95%CI= 0.5499-1.4162, P= 0.604). Also, we did not observe any significant associations in ethnicity-based stratified analyses. But bioinformatics studies have shown that this polymorphism can alter the physicochemical properties and secondary structure of the protein.

CONCLUSIONS

Based on results, the rs1695 polymorphism could not be considered a risk factor for oral cancer.

Molecular mechanisms involved in anosmia induced by SARS-CoV-2, with a focus on the transmembrane serine protease TMPRSS2

Since 2020, SARS-CoV-2 has caused a pandemic virus that has posed many challenges worldwide. Infection with this virus can result in a number of symptoms, one of which is anosmia. Olfactory dysfunction can be a temporary or long-term viral complication caused by a disorder of the olfactory neuroepithelium. Processes such as inflammation, apoptosis, and neuronal damage are involved in the development of SARS-CoV-2-induced anosmia. One of the receptors that play a key role in the entry of SARS-CoV-2 into the host cell is the transmembrane serine protease TMPRSS2, which facilitates this process by cleaving the viral S protein. The gene encoding TMPRSS2 is located on chromosome 21. It contains 15 exons and has many genetic variations, some of which increase the risk of disease. Delta strains have been shown to be more dependent on TMPRSS2 for cell entry than Omicron strains. Blockade of this receptor by serine protease inhibitors such as camostat and nafamostat can be helpful for treating SARS-CoV-2 symptoms, including anosmia. Proper understanding of the different functional aspects of this serine protease can help to overcome the therapeutic challenges of SARS-CoV-2 symptoms, including anosmia. In this review, we describe the cellular and molecular events involved in anosmia induced by SARS-CoV-2 with a focus on the function of the TMPRSS2 receptor.

CAG repeat polymorphism in androgen receptor and infertility: A case-control study

Background

Androgens play a role in the development of male phenotype and spermatogenesis during puberty, the function of which is regulated by the androgen receptor (AR) gene. There is a polymorphism site in exon 1 of the gene encoding this receptor that can have different frequencies of CAG trinucleotide repeats and leads to the formation of polyglutamine chains of different lengths in the N-terminal domain of the AR protein and reduced sperm production by affecting spermatogenesis.

Objective

To investigate whether the cause of a group of unexplained infertilities could be the increased frequency of CAG repeats in the AR gene of patients with oligozoospermia and azoospermia.

Materials and Methods

In this case-control study, 84 men including 42 with unexplained infertility As a case group and 42 fertile men as a control group were selected. The frequency of CAG repeats was determined by the polymerase chain reaction method and then the difference in the frequency of these repeats was determined based on the difference in band size on the agarose gel.

Results

The mean CAG repeat length in the azoospermia and oligozoospermia group was 17.5 ± 0.63 and in the fertile group it was 16.11 ± 0.75 (p = 0.46). In addition, most men (88.1% in the case group and 71.41% in the control group) had 13-23 repeats.

Conclusion

No significant correlation was found between CAG repeat length and the risk of male factor infertility in an ethnically defined population of Iranian men. The role of regulatory factors and epigenetic changes should be taken into account too.

Adolescent Transgender Females Present Impaired Semen Quality That Is Suitable for Intracytoplasmic Sperm Injection Even Before Initiating Gender-Affirming Hormone Treatment

The present study aimed to determine the semen quality and cryopreservation outcomes among adolescent transgender females at the time of fertility preservation (FP) before initiating gender-affirming hormone (GAH) treatment. This retrospective cohort study included 26 adolescent transgender females who underwent FP in our Fertility Institute between 06/2013 and 10/2020. Pre-freezing semen parameters were compared to WHO 2010 reference values. Post-thaw semen parameters were used to determine the adequate assisted reproductive technology (ART). A multivariate linear regression analysis was performed to assess the impact of medical and lifestyle factors on semen quality. The mean age at which adolescent transgender females underwent FP was 16.2 ± 1.38 years. The median values of all semen parameters in our study group were significantly lower compared to the WHO data, including volume (1.46 mL vs 3.2 mL, respectively, P = 0.001 ), sperm concentration (28 × 10⁶/mL vs 64 × 10⁶/mL, P < 0.001), total sperm number (28.2 × 10⁶ vs 196 × 10⁶, P < 0.001), total motility (51.6% vs 62%, P < 0.001), and normal morphology (2% vs 14%, P < 0.001). The frequency of semen abnormalities was teratozoospermia 72%, hypospermia 52%, oligozoospermia 28%, and azoospermia 4%. The median post-thaw total motile count was 0.17 × 10⁶/vial, and the quality was adequate only for ICSI in 87.7% of the thawed semen samples. No correlation was found between selected medical and lifestyle factors and poor semen parameters. Semen quality is strongly reduced among adolescent transgender females before hormone therapy and their stored sperm samples are suitable for intracytoplasmic sperm injection (ICSI) rather than conventional IVF/intrauterine insemination (IUI).

Genetic Landscape of Nonobstructive Azoospermia and New Perspectives for the Clinic

Nonobstructive azoospermia (NOA) represents the most severe expression of male infertility, involving around 1% of the male population and 10% of infertile men. This condition is characterised by the inability of the testis to produce sperm cells, and it is considered to have an important genetic component. During the last two decades, different genetic anomalies, including microdeletions of the Y chromosome, karyotype defects, and missense mutations in genes involved in the reproductive function, have been described as the primary cause of NOA in many infertile men. However, these alterations only explain around 25% of azoospermic cases, with the remaining patients showing an idiopathic origin. Recent studies clearly suggest that the so-called idiopathic NOA has a complex aetiology with a polygenic inheritance, which may alter the spermatogenic process. Although we are far from a complete understanding of the molecular mechanisms underlying NOA, the use of the new technologies for genetic analysis has enabled a considerable increase in knowledge during the last years. In this review, we will provide a comprehensive and updated overview of the genetic basis of NOA, with a special focus on the possible application of the recent insights in clinical practice.

Oxidative stress and male infertility: current knowledge of pathophysiology and role of antioxidant therapy in disease management

Infertility is a global health problem involving about 15% of couples. Approximately half of the infertility cases are related to male factors. The oxidative stress, which refers to an imbalance in levels of reactive oxygen species (ROS) and antioxidants, is one of the main causes of infertility in men. A small amount of ROS is necessary for the physiological function of sperm including the capacitation, hyperactivation and acrosomal reaction. However, high levels of ROS can cause infertility through not only by lipid peroxidation or DNA damage but inactivation of enzymes and oxidation of proteins in spermatozoa. Oxidative stress (OS) is mainly caused by factors associated with lifestyle. Besides, immature spermatozoa, inflammatory factors, genetic mutations and altering levels of sex hormones are other main source of ROS. Since OS occurs due to the lack of antioxidants and its side effects in semen, lifestyle changes and antioxidant regimens can be helpful therapeutic approaches to overcome this problem. The present study aimed to describe physiological ROS production, roles of genetic and epigenetic factors on the OS and male infertility with various mechanisms such as lipid peroxidation, DNA damage, and disorder of male hormone profile, inflammation, and varicocele. Finally, the roles of oral antioxidants and herbs were explained in coping with OS in male infertility.