Evaluation of the association between polymorphisms of PRM1 and PRM2 and the risk of male infertility: a systematic review, meta-analysis, and meta-regression

Deciphering the Molecular Characteristics of Human Idiopathic Nonobstructive Azoospermia from the Perspective of Germ Cells

Nonobstructive azoospermia (NOA) is one of the most important causes of male infertility, accounting for 10-15% of infertile men worldwide. Among these, more than 70% of cases are idiopathic NOA (iNOA), whose pathogenesis and molecular basis remain unknown. This work profiles 3696 human testicular single-cell transcriptomes from 17 iNOA patients, which are classified into four classes with different arrest periods and variable cell proportions based on the gene expression patterns and pathological features. Genes related to the cell cycle, energy production, and gamete generation show obvious abnormalities in iNOA germ cells. This work identifies several candidate causal genes for iNOA, including CD164, LELP1, and TEX38, which are significantly downregulated in iNOA germ cells. Notably, CD164 knockdown promotes apoptosis in spermatogonia. Cellular communications between spermatogonial stem cells and Sertoli cells are disturbed in iNOA patients. Moreover, BOD1L2, C1orf194, and KRTCAP2 are found to indicate testicular spermatogenic capacity in a variety of testicular diseases, such as Y-chromosome microdeletions and Klinefelter syndrome. In general, this study analyzes the pathogenesis of iNOA from the perspective of germ cell development, transcription factor (TF) regulatory networks, as well as germ cell and somatic cell interactions, which provides new ideas for clinical diagnosis.

Correlation of Single Nucleotide Polymorphisms of PRM1, PRM2, PYGO2, and DAZL Genes with Male Infertility in North West of Iran

OBJECTIVE

Almost half of infertility is related to male factors. Although the effect of genetic factors on male infertility is identified, about 30%-50% still has no proven cause and is classified as idiopathic infertility. This study was performed to investigate the correlation of some single nucleotide polymorphisms of PYGO2, DAZL, PRM1, and PRM2 genes with male infertility in idiopathic cases among the Iranian population.

MATERIAL AND METHODS

In this case-control study, 120 idiopathic azoospermia or severe oligospermia patients in the range of 25-45 years and 120 fertile men in the same age range were recruited as case and control groups, respectively. Eight different single nucleotide polymorphisms including PRM1 rs737008, PRM1 rs423668, PRM2 rs1646022, PRM2 rs11645592, PYGO2 rs141722381, PYGO2rs61758741, DAZL rs75931701, and DAZL rs188506466 were genotyped by using ampli ficat ion-r efrac tory mutation system polymerase chain reaction methods. Hardy-Weinberg was calculated by using online website. Statistical Package for Social Sciences software was applied for statistical analysis. P value <.05 was considered significant. Thirty percent of the samples were regenotyped to confirm the obtained results.

RESULTS

The obtained results showed a significant correlation between PYGO2 rs141722381 in the heterozygote form (odds ratio: 2.803, 95% CI: 1.397-5.626). Heterozygote over-dominance was also observed in this variant (odds ratio: 2.637, 95%CI: 1.321-5.264). There was no significant association between other studied single nucleotide polymorphisms and male infertility.

CONCLUSION

This study proposed a novel single nucleotide polymorphism as a predisposition of male infertility among the Iranian population, but more studies in larger populations are needed to confirm the results.

PRM1 Gene Expression and Its Protein Abundance in Frozen-Thawed Spermatozoa as Potential Fertility Markers in Breeding Bulls

Functional genes and proteins in sperm play an essential role in bulls’ reproductive processes. They are more accurate in determining bull fertility than conventional semen quality tests. Protamine-1 (PRM1) is a gene or protein crucial for packaging and protecting sperm DNA until fertilization affects normal sperm function. This study analyzes the genes and proteins potential from PRM1 as fertility markers for different breeds of bulls utilized in the artificial insemination programs, expected to be an accurate tool in interpreting bull fertility in Indonesia. This study used Limousin, Holstein, and Ongole Grade bulls divided into two groups based on fertility, high-fertility (HF) and low fertility (LF). The semen quality assessment included progressive motility (computer-assisted semen analysis), viability (eosin-nigrosine), and plasma membrane integrity (HOS test). Sperm DNA fragmentation (SDF) was assessed using the acridine orange staining and the Halomax test. Sperm PRM deficiency was evaluated with the chromomycin A3 method. Moreover, PRM1 gene expression was measured using qRT-PCR, and the PRM1 protein abundance was measured with the enzyme immunoassay method. Semen quality values, relative expression of PRM1 gene, and quantity of PRM1 protein were significantly higher (p < 0.05) in HF bulls than in LF bulls. The SDF and PRM deficiency values in LF bulls were significantly higher (p < 0.05) than HF bulls. Additionally, PRM1 at the gene and protein levels correlated significantly (p < 0.01) with fertility. Therefore, PRM1 is a potential candidate for fertility markers in bulls in Indonesia.

The expression, function, and utilization of Protamine1: a literature review

Objective

Protamine 1 (PRM1) is specific in sperm and plays essential roles in fertilization, also a member of cancer testis antigen (CTA) family. This study aims to summarize the expression and function of PRM1 in spermatogenesis, and to broaden the current knowledge and inspire future development of PRM1-based therapeutic strategies in cancer treatment and nanomedicine.

Background

The protamine proteins, are characterized by an arginine-rich core and cysteine residues. Humans express two types of protamine: PRM1 and PRM2. The abnormal expression or proportion of PRM1 and PRM2 is known to be associated with subfertility and infertility, especially for PRM1 which is highly evolutionary conserved in mammalians and expressed in all vertebrates. Biological functions of PRM1 have been unveiled in diverse cellular processes, such as tumorigenesis, somatic cell nucleus transfer, and drug delivery systems. Moreover, PRM1 is identified as a CTA in chronic leukemia (CLL) and colorectal cancer (CRC).

Methods

Literature was obtained using PubMed and the keywords protamine 1, PRM1, or P1, from January 1, 1980, through July 20, 2021. We also collect the additional evidence through screening references of articles identified through the PubMed searches.

Conclusions

PRM1 is well-studied in male infertility, and further researches and attempts to develop PRM1 as novel tumor marker, as well as drug delivery vector, will be of important clinical significance.

Epigenetic Modifications, A New Approach to Male Infertility Etiology: A Review

Recent studies have indicated that epigenetic alterations are critical for normal function and development of spermatozoa during the fertilization process. This review will focus on the latest advances in epigenome profiling of the chromatin modifications during sperm development, as well as the potential roles of epigenetic mechanisms in the context of male infertility. In this review, all data were collected from published studies that considered the effect of epigenetic abnormalities on human spermatogenesis, sperm parameters quality, fertilization process, embryo development and live births. The database PubMed was searched for all experimental and clinical studies using the Keywords "epigenetic modifications", "male infertility", "spermatogenesis", "embryo development" and "reproductive function". Post-translational modifications of histone, DNA methylations and chromatin remodeling are among the most common forms of epigenetic modifications that regulate all stages of spermatogenesis and fertilization process. Incorrect epigenetic modifications of certain genes involved in the spermatogenesis and sperm maturation may be a main reason of male reproductive disorder and infertility. Most importantly, abnormal patterns of epigenetic modifications or transgenerational phenotypes and miRNAs expression may be transmitted from one generation to the next through assisted reproductive techniques (ART) and cause an increased risk of birth defects, infertility and congenital anomalies in children. Epigenetic modifications must be considered as a one of the main factors of unexplained male infertility etiology. Due to high risk of transmitting incorrect primary imprints to offspring, there is a need for more research into epigenetic alterations in couples who benefit of ART support.

Differential impact of four sperm preparation techniques on sperm motility, morphology, DNA fragmentation, acrosome status, oxidative stress, and mitochondrial activity: A prospective study

BACKGROUND

Suboptimal human semen handling in vitro may induce sperm damage. However, the effects of semen swim-up, pellet swim-up, density gradient, and density gradient followed by SU on sperm motility, morphology, DNA fragmentation, acrosome reaction, intracellular reactive oxygen species, and mitochondrial activity were not fully understood.

OBJECTIVES

To study the impact of four sperm preparation techniques on sperm functional parameters.

MATERIALS AND METHODS

This study was conducted on 60 infertile men with a minimum sperm concentration of 20 × 10⁶ /ml and total sperm motility of ≥30%. Each raw semen sample was divided into four aliquots. Each aliquot was prepared by one of the tested techniques. Various sperm characteristics were assessed before and after sperm preparation.

RESULTS

Density gradient and density gradient followed by SU resulted in significantly higher DNA fragmentation percentages compared with semen swim-up (p < 0.001 and p < 0.001, respectively) and pellet swim-up (p < 0.001 and p < 0.001, respectively). Significantly higher percentages of spermatozoa with intact acrosome were detected in semen swim-up (p < 0.001) and pellet swim-up (p < 0.001) compared with raw semen. The percentage of reactive oxygen species-positive spermatozoa was significantly higher after pellet swim-up (p < 0.001), density gradient (p < 0.001), and density gradient followed by SU (p < 0.001) than raw semen. In addition, the percentages of 100% stained midpiece (active mitochondria) were significantly higher in semen swim-up (p < 0.001) and pellet swim-up (p < 0.001) compared with raw semen.

DISCUSSION AND CONCLUSION

To the best of our knowledge, this is the first report comparing the impact of these techniques on various sperm functional parameters. Semen swim-up was more effective than density gradient in selecting better spermatozoa in terms of DNA integrity, reactive oxygen species levels, acrosome status, and mitochondrial activity. Randomized clinical trials comparing these four techniques are required to test their impact on embryo development and pregnancy outcomes.

Reproductive potential of the male (RPM): the computer database of phenotypic and molecular genetic data for Russian men with impaired and normal fertility

Currently, a trend of decline in male fertility is observed all over the world. The study of this trend has not only of scientific, but also of socio-economic importance. Many countries conduct studies of male reproductive potential and search environmental and genetic causes of the mentioned phenomenon. Previously published studies have not included data on the Russian male population. This work presents novel database “Reproductive Potential of the Male population of Russia” (RPM), which is almost the only source of such information about Russia. RPM was created using relational database management system MariaDB and is available at www.sysbio.ru/rpm. The database includes reproductive information of 1390 male volunteers from five large cities of Russia: Arkhangelsk, Novosibirsk, Kemerovo, Ulan-Ude and Yakutsk. The important feature of the developed database is the unique data of a multifactorial measurement of male fertility: spermatogenic, hormonal, metabolic and anthropological indices. The scientists can use published information in their studies of male reproductive potential as data of some Russian regions and compare it with data from other countries. Also the published data can be used to identify markers of infertility and subfertility, as well as to study ethnic and regional trends in fertility variability and demographic risks in Russia.