GATA-1 mutation alters the spermatogonial phase and steroidogenesis in adult mouse testis

Perfluorohexane Sulfonic Acid Disrupts the Immune Microenvironment for Spermatogenesis by Damaging the Structure of the Blood-Testis Barrier in Mice

Perfluorohexane sulfonic acid (PFHxS) is extensively used in waterproof coatings and fire-fighting foams, and several studies have found it to be a potential health hazard, but there is still unknown about its effects on spermatogenesis. Our results showed that PFHxS-treated mice have significant reproductive toxicity, including a decrease in sperm count and motility, and the levels of sex hormones (P < 0.05). Concurrently, structural abnormalities are observed in sperm, affecting ≈60-75% of those in the PFHxS-treated group. Additionally, it is found that the structure of the blood-testis barrier (BTB) is damaged after PFHxS treatment, leading to higher expression levels of inflammatory cytokines in the microenvironment for spermatogenesis. Moreover, the expression of proteins associated with mitochondrial biogenesis, including PTEN-induced kinase 1 (PINK1) and NADPH oxidase 4 (NOX4), is dysregulated in the testes after PFHxS treatment. Based on metabolome data, the differential metabolite 3-hydroxybutanoic acid is identified in the PFHxS-treated group, which can regulate the histone Kac levels, especially H3K4ac and H3K9ac. In summary, the results of this study suggest that in the testes of PFHxS-treated mice, inflammatory factors disrupt the mitochondrial function and metabolic profiles and hinder the progress of gene transcription through histone Kac, ultimately causing sperm dysfunction.

GATA3: Orchestrating cellular fate through differentiation and proliferation

Cell proliferation and differentiation are two fundamental biological processes that occur in biological systems, tightly regulated by various factors such as transcription factors (TFs). Zinc finger proteins are TFs responsible for maintaining the biological balance via coordinating development and functionality within the living cells. GATA binding protein 3 (GATA3), one of the zinc finger proteins, plays an essential role in driving differentiation and proliferation-related processes, thereby contributing to the regulation of the dynamism and productivity of living cells. By elucidating the complex interactions governed by GATA3, this underscores its significance in maintaining cellular homeostasis. Thus, the current review delves into the molecular pathways influenced by GATA3, highlighting its involvement in multiple developmental processes of various tissues and body sites, particularly in the hematopoietic system (T-cell differentiation), neural tissue differentiation, adipose tissue, as well as epithelial cell maturation.

Defects in the H3t Gene Cause an Increase in Leydig Cells With Impaired Spermatogenesis in Mice

Abnormalities in spermatogenesis, a fundamental component of male reproductive function, can cause male infertility. Somatic cells constituting the testis microenvironment are essential for controlling normal spermatogenesis. Although testicular somatic cells are thought to sense and respond to germ cells to ensure proper spermatogenesis, the details of this signaling mechanism are unknown. Here, we investigated somatic cell dynamics in testicular tissue lacking spermatogenesis using the mice with deletion of the testis-specific histone H3 variant gene H3t. Testicular tissue sections of H3tΔ/Δ mice exhibited an increased interstitial area compared with those of wild-type mice, which was primarily attributed to an increase in Leydig cell numbers. Furthermore, this increase in Leydig cells led to increased testosterone synthesis, which occurred alongside cellular senescence-associated β-galactosidase activity. These findings suggest that Leydig cells monitor the progress of spermatogenesis and possess a mechanism to promote functional germ cell formation.

An association weight matrix identified biological pathways associated with bull fertility traits in a multi-breed population

Using seven indicator traits, we investigated the genetic basis of bull fertility and predicted gene interactions from SNP associations. We used percent normal sperm as the key phenotype for the association weight matrix-partial correlation information theory (AWM-PCIT) approach. Beyond a simple list of candidate genes, AWM-PCIT predicts significant gene interactions and associations for the selected traits. These interactions formed a network of 537 genes: 38 genes were transcription cofactors, and 41 genes were transcription factors. The network displayed two distinct clusters, one with 294 genes and another with 243 genes. The network is enriched in fertility-associated pathways: steroid biosynthesis, p53 signalling, and the pentose phosphate pathway. Enrichment analysis also highlighted gene ontology terms associated with 'regulation of neurotransmitter secretion' and 'chromatin formation'. Our network recapitulates some genes previously implicated in another network built with lower-density genotypes. Sequence-level data also highlights additional candidate genes relevant to bull fertility, such as FOXO4, FOXP3, GATA1, CYP27B1, and EBP. A trio of regulatory genes-KDM5C, LRRK2, and PME-was deemed core to the network because of their overarching connections. This trio probably influences bull fertility through their interaction with genes, both known and unknown as to their role in male fertility. Future studies may target the trio and their target genes to enrich our understanding of male fertility further.

Effects of superparamagnetic iron oxide nanoparticles (SPIONS) testicular injection on Leydig cell function and sperm production in a murine model

In the domain of medical advancement, nanotechnology plays a pivotal role, especially in the synthesis of biocompatible materials for therapeutic use. Superparamagnetic Iron Oxide Nanoparticles (SPIONs), known for their magnetic properties and low toxicity, stand at the forefront of this innovation. This study explored the reproductive toxicological effects of Sodium Citrate-functionalized SPIONs (Cit_SPIONs) in adult male mice, an area of research that holds significant potential yet remains largely unknown. Our findings reveal that Cit_SPIONs induce notable morphological changes in interstitial cells and the seminiferous epithelium when introduced via intratesticular injection. This observation is critical in understanding the interactions of nanomaterials within reproductive biological systems. A striking feature of this study is the rapid localization of Cit_SPIONs in Leydig cells post-injection, a factor that appears to be closely linked with the observed decrease in steroidogenic activity and testosterone levels. This data suggests a possible application in developing nanostructured therapies targeting androgen-related processes. Over 56 days, these nanoparticles exhibited remarkable biological distribution in testis parenchyma, infiltrating various cells within the tubular and intertubular compartments. While the duration of spermatogenesis remained unchanged, there were many Tunel-positive germ cells, a notable reduction in daily sperm production, and reduced progressive sperm motility in the treated group. These insights not only shed light on the intricate mechanisms of Cit_SPIONs interaction with the male reproductive system but also highlight the potential of nanotechnology in developing advanced biomedical applications.

Acute murine-betacoronavirus infection impairs testicular steroidogenesis and the quality of sperm production

Although several testicular alterations promoted by coronavirus infection have been demonstrated, the extent, causes, and players of testicular pathogenesis are not totally understood. The present study aimed to investigate the short-term effects on male fertility of intranasally administered murine hepatitis virus strain 3 (MHV-3), a member of the genus Betacoronavirus, which causes a severe systemic acute infection. This mouse model might be used as a in vivo prototype for investigating the impact of betacoronavirus on the endocrine and exocrine testicular functions with the advantage to be performed in a biosafety level 2 condition. Herein, we performed virological, histopathological, and molecular studies regarding the testicular spermatogenesis and the spermatic quality analyses in an MHV-3-infected C57BL/6 mice. The main outcomes showed that MHV-3 infects mouse testis and induces a testicular inflammatory state, impairing the steroidogenic pathway. The infection led to several alterations in the testicular parenchyma, such as: seminiferous epithelium sloughing, retention of residual bodies, germ cell apoptosis, alterations in intercellular junction proteins, and worse spermatogenic parameters. Moreover, the levels of plasmatic testosterone as well as the quality of sperm production reduced. Therefore, the present data suggest that the viral/inflammatory impairment of the steroidogenic pathway and the consequent imbalance of androgen levels is critical in testicular pathology, disturbing the SC barrier function and the germ cell differentiation. Our study is important for comprehending the effects of beta coronavirus infections on testis function in order to develop treatments that could prevent virus-mediated male infertility.

Male reproductive phenotypes of genetically altered laboratory mice (Mus musculus): a review based on pertinent literature from the last three decades

Laboratory mice (Mus musculus) are preferred animals for biomedical research due to the close relationship with humans in several aspects. Therefore, mice with diverse genetic traits have been generated to mimic human characteristics of interest. Some genetically altered mouse strains, on purpose or by accident, have reproductive phenotypes and/or fertility deviating from wild-type mice. The distinct reproductive phenotypes of genetically altered male mice mentioned in this paper are grouped based on reproductive organs, beginning with the brain (i.e., the hypothalamus and anterior pituitary) that regulates sexual maturity and development, the testis where male gametes and sex steroid hormones are produced, the epididymis, the accessory sex glands, and the penis which involve in sperm maturation, storage, and ejaculation. Also, distinct characteristics of mature sperm from genetically altered mice are described here. This repository will hopefully be a valuable resource for both humans, in terms of future biomedical research, and mice, in the aspect of the establishment of optimal sperm preservation protocols for individual mouse strains.

Identification of a New Enhancer That Promotes Sox9 Expression by a Comparative Analysis of Mouse and Sry-Deficient Amami Spiny Rat

INTRODUCTION

Testis differentiation is initiated by the SRY gene on the Y chromosome in mammalian species. However, the Amami spiny rat, Tokudaia osimensis, lacks both the Y chromosome and the Sry gene and acquired a unique Sox9 regulatory mechanism via a male-specific duplication upstream of Sox9, without Sry. In general mammalian species, the SRY protein binds to a testis-specific enhancer to promote SOX9 gene expression. Several enhancers located upstream of Sox9/SOX9 have been reported in mice and humans. In particular, the binding of SRY to the highly conserved enhancer Enh13 is thought to be a common mechanism underlying testis differentiation and sex determination in mammals.

METHODS

Sequences of T. osimensis homologues of three Sox9 enhancers that were previously reported in mice, Enh8, Enh14, and Enh13, were determined. We performed in vitro assays to confirm enhancer activity involved in Sox9 regulation in T. osimensis.

RESULTS

T. osimensis Enh13 showed enhancer activity when co-transfected with NR5A1 and SOX9. Mouse Enh13 was activated by NR5A1 and SRY; however, T. osimensis Enh13 did not respond to SRY, even though the binding sites of SRY and NR5A1 were conserved. To identify the key sequence that is present in mouse but absent from T. osimensis, we performed reporter gene assays using vectors in which partial sequences of T. osimensis Enh13 were replaced with mouse sequences. For T. osimensis Enh13 in which the second half (approximately 430 bp) was replaced with the corresponding mouse sequence, activity in response to NR5A1 and SRY was recovered. Further, reporter assays revealed that multiple regions in the second half of the mouse Enh13 sequence are required for the response to NR5A1 and SRY. The latter 49 bp was particularly important and contained four binding sites for three transcription factors, POU2F1, HOXA3, and GATA1.

CONCLUSION

We showed that there are unknown sequences responsible for the interaction between NR5A1 and SRY and mEnh13 based on comparative analyses of Sry-dependent and Sry-independent species. Our comparative analyses revealed new molecular mechanisms underlying mammalian sex determination.

Gold nanoparticle intratesticular injections as a potential animal sterilization tool: Long-term reproductive and toxicological implications

This study aimed to evaluate the gold nanoparticles (AuNPs) animal sterilizing potential after intratesticular injections and long-term adverse reproductive and systemic effects. Adult male Wistar rats were divided into control and gold nanoparticle (AuNPs) groups. The rats received 200µL of saline or AuNPs solution (16µg/mL) on experimental days 1 and 7 (ED1 and ED7). After 150 days, the testicular blood flow was measured, and the rats were mated with females. After mating, male animals were euthanized for histological, cellular, and molecular evaluations. The female fertility indices and fetal development were also recorded. The results indicated increased blood flow in the testes of treated animals. Testes from treated rats had histological abnormalities, shorter seminiferous epithelia, and oxidative stress. Although the sperm concentration was lower in the AuNP-treated rats, there were no alterations in sperm morphology. Animals exposed to AuNPs had decreased male fertility indices, and their offspring had lighter and less efficient placentas. Additionally, the anogenital distance was longer in female fetuses. There were no changes in the histology of the kidney and liver, the lipid profile, and the serum levels of LH, testosterone, AST, ALT, ALP, albumin, and creatinine. The primary systemic effect was an increase in MDA levels in the liver and kidney, with only the liver experiencing an increase in CAT activity. In conclusion, AuNPs have a long-term impact on reproduction with very slight alterations in animal health. The development of reproductive biotechnologies that eliminate germ cells or treat local cancers can benefit from using AuNPs.