Leydig Cell-Specific DAX1-Deleted Mice Has Higher Testosterone Level in the Testis During Pubertal Development

L-Cysteine Upregulates Testosterone Biosynthesis and Blood-Testis Barrier Genes in Cultured Human Leydig Cells and THP-1 Monocytes and Increases Testosterone Secretion in Human Leydig Cells

Leydig cells are the primary source of testosterone or androgen production in male mammals. The blood-testis barrier (BTB) maintains structural integrity and safeguards germ cells from harmful substances by blocking their entry into the seminiferous tubules. L-cysteine is essential to the production of glutathione, a powerful antioxidant crucial to protecting against oxidative stress-induced damage. Animal studies have demonstrated the protective effect of L-cysteine in preventing testicular damage caused by chemicals or radiation. This study examines whether L-cysteine enhances the expression of testosterone biosynthesis and the BTB genes in human Leydig cells and THP-1 monocytes. The Leydig cells and THP-1 monocytes were treated with L-cysteine for 24 h. RNA was extracted following treatment, and the gene expression was analyzed using quantitative RT-PCR. Testosterone levels in the cell supernatant were measured using an ELISA kit. L-cysteine treatment in Leydig cells significantly upregulated the expression of CYP11A1 (p = 0.03) and the BTB genes CLDN1 (p = 0.03), CLDN11 (p = 0.02), and TJP1 (p = 0.02). Similarly, L-cysteine significantly upregulated the expression of CYP11A1 (p = 0.03) and CYP19A1 (p < 0.01), and the BTB genes CLDN1 (p = 0.04), CLDN2 (p < 0.01), CLDN4 (p < 0.01), CLDN11 (p < 0.01), and TJP1 (p = 0.03) in THP-1 monocytes. Further, L-cysteine supplementation increased the testosterone secretion levels in human Leydig cells. The findings suggest that L-cysteine supplementation could be used as an adjuvant therapy to promote the integrity of the BTB genes, testosterone biosynthesis and secretion, and the maintenance of testicular functions, which in turn mitigates the risk of male infertility.

Diaph1 knockout inhibits mouse primordial germ cell proliferation and affects gonadal development

BACKGROUND

Exploring the molecular mechanisms of primordial germ cell (PGC) migration and the involvement of gonadal somatic cells in gonad development is valuable for comprehending the origins and potential treatments of reproductive-related diseases.

METHODS

Diaphanous related formin 1 (Diaph1, also known as mDia1) was screened by analyzing publicly available datasets (ATAC-seq, DNase-seq, and RNA-seq). Subsequently, the CRISPR-Cas9 technology was used to construct Diaph1 knockout mice to investigate the role of Diaph1 in gonad development.

RESULTS

Based on data from public databases, a differentially expressed gene Diaph1, was identified in the migration of mouse PGC. Additionally, the number of PGCs was significantly reduced in Diaph1 knockout mice compared to wild type mice, and the expression levels of genes related to proliferation (Dicer1, Mcm9), adhesion (E-cadherin, Cdh1), and migration (Cxcr4, Hmgcr, Dazl) were significantly decreased. Diaph1 knockout also inhibited Leydig cell proliferation and induced apoptosis in the testis, as well as granulosa cell apoptosis in the ovary. Moreover, the sperm count in the epididymal region and the count of ovarian follicles were significantly reduced in Diaph1 knockout mice, resulting in decreased fertility, concomitant with lowered levels of serum testosterone and estradiol. Further research found that in Diaph1 knockout mice, the key enzymes involved in testosterone synthesis (CYP11A1, 3β-HSD) were decreased in Leydig cells, and the estradiol-associated factor (FSH receptor, AMH) in granulosa cells were also downregulated.

CONCLUSIONS

Overall, our findings indicate that the knockout of Diaph1 can disrupt the expression of factors that regulate sex hormone production, leading to impaired secretion of sex hormones, ultimately resulting in damage to reproductive function. These results provide a new perspective on the molecular mechanisms underlying PGC migration and gonadal development, and offer valuable insights for further research on the causes, diagnosis, and treatment of related diseases.

Oral administration of Turnera diffusa willd. ex Schult. extract ameliorates steroidogenesis and spermatogenesis impairment in the testes of rats with type-2 diabetes mellitus

ETHNOPHARMACOLOGICAL RELEVANCE

Turnera diffusa Willd. ex Schult. (T. diffusa) has traditionally been used to treat male reproductive dysfunction and have aphrodisiac properties.

AIMS OF THE STUDY

This study aims to investigate the ability of T. diffusa to ameliorate the impairment in testicular steroidogenesis and spermatogenesis in DM that might help to improve testicular function, and subsequently restore male fertility.

MATERIALS AND METHODS

DM-induced adult male rats were given 100 mg/kg/day and 200 mg/kg/day T. diffusa leaf extract orally for 28 consecutive days. Rats were then sacrificed; sperm and testes were harvested and sperm parameter analysis were performed. Histo-morphological changes in the testes were observed. Biochemical assays were performed to measure testosterone and testicular oxidative stress levels. Immunohistochemistry and double immunofluorescence were used to monitor oxidative stress and inflammation levels in testes as well as Sertoli and steroidogenic marker proteins' expression.

RESULTS

Treatment with T. diffusa restores sperm count, motility, and viability near normal and reduces sperm morphological abnormalities and sperm DNA fragmentation in diabetic rats. T. diffusa treatment also reduces testicular NOX-2 and lipid peroxidation levels, increases testicular antioxidant enzymes (SOD, CAT, and GPx) activities, ameliorates testicular inflammation via downregulating NF-ΚB, p-Ikkβ and TNF-α and upregulating IκBα expression. In diabetic rats, T. diffusa treatment increases testicular steroidogenic proteins (StAR, CYP11A1, SHBG, and ARA54, 3 and 17β-HSD) and plasma testosterone levels. Furthermore, in diabetic rats treated with T. diffusa, Sertoli cell marker proteins including Connexin 43, N-cadherin, and occludin levels in the testes were elevated.

CONCLUSION

T. diffusa treatment could help to ameliorate the detrimental effects of DM on the testes, thus this plant has potential to be used to restore male fertility.

Nuclear Receptor Gene Variants Underlying Disorders/Differences of Sex Development through Abnormal Testicular Development

Gonadal development is the first step in human reproduction. Aberrant gonadal development during the fetal period is a major cause of disorders/differences of sex development (DSD). To date, pathogenic variants of three nuclear receptor genes (NR5A1, NR0B1, and NR2F2) have been reported to cause DSD via atypical testicular development. In this review article, we describe the clinical significance of the NR5A1 variants as the cause of DSD and introduce novel findings from recent studies. NR5A1 variants are associated with 46,XY DSD and 46,XX testicular/ovotesticular DSD. Notably, both 46,XX DSD and 46,XY DSD caused by the NR5A1 variants show remarkable phenotypic variability, to which digenic/oligogenic inheritances potentially contribute. Additionally, we discuss the roles of NR0B1 and NR2F2 in the etiology of DSD. NR0B1 acts as an anti-testicular gene. Duplications containing NR0B1 result in 46,XY DSD, whereas deletions encompassing NR0B1 can underlie 46,XX testicular/ovotesticular DSD. NR2F2 has recently been reported as a causative gene for 46,XX testicular/ovotesticular DSD and possibly for 46,XY DSD, although the role of NR2F2 in gonadal development is unclear. The knowledge about these three nuclear receptors provides novel insights into the molecular networks involved in the gonadal development in human fetuses.

Vitamin D Receptor affects male mouse fertility via regulation of lipid metabolism and testosterone biosynthesis in testis

Vitamin D and vitamin D receptor (VD/VDR) plays a vital role in the development of spermatozoa, which is largely determined by the testosterone level in serum. Testosterone biosynthesis is closely related to lipid metabolism in gonadal adipose around testes. VDR could regulate lipid metabolism in adipocytes as well. However, it still remains unknown how VDR regulates lipid metabolism to impact testosterone biosynthesis in testis. Hereby, various parameters of male fertility were compared between wildtype (WT) and Vdr knockout (Vdr-KO) male mouse. For Vdr-KO mice, the size of testis and gonadal adipose was smaller than that of WT, and the sperm quality and testosterone level were lower than WT. Subsequently, testis proteome data between Vdr-KO and WT mice indicated that dysregulation of lipid metabolism was closely associated with decreased testosterone biosynthesis in Vdr-deficient mouse. And further evaluation of VDR functions in Leydig cells verified that VDR impacted lipid metabolism and regulated the expression of a range of genes involved in testosterone biosynthesis. Knockdown VDR could significantly decrease testosterone synthesis and secretion in Leydig cells. Meanwhile, expression of genes involved in androgen synthesis was decreased but genes related to lipolysis were up-regulated. Collectively, the present study unveiled the relationship between lipid metabolism and testosterone biosynthesis mediated by VDR in mouse testis and its effect on male fertility. These findings will greatly enhance our current understanding of VDR intermediate in lipid metabolism and androgen synthesis.

Fancd2os Reduces Testosterone Production by Inhibiting Steroidogenic Enzymes and Promoting Cellular Apoptosis in Murine Testicular Leydig Cells

BACKGRUOUND

It is well-established that serum testosterone in men decreases with age, yet the underlying mechanism of this change remains elusive.

METHODS

The expression patterns of Fancd2 opposite-strand (Fancd2os) in BALB/c male mice and testicular tissue derived cell lines (GC-1, GC-2, TM3, and TM4) were assessed using real-time polymerase chain reaction (RT-PCR), Western blot and immunofluorescence. The Fancd2os-overexpressing or knockdown TM3 cells were constructed by infecting them with lentivirus particles and were used to evaluated the function of Fancd2os. The testosterone production was measured using enzyme linked immunosorbent assay (ELISA) and the steroidogenic enzymes such as steroidogenic acute regulatory protein (StAR), P450 cholesterol side-chain cleavage (P450scc), and 3β-hydroxysteroid dehydrogenase (3β-HSD) were analysed using RT-PCR. The apoptosis of TM3 cells induced by ultraviolet light or testicular tissues was detected using flow cytometry, Western blot or dUTP-biotin nick end labeling (TUNEL) assays. Pearson correlation analysis was used to assess the correlation between the Fancd2os expression and TUNEL-positive staining in mouse testicular Leydig cells.

RESULTS

The Fancd2os protein was predominantly expressed in mouse testicular Leydig cells and its expression increased with age. Fancd2os overexpression inhibited testosterone levels in TM3 Leydig cells, whereas knockdown of Fancd2os elevated testosterone production. Fancd2os overexpression downregulated the levels of StAR, P450scc and 3β-HSD, while Fancd2os knockdown reversed this effect. Fancd2os overexpression promoted ultraviolet light-induced apoptosis of TM3 cells. In contrast, Fancd2os knockdown restrained apoptosis in TM3 cells. In vivo assays revealed that higher Fancd2os levels and mouse age were associated with increased apoptosis in Leydig cells and decreased serum testosterone levels. Pearson correlation analysis exhibited a strong positive correlation between the expression of Fancd2os and TUNEL-positive staining in mouse testicular Leydig cells.

CONCLUSION

Our findings suggest that Fancd2os regulates testosterone synthesis via both steroidogenic enzymes and the apoptotic pathway.

Improvement of Astragalin on Spermatogenesis in Oligoasthenozoospermia Mouse Induced by Cyclophosphamide

More than 40% of infertile men are diagnosed with oligoasthenozoospermia and the incidence is still rising, but the effective treatments are not been found until now. Astragalin, one of the main active ingredients in traditional Chinese medicine, may be effective in the treatment of oligoasthenozoospermia. This study investigated the pharmacological effects of astragalin for treatment of oligoasthenozoospermia in male mice, induced by cyclophosphamide (CTX). Male mice were intraperitoneally injected by CTX (50 mg/kg), and astragalin (30 mg/kg) was given via oral gavage once daily. RNA-seq analysis highlighted astragalin upregulated gene expression of anti-apoptosis (AKT1and BCL2-XL), cell proliferation (ETV1, MAPKAPK2, and RPS6KA5) and synthesis of testosterone (STAR, CYP11A1, and PRKACB), but downregulated gene expression of cell apoptosis (BAD, BCL-2, CASPASE9, and CASPASE3) in mouse testis. Astragalin also significantly reversed the reduction in body weight, reproductive organs index, and sperm parameters (sperm concentration, viability, and motility) induced by CTX, and restored testicular abnormal histopathologic morphology induced by CTX. Furthermore, astragalin dramatically rescued the gene expression related to spermatogenesis (AKT1, BCL-2, CASPASE9, CASPASE3, MAPKAPK2, RPS6KA5, STAR, and PRKACB), and increased the level of testosterone by improving related proteins (STAR, CYP11A1, PRKACB) for oligoasthenozoospermia induced by CTX. In conclusion, astragalin may be a potential beneficial agent for oligoasthenozoospermia by increasing the testosterone levels in testis.