Increased Testosterone Production Research Articles

Causal association between low vitamin D and polycystic ovary syndrome: a bidirectional mendelian randomization study

BackgroundRecent studies have revealed the correlation between serum vitamin D (VD) level and polycystic ovary syndrome (PCOS), but the causality and specific mechanisms remain uncertain.ObjectiveWe aimed to investigate the cause-effect relationship between serum VD and PCOS, and the role of testosterone in the related pathological mechanisms.MethodsWe assessed the causality between serum VD and PCOS by using genome-wide association studies (GWAS) data in a bidirectional two-sample Mendelian randomization (TS-MR) analysis. Subsequently, a MR mediation analysis was conducted to examine the mediating action of testosterone in the causality between serum VD and PCOS. Ultimately, we integrated GWAS data with cis-expression quantitative loci (cis-eQTLs) data for gene annotation, and used the potentially related genes for functional enrichment analysis to assess the involvement of testosterone and the potential mechanisms.ResultsTS-MR analysis showed that individuals with lower level of serum VD were more likely to develop PCOS (OR = 0.750, 95% CI: 0.587–0.959, P = 0.022). MR mediation analysis uncovered indirect causal effect of serum VD level on the risk of PCOS via testosterone (OR = 0.983, 95% CI: 0.968–0.998, P = 0.025). Functional enrichment analysis showed that several pathways may be involved in the VD-testosterone-PCOS axis, such as steroid hormone biosynthesis and autophagy process.ConclusionOur findings suggest that genetically predicted lower serum VD level may cause a higher risk of developing PCOS, which may be mediated by increased testosterone production.

DENND1A desensitizes granulosa cells to FSH by arresting intracellular FSHR transportation.

Polycystic ovary syndrome (PCOS) is a complex disorder. Genome-wide association studies (GWAS) have identified several genes associated with this condition, including DENND1A. DENND1A encodes a clathrin-binding protein that functions as a guanine nucleotide exchange factor involved in vesicular transport. However, the specific role of DENND1A in reproductive hormone abnormalities and follicle development disorders in PCOS remain poorly understood. In this study, we investigated DENND1A expression in ovarian granulosa cells (GCs) from PCOS patients and its correlation with hormones. Our results revealed an upregulation of DENND1A expression in GCs from PCOS cases, which was positively correlated with testosterone levels. To further explore the functional implications of DENND1A, we generated a transgenic mouse model overexpressing Dennd1a (TG mice). These TG mice exhibited subfertility, irregular estrous cycles, and increased testosterone production following PMSG stimulation. Additionally, the TG mice displayed diminished responsiveness to FSH, characterized by smaller ovary size, less well-developed follicles, and abnormal expressions of FSH-priming genes. Mechanistically, we found that Dennd1a overexpression disrupted the intracellular trafficking of follicle stimulating hormone receptor (FSHR), promoting its internalization and inhibiting recycling. These findings shed light on the reproductive role of DENND1A and uncover the underlying mechanisms, thereby contributing valuable insights into the pathogenesis of PCOS and providing potential avenues for drug design in PCOS treatment.

A Systemic Review on Use of Medicinal Plant for Management of Male Infertility

A recent issue with current society is the fall in male infertility. In 50% of instances, couple infertility is caused by the failure in spermatogenesis of the male partner. The male reproductive system is impacted by a variety of factors that lead to infertility, including genitourinary tract infections, endocrine abnormalities, immunological factors, lifestyle, stress, and drug-related damage. There are medications and therapies for male infertility, but they are not very effective, have harmful side effects, and are contraindicated. Plants are among the greatest natural cures for illnesses since they have very few side effects and include a variety of phytoconstituents from different chemical classes. Depending on their concentration, plant bioactive such as flavonoids, polyphenols, glycosides, alkaloids, and terpenoids might have a variable effect on sperm quality - either positively or adversely. These compounds have been suggested as organic reactive oxygen species scavengers for the treatment of male infertility. This review makes an effort to compile the available information and offer perspectives for upcoming investigations on how plants affect male gonads. This review summarizes the most recent research on the use of phytoconstituents to increase testosterone production, support healthy spermatogenesis, and prevent age-related degenerative illnesses linked to low levels of testosterone. This review includes information on about 45 herbal plants that have been published in several papers. The articles have several headings, including plant taxonomy, bioactive components, impacts on fertility, and medical applications. This review provides information on the applications of natural sources for male fertility enhancement and their potential mechanisms of action.

In vitro effects of uncarboxylated osteocalcin on buffalo Leydig cell steroidogenesis.

Uncarboxylated osteocalcin (UcOCN), a bone derived circulating protein, has been demonstrated to influence steroidogenesis in testicular Leydig cells of murine and human species. However, the role of UcOCN in testosterone biosynthesis remains unexplored in domestic animals. The present study aimed to investigate the impact of UcOCN on the expressions of steroidogenic genes (HSD3β1, HSD3β6, CYP17A1, CYP11A1), testosterone production and GPRC6A receptor localization in buffalo Leydig cells. Leydig cells from the testes of adult Murrah buffalo were isolated, with an average cell count and viability after digestion and Percoll enrichment of 1.43 × 106 cells/g of testes and 78.5%, respectively. Immunophenotyping of Percoll-enriched cell suspension by flow cytometry showed populations of Leydig cells ranging between 69 and 73.9%. Immunostaining confirmed the presence of GPRC6A receptors and CYP11A1 positive Leydig cells. When these cells were cultured and incubated with varying levels of UcOCN (6, 12, 24, and 48 ng/ml) and LH, there was a significant (P < 0.01) increase in testosterone production and up-regulation (P < 0.05) of CYP11A1, CYP17A1, HSD3β1 and HSD3β6 gene expression. In summary, the present study underscored the effects of UcOCN on testosterone biosynthesis, expression of crucial steroidogenic genes and interaction with GPRC6A receptors in buffalo Leydig cells, emphasizing its potential implications in andrology.

Autophagy-related 7 proteindependent autophagy mediates resveratrol-caused upregulation of mitochondrial biogenesis and steroidogenesis in aged Leydig cell.

Mitochondrial dysfunction may contribute to decreased testosterone synthesis in aged Leydig cells. Resveratrol (RSV) as an antioxidant has been shown to exhibit multiple positive effects on mitochondrion, where steroidogenesis takes place. Whether RSV can improve steroidogenesis in aged testis is still unknown. This study investigates the effect of RSV on testosterone production during aging and corresponding changes in mitochondrial biogenesis and autophagy activity, which are closely associated with steroidogenesis. Whether ATG7, an important autophagy-related protein, functions in RSV-treated aged Leydig cells will also be explored. Two-month-old male C57BL/6 mice were fed for 16 months by customized regular diet with or without RSV as diet supplement. Leydig cell line TM3 cells were treated with D-galactose to induce senescence, followed with or without RSV treatment. Results found that RSV supplement increased testosterone production in both aged mice and D-galactose-induced senescent Leydig cells. Western blot results revealed that RSV treatment elevated levels of steroidogenic rate-limiting enzymes StAR and 3β-HSD, as well as autophagy-related proteins LC3II, Beclin1, ATG5 and ATG7 and mitochondrial function-related proteins mtTFA and COXIV. However, after Atg7 was knocked down in senescent Leydig cells, even though RSV was added, levels of these proteins declined significantly, accompanied by decreased levels of mitochondrial transcript factors PGC-1α, mtTFA and NRF-1 and more fragmented mitochondria, demonstrating that Atg7 knockdown wrecked the protective effects of RSV on steroidogenesis in senescent Leydig cells. ATG7-dependent autophagy plays a key role in RSV-brought testosterone production increase through regulating mitochondrial biogenesis in senescent Leydig cells.

The glucocorticoid-activating enzyme 11β-hydroxysteroid dehydrogenase type 1 catalyzes the activation of testosterone

Testosterone biosynthesis from its precursor androstenedione is thought to be exclusively catalysed by the 17β-hydroxysteroid dehydrogenases—HSD17B3 in testes, and AKR1C3 in the ovary, adrenal and peripheral tissues. Here we show for the first time that the glucocorticoid activating enzyme 11β-hydroxysteroid dehydrogenase type 1 (HSD11B1) can also catalyse the 17β-reduction of androstenedione to testosterone, using a combination of in vitro enzyme kinetic assays, mathematical modelling, and molecular docking analysis. Furthermore, we show that co-expression of HSD11B1 and AKR1C3 increases testosterone production several-fold compared to the rate observed with AKR1C3 only, and that HSD11B1 is likely to contribute significantly to testosterone production in peripheral tissues.

Studying the effect of hyperoside on recovery from cyclophosphamide induced oligoasthenozoospermia

Oligoasthenozoospermia is becoming a serious problem, but effective prevention or treatment is lacking. Hyperoside, one of the main active ingredients in traditional Chinese medicine, may be effective in the treatment of oligoasthenozoospermia. In this study, we used cyclophosphamide (CTX: 50 mg/kg) to establish a mouse model of Oligoasthenozoospermia to investigate the therapeutic effect of hyperoside (30 mg/kg) on CTX-induced oligoasthenozoospermia. All mice were divided into four groups: blank control group (Control), treatment control group (Hyp), disease group (CTX) and treatment group (CTX + H). Mice body weight, testicular weight, sperm parameters and testicular histology were used to assess the reproductive capacity of mice and to explore the underlying mechanism of hyperoside in the treatment of oligoasthenozoospermia by assessing hormone levels, protein levels of molecules related to hormone synthesis and transcript levels of important genes related to spermatogenesis. Treatment with hyperoside significantly improved sperm density, sperm viability and testicular function compared to untreated oligoasthenozoospermia mice. In mechanism, treatment with hyperoside resulted in significant improvement in pathological changes in spermatogenic tubules, with an increase in testosterone production, and upregulations of Protein Kinase CAMP-Activated Catalytic Subunit Beta (PRKACB), Steroidogenic Acute Regulatory Protein (STAR), and Cytochrome P450 Family 17 Subfamily A Member 1 (CYP17A1) for testosterone production. Hyperoside also promoted the cell cycle of germ cells and up-regulated meiosis and spermatogenesis-related genes, including DNA Meiotic Recombinase 1 (Dmc1), Ataxia telangiectasia mutated (Atm) and RAD21 Cohesin Complex Component (Rad21). In conclusion, hyperoside exerted protective effects on oligoasthenozoospermia mice by regulating testosterone production, meiosis and sperm maturation of germ cells.

Nesfatin-1 in a reptile: its role and hormonal regulation in wall lizard testis

Nesfatin-1 is a pleiotropic hormone implicated in various physiological functions including reproduction. Studies though limited, have established an important role of the peptide in regulation of testicular functions in mammals and fishes. However, role of nesfatin-1 in regulation of spermatogenesis and testicular steroidogenesis remains completely unexplored in reptiles. Therefore, present study aimed to develop an insight into reproductive phase-dependent testicular expression, function and regulation of nucb2/nesfatin-1 in a reptile, Hemidactylus flaviviridis. Expression of nucb2/nesfatin-1 in testis of wall lizard varied significantly depending upon reproductive phase, being highest in the active phase while lowest during regressed phase. Further, in vitro treatment of wall lizard testis with nesfatin-1 showed a concentration- and time-dependent stimulatory effect of the peptide on expression of cell proliferation and differentiation markers like scf, c-kit and pcna suggesting a spermatogenic role of nesfatin-1 in wall lizard. Also, nesfatin-1 stimulated the anti-apoptotic marker, bcl-2 while inhibited the apoptotic marker, caspase-3, suggesting its role as an inhibitor of apoptosis of testicular cells. Further, treatment with nesfatin-1 resulted in significantly higher expression of star along with a concomitant increase in testosterone production by the lizard testis. The present study also demonstrates hormonal regulation of testicular nucb2/nesfatin-1 wherein follicle-stimulating hormone (FSH) inhibited while sex steroids like dihydrotestosterone (DHT) and 17β-estradiol-3-benzoate (E2) stimulated the mRNA expression of nesfatin-1. Observations from the current study for the first time provide comprehensive evidence of spermatogenic and steroidogenic role of nesfatin-1 as well as its hormonal regulation in the testis of a reptile, H. flaviviridis.

Impact of Biotin Supplementation on Human Chorionic Gonadotropin Immunoassays Utilizing Biotin-Streptavidin Binding Methods in Urine.

Human chorionic gonadotropin (hCG) detection is indicative of pregnancy and can be indicative of some forms of cancerous tumors. The hCG drug itself, however, is a performance enhancing substance used by male athletes to increase testosterone production. Antidoping testing for hCG is conducted in urine, often on immunoanalyzer platforms, many of which utilize biotin-streptavidin dependent immunoassays in which the presence of biotin in samples is a known confounding factor. While biotin interference in serum has been well-studied, the extent of biotin interference in urine has not. Ten active male individuals underwent a 2-week hCG administration protocol concurrent with supplementation with biotin (20 mg/day) or placebo. Urine and serum samples were collected throughout the study and analyzed for hCG and biotin concentrations. Urinary biotin levels in the hCG + biotin group increased 500-fold over baseline and 29-fold over corresponding serum biotin levels after biotin supplementation. When using a biotin-dependent immunoassay, the hCG + placebo group produced hCG-positive results (hCG ≥ 5 mIU/mL) in 71% of urine samples, while the hCG + biotin group produced positive results in only 19% of samples. Both groups had elevated hCG values in serum measurements by a biotin-dependent immunoassay and in urine when using a biotin-independent immunoassay. Urinary hCG measurements and biotin levels from the hCG + biotin group showed a negative correlation (Spearman r = -0.46, P < 0.0001) when measured using a biotin-dependent immunoassay. Biotin supplementation can severely suppress urinary hCG values in assays utilizing biotin-streptavidin binding methods and therefore these types of assays are not recommended for use in urine samples containing high levels of biotin. Clinicaltrials.gov Registration Number: NCT05450900.

Selenium nanoparticles improve nickel-induced testosterone synthesis disturbance by down-regulating miR-708-5p/p38 MAPK pathway in Leydig cells.

The present study was designed to investigate the role of miR-708-5p/p38 mitogen-activated protein kinase (MAPK) pathway during the mechanism of selenium nanoparticles (Nano-Se) against nickel (Ni)-induced testosterone synthesis disorder in rat Leydig cells. We conducted all procedures based on in vitro culture of rat primary Leydig cells. After treating Leydig cells with Nano-Se and NiSO4 alone or in combination for 24 h, we determined the cell viability, reactive oxygen species (ROS) levels, testosterone production, and the protein expression of key enzymes involved in testosterone biosynthesis: steroidogenic acute regulatory (StAR) and cytochrome P450 cholesterol side chain cleavage enzyme (CYP11A1). The results indicated that Nano-Se antagonized cytotoxicity and eliminated ROS generation induced by NiSO4 , suppressed p38 MAPK protein phosphorylation and reduced miR-708-5p expression. Importantly, we found that Nano-Se upregulated the expression of testosterone synthase and increased testosterone production in Leydig cells. Furthermore, we investigated the effects of p38 MAPK and miR-708-5p using their specific inhibitor during Nano-Se against Ni-induced testosterone synthesis disorder. The results showed that Ni-inhibited testosterone secretion was alleviated by Nano-Se co-treatment with p38 MAPK specific inhibitor SB203580 and miR-708-5p inhibitor, respectively. In conclusion, these findings suggested Nano-Se could inhibit miR-708-5p/p38 MAPK pathway, and up-regulate the key enzymes protein expression for testosterone synthesis, thereby antagonizing Ni-induced disorder of testosterone synthesis in Leydig cells.

Enokitake Mushroom and Its Active Component, Adenosine, Which Restores Testosterone Production in Impaired and Fatigued Mouse Models

Several studies have reported the effects of the consumption of various mushroom species on the testes in animal experimental models. Mushrooms, including enokitake mushrooms (Flammulina velutipes), and vegetables contain adenosine may affect testosterone production. Here, we aimed to elucidate the effects of enokitake and its active component, adenosine, on testosterone production in primary cultures of testicular cells in vivo using mice models and in vitro. The administration of enokitake ethanolic extract increased testosterone production in the cisplatin-impaired mouse model. The direct effect of mushroom extracts on testicular cells was examined and liquid chromatography–mass spectrometry analysis confirmed that the mushroom- and vegetable-induced increase in testosterone production mainly involved adenosine. Additionally, the administration of enokitake extract or adenosine to wet floor fatigue model mice promoted testicular testosterone production and enhanced Leydig cell function through insulin-like peptide three level upregulation. Structurally related compounds, including cordycepin, showed lower bioactivity than adenosine. This study showed that the ingestion of adenosine-containing mushrooms and vegetables may effectively increase testicular testosterone production. We conclude that mushrooms with a relatively high adenosine content, such as enokitake, may be useful against aging and fatigue.

SARS-CoV-2 Enters Human Leydig Cells and Affects Testosterone Production In Vitro.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a SARS-like coronavirus, continues to produce mounting infections and fatalities all over the world. Recent data point to SARS-CoV-2 viral infections in the human testis. As low testosterone levels are associated with SARS-CoV-2 viral infections in males and human Leydig cells are the main source of testosterone, we hypothesized that SARS-CoV-2 could infect human Leydig cells and impair their function. We successfully detected SARS-CoV-2 nucleocapsid in testicular Leydig cells of SARS-CoV-2-infected hamsters, providing evidence that Leydig cells can be infected with SARS-CoV-2. We then employed human Leydig-like cells (hLLCs) to show that the SARS-CoV-2 receptor angiotensin-converting enzyme 2 is highly expressed in hLLCs. Using a cell binding assay and a SARS-CoV-2 spike-pseudotyped viral vector (SARS-CoV-2 spike pseudovector), we showed that SARS-CoV-2 could enter hLLCs and increase testosterone production by hLLCs. We further combined the SARS-CoV-2 spike pseudovector system with pseudovector-based inhibition assays to show that SARS-CoV-2 enters hLLCs through pathways distinct from those of monkey kidney Vero E6 cells, a typical model used to study SARS-CoV-2 entry mechanisms. We finally revealed that neuropilin-1 and cathepsin B/L are expressed in hLLCs and human testes, raising the possibility that SARS-CoV-2 may enter hLLCs through these receptors or proteases. In conclusion, our study shows that SARS-CoV-2 can enter hLLCs through a distinct pathway and alter testosterone production.

Testicular Adrenal Rest Tumor

A 17-year-old boy with a history of classic congenital adrenal hyperplasia (CAH) secondary to 21-α hydroxylase deficiency on treatment with hydrocortisone and fludrocortisone presented to the endocrinology clinic with bilateral painful testicular masses. Previous urologic evaluation revealed no evidence of hydrocele or epididymitis. Semen analysis showed azoospermia. Physical examination demonstrated Tanner stage V and normal phallus; the left testicle measured approximately 8 cm, and the right testicle measured 7 cm in largest diameter (Fig. 1 and 2). Laboratory evaluation showed the following: (1) alfa-fetoprotein level, 1.4 (reference range, 0.0-10.0) ng/mL; (2) human chorionic gonadotropin level, <0.1 (reference range, 0.0-1.0) mU/mL; (3) total testosterone level, 541 (reference range, 250-1100) ng/dL; (4) follicle-stimulating hormone level, 11.4 (reference range, 1.5-12.4) mU/mL; (5) luteinizing hormone level, 1.7 (reference range, 1.7-11) mU/mL; (6) adrenocorticotropic hormone level, 86 (reference range, 6-50) pg/mL; and (7) inhibin A level, <1 (reference range, <21) pg/mL.Fig. 2The left testicle measuring approximately 8 cm in largest diameter.View Large Image Figure ViewerDownload Hi-res image Download (PPT) Scrotal ultrasound revealed markedly enlarged testes (60 mL and 70 mL) with hyperemia and no discrete masses, findings consistent with testicular adrenal rest tumor (TART) (Fig. 3). Partial orchiectomy confirmed the diagnosis. TARTs are firm bilateral painful masses originating near the rete testes developed in men with poorly controlled classic 21-α hydroxylase deficiency under the influence of chronically elevated adrenocorticotropic hormone levels. In recent studies, an overall prevalence of 40% (14%-89%) has been reported in patients with classic CAH.1Engels M. Span P.N. van Herwaarden A.E. Sweep F.C.G.J. Stikkelbroeck N.M.M.L. Claahsen-van der Grinten H.L. Testicular adrenal rest tumors: current insights on prevalence, characteristics, origin, and treatment.Endocr Rev. 2019; 40: 973-987Crossref PubMed Scopus (53) Google Scholar Ultrasonography is the most sensitive method of diagnosis. This condition is the most common cause of infertility in male patients with CAH. Although surgery can relieve the pain associated with the mass, it does not lead to increased testosterone production and improved fertility. Intensified glucocorticoid therapy is sometimes, but not always, effective in decreasing TART size and restoring fertility.2Claahsen-van der Grinten H.L. Otten B.J. Stikkelbroeck M.M. Sweep F.C. Hermus A.R. Testicular adrenal rest tumours in congenital adrenal hyperplasia.Best Pract Res Clin Endocrinol Metab. 2009; 23: 209-220Crossref PubMed Scopus (111) Google Scholar Routine physical examination along with annual ultrasound screening is recommended for early detection of the disease. The importance of good medication compliance was discussed with the patient, and the dosage of glucocorticoids was increased. The plan was to proceed with microdissection of testicular sperm extraction with cryopreservation in case fertility is not achieved by medical approach. The authors have no multiplicity of interest to disclose.

Schisandrol A and gomisin N from Schisandra chinensis extract improve hypogonadism via anti-oxidative stress in TM3 Leydig cells.

Male hypogonadism is a condition where the body does not produce enough testosterone and significantly impacts health. Age, obesity, genetics, and oxidative stress are some physiological factors that may contribute to testosterone deficiency. Previous studies have shown many pharmacological benefits of Schisandra chinensis (S. chinensis) Baillon as an anti-inflammatory and antioxidant. However, the molecular mechanism of attenuating hypogonadism is yet to be well established. This research was undertaken to study the effects of S. chinensis extract (SCE) on testosterone deficiency. S. chinensis fruit was pulverized and extracted using 60% aqueous ethanol. HPLC analysis was performed to analyze and quantify the lignans of the SCE. The 2,2-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) scavenging assays confirmed that the SCE and its major lignans (schisandrol A and gomisin N) inhibit oxidative stress. Effects of SCE analysis on the testosterone level under oxidative stress conditions revealed that both schisandrol A and gomisin N were able to recover the lowered testosterone levels. Through mRNA expression of TM3 Leydig cell, we observed that the SCE lignans were able to induce the enzymes involved in testosterone biosynthesis-related genes such as 3β-HSD4 (P < 0.01 for SCE, and P < 0.001 for schisandrol A and gomisin N), 17β-HSD3 (P < 0.001 for SCE, schisandrol A and gomisin N), and 17, 20-desmolase (P < 0.01 for schisandrol A, and P < 0.001 for SCE and gomisin N). These results support that SCE and its active components could be potential therapeutic agents for regulating and increasing testosterone production.

Korean Ginseng Berry Extract Enhances the Male Steroidogenesis Enzymes In Vitro and In Vivo.

Testosterone hormonal replacement is the most commonly prescribed solution for men with reproductive issues; however, this treatment has various drawbacks. Hence, the identification of a natural product that promotes steroidogenesis is urgently needed. Ginseng is a popular traditional medicine. This study aimed to investigate steroidogenic effects of Korean ginseng berry extract (GBE; Panax ginseng C.A. Meyer) in vitro and in vivo. In vitro model, mouse Leydig cells were treated with varying concentrations of GBE, and the levels of steroidogenesis-related genes and proteins and testosterone were measured using western blotting, qRT-PCR, and enzyme-linked immunosorbent assay (ELISA). Similarly, in an in vivo model using lipopolysaccharide-injected C57BL/6J mice, expression of steroidogenesis-related genes and proteins and testosterone levels were analyzed. Additionally, sleep deprivation was used to simulate common life stressors related to late-onset hypogonadism (LOH) and the natural effects of aging. Mice were fed sham or GBE before being subjected to paradoxical sleep deprivation. In vitro, GBE induced steroidogenic effects by increasing the levels of enzymes associated with steroidogenesis, steroidogenic acute regulatory protein (STAR), CYP11A1, and CYP17A1. In vivo, GBE significantly increased mRNA and protein levels of steroidogenic enzymes. Furthermore, the synthetic testosterone levels in mouse Leydig cell supernatants and blood sera were increased. In the sleep deprivation study, mice fed GBE showed increased testosterone production and survival under such stressful conditions. GBE increased mRNA and protein levels of steroidogenesis-related enzymes STAR, CYP11A1, and CYP17A1. These key enzymes induced the increased production of testosterone both in vivo and in vitro. Thus, GBE might be a promising therapeutic or additive nutritional agent for improving men's health by increasing steroidogenesis or improving LOH.

Biotin Enhances Testosterone Production in Mice and Their Testis-Derived Cells.

Late-onset hypogonadism, a male age-related syndrome characterized by a decline in testosterone production in the testes, is commonly treated with testosterone replacement therapy, which has adverse side effects. Therefore, an alternative treatment is highly sought. Supplementation of a high dosage of biotin, a water-soluble vitamin that functions as a coenzyme for carboxylases involved in carbohydrate, lipid, and amino acid metabolism, has been shown to influence testis functions. However, the involvement of biotin in testis steroidogenesis has not been well clarified. In this study, we examined the effect of biotin on testosterone levels in mice and testis-derived cells. In mice, intraperitoneal treatment with biotin (1.5 mg/kg body weight) enhanced testosterone levels in the serum and testes, without elevating serum levels of pituitary luteinizing hormone. To investigate the mechanism in which biotin increased the testosterone level, mice testis-derived I-10 cells were used. The cells treated with biotin increased testosterone production in a dose- and time-dependent manner. Biotin treatment elevated intracellular cyclic adenosine monophosphate levels via adenylate cyclase activation, followed by the activation of protein kinase A and testosterone production. These results suggest that biotin may have the potential to improve age-related male syndromes associated with declining testosterone production.

Testosterone promotion effect of Eucommia ulmoides staminate flower via the steroidogenic pathway and potential hormonal mechanism

Eucommia ulmoides staminate flowers (EUF), a newly approved functional food in China, have great potential for hormonal regulation. Herein, we aim to demonstrate the chemical composition and pharmacological activity of EUF in testosterone production and hormonal regulation. EUF extract and its components, kaempferol and geniposidic acid, exhibited a strong stimulating effect by increasing testosterone secretion, reducing ROS production, or promoting viability in Leydig cells. Meanwhile, the increased testosterone production was related to the upregulation of mRNA and protein expression of the steroidogenic pathway, such as steroidogenic acute-regulatory protein (StAR), 3β -hydroxysteroid dehydrogenase type 1 (HSD3B1), 17α-hydroxylase/17,20-lyase (CYP17A1), and nuclear receptor subfamily 5 group A member 1 (NR5A1). However, PKA inhibitor H89 or adenylyl cyclase inhibitor SQ22536 could block their effect. The results of transgenic yeast models showed the androgenic agonistic effects of kaempferol and naringenin and the estrogenic agonistic effects of rutin. These results indicated that the testosterone promotional effect of EUF was related to the activation of the steroidogenic pathway and potential hormonal regulation. Kaempferol and geniposidic acid might be the key active ingredients.

Bioproduction of testosterone from phytosterol by Mycolicibacterium neoaurum strains: “one-pot”, two modes

The main male hormone, testosterone is obtained from cheap and readily available phytosterol using the strains of Mycolicibacterium neoaurum VKM Ac-1815D, or Ac-1816D. During the first “oxidative” stage, phytosterol (5–10 g/L) was aerobically converted by Ac-1815D, or Ac-1816D to form 17-ketoandrostanes: androstenedione, or androstadienedione, respectively. At the same bioreactor, the 17-ketoandrostanes were further transformed to testosterone due to the presence of 17β-hydroxysteroid dehydrogenase activity in the strains (“reductive” mode). The conditions favorable for “oxidative” and “reductive” stages have been revealed to increase the final testosterone yield. Glucose supplement and microaerophilic conditions during the “reductive” mode ensured increased testosterone production by mycolicibacteria cells. Both strains effectively produced testosterone from phytosterol, but highest ever reported testosterone yield was achieved using M. neoaurum VKM Ac-1815D: 4.59 g/l testosterone was reached from 10 g/l phytosterol thus corresponding to the molar yield of over 66%. The results contribute to the knowledge on phytosterol bioconversion by mycolicibacteria, and are of significance for one-pot testosterone bioproduction from phytosterol bypassing the intermediate isolation of the 17-ketoandrostanes.Graphical

Characterization of Longitudinal Testosterone, Cortisol, and Musth in Male Asian Elephants (Elephas maximus), Effects of Aging, and Adrenal Responses to Social Changes and Health Events.

Simple SummaryThe conservation of endangered species and sustainability of managed populations requires good health and welfare of individuals. Male elephants experience a biological phenomenon called “musth”, characterized by a suite of physiological and behavioral changes which serve to facilitate copulation between the sexes, but can also pose unique challenges under human care. This study characterized longitudinal patterns of circulating testosterone and cortisol in relation to musth in four adult Asian elephant bulls and assessed age-related effects on musth activity and adrenal responses to social changes and clinical health events. All bulls exhibited regular annual musth cycles, and there was no clear evidence of chronically elevated cortisol secretion outside of musth. Circulating cortisol covaried positively with testosterone and musth, highlighting intrinsic patterns that should be considered when evaluating the impact of changes on adrenal glucocorticoid activity. Testosterone decreased with age in sexually mature bulls, whereas age-related changes in cortisol varied across individuals, with the three older bulls showing the greatest rate of change during musth. Changes in cortisol were associated with treatment for Mycobacterium tuberculosis in two bulls, but not with activation of disease. In contrast to physiological factors, there was no evidence that social changes involving male herdmates impacted adrenal glucocorticoid activity in the short term. This study highlights the importance of longitudinal hormone monitoring to track changes in physiological function and identify factors that may influence welfare, which is important for making more informed decisions on how to manage male elephants under varying degrees of human care.The conservation of endangered species and sustainability of managed populations requires considerations to ensure the health and welfare of individuals. Male elephants experience a biological phenomenon called “musth”, which is characterized by increased testosterone production, temporal gland secretion and urine dribbling, heightened aggression and sexual behavior, and therefore can pose unique challenges for human safety and animal welfare. This study characterized longitudinal (9 to 22 years) patterns of circulating testosterone and cortisol in relation to musth in four adult Asian elephant bulls spanning ages from 12 to 54 years. Age-related effects on musth activity and adrenal responses to social changes and clinical health events were also examined. All bulls exhibited regular annual musth cycles. Circulating cortisol covaried positively with testosterone and musth, highlighting intrinsic patterns that should be considered when evaluating the impact of social, health, and environmental changes on adrenal glucocorticoid activity. Except for an end-of-life cortisol increase in one bull, there was no clear evidence of chronically elevated cortisol secretion outside of musth in any individual. Testosterone decreased with age in sexually mature bulls, whereas age-related changes in cortisol varied across individuals, with the three older bulls showing the greatest rate of change during musth versus inter-musth periods. In contrast to physiological factors, there was no evidence of social factors, such as addition of a new male and death of male herdmates, impacting adrenal glucocorticoid activity in these bulls in the short term. Changes in cortisol were associated with treatment for Mycobacterium tuberculosis (M. tb) in two bulls, increasing after start of treatment and decreasing with cessation of treatment, but were not clearly associated with activation of disease. This study highlights the importance of longitudinal hormone monitoring to track changes in physiological function and responses to social, health, and environmental change in elephant bulls, which is important for making more informed decisions on how to manage male elephants under varying degrees of human care to ensure welfare and safety.

Leptin secreted from testicular microenvironment modulates hedgehog signaling to augment the endogenous function of Leydig cells

Although testosterone deficiency (TD) may be present in one out of five men 40 years or older, the factors responsible for TD remain largely unknown. Leydig stem cells (LSCs) differentiate into adult Leydig cells (ALC) and produce testosterone in the testes under the pulsatile control of luteinizing hormone (LH) from the pituitary gland. However, recent studies have suggested that the testicular microenvironment (TME), which is comprised of Sertoli and peritubular myoid cells (PMC), plays an instrumental role in LSC differentiation and testosterone production under the regulation of the desert hedgehog signaling pathway (DHH). It was hypothesized that the TME releases paracrine factors to modulate LSC differentiation. For this purpose, cells (Sertoli, PMCs, LSCs, and ALCs) were extracted from men undergoing testis biopsies for sperm retrieval and were evaluated for the paracrine factors in the presence or absence of the TME (Sertoli and PMC). The results demonstrated that TME secretes leptin, which induces LSC differentiation and increases testosterone production. Leptin’s effects on LSC differentiation and testosterone production, however, are inversely concentration-dependent: positive at low doses and negative at higher doses. Mechanistically, leptin binds to the leptin receptor on LSCs and induces DHH signaling to modulate LSC differentiation. Leptin-DHH regulation functions unidirectionally insofar as DHH gain or loss of function has no effect on leptin levels. Taken together, these findings identify leptin as a key paracrine factor released by cells within the TME that modulates LSC differentiation and testosterone release from mature Leydig cells, a finding with important clinical implications for TD.