Testosterone signaling and the regulation of spermatogenesis

Male Sex Hormones, Metabolic Syndrome, and Aquaporins: A Triad of Players in Male (in)Fertility

Infertility is becoming a chronic and emerging problem in the world. There is a resistant stigma that this health condition is mostly due to the female, although the literature supports that the responsibility for the onset of infertility is equally shared between both sexes in more or less equal proportions. Nevertheless, male sex hormones, particularly testosterone (T), are key players in male-related infertility. Indeed, hypogonadism, which is also characterized by changes in T levels, is one of the most common causes of male infertility and its incidence has been interconnected to the increased prevalence of metabolic diseases. Recent data also highlight the role of aquaporin (AQP)-mediated water and solute diffusion and the metabolic homeostasis in testicular cells suggesting a strong correlation between AQPs function, metabolism of testicular cells, and infertility. Indeed, recent studies showed that both metabolic and sexual hormone concentrations can change the expression pattern and function of AQPs. Herein, we review up-to-date information on the involvement of AQP-mediated function and permeability in men with metabolic syndrome and testosterone deficit, highlighting the putative mechanisms that show an interaction between sex hormones, AQPs, and metabolic syndrome that may contribute to male infertility.

Triazole pesticides exposure impaired steroidogenesis associated to an increase in AHR and CAR expression in testis and altered sperm parameters in chicken

Since several decades, we observe the decline of various bird populations that could be partly linked to the agricultural intensification and the use of large amount of pesticides. Even if triazoles compounds are the most widely used fungicides, their effects on the reproductive parameters in birds are not clearly known. In the present study, we investigated the in vitro effects of 8 triazoles compounds alone (propiconazole (PP, from 0 to 10 µM), prothioconazole (PT), epoxiconazole (Epox), tetraconazole (TT), tebuconazole (TB), difenoconazole (Dif), cyproconazole (Cypro), metconazole (MC) (from 0 to 1 mM)) on the male chicken reproductive functions by using testis explants, primary Sertoli cells and sperm samples. In testis, all triazoles at the higher concentrations for 48 h inhibited lactate and testosterone secretion mostly in association with reduced expression of HSD3B and/or STAR mRNA levels. These data were also associated with increased expression of the nuclear receptors Aryl Hydrocarbon Receptor (AHR) and Constitutive Androstane Receptor (CAR) mRNA levels in testis and for all triazoles except for PP a reduction in Sertoli cell viability. When focusing on the sperm parameters, we demonstrated that most of the triazoles (MC, Epox, Dif, TB, TT and Cypro) at 0.1 or 1 mM for either 2, 12 or 24 min of exposure decreased sperm motility and velocity and increased the percentage of spermatozoa abnormal morphology. At the opposite, PP increased sperm motility in a dose dependent manner after 2 min of exposure whereas no significant effect was observed in response to PT whatever the dose and the time of exposure. Moreover, these effects were associated with an increase in the production of reactive oxygen species in spermatozoa. Taken together, most of the triazoles compounds impair testis steroidogenesis and semen parameters potentially through an increase in AHR and CAR expression and in oxidative stress, respectively.

Data Availability Statement

All the data will be available.

Rhamnetin alleviates polystyrene microplastics-induced testicular damage by restoring biochemical, steroidogenic, hormonal, apoptotic, inflammatory, spermatogenic and histological profile in male albino rats

The current research was performed to evaluate the ameliorative effects of Rhamnetin (RHM) on polystyrene microplastics (PS-MPs)-instigated testicular dysfunction in male albino rats. 48 albino rats were distributed in four groups, i.e., control, PS-MPs treated, PS-MPs + RHM co-treated and RHM only supplemented group. PS-MPs exposure considerably reduced anti-oxidant enzymes i.e., catalase (CAT), glutathione peroxidase (GSR), superoxide dismutase (SOD) and glutathione reductase (GPx) activities. Whereas, reactive oxygen species (ROS) level along with malondialdehyde (MDA) was considerably escalated in PS-MPs treated rats as well as a potential decline was observed in sperm progressive motility. Additionally, a substantial upsurge was noticed in the count of dead sperms, deformity in the tail, mid-piece and head of sperms in PS-MPs treated rats. PS-MPs exposure also decreased steroidogenic enzymes, 17β-hydroxysteroid dehydrogenase (17β-HSD), steroidogenic acute regulatory protein (StAR) and 3β-hydroxysteroid dehydrogenase (3β-HSD) expressions. Moreover, the levels of inflammatory indices i.e., Interleukin-6 (IL-6), Nuclear factor kappa-B (NF-κB), Interleukin-1β (IL-1β), tumour necrosis factor-α (TNF-α) and cyclooxygenase-2 (COX-2) activity were also increased in PS-MPs administrated group. Besides it increased the expression of apoptotic markers (Bax and caspase-3) expression. Whereas, anti-apoptotic marker i.e., Bcl-2 expression was reduced. Moreover, luteinizing hormone (LH), follicle-stimulating hormone (FSH) as well as plasma testosterone levels were also decreased. PS-MPs exposure also led to a substantial histopathological damage in testicular tissues. However, RHM supplementation potentially reduced the damaging effects of PS-MPs in the reproductive tissues of male albino rats. Thus, the current study revealed, RHM possesses potential to prevent PS-MPs-induced testicular damage due to its anti-oxidant anti-apoptotic, anti-inflammatory as well as androgenic properties.

Glycine protects the male reproductive system against lead toxicity via alleviating oxidative stress, preventing sperm mitochondrial impairment, improving kinematics of sperm, and blunting the downregulation of enzymes involved in the steroidogenesis

Lead (Pb) is a highly toxic heavy metal widely dispersed in the environment because of human industrial activities. Many studies revealed that Pb could adversely affect several organs, including the male reproductive system. Pb-induced reproductive toxicity could lead to infertility. Thus, finding safe and clinically applicable protective agents against this complication is important. It has been found that oxidative stress plays a fundamental role in the pathogenesis of Pb-induced reprotoxicity. Glycine is the simplest amino acid with a wide range of pharmacological activities. It has been found that glycine could attenuate oxidative stress and mitochondrial impairment in various experimental models. The current study was designed to evaluate the role of glycine in Pb-induced reproductive toxicity in male mice. Male BALB/c mice received Pb (20 mg/kg/day; gavage; 35 consecutive days) and treated with glycine (250 and 500 mg/kg/day; gavage; 35 consecutive days). Then, reproductive system weight indices, biomarkers of oxidative stress in the testis and isolated sperm, sperm kinetic, sperm mitochondrial indices, and testis histopathological alterations were monitored. A significant change in testis, epididymis, and Vas deferens weight was evident in Pb-treated animals. Markers of oxidative stress were also significantly increased in the testis and isolated sperm of the Pb-treated group. A significant disruption in sperm kinetic was also evident when mice received Pb. Moreover, Pb exposure caused significant deterioration in sperm mitochondrial indices. Tubular injury, tubular desquamation, and decreased spermatogenic index were histopathological alterations detected in Pb-treated mice. It was found that glycine significantly blunted oxidative stress markers in testis and sperm, improved sperm mitochondrial parameters, causing considerable higher velocity-related indices (VSL, VCL, and VAP) and percentages of progressively motile sperm, and decreased testis histopathological changes in Pb-exposed animals. These data suggest glycine as a potential protective agent against Pb-induced reproductive toxicity. The effects of glycine on oxidative stress markers and mitochondrial function play a key role in its protective mechanism.

Sperm quality and testicular histopathology of Wistar albino male rats treated with hydroethanolic extract of Cordia dichotoma fruits

CONTEXT

Cordia dichotoma Forst. (Boraginaceae) has potent pharmacological impact. Meanwhile, its effect on fertility is unclear.

OBJECTIVE

This study investigates the effect of Cordia fresh fruits hydroethanolic extract on fertility.

MATERIALS AND METHODS

120 Wistar albino male rats were divided into four groups (n = 30). The first group was negative control, and the second, third, and fourth groups received 125, 250, and 500 mg extract/kg bodyweight for 56 days. After 56 days, Cordia force-feeding stopped, and all groups were kept under laboratory conditions for another month to study the recovering effect.

RESULTS

After day 56, extract at 500 mg/kg significantly reduced sperm total count, motility%, and alive%, to 47.60 ± 2.27 × 10⁶ sperm/mL, 43.33% ± 1.49, and 63.67% ± 1.19, respectively, abnormalities% increased considerably (26.67% ± 0.54), compared to the negative control. Also, significant depletion on follicle-stimulating hormone (2.66 ± 0.21 mIU/L), luteinizing hormone (1.07 ± 0.06 mIU/L), and testosterone (2.69 ± 0.13 nmol/L) level was recorded, compared to the negative control. Cordia negative effect showed on histopathological studies of testes, prostate, and seminal vesicles. Fortunately, these adverse effects of Cordia recovered remarkably after stopping administration for one month.

CONCLUSIONS

Cordia antifertility effect may be due to its hypocholesterolemic effect, where cholesterol, the steroid cycle precursor, was significantly reduced. This study can be incorporated in clinical research after being repeated on another small experimental animal, their offspring, and one large experimental animal, then going to a clinical study that we plan to do in the future.

The Roles of Androgens in Humans: Biology, Metabolic Regulation and Health

Androgens are an important and diverse group of steroid hormone molecular species. They play varied functional roles, such as the control of metabolic energy fate and partition, the maintenance of skeletal and body protein and integrity and the development of brain capabilities and behavioral setup (including those factors defining maleness). In addition, androgens are the precursors of estrogens, with which they share an extensive control of the reproductive mechanisms (in both sexes). In this review, the types of androgens, their functions and signaling are tabulated and described, including some less-known functions. The close interrelationship between corticosteroids and androgens is also analyzed, centered in the adrenal cortex, together with the main feedback control systems of the hypothalamic-hypophysis-gonads axis, and its modulation by the metabolic environment, sex, age and health. Testosterone (T) is singled out because of its high synthesis rate and turnover, but also because age-related hypogonadism is a key signal for the biologically planned early obsolescence of men, and the delayed onset of a faster rate of functional losses in women after menopause. The close collaboration of T with estradiol (E2) active in the maintenance of body metabolic systems is also presented Their parallel insufficiency has been directly related to the ravages of senescence and the metabolic syndrome constellation of disorders. The clinical use of T to correct hypoandrogenism helps maintain the functionality of core metabolism, limiting excess fat deposition, sarcopenia and cognoscitive frailty (part of these effects are due to the E2 generated from T). The effectiveness of using lipophilic T esters for T replacement treatments is analyzed in depth, and the main problems derived from their application are discussed.

Predictors of testosterone in zoo-managed male African elephants (Loxodonta Africana)

Reproductive complications for both male and female zoo-managed African elephants (Loxodonta africana) contribute to the rapidly declining population. In zoo-managed bull elephants, few studies have explored the potential physiological, physical, social, and environmental factors that influence bull fertility, particularly, androgen production. Testosterone is the essential steroid hormone for male sexual maturation and inadequate concentrations can be detrimental for spermatogenesis. Testosterone, fecal glucocorticoid metabolites, leptin, glucose, insulin, and triglycerides were analyzed from weekly fecal and blood serum samples taken over 6 months from six zoo-managed African elephant bulls (10-19 years of age). Testosterone levels were compared to endocrine factors, weekly social and environmental variables, daily musth signs, and body condition scores (BCS). The glucose-to-insulin ratio (G:I) was the only physiological biomarker found to be positively associated with testosterone. Predictive physical variables included Musth Score (+) and Moderate Exercise (+). Bulls with BCS signifying overweight (BCS 4) had lower testosterone (36.6 ± 1.6 ng/g fecal extraction [FE]) than bulls with healthy BCS 3; 51.2 ± 4.9 ng/g FE). Numerous social variables influenced testosterone concentrations, including Total Contact Day (+), Female Interaction Day (+), Indirect Contact Day (+), Indirect Contact Night (+) and Total No Contact (-). Both percentage of Time Outdoor and Time Mixed positively influenced testosterone, whereas testosterone decreased for percentage of Time Indoors. Each additional daily browse opportunity increased testosterone by approximately 7 ng/g FE. In managed care, the emphasis should be placed on optimizing these predictors of testosterone production to promote bull reproductive health.

Sub-chronic restraint stress exposure in adult rats: An insight into possible inhibitory mechanism on testicular function in relation to germ cell dynamics

Psychological stress is now widely recognized as one of the major risk factors for male fertility. Its impact on the dynamics of testicular germ cells, however, has yet to be fully investigated. Therefore, we used the rat restraint stress (RS) model as a psychological stressor to assess the impact of psychological stress on testicular germ cell dynamics. Adult male SD rats were exposed to sub-chronic RS for 1.5 and 3 h per day for 30 days. The quality of cauda epididymis spermatozoa was adversely affected by RS exposure, and the frequency of spermatozoa with tail abnormalities was higher than that of spermatozoa with head abnormalities. RS exposure adversely affected testicular daily sperm production by disturbing the meiotic and post meiotic germ cell kinetics in the testis. The histomorphology of the testis was altered by loosening and vacuolization in the seminiferous epithelium, germ cell exfoliation and the presence of giant cells. Seminiferous tubules of stage I-VI and VII-VIII were severely affected in rats exposed to RS for 3 h. By interfering with steroidogenic enzymes, RS exposure disrupts testosterone biosynthesis. The testicular oxidative balance was also disturbed by RS exposure, which disrupted the levels/activities of lipid peroxidation, Nrf-2, superoxide dismutase and catalase. There was also an increase in caspase-3 activity and a decrease in the Bax-Bcl2 ratio. In conclusion, our findings suggest that psychological stressors like RS impair testicular functions in rats by disrupting germ cell dynamics, downregulating testicular androgenesis and increasing oxidative stress and apoptosis.

Assessment of sodium nitrate (NaNO3) effects on the reproductive system, liver, pancreas and kidney of male rats

Nitrate (NO₃) toxicity is a serious global issue that results in impairment of physiological systems of our body. The present study aimed to investigate the effects of different concentration of NaNO₃ (10, 100, 500 and 1000 mg/kg bw) on the male reproductive system, liver, kidney and pancreas. Adult male Wistar rats were divided into five groups of five animals each (n = 5). The first group served as controls. The second, third, fourth and fifth groups of rat were orally intubated with 10, 100, 500 and 1000 mg/kg bw of NaNO₃ for 52 days. After the treatment period, the rats were sacrificed and NO₃ induced alterations on selected organs were assessed. There was a dose dependent decrease in sperm motility, serum concentration of testosterone, body weight and organ weight, and increase in abnormal sperm morphology in the NaNO₃ treated groups compared with the controls. Further, histological analysis confirmed that NO₃ induced toxicity. Shrunken seminiferous tubules and loss of spermatids in testes, shrinkage of acinar cells of the pancreas, sinusoidal congestion and necrosis in the liver, atrophy of glomeruli and congestion of renal tubules of the kidney were the histological alterations observed in rats treated with100 and 500 mg/kg NaNO₃. However, 100% mortality was observed in rats treated with 1000 mg/kg NaNO₃. The present study clearly demonstrated the toxic effects of NaNO₃ on both the reproductive system and other organs of the body. The study might inform human studies; where in the chances of male infertility may be more a problem for individuals in areas with NO₃-rich ground water.

Role of p38 MAPK Signalling in Testis Development and Male Fertility

The testis is an important male reproductive organ, which ensures reproductive function via the secretion of testosterone and the generation of spermatozoa. Testis development begins in the embryonic period, continues after birth, and generally reaches functional maturation at puberty. The stress-activated kinase, p38 mitogen-activated protein kinase (MAPK), regulates multiple cell processes including proliferation, differentiation, apoptosis, and cellular stress responses. p38 MAPK signalling plays a crucial role in testis development by regulating spermatogenesis, the fate determination of pre-Sertoli, and primordial germ cells during embryogenesis, the proliferation of testicular cells in the postnatal period, and the functions of mature Sertoli and Leydig cells. In addition, p38 MAPK signalling is involved in decreased male fertility when exposed to various harmful stimuli. This review will describe in detail the biological functions of p38 MAPK signalling in testis development and male reproduction, together with its pathological role in male infertility.

Transcriptome sequencing reveals differences between leydig cells and sertoli cells of yak

In this study, we detected the expression of mRNAs, lncRNAs, and miRNAs in primary cultured leydig cells (LCs) and sertoli cells (SCs) of yak by RNA sequencing technology. A total of 84 differently expression mRNAs (DEmRNAs) (LCs vs. SCs: 15 up and 69 down), 172 differently expression lncRNAs (DElncRNAs) (LCs vs. SCs: 36 up and 136 down), and 90 differently expression miRNAs (DEmiRNAs) (LCs vs. SCs: 72 up and 18 down) were obtained between the two types of cells. GO enrichment and KEGG analysis indicated that the differential expression genes (DEGs) were more enriched in the regulation of actin cytoskeleton, Rap1/MAPK signaling pathway, steroid biosynthesis, focal adhesion, and pathways associated with metabolism. Targeted regulation relationship pairs of 3β-HSD and MSTRG.54630.1, CNTLN and MSTRG.19058.1, BRCA2 and MSTRG.28299.4, CA2 and novel-miR-148, and ceRNA network of LAMC3-MSTRG.68870.1- bta-miR-7862/novel-miR-151/novel-miR-148 were constructed by Cytoscape software. In conclusion, the differences between LCs and SCs were mainly reflected in steroid hormone synthesis, cell proliferation and metabolism, and blood-testicular barrier (BTB) dynamic regulation, and 3β-HSD, CNTLN, BRCA2, CA2, and LAMC3 may be the key factors causing these differences, which may be regulated by ncRNAs. This study provides a basic direction for exploring the differential regulation of LCs and SCs by ncRNAs.

Eugenol reduces serum testosterone levels and sperm viability in adult Wistar rats

Eugenol is the main constituent of clove extract. It is a remarkably versatile molecule incorporated as a functional ingredient in several food products and widely applied in the pharmaceutical industry. Men consume natural products enriched with eugenol for treating sexual disorders and using as aphrodisiacs. Nevertheless, there is no information about the impact of eugenol intake on the reproductive parameters of healthy males. Therefore, we provided 10, 20, and 40 mg kg^-1 pure eugenol to adult Wistar rats for 60 days. Testis, epididymis, and spermatozoa were analyzed under microscopic, biochemical, and functional approaches. This phenolic compound did not alter testicular and epididymal biometry and microscopy. However, 20 and 40 mg kg^-1 eugenol reduced serum testosterone levels. The highest dose altered lactate and glucose concentrations in the epididymis. All the eugenol concentrations diminished CAT activity and MDA levels in the testis and increased FRAP and CAT activity in the epididymis. Epididymal sperm from rats receiving 10, 20, and 40 mg kg^-1 eugenol presented high Ca²⁺ ATPase activity and low motility. In conclusion, eugenol at low and high doses negatively impacted the competence of epididymal sperm and modified oxidative parameters in male organs, with no influence on their microscopy.

SCP2 variant is associated with alterations in lipid metabolism, brainstem neurodegeneration, and testicular defects

BACKGROUND

The detoxification of very long-chain and branched-chain fatty acids and the metabolism of cholesterol to form bile acids occur largely through a process called peroxisomal β-oxidation. Mutations in several peroxisomal proteins involved in β-oxidation have been reported, resulting in diseases characterized by neurological defects. The final step of the peroxisomal β-oxidation pathway is catalyzed by sterol carrier protein-x (SCPx), which is encoded by the SCP2 gene. Previously, there have been two reports of SCPx deficiency, which resulted from a homozygous or compound heterozygous SCP2 mutation. We report herein the first patient with a heterozygous SCP2 mutation leading to SCPx deficiency.

RESULTS

Clinical presentations of the patient included progressive brainstem neurodegeneration, cardiac dysrhythmia, muscle wasting, and azoospermia. Plasma fatty acid analysis revealed abnormal values of medium-, long-, and very long-chain fatty acids. Protein expression of SCPx and other enzymes involved in β-oxidation were altered between patient and normal fibroblasts. RNA sequencing and lipidomic analyses identified metabolic pathways that were altered between patient and normal fibroblasts including PPAR signaling, serotonergic signaling, steroid biosynthesis, and fatty acid degradation. Treatment with fenofibrate or 4-hydroxytamoxifen increased SCPx levels, and certain fatty acid levels in patient fibroblasts.

CONCLUSIONS

These findings suggest that the patient's SCP2 mutation resulted in decreased protein levels of SCPx, which may be associated with many metabolic pathways. Increasing SCPx levels through pharmacological interventions may reverse some effects of SCPx deficiency. Collectively, this work provides insight into many of the clinical consequences of SCPx deficiency and provides evidence for potential treatment strategies.

Resistance to prostate cancer treatments

A review of the current treatment options for prostate cancer and the formation of resistance to these regimens has been compiled including primary, acquired, and cross-resistance. The diversification of the pathways involved and the escape routes the tumor is utilizing have been addressed. Whereas early stages of tumor can be cured, there is no treatment available after a point of no return has been reached, leaving palliative treatment as the only option. The major reasons for this outcome are the heterogeneity of tumors, both inter- and intra-individually and the nearly endless number of escape routes, which the tumor can select to overcome the effects of treatment. This means that more focus should be applied to the individualization of both diagnosis and therapy of prostate cancer. In addition to current treatment options, novel drugs and ongoing clinical trials have been addressed in this review.

Human-specific gene CT47 blocks PRMT5 degradation to lead to meiosis arrest

Exploring the functions of human-specific genes (HSGs) is challenging due to the lack of a tractable genetic model system. Testosterone is essential for maintaining human spermatogenesis and fertility, but the underlying mechanism is unclear. Here, we identified Cancer/Testis Antigen gene family 47 (CT47) as an essential regulator of human-specific spermatogenesis by stabilizing arginine methyltransferase 5 (PRMT5). A humanized mouse model revealed that CT47 functions to arrest spermatogenesis by interacting with and regulating CT47/PRMT5 accumulation in the nucleus during the leptotene/zygotene-to-pachytene transition of meiosis. We demonstrate that testosterone induces nuclear depletion of CT47/PRMT5 and rescues leptotene-arrested spermatocyte progression in humanized testes. Loss of CT47 in human embryonic stem cells (hESCs) by CRISPR/Cas9 led to an increase in haploid cells but blocked the testosterone-induced increase in haploid cells when hESCs were differentiated into haploid spermatogenic cells. Moreover, CT47 levels were decreased in nonobstructive azoospermia. Together, these results established CT47 as a crucial regulator of human spermatogenesis by preventing meiosis initiation before the testosterone surge.

In vitro production of mouse morphological sperm in artificial testis bioengineered by 3D printing of extracellular matrix

Since autologous stem cell transplantation is prone to cancer recurrence, in vitro sperm production is regarded a safer approach to fertility preservation. In this study, the spermatogenesis process on testicular tissue extracellular matrix (T-ECM)-derived printing structure was evaluated. Ram testicular tissue was decellularized using a hypertonic solution containing triton and the extracted ECM was used as a bio-ink to print an artificial testis. Following cell adhesion and viability examination, pre-meiotic and post-meiotic cells in the study groups (as testicular suspension and co-culture with Sertoli cells) were confirmed by real-time PCR, flow-cytometry and immunocytochemistry methods. Morphology of differentiated cells was evaluated using transmission electron microscopy (TEM), toluidine blue, Giemsa, and hematoxylin and eosin (H&E) staining. The functionality of Leydig and Sertoli cells was determined by their ability for hormone secretion. The decellularization of testicular tissue fragments was successful and had efficiently removed the cellular debris and preserved the ECM compounds. High cell viability, colonization, and increased expression of pre-meiotic markers in cultured testicular cells on T-ECM-enriched scaffolds confirmed their proliferation. Furthermore, the inoculation of neonatal mouse testicular cells onto T-ECM-enriched scaffolds resulted in the generation of sperm. Morphology evaluation showed that the structure of these cells was quite similar to mature sperm with a specialized tail structure. The hormonal analysis also confirmed production and secretion of testosterone and inhibin B by Leydig and Sertoli cells. T-ECM printed artificial testis is a future milestone that promises for enhancing germ cell maintenance and differentiation, toxicology studies, and fertility restoration to pave the way for new human infertility treatments in the future.

BPA disrupted the testis testosterone levels by interfering ER enrichments within StAR 5' flanking region in rare minnow Gobiocypris rarus

Bisphenol A (BPA) is a widely used endocrine disruptor, which has attracted much attention due to its harmful effects on male reproduction. To investigate the interference of BPA on steroid synthesis in males, male rare minnows (Gobiocypris rarus) were exposed to 15 μg L^-1 BPA for 7, 14 and 21 d. Meanwhile, a positive control group was performed with 25 ng L^-1 17α-ethynyl estradiol (EE2). Results showed that BPA exposure induced lower testosterone (T) levels, while affecting the transcripts of steroidogenic gene StAR. Moreover, BPA induced abnormal germ cells proliferation in the testis in rare minnow. Transcriptome analysis showed that 354 transcripts significantly differentially expressed after BPA exposure for 14 d, several of them were enriched in the signaling pathways of cell cycle process, PPAR signaling pathway, the steroid synthesis pathway and estrogen signaling pathway. BPA significantly increased estrogen receptor (ER) levels and induced abnormal protein levels of PPARγ. BPA disrupted the StAR expression by interfering ER enrichments within StAR 5' flanking region. Additionally, our study also revealed that BPA and EE2 might have different mechanisms for interfering with steroid hormone levels and germ cells proliferation in the testis.

Understanding and managing the suppression of spermatogenesis caused by testosterone replacement therapy (TRT) and anabolic–androgenic steroids (AAS)

Use of testosterone replacement therapy (TRT) and anabolic–androgenic steroids (AAS) has increased over the last 20 years, coinciding with an increase in men presenting with infertility and hypogonadism. Both agents have a detrimental effect on spermatogenesis and pose a clinical challenge in the setting of hypogonadism and infertility. Adding to this challenge is the paucity of data describing recovery of spermatogenesis on stopping such agents. The unwanted systemic side effects of these agents have driven the development of novel agents such as selective androgen receptor modulators (SARMs). Data showing natural recovery of spermatogenesis following cessation of TRT are limited to observational studies. Largely, these have shown spontaneous recovery of spermatogenesis after cessation. Contemporary literature suggests the time frame for this recovery is highly variable and dependent on several factors including baseline testicular function, duration of drug use and age at cessation. In some men, drug cessation alone may not achieve spontaneous recovery, necessitating hormonal stimulation with selective oestrogen receptor modulators (SERMs)/gonadotropin therapy or even the need for assisted reproductive techniques. However, there are limited prospective randomized data on the role of hormonal stimulation in this clinical setting. The use of hormonal stimulation with agents such as gonadotropins, SERMs, aromatase inhibitors and assisted reproductive techniques should form part of the counselling process in this cohort of hypogonadal infertile men. Moreover, counselling men regarding the detrimental effects of TRT/AAS on fertility is very important, as is the need for robust randomized studies assessing the long-term effects of novel agents such as SARMs and the true efficacy of gonadotropins in promoting recovery of spermatogenesis.

Androgen and androgen receptor control of mitochondrial function

The effects of androgens have been extensively studied in a variety of organs and cell types with increasing focus on the sexually dimorphic role androgens play not only with respect to cellular functions but also in metabolism. Although the classical mechanism of androgen action is via ligand-dependent binding with the nuclear transcription factor, androgen receptor (AR), cytosolic AR can also activate second messenger signaling pathways. Given that cytosolic AR can signal in this manner, there has been increased interest in the mechanisms by which androgens may control cellular organelle function. This review highlights the effects that androgens have on mitochondrial structure and function with emphasis on biogenesis, fusion/fission, mitophagy, bioenergetics (oxidative phosphorylation), and reactive oxygen species production. There are a number of publications on the effects of androgens in these general areas of mitochondrial function. However, the precise mechanisms by which androgens cause these effects are not known. Additionally, given that the nucleus and mitochondria work in tandem to control mitochondrial function and the mitochondria has its own DNA, future research efforts should focus on the direct, mechanistic effects of androgens on mitochondrial function.

Treatment of copper nanoparticles (CuNPs) for two spermatogenic cycles impairs testicular activity via down-regulating steroid receptors and inhibition of germ cell proliferation in a mice model

Although copper is an indispensable trace metal for biological functions, its excess exposure causes hazardous effects on health. Copper in the form of nanoparticles (CuNPs) is widely used at present and therefore, the living organism is at continuous risk of its adverse effect. The prolonged treatment of CuNPs has not been evaluated yet on the male reproductive system. To demonstrate the combined adverse effects and the mechanism of copper nanoparticles (CuNPs), three doses of CuNPs, 10, 100 and 200 mg/kg were orally given to mice for 70 days. The present study demonstrated that CuNPs decreased the sperm quality parameters, male circulating hormones, induces testicular damages, increased oxidative stress, apoptosis, decreases antioxidant enzymes, germ cell proliferation, and increases the expression of 8-oxoguanine DNA glycosylase-1 (OGG1), apelin receptor (APJ) as well. CuNPs also down-regulated the expression of AR and Erα in the testis. These results suggest that CuNPs manifested their adverse effect on testis via modulating steroid and cytokine (apelin) receptors. The adverse effect of testis was most pronounced at the highest dose (200 mg/kg) of CuNPs, however, other doses show a less toxic effect on various parameters. In conclusion, results indicated that CuNPs may impair spermatogenesis via oxidative stress-mediated DNA damage and germ cell apoptosis at high doses.

The Role of Testosterone in Spermatogenesis: Lessons From Proteome Profiling of Human Spermatozoa in Testosterone Deficiency

Testosterone is essential to maintain qualitative spermatogenesis. Nonetheless, no studies have been yet performed in humans to analyze the testosterone-mediated expression of sperm proteins and their importance in reproduction. Thus, this study aimed to identify sperm protein alterations in male hypogonadism using proteomic profiling. We have performed a comparative proteomic analysis comparing sperm from fertile controls (a pool of 5 normogonadic normozoospermic fertile men) versus sperm from patients with secondary hypogonadism (a pool of 5 oligozoospermic hypogonadic patients due to isolated LH deficiency). Sperm protein composition was analyzed, after peptide labelling with Isobaric Tags, via liquid chromatography followed by tandem mass spectrometry (LC-MS/MS) on an LTQ Velos-Orbitrap mass spectrometer. LC-MS/MS data were analyzed using Proteome Discoverer. Criteria used to accept protein identification included a false discovery rate (FDR) of 1% and at least 1 peptide match per protein. Up to 986 proteins were identified and, of those, 43 proteins were differentially expressed: 32 proteins were under-expressed and 11 were over-expressed in the pool of hypogonadic patients compared to the controls. Bioinformatic analyses were performed using UniProt Knowledgebase, and the Gene Ontology Consortium database based on PANTHER. Notably, 13 of these 43 differentially expressed proteins have been previously reported to be related to sperm function and spermatogenesis. Western blot analyses for A-Kinase Anchoring Protein 3 (AKAP3) and the Prolactin Inducible Protein (PIP) were used to confirm the proteomics data. In summary, a high-resolution mass spectrometry-based proteomic approach was used for the first time to describe alterations of the sperm proteome in secondary male hypogonadism. Some of the differential sperm proteins described in this study, which include Prosaposin, SMOC-1, SERPINA5, SPANXB1, GSG1, ELSPBP1, fibronectin, 5-oxoprolinase, AKAP3, AKAP4, HYDIN, ROPN1B, ß-Microseminoprotein and Protein S100-A8, could represent new targets for the design of infertility treatments due to androgen deficiency.

Effects of Iron Supplementation on Testicular Function and Spermatogenesis of Iron-Deficient Rats

Iron deficiency is the most common micronutrient deficiency in the world. Previous studies have shown that iron deficiency increases oxidative stress and decreases antioxidant enzymes, and studies of male infertility indicated that oxidative stress may affect male reproductive functions. The aim of this study was to investigate the effects of iron supplementation on spermatogenesis and testicular functions in iron-deficient rats. Three-week-old male Sprague Dawley (SD) rats were randomly divided into two groups: an iron-adequate control (AI group, 35 ppm FeSO4) and an iron-deficient group (ID group, <5 ppm FeSO4). After three weeks, the iron-deficient group was divided into an original iron-deficient group and five iron-supplemented groups, the latter fed diets containing different doses of FeSO4 (6, 12, 18, 24, and 35 ppm). After five weeks, blood and testis tissue were analyzed. We presented as median (interquartile range, IQR) for continuous measurements and compared their differences using the Kruskal−Wallis test followed by the Mann−Whitney U test among groups. The results showed that as compared with the AI group, the ID group had significantly lower serum testosterone and poorer spermatogenesis (The medians (QR) were 187.4 (185.6−190.8) of AI group vs. 87.5 (85.7−90.4) of ID group in serum testosterone, p < 0.05; 9.3 (8.8−10.6) of AI group vs. 4.9 (3.4−5.4) of ID group in mean testicular biopsy score (MTBS], p < 0.05); iron supplementation reversed the impairment of testis tissue. In the testosterone biosynthesis pathway, iron supplementation improved the lowered protein expressions of hydroxysteroid dehydrogenases caused by iron deficiency. Additionally, decreased activities of glutathione peroxidase and catalase, and increased cleaved-caspase 8 and caspase 3 expression, were found in the iron-deficient rats. The iron-supplemented rats that received > 12 ppm FeSO4 exhibited improvements in antioxidant levels. In conclusion, iron supplementation can abrogate testis dysfunction due to iron deficiency through regulation of the testicular antioxidant capacity.

Beneficial effects of roots of Argyreia nervosa (Brum.f.) Bojer on testosterone biosynthesis in testis and spermatogenesis in Wistar rats

ETHNOPHARMACOLOGICAL RELEVANCE

Roots of Argyreia nervosa (Burm.f.) Bojer is used traditionally as an aphrodisiac and mentioned in the indigenous system of medicine as spermatogenic. The roots of the plant are also used as bitter, tonic, and alternative.

AIM OF THE STUDY

To study the effect of n-butanol fraction (BTF) and ethyl acetate fraction (ETF) of methanol extract prepared from the roots of Argyreia nervosa and scopoletin isolated from ETF on testosterone biosynthesis in testis and spermatogenesis using rats.

MATERIALS AND METHODS

The effect of BTF, ETF, and scopoletin on the testosterone biosynthesis was evaluated by determining the alteration in expression of mRNA corresponding to steroidogenic enzymes and concentration of testosterone using TM-3 cell line. The ability of BTF and ETF in altering the level of testicular cholesterol and testosterone along with mRNA expression corresponding to 3β-Hydroxy-Δ⁵-steroid dehydrogenase (3β-HSD) and Acute Steroid Regulatory Protein (StAR) was evaluated using rats as experimental animals. The sperm concentration in the seminal fluid was determined, and histological studies of testicular tissues were also carried out.

RESULTS

Test solutions containing BTF, ETF, and scopoletin showed a dose-dependent and statistically significant increase in the testosterone content when incubated with TM-3 cells. The test solutions also increased the fold expression of mRNA corresponding to StAR and 3β-HSD enzymes from TM-3 cells. BTF and ETF elevated testicular testosterone levels by 3.57 and 3.84-fold as compared to control animals, while the fractions showed 9.04 and 10.41-fold alteration in expression of mRNA corresponding to StAR, respectively. BTF and ETF altered the expression of mRNA corresponding to 3β-HSD by 13.43 and 15.04-fold in testicular tissues; moreover, they elevated the activity of 3β-HSD by 7.11 and 7.73 fold, respectively. The animals treated with BTF and ETF showed increased sperm concentration. Histological observations showed that the lumen of seminiferous tubules was densely populated with spermatozoa and Leydig cells were intensely stained. Extract prepared from fruits of Tribulus terrestris Linn and testosterone served as positive controls.

CONCLUSION

BTF, ETF, and scopoletin could promote testosterone biosynthesis by elevating mRNA expression corresponding to StAR, 3β-HSD, and by increasing 3β-HSD activity in the testicular tissues. Elevated testosterone concentration in testis promoted spermatogenesis. The studies provided the probable mechanism through which the roots of A. nervosa act as spermatogenic.

The Fate of Leydig Cells in Men with Spermatogenic Failure

The steroidogenic cells in the testicle, Leydig cells, located in the interstitial compartment, play a vital role in male reproductive tract development, maintenance of proper spermatogenesis, and overall male reproductive function. Therefore, their dysfunction can lead to all sorts of testicular pathologies. Spermatogenesis failure, manifested as azoospermia, is often associated with defective Leydig cell activity. Spermatogenic failure is the most severe form of male infertility, caused by disorders of the testicular parenchyma or testicular hormone imbalance. This review covers current progress in knowledge on Leydig cells origin, structure, and function, and focuses on recent advances in understanding how Leydig cells contribute to the impairment of spermatogenesis.

Mechanism of Action of an Environmentally Relevant Organochlorine Mixture in Repressing Steroid Hormone Biosynthesis in Leydig Cells

Within Leydig cells, steroidogenesis is induced by the pituitary luteinizing hormone (LH). The binding of LH to its receptor increases cAMP production, which then activates the expression of genes involved in testosterone biosynthesis. One of these genes codes for the steroidogenic acute regulatory (STAR) protein. STAR is part of a complex that shuttles cholesterol, the precursor of all steroid hormones, through the mitochondrial membrane where steroidogenesis is initiated. Organochlorine chemicals (OCs) are environmental persistent organic pollutants that are found at high concentrations in Arctic areas. OCs are known to affect male reproductive health by decreasing semen quality in different species, including humans. We previously showed that an environmentally relevant mixture of OCs found in Northern Quebec disrupts steroidogenesis by decreasing STAR protein levels without affecting the transcription of the gene. We hypothesized that OCs might affect STAR protein stability. To test this, MA-10 Leydig cell lines were incubated for 6 h with vehicle or the OCs mixture in the presence or absence of 8Br-cAMP with or without MG132, an inhibitor of protein degradation. We found that MG132 prevented the OC-mediated decrease in STAR protein levels following 8Br-cAMP stimulation. However, progesterone production was still decreased by the OC mixture, even in the presence of MG132. This suggested that proteins involved in steroid hormone production in addition to STAR are also affected by the OC mixture. To identify these proteins, a whole cell approach was used and total proteins from MA-10 Leydig cells exposed to the OC mixture with or without stimulation with 8Br-cAMP were analyzed by 2D SDS-PAGE and LC-MS/MS. Bioinformatics analyses revealed that several proteins involved in numerous biological processes are affected by the OC mixture, including proteins involved in mitochondrial transport, lipid metabolism, and steroidogenesis.

Fertility Considerations in Hypogonadal Men

Hypogonadism can be present in up to 40% in men who present with couple infertility. Testosterone is the major androgen regulating-spermatogenesis in men; as a result, men with either primary or secondary hypogonadism may be subfertile because of impaired spermatogenesis. The clinical impact of hypogonadism on fertility potential depends on the timing of its onset (fetal, prepubertal, or postpubertal) and effect on semen parameters. Treatment pathways and success rates differ according to the cause of hypogonadism and the time of its onset. When medical therapy fails to induce sufficient sperm, assisted reproductive technologies are considered.

Clinical utility of serum 17-hydroxyprogesterone as a marker for medical therapy for male infertility: recommendations based on clinical scenarios

Traditional serum hormone testing in the evaluation of male infertility consists of testosterone, follicle-stimulating hormone, luteinizing hormone, and estradiol. Based on these values, medical therapy is often initiated in an attempt to increase intratesticular testosterone levels and, in turn, promote spermatogenesis. While this hormone panel provides serum testosterone levels, it does not evaluate intratesticular testosterone, obviously an important factor that is critical for spermatogenesis. 17-hydroxyprogesterone (17-OHP) is an intermediate in the steroidal pathway of cholesterol to testosterone conversion that has recently demonstrated promise as an accurate serum biomarker for intratesticular testosterone. At present, 17-OHP has not been widely adopted as a clinical tool in the evaluation of male infertility, which likely stems, in part, from a lack of concrete indications for its use. In this review, we present five commonly encountered scenarios of male infertility where the utilization of 17-OHP has aided in the management and provided a more personalized approach to treatment.

α-Tocopherol restores semen quality in rats exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin

Background and Aim:

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a persistent organic pollutant toxic to the human reproductive system. This study aimed to evaluate the effect of α-Tocopherol administration on the male fertility parameters of a rat model exposed to TCDD.

Materials and Methods:

Fifty healthy 12-week-old male rats were randomly divided into five groups. Rats in the control group were given corn oil twice daily in 4 h intervals. In the treatment groups, all rats were given TCDD at a dose of 700 ng/kg of body weight (BW)/day for 45 days. Four hours after receiving the TCDD, T0 rats were given corn oil, and T1, T2, and T3 rats were given α-Tocopherol at doses of 77, 140, and 259 mg/kg BW/day, respectively, for 45 days. On day 46, experimental animals were sacrificed to collect blood and testicular samples.

Results:

TCDD exposure decreased superoxide dismutase activity, plasma membrane integrity, Leydig cell count, sperm cell count, sperm viability and motility, and increased malondialdehyde levels, serum testosterone levels, and sperm morphological abnormalities. The administration of α-Tocopherol mitigated the effects of TCDD exposure, and the 140 and 259 mg/kg BW/day treatments returned those male fertility parameters to normal levels.

Conclusion:

The administration of 140 mg/kg BW/day α-Tocopherol restored male semen quality in rats exposed to TCDD. We found dynamics serum testosterone levels in rats exposed to TCDD that need to be further studied.

The crucial role of oxidative stress in non-alcoholic fatty liver disease-induced male reproductive toxicity: the ameliorative effects of Iranian indigenous probiotics

Several studies have focused on the high potential effects of probiotics on the reproductive system. However, there is a paucity of information regarding the ameliorative intracellular roles of indigenous Iranian yogurt-extracted/cultured probiotics on animals' reproductive health suffering from obesity and/or fatty liver disease, such as non-alcoholic fatty liver disease (NAFLD). For this purpose, simultaneously with the consumption of D-fructose (200 g/1000 mL water, induction of NAFLD model), all pubertal animals were also gavaged every day for 63 consecutive days with extracted probiotics, including 1 × 109 CFU/mL of Lactobacillus acidophilus (LA), Bifidobacterium spp. (BIF), Bacillus coagulans (BC), Lactobacillus rhamnosus (LR), and a mixture form (LA + BIF + BC + LR). At the end of the ninth week, the indices of epididymal sperm, and oxidative stress, as well as histopathological changes, were assessed. The results show that NAFLD could induce robust oxidative stress, highlighted as considerable increments in ROS level, TBARS content, total oxidized protein levels, along with severe decrements in reduced glutathione reservoirs, total antioxidant capacity in the hepatic and testicular tissues, as well as testicular and hepatic histopathological alterations. Moreover, a significant decrease in the percentage of sperm progressive motility, sperm count, and membrane integrity along with an increment in the percentage of sperm abnormality was detected in NAFLD animals. The observed adverse effects were significantly reversed upon probiotics treatment, especially in the group challenged with a mixture of all probiotics. Taken together, these findings indicate that the indigenous yogurt-isolated/cultured probiotics had a high potential antioxidant activity and the ameliorative effect against reprotoxicity and blood biochemical alterations induced by the NAFLD model. Highlights: 1. Reproductive indices could be reversely affected by xenobiotics and diseases. 2. NAFLD and cholestasis considerably affect the reproductive system in both genders. 3. NAFLD induced hepatic and testicular oxidative stress (OS). 4. NAFLD induced histopathological alterations and spermatotoxicity through OS. 5. The adverse effects were significantly reversed upon exposure to probiotics.

Endocrine disorders and fertility and pregnancy: An update

It is estimated that more and more couples suffer from fertility and pregnancy maintenance disorders. It is associated with impaired androgen secretion, which is influenced by many factors, ranging from genetic to environmental. It is also important to remember that fertility disorders can also result from abnormal anatomy of the reproductive male and female organ (congenital uterine anomalies - septate, unicornuate, bicornuate uterus; acquired defects of the uterus structure - fibroids, polyps, hypertrophy), disturbed hormonal cycle and obstruction of the fallopian tubes resulting from the presence of adhesions due to inflammation, endometriosis, and surgery, abnormal rhythm of menstrual bleeding, the abnormal concentration of hormones. There are many relationships between the endocrine organs, leading to a chain reaction when one of them fails to function properly. Conditions in which the immune system is involved, including infections and autoimmune diseases, also affect fertility. The form of treatment depends on infertility duration and the patient's age. It includes ovulation stimulation with clomiphene citrate or gonadotropins, metformin use, and weight loss interventions. Since so many different factors affect fertility, it is important to correctly diagnose what is causing the problem and to modify the treatment regimen if necessary. This review describes disturbances in the hormone secretion of individual endocrine organs in the context of fertility and the maintenance of pregnancy.

Harmful Consequences of Proton Pump Inhibitors on Male Fertility: An Evidence from Subchronic Toxicity Study of Esomeprazole and Lansoprazole in Wistar Rats

Proton pump inhibitors (PPIs) are frequently prescribed as gastric acid-suppressing agents. Nevertheless, there is limited evidence supporting the risk of detrimental effects of PPIs on male fertility. The purpose of the current study was to evaluate the effect of subchronic use of proton pump inhibitors on male fertility. Seventy adult male Wistar rats were assigned into seven groups. The normal control group orally received solvent only. Groups 2, 3, and 4 were orally given esomeprazole while groups 5, 6, and 7 received lansoprazole at 2.5, 5, and 10 mg/kg/day, respectively. After 45 days of treatment, blood samples, epididymis, and testis were collected. Sperm count, motility, and morphology were determined. The level of hormones such as testosterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) and oxidative status of testis tissue, such as superoxide dismutase, catalase, reduced glutathione, malondialdehyde (MDA), and nitric oxide (NO) were estimated. Results demonstrated a significant decline in sperm count, motility, morphology, testosterone, and catalase at 10 mg/kg/day and GSH at 2.5 mg/kg/day. A significant increase in FSH, LH, and MDA at 10 mg/kg/day and NO at 2.5 mg/kg/day was found as compared to the control group. The pathological alterations specifically dilation of Leydig cells, vacuolization, and degeneration of the seminiferous tubules were also evident. It is concluded that PPIs had caused male reproductive toxicity in Wistar rats due to altered levels of hormones such as testosterone, FSH, and LH, elevated levels of NO, and oxidative stress.

Tetrapeptides Modelled to the Androgen Binding Site of ZIP9 Stimulate Expression of Tight Junction Proteins and Tight Junction Formation in Sertoli Cells

Androgens stimulate the expression of tight junction (TJ) proteins and the formation of the blood-testis barrier (BTB). Interactions of testosterone with the zinc transporter ZIP9 stimulate the expression of TJ-forming proteins and promote TJ formation in Sertoli cells. In order to investigate androgenic effects mediated by ZIP9 but not by the nuclear androgen receptor (AR), the effects of three tetrapeptides fitting the androgen binding site of ZIP9 were compared with those induced by testosterone in a Sertoli cell line expressing ZIP9 but not the AR. Three tetrapeptides and testosterone displaced testosterone-BSA-FITC from the surface of 93RS2 cells and stimulated the non-classical testosterone signaling pathway that includes the activation of Erk1/2 kinases and transcription factors CREB and ATF-1. The expression of the TJ-associated proteins ZO-1 and claudin-5 was triggered as was the re-distribution of claudin-1 from the cytosol to the membrane and nucleus. Furthermore, TJ formation was stimulated, indicated by increased transepithelial electrical resistance. Silencing ZIP9 expression by siRNA prevented all of these responses. These results are consistent with an alternative pathway for testosterone action at the BTB that does not involve the nuclear AR and highlight the significant role of ZIP9 as a cell-surface androgen receptor that stimulates TJ formation.

Comparative transcriptomic analysis of gonadal development and renewal in the ovoviviparous black rockfish (Sebastes schlegelii)

BACKGROUND

The black rockfish (Sebastes schlegelii) has an ovoviviparous reproductive pattern and long-term sperm storage, resulting in asynchronous gonadal development between the sexes. However, the comprehensive understanding of gonadal development in black rockfish has not yet been achieved. Here, we studied gonadal development and germ cell renewal using histology and RNA-seq.

RESULTS

In this study, RNA-seq was performed on testes and ovaries to characterize key pathways and genes that are active during development and gamete maturation in black rockfish. Differentially expressed genes (DEGs) were identified and annotated in 4 comparisons (F_III vs. F_IV, F_IV vs. F_V, M_III vs. M_IV and M_IV vs. M_V). Based on analysis of DEGs enriched in the testis, 11 and 14 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were mapped to the M_III vs. M_IV group and the M_IV vs. M_V group, respectively. DEGs in ovarian development were also classified into 10 groups according to their biological functions. The expression patterns of the selected genes determined by qPCR were significantly correlated with the RNA-Seq results, supporting the reliability and accuracy of the RNA-Seq analysis. E2 levels showed down regulation from previtellogenesis to mature stage in female and T level showed down regulation from spermatogenesis to regressed stage in the male.

CONCLUSIONS

The categories "intercellular interaction and cytoskeleton", "molecule amplification" and "repair in the cell cycle" were revealed to be crucial in testis development and spermatogenesis, as was the biosynthesis of a series of metabolites. Our results provide comprehensive insight into black rockfish gonadal development and provide a basis for further study of reproductive physiology and molecular biology in ovoviviparity teleosts.

Impact of seminal and serum zinc on semen quality and hormonal status: A population-based cohort study of Russian young men

BACKGROUND

Trace elements are important factors in human reproductive health. Among them, special attention is paid to zinc, which is an essential trace element and is necessary for the normal functioning of the male reproductive system and the process of spermatogenesis. The aim of the study was to investigate the association between seminal and serum zinc concentrations and semen quality and reproductive hormone levels in population of Russian young men.

METHODS

The study population consisted of 626 young Russian men (median age 22.5 years), recruited from the general population, regardless of their fertility status. Each participant provided semen and blood sample, information about his lifestyle and ethnicity. Semen quality (sperm concentration, motility and morphology), reproductive hormone levels (testosterone, estradiol, LH, FSH and inhibin B), and serum and seminal zinc concentrations were evaluated. The semen samples were analyzed according to the WHO laboratory manual (WHO, 2010). Serum hormones were measured by enzyme immunoassay, zinc concentrations were determined using spectrophotometry and direct colorimetry without deproteinization.

RESULTS

Zinc was present in the seminal plasma in a significantly higher concentration than in the blood serum (median serum Zn concentration was 23.6 μmol/L vs seminal Zn concentration 1571.8 μmol/L). The seminal zinc concentration was positively related to the total sperm count, sperm concentration, progressive motility and normal morphology (Spearman's test: 0.221; 0.286; 0.269; 0.183, respectively, p < 0.001), while the serum Zn concentration was negatively related to serum testosterone and estradiol levels (r = -0.249 and r = -0.096, respectively, p < 0.001-0.05). It was found that the seminal Zn content in men with normal semen quality was higher compared to men with lowered semen quality (means: 6.37 and 5.03 μmol/ejaculate, respectively, p < 0.001). Similarly, the semen volume, total sperm count, sperm concentration, progressive motility, normal morphology and the serum testosterone level in men with the seminal Zn deficiency were lower than in men with the normal seminal Zn content.

CONCLUSION

Based on the results of our population-based study, seminal Zn levels were closely associated with semen parameters in young men, so Zn deficiency may be an important risk factor for lowered semen quality. Seminal Zn determinations should be considered as a useful tool in addition to other parameters in assessing male fertility.

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.

Combined exposure to environmentally relevant copper and 2,2'-dithiobis-pyridine induces significant reproductive toxicity in male guppy (Poecilia reticulata)

Metal pyrithiones (MePTs), the most widely used biocides in antifouling paints (AFs) coated on the hulls, are usually used in combination with Cu-containing substances. In the aquatic environment, 2,2'-dithiobis-pyridine ((PS)₂), the main degradation product of MePTs, and Cu usually coexist. However, their combined impacts on aquatic organisms are unclear. This study exposed male guppy (Poecilia reticulata) to an environmentally realistic concentration of Cu (10 μg/L) alone or Cu (10 μg/L) combined with 20, 200, and 2000 ng/L (PS)₂ to explore their combined reproductive toxicity. The results showed that co-exposure to Cu and (PS)₂ increased Cu accumulation in the fish body in a dose-dependent manner and induced obvious spermatozoon apoptosis and necrosis, which was mediated by the peroxidation and caspase activation. Compared to Cu alone, co-exposure to Cu and 200, 2000 ng/L (PS)₂ significantly decreased the testosterone level and collapsed spermatogenesis, and depressed male's sexual interest and mating behavior were observed in three co-exposure groups. Moreover, co-exposure to Cu and (PS)₂ increased the disturbance on cyp19a and cyp19b transcription and suppressed the "display" reproductive behavior. Eventually, co-exposure to Cu and (PS)₂ caused male reproductive failure. Therefore, the concurrence of Cu and (PS)₂ induced significant reproductive toxicity in male guppies and would threaten the sustainability of fish populations. Considering the extensive usage of MePTs products in the AFs, their ecological risk warrants more evaluation.

Amodiaquine promotes testosterone production and de novo synthesis of cholesterol and triglycerides in Leydig cells

Testosterone is a hormone essential for male reproductive function. It is produced primarily by Leydig cells in the testicle through activation of steroidogenic acute regulatory protein and a series of steroidogenic enzymes, including a cytochrome P450 side-chain cleavage enzyme (cytochome P450 family 11 subfamily A member 1), 17α-hydroxylase (cytochrome P450 family 17 subfamily A member 1), and 3β-hydroxysteroid dehydrogenase. These steroidogenic enzymes are mainly regulated at the transcriptional level, and their expression is increased by the nuclear receptor 4A1. However, the effect on Leydig cell function of a small molecule-activating ligand, amodiaquine (AQ), is unknown. We found that AQ effectively and significantly increased testosterone production in TM3 and primary Leydig cells through enhanced expression of steroidogenic acute regulatory protein, cytochome P450 family 11 subfamily A member 1, cytochrome P450 family 17 subfamily A member 1, and 3β-hydroxysteroid dehydrogenase. Concurrently, AQ dose-dependently increased the expression of 3-hydroxy-3-methylglutaryl-CoA reductase, a key enzyme in the cholesterol synthesis pathway, through induction of the transcriptional and DNA-binding activities of nuclear receptor 4A1, contributing to increased cholesterol synthesis in Leydig cells. Furthermore, AQ increased the expression of fatty acid synthase and diacylglycerol acyltransferase and potentiated de novo synthesis of fatty acids and triglycerides (TGs). Lipidomics profiling further confirmed a significant elevation of intracellular lipid and TG levels by AQ in Leydig cells. These results demonstrated that AQ effectively promotes testosterone production and de novo synthesis of cholesterol and TG in Leydig cells, indicating that AQ may be beneficial for treating patients with Leydig cell dysfunction and subsequent testosterone deficiency.

Evaluation of co-cultured spermatogonial stem cells encapsulated in alginate hydrogel with Sertoli cells and their transplantation into azoospermic mice

An in vitro spermatogonial stem cell (SSC) culture can serve as an effective technique to study spermatogenesis and treatment for male infertility. In this research, we compared the effect of a three-dimensional alginate hydrogel with Sertoli cells in a 3D culture and co-cultured Sertoli cells. After harvest of SSCs from neonatal mice testes, the SSCs were divided into two groups: SSCs on a 3D alginate hydrogel with Sertoli cells and a co-culture of SSCs with Sertoli cells for 1 month. The samples were evaluated by quantitative reverse transcription polymerase chain reaction (qRT-PCR) assays and bromodeoxyuridine (BrdU) tracing, haematoxylin and eosin (H&E) and periodic acid-Schiff (PAS) staining after transplantation into an azoospermic testis mouse. The 3D group showed rapid cell proliferation and numerous colonies compared with the co-culture group. Molecular assessment showed significantly increased integrin alpha-6, integrin beta-1, Nanog, Plzf, Thy-1, Oct4 and Bcl2 expression levels in the 3D group and decreased expression levels of P53, Fas, and Bax. BrdU tracing, and H&E and PAS staining results indicated that the hydrogel alginate improved spermatogenesis after transplantation in vivo. This finding suggested that cultivation of SSCs on alginate hydrogel with Sertoli cells in a 3D culture can lead to efficient proliferation and maintenance of SSC stemness and enhance the efficiency of SSC transplantation.

Impact of Toxoplasma gondii infection on TM3 Leydig cells: Alterations in testosterone and cytokines levels

Leydig cells play pivotal roles in eliciting male characteristics by producing testosterone and any damage to these cells can compromise male fertility Toxoplasma gondii (T. gondii) is an intracellular parasite capable to invade any nucleated cell, including cells from male reproductive system. Herein, we evaluated the capacity of RH strain of T. gondii to infect TM3 Leydig cells and the impact of this infection on testosterone and inflammatory mediators production. We first, by performing adherence, infection, and intracellular proliferation assays, we found a significant increase in the number of infected Leydig cells, peaking 48 h after the infection with T. gondii. Supernatants of TM3 infected cells exhibited, in a time-dependent manner, increased levels of testosterone as well as monocyte chemoattractant protein-1 (MCP-1) and interferon-γ (IFN-γ), which is correlated with the robust T. gondii infection. In conclusion, our study provides new insights regarding the harmful effects of T. gondii infection on male reproductive system.

Current insights into the implications of m6A RNA methylation and autophagy interaction in human diseases

Autophagy is a conserved degradation process crucial to maintaining the primary function of cellular and organismal metabolism. Impaired autophagy could develop numerous diseases, including cancer, cardiomyopathy, neurodegenerative disorders, and aging. N6-methyladenosine (m6A) is the most common RNA modification in eukaryotic cells, and the fate of m6A modified transcripts is controlled by m6A RNA binding proteins. m6A modification influences mRNA alternative splicing, stability, translation, and subcellular localization. Intriguingly, recent studies show that m6A RNA methylation could alter the expression of essential autophagy-related (ATG) genes and influence the autophagy function. Thus, both m6A modification and autophagy could play a crucial role in the onset and progression of various human diseases. In this review, we summarize the latest studies describing the impact of m6A modification in autophagy regulation and discuss the role of m6A modification-autophagy axis in different human diseases, including obesity, heart disease, azoospermatism or oligospermatism, intervertebral disc degeneration, and cancer. The comprehensive understanding of the m6A modification and autophagy interplay may help in interpreting their impact on human diseases and may aid in devising future therapeutic strategies.

Mechanisms of temperature modulation in mammalian seasonal timing

Global warming is predicted to have major effects on the annual time windows during which species may successfully reproduce. At the organismal level, climatic shifts engage with the control mechanism for reproductive seasonality. In mammals, laboratory studies on neuroendocrine mechanism emphasize photoperiod as a predictive cue, but this is based on a restricted group of species. In contrast, field-oriented comparative analyses demonstrate that proximate bioenergetic effects on the reproductive axis are a major determinant of seasonal reproductive timing. The interaction between proximate energetic and predictive photoperiodic cues is neglected. Here, we focused on photoperiodic modulation of postnatal reproductive development in common voles (Microtus arvalis), a herbivorous species in which a plastic timing of breeding is well documented. We demonstrate that temperature-dependent modulation of photoperiodic responses manifest in the thyrotrophin-sensitive tanycytes of the mediobasal hypothalamus. Here, the photoperiod-dependent expression of type 2 deiodinase expression, associated with the summer phenotype was enhanced by 21°C, whereas the photoperiod-dependent expression of type 3 deiodinase expression, associated with the winter phenotype, was enhanced by 10°C in spring voles. Increased levels of testosterone were found at 21°C, whereas somatic and gonadal growth were oppositely affected by temperature. The magnitude of these temperature effects was similar in voles photoperiodical programmed for accelerated maturation (ie, born early in the breeding season) and in voles photoperiodical programmed for delayed maturation (ie, born late in the breeding season). The melatonin-sensitive pars tuberalis was relatively insensitive to temperature. These data define a mechanistic hierarchy for the integration of predictive temporal cues and proximate thermo-energetic effects in mammalian reproduction.

Generation of a Highly Biomimetic Organoid, Including Vasculature, Resembling the Native Immature Testis Tissue

The creation of a testis organoid (artificial testis tissue) with sufficient resemblance to the complex form and function of the innate testis remains challenging, especially using non-rodent donor cells. Here, we report the generation of an organoid culture system with striking biomimicry of the native immature testis tissue, including vasculature. Using piglet testis cells as starting material, we optimized conditions for the formation of cell spheroids, followed by long-term culture in an air–liquid interface system. Both fresh and frozen-thawed cells were fully capable of self-reassembly into stable testis organoids consisting of tubular and interstitial compartments, with all major cell types and structural details expected in normal testis tissue. Surprisingly, our organoids also developed vascular structures; a phenomenon that has not been reported in any other culture system. In addition, germ cells do not decline over time, and Leydig cells release testosterone, hence providing a robust, tunable system for diverse basic and applied applications.

Relationship between the seasonal changes in plasma testosterone and thyroxine concentrations with sperm cryoresistance in Gabon bucks

Gabon buck is a breed with little marked seasonality in our latitude (Uruguay, 35° SL). The role of thyroid hormones on the regulation of their seasonal reproductive activity and sperm cryoresistance is unknown. Seasonal changes in testosterone concentration can affect sperm variables, but the influence of testosterone changes on sperm cryoresistance in other species determines that the recommended time for freezing sperm does not coincide with the period with greater sperm fresh quality. The objectives of the present work were to (i) describe the thyroxine seasonal pattern in bucks in a subtropical area, and its association with annual changes in sperm variables; (ii) relate the seasonal changes of testosterone and thyroxine concentrations with the sperm cryoresistance. For one year, semen of 10 adult Gabon bucks was collected by electroejaculation every two weeks. After sperm selection, the sample was frozen. Testosterone and thyroxine concentrations varied according to the month (P < 0.0001). Testosterone reached the greatest values in April (P < 0.0001) and May (P < 0.0001) and thyroxine reached minimum values (P < 0.0001) in the same months. During these months, a negative correlation ratio (CR) was found between testosterone concentration and CR-functional membrane (R =  - 0.50; P < 0.0001). CR values for most sperm variables decreased during March-May, coinciding with the presence of maximum testosterone concentrations. In conclusion, high testosterone levels are associated with the worst sperm response to freezing-thawing process. Thyroxine concentrations have a strong seasonal pattern, but there was no relationship to sperm cryoresistance.

Improvement in quality and storage ability of rabbit semen by using black or thyme seed as dietary supplementation

The quality of incubated or chilled rabbit semen is quickly lowered with time due to high-rate production of reactive oxygen species (ROS). Black seed (BS) and thyme (THY) are rich sources of natural antioxidants, which may be able to control ROS production and improve semen quality for use in artificial insemination. In this study, V-line rabbit bucks, seven months old, were fed diets supplemented with 50 or 100 g of BS or THY for 60 days. Semen was collected twice weekly. The quality of fresh sperm was measured, and diluted sperm was incubated for up to 12 h. Chilled, diluted sperm, stored at 4℃ for up to 3 days, was evaluated. The results indicated that BS and THY increased rabbit libido, decreased abnormal sperm and non-viable sperm percentages and significantly lowered total bacteria counts of diluted sperm. In conclusion, bucks fed a diet supplemented with BS or THY had enhanced semen quality and storage life, because of the antioxidant properties of BS and THY. The best incubation results were obtained with the THY100 treatment, whereas the best-chilled results were obtained with the BS100 group.

Review of endocrine disruptors on male and female reproductive systems

Endocrine disruptors (EDs) interfere with different hormonal and metabolic processes and disrupt the development of organs and tissues, as well as the reproductive system. In toxicology research, various animal models have been utilized to compare and characterize the effects of EDs. We reviewed studies assessing the effect of ED exposure in humans, zebrafish, and mouse models and the adverse effects of EDs on male and female reproductive systems. This review outlines the distinctive morphological characteristics, as well as gene expression, factors, and mechanisms that are known to occur in response to EDs. In each animal model, disturbances in the reproductive system were associated with certain factors of apoptosis, the hypothalamic-pituitary-gonadal axis, estrogen receptor pathway-induced meiotic disruption, and steroidogenesis. The effects of bisphenol A, phthalate, and 17α-ethinylestradiol have been investigated in animal models, each providing supporting outcomes and elaborating the key regulators of male and female reproductive systems.

Proteomics analysis reveals the effect of 1α,25(OH)2VD3-glycosides on development of early testes in piglets

1α,25(OH)₂VD₃ is the most active form of VD3 in animals. It plays an important role in regulating mineral metabolism but also in reproduction. Testes are the main reproductive organs of male mammals. Our research aims to reveal the effect of 1α,25(OH)₂VD₃-glycosides on development of early testes in piglets. 140 weaned 21-day old piglets were selected. The piglets were randomly divided into four groups and were fed a commercial diet supplemented with 0, 1, 2 and 4 μg/kg of 1α,25(OH)₂VD₃, provided as 1α,25(OH)₂VD₃-glycosides. Sixty days after the start of the experiment, at piglet age 82 days, testes were harvested. The morphology and histology of early testicular development were assessed. In addition, the proteomic TMT/iTRAQ labelling technique was used to analyse the protein profile of the testes in each group. Western blotting was applied to verify the target of differentially abundant proteins (DAPs). The analysis of morphology and histology of testes showed that a certain concentration of 1α,25(OH)₂VD₃-glycosides had a positive and significant effect on testicular development. And the results of proteomics analysis showed that of the identified 132,715 peptides, 122,755 were unique peptides. 7852 proteins, of which 6573 proteins contain quantitative information. Screening for DAPs focused on proteins closely related to the regulation of testicular development such as steroid hormone synthesis, steroid biosynthesis, peroxisome and fatty acid metabolism pathways. These results indicated that 1α,25(OH)₂VD₃ is involved in the regulation of early testicular development in piglets. At the same time, these findings provide valuable information for the proteins involved in the regulation of testicular development, and help to better understand the mechanisms of 1α,25(OH)₂VD₃ in regulating the development of piglets’ testes.