Annexin A5 regulates Leydig cell testosterone production via ERK1/2 pathway

Management of Male Infertility with Coexisting Sexual Dysfunction: A Consensus Statement and Clinical Recommendations from the Asia-Pacific Society of Sexual Medicine (APSSM) and the Asian Society of Men's Health and Aging (ASMHA)

Male infertility (MI) and male sexual dysfunction (MSD) can often coexist together due to various interplay factors such as psychosexual, sociocultural and relationship dynamics. The presence of each form of MSD can adversely impact male reproduction and treatment strategies will need to be individualized based on patients' factors, local expertise, and geographical socioeconomic status. The Asia Pacific Society of Sexual Medicine (APSSM) and the Asian Society of Men's Health and Aging (ASMHA) aim to provide a consensus statement and practical set of clinical recommendations based on current evidence to guide clinicians in the management of MI and MSD within the Asia-Pacific (AP) region. A comprehensive, narrative review of the literature was performed to identify the various forms of MSD and their association with MI. MEDLINE and EMBASE databases were searched for the following English language articles under the following terms: "low libido", "erectile dysfunction", "ejaculatory dysfunction", "premature ejaculation", "retrograde ejaculation", "delayed ejaculation", "anejaculation", and "orgasmic dysfunction" between January 2001 to June 2022 with emphasis on published guidelines endorsed by various organizations. This APSSM consensus committee panel evaluated and provided evidence-based recommendations on MI and clinically relevant MSD areas using a modified Delphi method by the panel and specific emphasis on locoregional socio-economic-cultural issues relevant to the AP region. While variations exist in treatment strategies for managing MI and MSD due to geographical expertise, locoregional resources, and sociocultural factors, the panel agreed that comprehensive fertility evaluation with a multidisciplinary management approach to each MSD domain is recommended. It is important to address individual MI issues with an emphasis on improving spermatogenesis and facilitating reproductive avenues while at the same time, managing various MSD conditions with evidence-based treatments. All therapeutic options should be discussed and implemented based on the patient's individual needs, beliefs and preferences while incorporating locoregional expertise and available resources.

Ginsenoside - a promising natural active ingredient with steroidal hormone activity

Ginsenosides are a class of natural products with hormone-like activity of triterpenoid saponins and have a variety of pharmacological activities such as anti-aging, immune regulation and cognitive improvement. With the great research interest in alternative medicine and natural products, they are gradually becoming research hotspots. Ginsenosides have a four-ring rigid steroid backbone similar to steroid hormones, and a series of experimental studies have shown that they can exhibit hormone-like activity by binding to nuclear receptors or affecting hormone levels, thereby affecting a wide range of inflammatory conditions, cancers, and menopause-related diseases. This review summarizes the mechanisms and potential health effects of ginsenosides exhibiting estrogen-like, glucocorticoid-like and androgen-like activities, providing an important reference for the exploration of safe phytohormone replacement therapy.

Developmental toxicity window of fetal testicular injury in offspring mice induced by prenatal amoxicillin exposure at different time, doses and courses

Amoxicillin is widely used in the clinical treatment of syphilis, gonorrhea and other infectious diseases during pregnancy, but the effects of prenatal amoxicillin exposure (PAmE) on fetal testicular development have not been reported. Based on the characteristics of clinical medication, Kunming mice were orally gavaged with amoxicillin during pregnancy at different time (mid- or late-pregnancy), doses (75, 150 or 300 mg/kg·d) or courses (single- or multi-course). The results showed that compared with the control group, PAmE resulted in fetal testicular abnormal morphological development, cell proliferation inhibition and apoptosis enhancement, Leydig cell steroid synthase system (SF1, StAR, P450scc, CYP17a1) expression inhibition, and fetal blood testosterone levels decreased. Among them, the late-pregnancy and high-dose amoxicillin groups had severe damage, while the damage in different course groups was basically the same. Meanwhile, PAmE could damage the number and function of germ cells at all time, doses and courses, but had no obvious effect on Sertoli cells. It was further found that PAmE inhibited fetal testis AKT and ERK signaling pathways in late pregnancy and high dose, while the damage in different course groups was basically the same. In summary, this study proposed the developmental toxicity window of fetal testicular injury induced by PAmE in late-pregnancy and high-dose and its related mechanism of AKT and ERK signaling pathway, which provided a theoretical and experimental basis for guiding rational drug use during pregnancy and effectively evaluating the risk of fetal testicular developmental toxicity.

Exposure to acrylamide inhibits testosterone production in mice testes and Leydig cells by activating ERK1/2 phosphorylation

Acrylamide (ACR) is formed during the cooking of starchy foods at high temperatures. Accumulating evidence has shown that ACR has toxic effects, but the mechanism of its potential reproductive toxicity remains unclear. In this study, we observed that ACR caused weight loss in mice. There was no significant difference in the weight of testis and epididymis between the low/medium-dose ACR group and the control group. And the number of epididymal sperms, testicular Leydig cells, serum testosterone level, testicular steroidogenic genes and enzymes, including cytochrome P450 family 11 subfamily A member 1 (CYP11A1) and cytochrome P450 family 17 subfamily A member 1 (CYP17A1), were decreased in the medium/high-dose ACR group. Additional cell experiments showed that the apoptosis rate and the level of reactive oxygen species (ROS) were increased, and testosterone levels and CYP17A1 protein expression were reduced in Leydig cells with treated ACR. Furthermore, the phosphorylation levels of extracellular signal-regulated kinases (ERK1/2) increased significantly; however, there was no significant difference in the levels of serine-threonine protein kinase (AKT) phosphorylation in the testis of mice and Leydig cells treated with ACR. These results suggest that ACR exposure leads to the damage of testicular structure and function and a decline in testosterone synthesis in Leydig cells and mouse testis, which may be related to the activated phosphorylation of ERK1/2.

Frankincense extract protects against testicular damage through augmentation of antioxidant defense mechanisms and modulation of apoptotic genes expression

Frankincense (Boswellia sacra Fluck.,) is traditionally used in the treatment of altered male fertile potential in several countries. This study evaluated the cytoprotective action of B. sacra oleo gum resin extract against cyclophosphamide (CP) induced testicular toxicity in rats (in-vivo) and lipopolysaccharide (LPS) induced cytotoxicity in human Leydig cells (in-vitro). The methanolic extract of B. sacra was standardized for the presence of different boswellic acids using high-performance liquid chromatography (HPLC) and volatile constituents in the extract were detected by gas chromatography–mass spectrometry (GC–MS). Two doses of B. sacra extract were used in the in-vivo study. The HPLC analysis showed that extract contains about 36% w/w of total boswellic acids and GC–MS analysis revealed the presence of another 71 different constituents. Administration of B. sacra extract to rats increased serum testosterone levels, antioxidant enzyme activities, and sperm count with improved sperm quality in a dose-dependent manner, when compared to CP treated animals. Boswellia sacra extract also protected the human Leydig cells against LPS-induced damage and increased the expression of the Bcl-2 gene along with a decrease in caspase-3 gene expression. The results of this study show that B. sacra extract has a protective effect on the male reproductive system.

Low-dose perfluorooctanoic acid stimulates steroid hormone synthesis in Leydig cells: Integrated proteomics and metabolomics evidence

Perfluorooctanoic acid (PFOA), one of the well-known perfluoroalkyl substances (PFASs), has been widespread in the environment and associated with male reproductive toxicity. However, the molecular mechanism involved in low-level PFOA-induced male endocrine disruption remains to be elucidated. In this study, we performed a combined proteomics and metabolomics analysis to investigate the proteomic and metabolic alterations in MLTC-1 Leydig cells responsive to low levels of PFOA exposure. The results showed that PFOA significantly regulated the expressions of 67 proteins and 17 metabolites, among which 18 proteins and 7 metabolites were specifically tied to lipid and fatty acid metabolism as well as testicular steroidogenesis. It is further suggested that low-dose PFOA stimulates steroid hormone synthesis by accelerating fatty acid metabolism and steroidogenic process, which is involved in the repression of p38 and cAMP-dependent ERK signaling pathway. The animal studies also revealed that environmentally relevant levels of PFOA increased serum steroid hormone levels accompanied by the activated cAMP and inhibited p38/ERK pathway in testis, which confirmed our in vitro findings. Overall, the present study will provide novel insights into the toxicological mechanisms of low-level PFOA-mediated steroidogenic disturbance, and may implicate the reproductive health risk of humans with environmental PFOA exposure.

In Vitro Analysis of Deoxynivalenol Influence on Steroidogenesis in Prostate

Deoxynivalenol (DON) is a type-B trichothecene mycotoxin produced by Fusarium species, reported to be the most common mycotoxin present in food and feed products. DON is known to affect the production of testosterone, follicle stimulating hormone (FSH) and luteinizing hormone (LH) in male rats, consequently affecting reproductive endpoints. Our previous study showed that DON induces oxidative stress in prostate cancer (PCa) cells, however the effect of DON on the intratumor steroidogenesis in PCa and normal prostate cells was not investigated. In this study human normal (PNT1A) and prostate cancer cell lines with different hormonal sensitivity (PC-3, DU-145, LNCaP) were exposed to DON treatment alone or in combination with dehydroepiandrosterone (DHEA) for 48 h. The results of the study demonstrated that exposure to DON alone or in combination with DHEA had a stimulatory effect on the release of estradiol and testosterone and also affected progesterone secretion. Moreover, significant changes were observed in the expression of genes related to steroidogenesis. Taken together, these results indicate that DON might affect the process of steroidogenesis in the prostate, demonstrating potential reproductive effects in humans.

Overexpression of miR-506-3p Aggravates DBP-Induced Testicular Oxidative Stress in Rats by Downregulating ANXA5 via Nrf2/HO-1 Signaling Pathway

Background

Di-N-butylphthalate (DBP) is a kind of unique endocrine toxicity linked to hormonal disruptions that affects the male reproductive system and has given rise to more and more attention. However, the mechanism of DBP-induced testicular injury remains unclear. Here, the objective of this study was to investigate the potential molecular mechanism of miR-506-3p in DBP-induced rat testicular oxidative stress injury via ANXA5 (Annexin A5)/Nrf2/HO-1 signaling pathway.

Methods

In vivo, a total of 40 adolescent male rats were treated from 2 weeks with 800 mg/kg/day of DBP in 1 mL/kg corn oil administered daily by oral gavage. Among them, some rats were also injected subcutaneously with 2 nmol agomir-506-3p and/or 10 nmol recombinant rat ANXA5. The pathomorphological changes of testicular tissue were assessed by histological examination, and the antioxidant factors were evaluated. Subsequently, ANXA5, Nrf2, and its dependent antioxidant enzymes, such as HO-1, NQO1, and GST, were detected by Western blotting or immunohistochemical staining. In vitro, TM3 cells (Leydig cells) were used to detect the cell activity by CCK-8 and the transfection in the DBP-treated group.

Results

Differentially expressed miRNAs between the DBP-treated and normal rats were analyzed, and qRT-PCR showed miR-506-3p was highly expressed in testicular tissues of the DBP-treated rats. DBP-treated rats presented severe inflammatory infiltration, increased abnormal germ cells, and missed cell layers frequently existed in seminiferous tubules, resulted in oxidative stress and decreased testicular function. Meanwhile, upregulation of miR-506-3p aggravated the above changes. In addition, miR-506-3p directly bound to ANXA5, and overexpression of miR-506-3p could reduce the ANXA5 expression and also decrease the protein levels of Nrf2/HO-1 signaling pathway. Additionally, we found that recombinant rat ANXA5 reversed the DBP-treated testicular oxidative stress promoting injury of miR-506-3p in rats. In vivo results were reproduced in in vitro experiments.

Conclusions

This study provided evidence that miR-506-3p could aggravate the DBP-treated testicular oxidative stress injury in vivo and in vitro by inhibiting ANXA5 expression and downregulating Nrf2/HO-1 signaling pathway, which might provide novel understanding in DBP-induced testicular injury therapy.

Oxidized-LDL inhibits testosterone biosynthesis by affecting mitochondrial function and the p38 MAPK/COX-2 signaling pathway in Leydig cells

Abnormal lipid/lipoprotein metabolism induced by obesity may affect spermatogenesis by inhibiting testosterone synthesis in Leydig cells. It is crucial to determine which components of lipoproteins inhibit testosterone synthesis. Circulating oxidized low-density lipoprotein (oxLDL), the oxidized form of LDL, has been reported to be an independent risk factor for decreased serum testosterone levels. However, whether oxLDL has a damaging effect on Leydig cell function and the detailed mechanisms have been rarely studied. This study first showed the specific localization of oxLDL and mitochondrial structural damage in testicular Leydig cells of high-fat diet-fed mice in vivo. We also found that oxLDL reduced the mitochondrial membrane potential (MMP) by disrupting electron transport chain and inhibited testosterone synthesis-related proteins and enzymes (StAR, P450scc, and 3β‑HSD), which ultimately led to mitochondrial dysfunction and decreased testosterone synthesis in Leydig cells. Further experiments demonstrated that oxLDL promoted lipid uptake and mitochondrial dysfunction by inducing CD36 transcription. Meanwhile, oxLDL facilitated COX2 expression through the p38 MAPK signaling pathway in Leydig cells. Blockade of COX-2 attenuated the oxLDL-induced decrease in StAR and P450scc. Our clinical results clarified that the increased serum oxLDL level was associated with a decline in circulating testosterone levels. Our findings amplify the damaging effects of oxLDL and provide the first evidence that oxLDL is a novel metabolic biomarker of male-acquired hypogonadism caused by abnormal lipid metabolism.

Down regulating PHGDH affects the lactate production of sertoli cells in varicocele

BACKGROUND

Although varicocele is considered to be one of the leading causes of male infertility, the precise mechanism underlying how varicocele leads to male infertility is not completely understood. We found the lactate concentration on the varicocele side of the patients was decreased compare with peripheral venous blood. In the testicles, the lactate produced by the sertoli cells through the glycolysis pathway provides most of the energy needed for spermatogenesis, the reduction of lactate will affect spermatogenesis. The objective of this study was to investigate the mechanism of this abnormal energy metabolism phenomenon in varicocele.

METHODS

In this study, we collected the testicular tissue from patients with varicocele, the glycolysis related proteins PHGDH was identified by iTRAQ proteomics technology. Experimental rat varicocele model was constructed according to our new clip technique, the mRNA and protein expression levels of PHGDH were examined with qRT-PCR and Western blotting. We constructed a sertoli cell of PHGDH down-regulation model, and then detected the glucose consumption, LDH activities and lactate production in the sertoli cells. Western blot was conducted to investigate the effects of PHGDH on the expression of phosphoserine phosphatase (PSPH) and Pyruvate kinase M2 (PKM2). Flow cytometry was used to detect the cell apoptosis and cell cycle in sertoli cells.

RESULTS

The results showed that testicular protein PHGDH was down-regulated in patients with varicocele and in experimental rat varicocele model. Down-regulation of PHGDH in sertoli cells significantly decreased the glucose consumption, LDH activities and lactate production in the sertoli cells, indicating that the low expression of PHGDH ultimately led to a decrease in lactate production by affecting the glycolysis. The Western blot results showed that the down-regulation of PHGDH significantly reduced the expression of pathway protein PSPH and PKM2, leading to the reduction of lactate production. Moreover, PHGDH knockdown can promote apoptosis and inhibit cell cycle to affect cell growth.

CONCLUSIONS

Overall, we conformed that varicocele lead to the decreasing of testis lactate production. Down-regulation of PHGDH in sertoli cells may mediate the process of abnormal glucose metabolism. Our study provide new insight into the mechanisms underlying metabolism-associated male infertility and suggests a novel therapeutic target for male infertility.

The role of ANXA5 in DBP-induced oxidative stress through ERK/Nrf2 pathway

Di-N-butylphthalate (DBP) have given rise to more and more attention due to its unique endocrine toxicity to male reproductive system. Our previous studies have demonstrated antioxidative Nrf2 (nuclear factor erythroid related factor 2) pathway play a vital role in DBP induced oxidative stress injury. ANXA5 (annexin A5), which is highly expressed in testicular Leydig and Sertoli cells, was found upregulated after DBP stimulation. Mouse Leydig and Sertoli cells were exposed to different concentration of DBP for 24 h to examine the ROS (Reactive oxygen species), MDA (Malondialdehyde), SOD (superoxide dismutase) level and ANXA5, Nrf2, NQO1 (NAD(P)H-quinone oxidoreductase 1), HO-1 (heme oxygenase 1) and ERK/P-ERK protein expression by DHE (Dihydroethidium) staining, ELISA (enzyme-linked immunosorbent assay) and Western blot respectively. Firstly, the oxidative stress injury induced by DBP was re-validated. Then, we confirmed the change of Nrf2 pathway and ANXA5 level after DBP exposure to testicular cells. Additionally, overexpressed ANXA5 could activate Nrf2/HO-1/NQO1 antioxidant pathway and significantly attenuate DBP-induced oxidative stress. Ultimately, we demonstrated ANXA5 could increase ERK phosphorylated level and the activated role of ANXA5 on ERK/Nrf2 pathway could be reversed by ERK inhibitor. Overall, this study illuminated that ANXA5 could defend testicle Leydig and Sertoli cells against DBP-induced oxidative stress injury through ERK/Nrf2 pathway.

Propofol Inhibits Androgen Production in Rat Immature Leydig Cells

Background: Propofol is a widely used anesthetic. Whether propofol inhibits androgen production by rat Leydig cells and the underlying mechanism remains unclear. The objective of the current study was to examine the effects of propofol exposure to rat primary immature Leydig cells and to define propofol-induced inhibition of steroidogenic enzymes in both rat and human testes in vitro.

Methods: Immature Leydig cells were purified from 35-day-old male Sprague–Dawley rats and were exposed to propofol for 3 h. The androgen production by Leydig cells under basal, luteinizing hormone, 8bromo-cAMP, and steroid-substrate stimulated conditions and gene expression of Leydig cells after exposure to propofol were measured. Immature Leydig cells were treated with propofol for 3 h and switched to propofol-free medium for additional 3 and 9 h to test whether propofol-induced inhibition is reversible. ³H-Steroids were used to evaluate the direct action of propofol on cytochrome P450 cholesterol side chain cleavage (CYP11A1), 3β-hydroxysteroid dehydrogenase (HSD3B), cytochrome P450 17α-hydroxylase/17,20-lyase (CYP17A1), and 17β-hydroxysteroid dehydrogenase 3 (HSD17B3) activities in rat and human testes in vitro.

Results: Propofol significantly lowered luteinizing hormone and 8bromo-cAMP stimulated androgen production by Leydig cells after 3-h exposure. Further investigation showed that propofol down-regulated the expression of Cyp11a1 and Cyp17a1 and their proteins at 5 and 50 µM, although it up-regulated Lhcgr expression at 50 µM. Propofol significantly suppressed phosphorylation of ERK1/2 and induced ROS production in immature Leydig cells at 5 and 50 µM. Propofol significantly induced apoptosis of immature Leydig cells at 50 µM. Propofol specifically inhibited rat and human testis HSD3B activities in vitro. The half maximal inhibitory concentrations of propofol for rat and human HSD3B enzymes were 1.011 ± 0.065 and 3.498 ± 0.067 µM, respectively. The mode of action of propofol of inhibiting HSD3B was competitive when pregnenolone was added. At 50 µM, propofol did not directly inhibit rat and human testis CYP11A1, CYP17A1, and HSD17B3 activities in vitro.

Conclusion: Propofol inhibits androgen production via both directly inhibiting HSD3B activity and down-regulating Cyp11a1 and Cyp17a1 expression in Leydig cells. Suppression of steroidogenic enzymes is presumably associated with the lower production of androgen by Leydig cells after propofol treatment. However, propofol-induced inhibition on androgen production is reversible.

With a new clip technique surgically inducing varicocele in Sprague-Dawley rats

BACKGROUND

We introduced and recreated a more consistent and effective experimental varicocele rat model by a new clip technique.

METHODS

A total of 40 rats were numbered and randomly assigned to 5 groups of 8 each, including sham surgery (Group I), conventional (Group II) and clip groups with 0.7, 0.8, 0.9 mm gap widths, respectively (Group III, IV, V). All of the rats in each group were sacrificed at 8 weeks after initial surgery, and the rats forming out with less than 1 mm diameter of left spermatic vein or no presence of the pampiniform plexus dilation were excluded from the experimental groups. The left spermatic vein (LSV) diameter, testicular weight, left kidney weight to body weight coefficients, kidney and testicular histology were determined.

RESULTS

The baseline mean diameter of the LSV in Group I, II and III was 0.22 ± 0.02, 0.23 ± 0.02 and 0.22 ± 0.03 mm, respectively (P = 0.7504). At 8 weeks after initial surgery, varicocele was successfully created in 6/8 (75%), 7/8 (87.5%), 3/8 (37.5%), 3/8 (37.5%) in GroupII-V, no varicocele was observed in Group I. In Group I, II and III, no pathological changes were observed and the left kidney weight to body weight coefficients showed no significant differences. The diameter of LSV was remarkably increased both in Group II and III compared to Group I (1.72 ± 0.13, 1.57 ± 0.19 and 0.25 ± 0.02, respectively), and Group II and III had a smaller testicular weight than the rats in Group I (1.67 ± 0.05, 1.62 ± 0.06, and 1.92 ± 0.12, respectively).

CONCLUSIONS

With a new clip technique, surgically inducing varicocele rat model becomes convenient and safe. This appears to improve the effectiveness of the model and this innovation may allow us to further understand the pathophysiology of varicocele.

Oridonin induces apoptosis in oral squamous cell carcinoma probably through the generation of reactive oxygen species and the p38/JNK MAPK pathway

The anti-inflammatory effects of oridonin (Ordn) have been well established in previous studies. However, the apoptotic effects of Ordn on oral cancer cells have not yet been evaluated, at least to the best of our knowledge. The aim of this study was to examine the apoptotic activity of Ordn in oral squamous cell carcinoma cells and to eluciudate the underlying mechanisms. For this purpose, we employed experimental techniques, such as MTT assay, DAPI staining, soft agar assay, flow cytometry and western blot analysis. Our results revealed that Ordn suppressed oral cancer cell proliferation and soft agar colony formation, while it induced reactive oxygen species (ROS)-dependent apoptosis in a dose or time-dependent manner. The generation of ROS was detected in HN22 and HSC4 cells treated with Ordn and the use of the free radical scavenger, N-acetyl-L-cysteine, almost blocked Ordn-induced apoptosis. The phosphorylation of JNK and p38 mitogen-activated protein kinase (MAPK) was manifested in the Ordn-treated cells. Furthermore, Ordn induced the apoptosis of oral cancer cells through the mitochondrial-dependent pathway, involving the loss of mitochondrial membrane potential, the release of cytochrome c, the induction of poly(ADP-Ribose) polymerase (PARP) cleavage, alterations in the ratios of apoptotic proteins and the activation of the caspase cascade. Taken together, these findings indicate that Ordn induces the apoptosis of oral cancer cells probably via ROS-mediated JNK/p38 MAPK and mitochondrial pathways; thus, Ordn may have potential for use in the treatment of oral cancer.

Smoke, alcohol and drug addiction and male fertility

In recent decades, the decline in human fertility has become increasingly more worrying: while therapeutic interventions might help, they are vexing for the couple and often burdened with high failure rates and costs. Prevention is the most successful approach to fertility disorders in males and females alike. We performed a literature review on three of the most common unhealthy habits - tobacco, alcohol and drug addiction - and their reported effects on male fertility. Tobacco smoking is remarkably common in most first-world countries; despite a progressive decline in the US, recent reports suggest a prevalence of more than 30% in subjects of reproductive age - a disturbing perspective, given the well-known ill-effects on reproductive and sexual function as well as general health. Alcohol consumption is often considered socially acceptable, but its negative effects on gonadal function have been consistently reported in the last 30 years. Several studies have reported a variety of negative effects on male fertility following drug abuse - a worrying phenomenon, as illicit drug consumption is on the rise, most notably in younger subjects. While evidence in these regards is still far from solid, mostly as a result of several confounding factors, it is safe to assume that cessation of tobacco smoking, alcohol consumption and recreational drug addiction might represent the best course of action for any couple trying to achieve pregnancy.