Androgen receptor expression relationship with semen variables in infertile men with varicocele

Long-term carbaryl exposure leads to behavioral abnormalities and reproductive toxicity in male marine medaka through apoptosis-mediated HPA and HPG axes dysregulation

Carbaryl is a widely used carbamate pesticide that has been detected in the marine environment, but its effects on marine fish are still unknown. This study was aimed to investigate the effects of long-term exposure of carbaryl on male marine medaka. For this purpose, we set up five exposure concentration groups of 0, 0.1, 1, 10, and 100 µg/L for 180 days. On the one hand, we observed increased aggression and decreased ability to avoid predators in males after exposure, which was affected by the levels of HPA-axis hormones, especially decreased cortisol level. On the other hand, after exposure, HPG axis hormone levels and gene transcription levels were disturbed. Males exhibited a decreased gonadosomatic index and a notable reduction in mature sperm proportion and the F1 generation displayed a significant increase in malformation rate. Additionally, the number of apoptotic cells and the transcription level of apoptosis-related genes in the brains of male marine medaka substantially increased after exposure. Apoptosis of brain cells may be responsible for the disturbance of HPA and HPG axes, consequently leading to behavioral and reproductive abnormalities. These findings provide novel insights into evaluating the toxic effects of carbaryl on male marine medaka and emphasizing the criticality of exploring the potential environmental risks posed by carbaryl in the marine environment, thus providing toxicity value basis for further strengthening marine environmental monitoring and the protection of biological resources.

Therapeutic potential of testosterone on sperm parameters and chromatin status in fresh and thawed normo and asthenozoospermic samples

BACKGROUND

Hormonal changes alter the physiological level of ROS and cause oxidative stress in the cell. As estimated, hormonal deficiencies, environmental and ideological factors make up about 25% of male infertility. Pathogenic reactive oxygen species (ROS) is a chief cause of unexplained infertility. Limited studies exist on the effects of testosterone on human sperm culture. Therefore, in the current study, the effect of different doses of testosterone on sperm parameters and chromatin quality was investigated.

MATERIALS AND METHODS

Semen samples from 15 normospermic and 15 asthenospermic patients were prepared by swim up method, and then were divided into four groups by exposing to different concentrations of testosterone (1, 10, and 100nM) for 45min. Samples without any intervention were considered as control group. All samples were washed twice. Sperm parameters and chromatin protamination were assessed in each group and the remains were frozen. After two weeks, all tests were repeated for sperm thawed. Also, the MSOM technique was used to determine the sperm morphology of class 1.

RESULTS

Although sperm parameters were not show any significant differences in normospermic and asthenospermic samples exposed to different concentrations of testosterone before and after freezing, chromatin protamination was significantly decreased in the normospermic samples exposed to 10nM of testosterone before freezing (p<0.006), as well as 1 and 10nM of testosterone after freezing compared to control samples (p=0.001 and p=0.0009, respectively). Similarly, chromatin protamination in the asthenospermic samples was significantly decreased at concentration of 1nM of testosterone before and after freezing (p=0.0014 and p=0.0004, respectively), and at concentration of 10nM of testosterone before and after freezing (p=0.0009, p=0.0007) compared to control samples.

CONCLUSION

Using a low dose of testosterone in the sperm culture medium, has positive effects on chromatin quality.

Identification and verification of key genes in varicocele rats through high-throughput sequencing and bioinformatics analysis

Varicocele (VC) is the most common treatable cause of infertility, but it is difficult to distinguish fertile from infertile VC populations because the pathogenesis is unclear. In order to study the related mechanism of VC causing male sterility, we made VC rat model by surgery, analysed the rat epididymal spermatozoa and used the transcriptome sequencing to compare all the mRNA expression differences in testicular tissue between VC rats and control rats. The differentially expressed genes (DEGs) of testicular tissue were also screened by the limma package in R software (version 3.6.1). The 273 DEGs were identified from the four profile data sets including 124 up-regulated genes and 149 down-regulated genes in the VC group compared to control group. We found that Sod1, Casp9, Atg7, Casp3 and Sirt1 in module 1 had higher degrees of connectivity in the first 10 hub genes. Gene ontology (GO) functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis demonstrated that Sod1, Casp9, Atg7, Casp3 and Sirt1 are enriched in regulation of oxidative stress-induced cell death (GO:1,903,201) and Amyotrophic lateral sclerosis (KEGG:05,014). From the above evidence, we speculate that hypoxia plays an important role in the occurrence and development of VC, and it induced the abnormal expression of autophagy and apoptosis-related proteins may involve in the development of VC-associated infertility. Sod1, Casp9, Atg7, Casp3 and Sirt1 as well as their module are hub genes for VC, which will have attractive applications to provide new treatment targets for VC.

Independent and combined effects of diethylhexyl phthalate and polychlorinated biphenyl 153 on sperm quality in the human and dog

A temporal decline in human and dog sperm quality is thought to reflect a common environmental aetiology. This may reflect direct effects of seminal chemicals on sperm function and quality. Here we report the effects of diethylhexyl phthalate (DEHP) and polychlorinated biphenyl 153 (PCB153) on DNA fragmentation and motility in human and dog sperm. Human and dog semen was collected from registered donors (n = 9) and from stud dogs (n = 11) and incubated with PCB153 and DEHP, independently and combined, at 0x, 2x, 10x and 100x dog testis concentrations. A total of 16 treatments reflected a 4 × 4 factorial experimental design. Although exposure to DEHP and/or PCB153 alone increased DNA fragmentation and decreased motility, the scale of dose-related effects varied with the presence and relative concentrations of each chemical (DEHP.PCB interaction for: DNA fragmentation; human p < 0.001, dog p < 0.001; Motility; human p < 0.001, dog p < 0.05). In both human and dog sperm, progressive motility negatively correlated with DNA fragmentation regardless of chemical presence (Human: P < 0.0001, r = −0.36; dog P < 0.0001, r = −0.29). We conclude that DEHP and PCB153, at known tissue concentrations, induce similar effects on human and dog sperm supporting the contention of the dog as a sentinel species for human exposure.

Exposure to difenoconazole inhibits reproductive ability in male marine medaka (Oryzias melastigma)

Difenoconazole (DFZ) is a triazole fungicide which has been detected in the aquatic environment, including estuaries and embayments. However, few studies addressing the reproductive toxicity and transgenerational effects of DFZ on marine fishes are available. The present study was conducted to investigate the effects of DFZ on male marine medaka (Oryzias melastigma). After exposure of the embryo to 1, 10, 100 and 1000ng/L DFZ for 180days, the gonadosomatic index was significantly decreased in the 1000ng/L treatment. The number of sperm was reduced while the abundances of spermatocytes and spermatogonia in the testes were increased in all the treatments. The mRNA levels of salmon-type gnrh (sgnrh), the luteinizing hormone (lhβ) and the follicle-stimulating hormone (fshβ) genes in the brain all exhibited a significant down-regulation, the expression of androgen receptors (arα and arβ) was decreased and that of estrogen receptor β and cytochrome P450 aromatase (cyp19B) was increased in the testes. The expression levels of cyp19A and cyp19B were increased in the liver. The decrease of ars mRNA levels might be one of the reasons causing the reduction of sperm. The down-regulation of sgnrh, lhβ and fshβ mRNA levels suggested that DFZ might impact the spermatogenesis via the brain-pituitary-gonad pathway. The decrease of the fertilization success, the hatch ability and the swim-up success in the F1 generation indicated that DFZ pollution at environmental levels might cause a decrease of wild fish populations.

Genetics and epigenetics of varicocele pathophysiology: an overview

Varicocele is found in approximately 20% of adults and adolescents and in 19-41% of men seeking treatment for infertility. It is associated with a decrease in sperm count as well as sperm motility and morphology. The currently accepted description of the pathophysiology of varicocele does not explain all its clinical manifestations; therefore, other factors such as genetic and epigenetic changes, associated with the environment, might be involved in causing infertility and decrease in sperm quality. It has been reported that the varicocele-induced deterioration of testicular function is progressive and interferes with fertility; hence, early and efficient assessment of the genetic manifestations in patients would be important for developing future medical interventions. Chromosomal disorders, mutations, polymorphisms, changes in gene expression, and epigenetic changes have all been reported to be associated with varicocele. Several studies are underway to unravel the genetic basis of this disease, as it is important to understand the origin and the aggravating factors to ensure appropriate guidance and intervention. Here, we review the available literature regarding the genetic and epigenetic changes associated with varicocele, and how these alterations are related to the different clinical manifestations of the disease.

TNF-α -308 polymorphisms and male infertility risk: A meta-analysis and systematic review

This study aimed to conduct a systematic review and meta-analysis of prospective studies discussing TNF-α -308 polymorphism and male infertility. This study was conformed to Preferred Reported Items for Systematic Reviews and Meta-Analyses guidelines. PubMed, Embase and Scopus databases were searched to identify relevant studies by two independent reviewers. Hazard ratios were pooled using fixed-effect or random-effects models when appropriate. Q-test was performed to evaluate study heterogeneity and publication bias appraised using funnel plots. The search yielded five studies (three of Caucasians ethnicity and 2 of Asian ethnicity) comprising 2939 men (2262 infertile men and 677 fertile controls). Most of the studied cases were carried out on TNF-α promoter region at positions -308 G/A (four studies) where -308 C/T was dealt with in one study. Overall, significant associations between TNF-α -308 gene polymorphisms and idiopathic male infertility risk were observed (fixed effect: OR = 0.472, 95% CI: 0.378-0.589; P = 0.001; random effect: OR = 0.407, 95% CI: 0.211-0.785; P = 0.007) with robust findings according to sensitivity analyses. Funnel plot inspections did not give evidences of publication bias. A stratified analysis performed for ethnic groups revealed significant association in both Caucasian and Asian populations. It is concluded that there are evidences of associations between TNF-α -308 gene polymorphisms and male infertility risk.

Cytochrome P450-2D6*4 polymorphism seminal relationship in infertile men

This study aimed to assess cytochrome (CY) P450-2D6*4 polymorphism relationship with semen variables in infertile men. In all, 308 men were included; fertile normozoospermia (N) (n = 77), asthenozoospermia (A) (n = 70), asthenoteratozoospermia (AT) (n = 75) and oligoasthenoteratozoospermia (OAT) (n = 86). They were subjected to history taking, clinical examination, semen analysis, sperm acrosin activity, seminal malondialdehyde (MDA) and CYP450-2D6*4 genotyping. CYP450-2D6*4 wild-type allele was represented in 76.5% of N, 70% of A, 66.7% of AT and 57.7% of OAT men where homozygous gene mutation was present in 5.9% of N, 20% of A, 26.6% of AT and 26.9% of OAT men, respectively. Sperm acrosin activity, sperm concentration, sperm motility, linear sperm velocity and sperm normal forms were significantly higher, and seminal MDA level was significantly lower in men with CYP450-2D6*4 wild-type allele compared with men with homozygous mutation. It is concluded that CYP450-2D6*4 wild-type allele has higher frequency where homozygous-type allele has lower frequency in N men compared with A, AT and OAT men. Sperm acrosin activity index, sperm concentration, sperm motility, linear sperm velocity and sperm normal forms were significantly higher, and seminal MDA level was significantly lower in men with CYP450-2D6*4 wild-type allele compared with men with homozygous mutation.

Human sperm anatomy and endocrinology in varicocele: role of androgen receptor

The study of androgens involved in male reproduction has been object of intense efforts, while their reported action on human male gametes is limited. We previously described the presence of androgen receptor (AR) in sperm with a role related to the modulation of the PI3K pathway. In the present study, we investigated the expression of AR and its ultrastructural location in normal sperm as well as in spermatozoa obtained from varicocele patients. We observed a reduced AR content in varicocele sperm with respect to healthy sperm by western blot analysis and transmission electron microscopy (TEM). The ultrastructural location of AR was detected mainly on the head membrane as well as in the nucleus, neck, and mitochondria. Influence of dihydrotestosterone (DHT) treatment on cholesterol efflux was increased in normal sperm, while it was reduced or absent in varicocele sperm. To better understand DHT/AR significance in human male gametes, we evaluated triglyceride content and lipase, acyl-CoA dehydrogenase, and glucose-6-phosphate dehydrogenase activities upon DHT treatment. The metabolic outcome glimpsed in normal sperm was an increased metabolic rate, while ‘varicocele’ sperm economized energy. Taken together, our results reveal DHT and AR as new players in sperm endocrinology, indicating that varicocele sperm may have difficulty in switching to the capacitated status. A decreased AR expression and a consequent reduced responsiveness to DHT in sperm may represent molecular mechanisms involved in the pathophysiology of varicocele leading to male infertility. This study revealed new detrimental effects of varicocele on sperm at the molecular level.

Molecular mechanisms involved in varicocele-associated infertility

Varicocele is a pathologic enlargement of the pampiniform venous plexus within the spermatic cord, a condition that is a common cause of impaired sperm production and decreased quality of sperm. While varicocele is the most common surgically correctable risk factor for male infertility, not all males with varicocele experience infertility. In fact, most men with varicocele have normal spermatogenesis. Despite its prevalence, the molecular mechanisms of varicocele and its effect on testicular function are yet to be completely understood. We postulate that men with varicocele-associated infertility could have preexisting genetic lesions or defects in molecular mechanisms that make them more susceptible to varicocele-mediated testicular injury affecting spermatogenesis.

Glutathione-S-transferase-oxidative stress relationship in the internal spermatic vein blood of infertile men with varicocele

This study aimed to assess glutathione-S-transferase (GST) enzyme- oxidative stress (OS) relationship in the internal spermatic vein (ISV) of infertile men associated with varicocele (Vx). Ninety five infertile oligoasthenoteratozoospemic (OAT) men associated with Vx were subjected to history taking, clinical examination and semen analysis. During inguinal varicocelectomy, GST, malondialdehyde (MDA) and glutathione peroxidase (GPx) were estimated in the blood samples drawn from ISV and median cubital veins. The mean levels of GST, GPx were significantly decreased and the mean level of GPx was significantly increased in the ISV compared with the peripheral blood. The mean level of GST and GPx in the ISV was significantly decreased, and the mean level of MDA was significantly increased in Vx grade III compared with Vx grade II cases. There was nonsignificant difference in the mean level of GST in the ISV in unilateral Vx cases compared with bilateral Vx cases. There was significant positive correlation of GST with sperm count, sperm motility, GPx and significant negative correlation with sperm abnormal forms, MDA. It is concluded that ISV of infertile men associated with Vx has decreased levels of GST compared with peripheral venous circulation that is correlated with both OS and Vx grade.

Ginseng and male reproductive function

Ginseng is often referred to as the King of all herbs, and is found to be a promising agent to improve general well-being. Ginseng has also been reputed as an aphrodisiac, and is used to treat sexual dysfunction as well as to enhance sexual behavior in traditional Chinese medical practices. Data from animal studies have shown a positive correlation among ginseng, libido, and copulatory performances, and these effects have been confirmed in case-control studies in human. In addition, ginseng is found to improve the sperm quality and count of healthy individuals as well as patients with treatment-related infertility. These actions are mostly attributed to ginsenosides, the major pharmacological active components of ginseng. This review compiles the current knowledge about the multifaceted effects of ginseng on male reproductive function, and also focuses on its mechanisms of action that may represent novel therapeutic strategies for the treatment of male reproductive diseases or disorders.

Seminal androgens, oestradiol and progesterone in oligoasthenoteratozoospermic men with varicocele

This study aimed to assess seminal androgens, oestradiol, progesterone levels in oligoasthenoteratozoospermic (OAT) men with varicocele (Vx). In all, 154 men with matched age and body mass index were investigated that were divided into healthy fertile controls (n = 35), OAT men with Vx (n = 55), OAT men without Vx (n = 64). They were subjected to assessment of semen parameters, seminal levels of testosterone (T), androstenedione (A), 5α-androstane-3 α,17 β-diol (3 α-diol), oestradiol (E2 ), 17-hydroxyprogesterone (17-OHP) and progesterone (P). Seminal levels of T and A were significantly decreased where seminal levels of 3 α-diol, E2 , 17-OHP, P were significantly higher in OAT men with/without Vx compared with fertile controls. Sperm count, sperm motility and sperm normal forms percentage demonstrated significant positive correlation with seminal T and A and significant negative correlation with seminal 3 α-diol, E2 , P. It is concluded that in fertile men, seminal T and A are significantly increased and seminal 3 α-diol, E2 , 17-OHP, P are significantly decreased compared with infertile OAT men with/without Vx. Association of Vx demonstrated a nonsignificant influence on these hormonal levels in OAT cases. Sperm count, sperm motility and sperm normal forms demonstrated significant positive correlation with seminal T, A and significant negative correlation with seminal 3 α-diol, E2 , P.