Endocrine disruptors and estrogenic effects on male reproductive axis

Concept of a six-fold multiplex planar bioassay to distinguish endocrine agonist, antagonist, cytotoxic and false-positive responses

To analyze a complex sample for endocrine activity, different tests must be performed to clarify androgen/estrogen agonism, antagonism, cytotoxicity, anti-cytotoxicity, and corresponding false-positive reactions. This means a large amount of work. Therefore, a six-fold planar multiplex bioassay concept was developed to evaluate up to the mentioned six endpoints or mechanisms simultaneously in the same sample analysis. Separation of active constituents from interfering matrix via high-performance thin-layer chromatography and effect differentiation via four vertical stripes (of agonists and end-products of the respective enzyme-substrate reaction) applied along each separated sample track were key to success. First, duplex endocrine bioassay versions were established. For the androgen/anti-androgen bioassay applied via piezoelectric spraying, the mean limit of biological detection of bisphenol A was 14 ng/band and its mean half maximal inhibitory concentration IC50 was 116 ng/band. Applied to trace analysis of six migrate samples from food packaging materials, 19 compound zones with agonistic or antagonistic estrogen/androgen activities were detected, with up to seven active compound zones within one migrate. For the first time, the S9 metabolism of endocrine effective compounds was studied on the same surface and revealed partial deactivation. Coupled to high-resolution mass spectrometry, molecular formulas were tentatively assigned to compounds, known to be present in packaging materials or endocrine active or previously unknown. Finally, the detection of cytotoxicity/anti-cytotoxicity and false-positives was integrated into the duplex androgen/anti-androgen bioassay. The resulting six-fold multiplex planar bioassay was evaluated with positive control standards and successfully applied to one migrate sample. The streamlined stripe concept for multiplex planar bioassays made it possible to assign different mechanisms to individual active compounds in a complex sample. The concept is generic and can be transferred to other assays.

Effects and mechanisms of endocrine disruptor bisphenol AF on male reproductive health: A mini review

Bisphenol AF (BPAF), an analogue of bisphenol A (BPA), is commonly found in manufacturing industries and known for its endocrine-disrupting properties. Despite potential similarities in adverse effects with BPA, limited toxicological data exist specifically for BPAF and its impact on male reproductive physiology. This mini-review aims to elucidate the influence of BPAF on the male reproductive system, focusing on estrogenic effects, effects on the hypothalamus-pituitary-gonad (HPG) axis, steroidogenesis, spermatogenesis, and transgenerational reproductive toxicity. Additionally, we outline the current insights into the potential mechanisms underlying BPAF-induced male reproductive disorders. BPAF exposure, either directly or maternally, has been associated with detrimental effects on male reproductive functions, including damage to the blood-testis barrier (BTB) structure, disruptions in steroidogenesis, testis dysfunction, decreased anogenital distance (AGD), and defects in sperm and semen quality. Mechanistically, altered gene expression in the HPG axis, deficits in the steroidogenesis pathway, activation of the aromatase pathway, cascade effects induced by reactive oxygen species (ROS), activation of ERK signaling, and immunological responses collectively contribute to the adverse effects of BPAF on the male reproductive system. Given the high prevalence of male reproductive issues and infertility, along with the widespread environmental distribution of bisphenols, this study provides valuable insights into the negative effects of BPAF. The findings underscore the importance of considering the safe use of this compound, urging further exploration and regulatory attention to decrease potential risks associated with BPAF exposure.

Association between exposure to persistent organic pollutants and pubertal timing in boys and girls: A systematic review and meta-analysis

In recent years, the phenomenon of abnormal pubertal timing in children has become increasingly common worldwide. Persistent organic pollutants (POPs) may be one of the risk factors contributing to this phenomenon, but the relationship between them is unclear based on current evidence. The purpose of this study was to determine the association of POPs exposure with pubertal timing in girls and boys by conducting a systematic review and meta-analysis. We searched PubMed and Embase databases for studies before June 1, 2023. Meta-analysis was performed by pooling relative risk (RR) or odds ratio (OR) or prevalence ratio (PR) or hazard ratio (HR) estimates with 95 % confidence intervals (CIs). Subgroup analysis, publication bias assessment and sensitivity analysis were also carried out. A total of 21 studies were included, involving 2479 boys and 8718 girls. The results of meta-analysis showed that exposure to POPs was significantly associated with delayed pubertal timing in girls (RR: 0.85; 95 % CI: 0.79-0.91; p < 0.001). There was no statistically significant association between exposure to POPs and pubertal timing in boys (RR: 1.18; 95 % CI: 0.99-1.40; p = 0.070). Subgroup analysis showed that there may be gender differences in the effects of exposure to POPs on pubertal timing. Our results suggested that exposure to POPs could delay pubertal timing in girls. However, based on current evidence, no significant association was found between POPs exposure and pubertal timing in boys.

Effects of chronic dichlorodiphenyldichloroethylene exposure on testosterone secretion and steroidogenic pathway in the male gonad

Endocrine disrupting chemicals are present in the environment and/or in consumer products. These agents have the capacity to mimic and/or antagonize endogenous hormones and thus perturb the endocrine axis. The male reproductive tract expresses steroid hormone (androgen and estrogen) receptors at high levels and is a major target for endocrine disrupting chemicals. In this study, Long-Evans male rats were exposed to dichlorodiphenyldichloroethylene, a metabolite of dichlorodiphenyltrichloroethane and a chemical present in the environment, in drinking water at 0.1 and 10 μg/L for 4 weeks. At the end of exposure, we measured steroid hormone secretion and analyzed steroidogenic proteins, including 17β-hydroxysteroid dehydrogenase, 3β-hydroxysteroid dehydrogenase, steroidogenic acute regulatory protein, aromatase, and the LH receptor. We also analyzed Leydig cell apoptosis (poly-(ADP-ribose) polymerase) and caspase-3 in the testes. Testicular testosterone (T) and 17β-estradiol (E2) were both affected by exposure to dichlorodiphenyldichloroethylene by displaying altered steroidogenic enzyme expression. Dichlorodiphenyldichloroethylene exposure also increased the expression of enzymes mediating the pathway for programmed cell death, including caspase 3, pro-caspase 3, PARP, and cleaved PARP. Altogether, the present results demonstrate that dichlorodiphenyldichloroethylene directly and/or indirectly can target specific proteins involved in steroid hormone production in the male gonad and suggest that exposure to environmentally relevant dichlorodiphenyldichloroethylene levels has implications for male reproductive development and function.

Ginkgo biloba supplement abates lead-induced endothelial and testicular dysfunction in Wistar rats via up-regulation of Bcl-2 protein expression, pituitary-testicular hormones and down-regulation of oxido-inflammatory reactions

BACKGROUND

Apoptotic and oxido-inflammatory pathways have been found to be up-regulated in lead acetate poisoning which has been associated to endothelial and testicular dysfunctions. It is yet uncertain, nevertheless, if treatment with Ginkgo biloba supplements (GBS), a flavonoid-rich natural product can lessen the adverse effects of lead on endothelial and testicular functions. This study investigated the impact of Ginkgo biloba supplementation on lead-induced endothelial and testicular dysfunctions.

METHODS

The animals were treated with GBS (50 mg/kg and 100 mg/kg orally) for 14 days following oral exposure to lead acetate (25 mg/kg) for 14 days. After euthanasia, blood samples, epididymal sperm, testes, and aorta were collected. The quantities of the hormones (testosterone, follicle stimulating hormone (FSH) and luteinizing hormone (LH), as well as the anti-apoptotic, oxidative, nitrergic, inflammatory markers, were then determined using immunohistochemistry, ELISA, and conventional biochemical methods.

RESULTS

GBS reduced lead-induced oxidative stress by increasing the levels of the antioxidant enzymes catalase (CAT), glutathione (GSH), and superoxide dismutase (SOD), while lowering malondialdehyde (MDA) in endothelium and testicular cells. Normal testicular weight was restored by GBS which also decreased endothelial endothelin-I and increased nitrite levels. TNF-α and IL-6 were decreased while Bcl-2 protein expression was enhanced. Lead-induced alterations in reproductive hormones (FSH, LH, and testosterone) were also restored to normal.

CONCLUSION

According to our result, using Ginkgo biloba supplement prevented lead from causing endothelial and testicular dysfunction by raising pituitary-testicular hormone levels, boosting Bcl-2 protein expression and lowering oxidative and inflammatory stress in the endothelium and testes.

Galaxolide and Irgacure 369 are novel environmental androgens

Endocrine disruptors are environmental chemicals that can interfere with the endocrine system. However, research on endocrine disruptors that interfere with androgen's actions is still limited. The purpose of this study is to use in silico computation, i.e., molecular docking to facilitate the identification of environmental androgens. Computational docking was used to study the binding interactions of environmental/industrial compounds with the three dimensional structure of human androgen receptor (AR). Then reporter assay and cell proliferation assay using AR-expressing LNCaP prostate cancer cells were used to determine their in vitro androgenic activity. Animal studies using immature male rats were also carried out to test their in vivo androgenic activity. Two novel environmental androgens were identified. As a photoinitiator, 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone (Irgacure 369, abbreviated as IC-369) is widely used in the packaging and electronics industries. Galaxolide (HHCB) is widely used in the production of perfume, fabric softeners and detergents. We found that both IC-369 and HHCB could activate AR transcriptional activity and promote cell proliferation in AR-sensitive LNCaP cells. Furthermore, IC-369 and HHCB could induce cell proliferation and histological changes of seminal vesicles in immature rats. RNA sequencing and qPCR analysis showed that androgen-related genes in seminal vesicle tissue were up-regulated by IC-369 and HHCB. In conclusion, IC-369 and HHCB are new environmental androgens that bind AR and induce AR transcriptional activity, thereby exerting toxicological effects on the development of male reproductive organs.

The Emerging Role of Epigenetics in Metabolism and Endocrinology

Each cell in a multicellular organism has its own phenotype despite sharing the same genome. Epigenetics is a somatic, heritable pattern of gene expression or cellular phenotype mediated by structural changes in chromatin that occur without altering the DNA sequence. Epigenetic modification is an important factor in determining the level and timing of gene expression in response to endogenous and exogenous stimuli. There is also growing evidence concerning the interaction between epigenetics and metabolism. Accordingly, several enzymes that consume vital metabolites as substrates or cofactors are used during the catalysis of epigenetic modification. Therefore, altered metabolism might lead to diseases and pathogenesis, including endocrine disorders and cancer. In addition, it has been demonstrated that epigenetic modification influences the endocrine system and immune response-related pathways. In this regard, epigenetic modification may impact the levels of hormones that are important in regulating growth, development, reproduction, energy balance, and metabolism. Altering the function of the endocrine system has negative health consequences. Furthermore, endocrine disruptors (EDC) have a significant impact on the endocrine system, causing the abnormal functioning of hormones and their receptors, resulting in various diseases and disorders. Overall, this review focuses on the impact of epigenetics on the endocrine system and its interaction with metabolism.

Effect of di(n-butyl) phthalate on the blood-testis barrier during puberty onset

Di(n-butyl) phthalate (DBP) is considered a substance of serious concern because of its reproductive toxicity and endocrine-disrupting properties. Exposure to DBP causes morphological and functional changes in the male reproductive system of birds and mammals. However, there are no detailed reports on the effects of DBP on the Sertoli cell and junctional complexes of the blood-testis barrier (BTB) in birds. The present study investigated dose-related ultrastructural changes in Sertoli cells and junctional complexes of the BTB in adult Japanese quail (Coturnix coturnix japonica) exposed to DBP prior to puberty. A total of 25 Japanese quail were used for the study. Exposure to DBP doses of 50, 200 and 400 mg DBP/kg/d caused dose-related ultrastructural changes in junctional complexes including dilation and separation, while disruption of cytoplasmic membranes and mitochondria was observed in Sertoli cells. There was a significant difference in the sum of vacuoles, vacuole diameter, nuclear width, nuclear length, nuclear area, sum of damaged spherical mitochondria, width of elongated mitochondria and the sum of damaged elongated mitochondria among the five treatment groups (p ˂ 0.05). Prepubertal exposure to DBP at doses of 50, 200 and 400 mg DBP/kg/d for 30 days led to adverse effects in the adult male Japanese quail reproductive system by inducing structural changes in the Sertoli cells and junctional complexes. Such changes might disrupt the BTB and potentially interfere with spermatogenesis. Results indicated that the Sertoli cell is sensitive to DBP exposure and might be an important cellular target for DBP-induced testicular toxicity.

Expression of estrogen receptors, PELP1, and SRC in human spermatozoa and their associations with semen quality

Sperm cells are target cells for both estrogens and xenoestrogens. Due to the specific structure of spermatozoa, these hormonal compounds may act on sperm in a non-genomic mechanism only. However, the ESR-mediated signaling pathways are still poorly understood. In this study, we obtained 119 samples from male participants of Caucasian descent who donated semen for standard analysis. We analyzed gene expression of estrogen receptors (ESR1 and ESR2) and their coregulators-proline-, glutamic acid-, and leucine-rich protein 1 (PELP1), and cellular kinase c-Src (SRC). RNA level was established using reverse-transcribed RNA as a template, followed by a polymerase chain reaction. Proteins' presence was confirmed by western blot and immunocytochemistry techniques. "Normal" values of semen parameters were defined as follows: > 32% sperm with progressive motility, > 4% sperm cells with normal morphology, > 15 × 10⁶ sperm per mL, > 58% live spermatozoa and leukocyte amount < 10⁶ cells per mL, according to WHO 2010 reference. Semen parameters that deviated from these "normal" values were labeled as "abnormal". Gene expression ratios revealed significant, moderate, and negative correlations for ESR1/ESR2 and weak, negative ESR2/PELP1 correlations in the subgroup of patients with abnormal values of semen parameters. In addition, SRC/PELP1 was moderately and positively correlated in the subgroup with parameters within the reference values established by WHO 2010. Our study showed that both PELP1 scaffolding protein and SRC kinase might influence semen quality via ESRs. It seems that not the expression of a single gene may affect the sperm quality, but more gene-to-gene mutual ratio. Characterization of estrogen-signaling pathway-related genes' modulated expression in sperm cells could aid in better understanding sperm biology and quality.

Identification of endocrine-disrupting chemicals targeting the genes and pathways of genital anomalies in males

Hypospadias and cryptorchidism are the most common congenital malformations in male neonates, both of which are also the important clinical manifestations of testicular dysgenesis syndrome and share a same origin. Many studies have suggested that prenatal exposure to endocrine-disrupting chemicals (EDCs) is associated with hypospadias and cryptorchidism development. However, the consistent mechanisms remain unclear. To identify the key EDCs, genes and biological networks related to the development of hypospadias and cryptorchidism respectively and commonly, we conduct the present study and found a new method for predicting the correlation between the interactive genes of hypospadias/cryptorchidism and chemicals. Transcriptome profiles were obtained from the Comparative Toxicogenomics Database (CTD). Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways enrichment analyses and protein-protein interaction (PPI) network were applied for integrative analyses. The rat model and molecular docking were applied to furtherly verifying the findings of the integrative analyses. Besides the highly related genes, most enriched pathways and chemicals for hypospadias and cryptorchidism respectively, we found hypospadias and cryptorchidism share many same highly associated EDCs (e.g., dibutyl phthalate) and genes (e.g., androgen receptor and estrogen receptor 1) through comparing highly related chemicals or genes of hypospadias and cryptorchidism respectively. GO and KEGG analysis showed that these same interactive genes were mainly enriched in steroidogenesis, response to steroid hormone and nuclear receptor activity. PPI network analysis identified 15 biological hub genes. Furtherly, hypospadias and cryptorchidism were induced by prenatal dibutyl phthalate exposure. Decreased serum testosterone level, downregulation of nuclear androgen-dependent and upregulation of cytoplasmic estrogen-dependent pathways may lead to hypospadias and cryptorchidism. This study proposed a new method for predicting the correlation between the interactive genes of hypospadias/cryptorchidism and chemicals and found that hypospadias and cryptorchidism share many same highly associated EDCs and genes.

Adaptive morphofunctional rearrangements in the adult rats adenohypophysis after long-term exposure of heavy metal salts

Important environmental problem of some northern regions of Ukraine is the accumulation of heavy metal salts in the soil, water and air, which is observed in various combinations depending on the region and causes adverse effects on population’s health. The central link, in particular the pituitary gland, is involved in triggering a stress response, limiting its further development preventing adverse effects on the body. The study of morphofunctional rearrangements in the pituitary gland of adult male rats under the influence of heavy metal salts complex on the body remains a relevant aspect of modern morphology. The experiment was performed on 12 white mature male rats weighing 200-250g at the age of 7-8 months, which were divided into 2 groups (control and experimental). The experimental group included rats, which after 90 days of use of a heavy metals salts complex (zinc, copper, iron, manganese, lead and chromium) for 30 days used ordinary drinking water. General morphological (histological, morphometric), mmunohistochemical, biochemical and statistical research methods were used. Results showed a decrease in the linear parameters of the adenohypophysis, there was a significant increase in the value of fibrous connective tissue component in the stroma, increased collagenization of large vessels, significant diffuse stromal edema and edematous processes in the gland parenchyma persisted. Measurements revealed an increase in the number of chromophobes and at the same time a decrease in the number of chromophilic basophils compared to control animals, the presence of cysts in the parenchyma was found out. number of morphological features still indicated the development of adaptive and compensatory processes in the adenohypophysis (vascular plethora decreased, significantly improved the rheological properties of blood, an increase in the number of adenocytes with increasing expression of hsp90 in their cytoplasm). However, despite the positive dynamics of adaptive processes, it should be noted that the 30-day period of adaptation is insufficient for complete recovery of the organ.

Junctional complexes of the blood-testis barrier in the Japanese quail (Coturnix Coturnix japonica)

This study investigated the developmental changes in the adherens junctions, gap junctions, as well as tight junctions forming the blood-testis barrier (BTB) in Japanese quail (Coturnix Coturnix japonica) testis. Testicular tissue from pre-pubertal, pubertal, adult, and aged Japanese quail were examined by immunohistochemistry and transmission electron microscopy (TEM). The tight junction proteins claudin-3, claudin-11, occludin and zonula occludens-1 (ZO-1), were generally localised in the cytoplasm of Sertoli cells, spermatogonia, and spermatocytes of pre-pubertal, pubertal, some adult birds. The adherens junction protein E-cadherin had a similar distribution pattern. During pre-pubertal development, the gap junction protein connexin-43 (Cx43) was only localised between Leydig cells in the testicular interstitium. However, TEM revealed the presence of gap junctions between cells of the seminiferous epithelium as early as the pre-pubertal stage. Furthermore, TEM confirmed the presence of tight and adherens junctions in the seminiferous epithelia of all age groups. The findings of this study document age-related differences in the immunolocalisation and intensity of the junctional proteins and the ultrastructure of the junctional complexes forming the BTB in quail testes. Additionally, the junctional complexes forming the BTB in the Japanese quail are well established prior to puberty. This study provides baseline information for the future evaluation of pathological changes in the BTB of avian species at different developmental stages.

The effects of Aroclor 1254 alone and in combination with X-rays on the male mice germ cells quantity and quality

The effects of chemical and physical environmental factors are concerned as the main reason of diminished male fertility. The aim of the study was the investigation of the effects of low doses of Aroclor 1254 or combined exposure to low doses of Aroclor 1254 and low doses of ionizing radiation on the sperm quantity and quality of male germ cells including damage to genetic material of adult male mice. Mice were exposed for 2 weeks, 3 times per week by intraperitoneal injection with Aroclor 1254 diluted in corn oil at doses of 1, 2 and 4 mg/kg bw or to whole body X-rays irradiation at doses 0.05 Gy, 0.10 Gy and 0.15 Gy or to combination of X-rays and Aroclor 1254 at following doses 0.05 Gy + 1 mg/kg bw Aroclor 1254, 0.10 Gy + 2 mg/kg bw Aroclor 1254. The samples for sperm count, motility, morphology and DNA integrity of male germ cells estimation were taken from animals just after the end of exposure and 5 weeks later. Irradiation alone deteriorated sperm count and quality. Aroclor 1254 significantly reduced the sperm motility and increased sperm abnormality and at the highest dose also induced DNA damage of gametes. The combined exposure to 0.10 Gy + 2 mg/kg bw of Aroclor 1254 showed the increase in the sperm concentration and the decrease of percentage of abnormal spermatozoa compared to results after irradiation to 0.10 Gy alone. In conclusion, the low doses of Aroclor 1254 used in this study did not significantly reduce the sperm count, but affected the sperm motility, morphology and sometimes also DNA integrity of gametes. In combination with low doses of irradiation, low doses of Aroclor 1254 may ameliorate the harmful effect of irradiation on the male gametes.

The impact of preconceptional exposure of F0 male mice to bisphenol A alone or in combination with X-rays on the intrauterine development of F2 progeny

Bisphenol A (BPA) is used for the production of polycarbonates and epoxy resins. Exposure to chemical and physical environmental factors may influence the health of exposed individuals, and of the next generations. This paper describes the prenatal effects in the F2 generation of mice after exposure of F0 pubescent or mature males to BPA (5 mg/kg bw, 10 mg/kg bw, 20 mg/kg bw), X-rays (0.05 Gy) or a combination of both factors in low doses (0.05 Gy + 5 mg/kg bw BPA) for 8 weeks. F1 males were mated with females from the same group but from a different litter. The females were sacrificed before parturition and examined for the number of implantations, live foetuses, as well as early and late post-implantation deaths. The fertility of males and the percentage of pregnant females in each group were also assessed. Exposure of pubescent F0 males to 10 mg/kg bw of BPA decreased the frequency of fertile males. Following exposure of pubescent males, the frequency of pregnant females decreased in the groups of 10 mg/kg bw and 20 mg/kg bw of BPA, whereas after exposure of adult F0 males in the groups of 5 mg/kg bw and 20 mg/kg bw of BPA, no significant changes in the frequency of total, live and dead implantations in all the experimental groups were found. The results observed in regard to prenatal development of the F2 generation suggest that sperm of the sons of F0 pubescent males exposed to BPA contains genetic defects that affect the possibility of fertilization. The results of both pubescent and mature males exposed to BPA showed that fertilized eggs died before implantation, probably due to defects induced in the sperm. This confirmed that BPA induced transgenerational effects in male germ cells.

Impacts of endocrine-disrupting chemicals on prostate function and cancer

Because of their historical mode of action, endocrine-disrupting chemicals (EDCs) are associated with sex-steroid receptors, namely the two estrogen receptors (ERα and ERβ) and the androgen receptor (AR). Broadly, EDCs can modulate sex-steroid receptor functions. They can also indirectly impact the androgen and estrogen pathways by influencing steroidogenesis, expression of AR or ERs, and their respective activity as transcription factors. Additionally, many of these chemicals have multiple cellular targets other than sex-steroid receptors, which results in a myriad of potential effects in humans. The current article reviews the association between prostate cancer and the endocrine-disrupting functions of four prominent EDC families: bisphenols, phthalates, phytoestrogens, and mycoestrogens. Results from both in vitro and in vivo models are included and discussed to better assess the molecular mechanisms by which EDCs can modify prostate biology. To overcome the heterogeneity of results published, we established common guidelines to properly study EDCs in the context of endocrine diseases. Firstly, the expression of sex-steroid receptors in the models used must be determined before testing. Then, in parallel to EDCs, pharmacological compounds acting as positive (agonists) and negative controls (antagonists) have to be employed. Finally, EDCs need to be used in a precise range of concentrations to modulate sex-steroid receptors and avoid off-target effects. By adequately integrating molecular endocrinology aspects in EDC studies and identifying their underlying molecular mechanisms, we will truly understand their impact on prostate cancer and distinguish those that favor the progression of the disease from those that slow down tumor development.

Long-term residential exposure to air pollution and risk of testicular cancer in Denmark: A population-based case-control study

BACKGROUND

The incidence rate risk of testicular cancer has increased over the last four decades, and most significant increase has been among Caucasian men in Nordic countries. Second-generation immigrant studies indicate a significant role of environmental exposure in testicular cancer.

METHODS

We conducted a nationwide register-based case-control study, including 6,390 testicular cancer cases registered in the Danish Cancer Registry between 1989 and 2014. Up to four age-matched controls for each case (n=18,997) were randomly selected from Civil Registration System. Ambient air pollution levels were estimated at addresses of cases and controls with a state-of-the-art air pollution modeling system.

RESULTS

We mostly found ORs close to 1.00 and with 95% confidence intervals (CI) spanning 1.00. Exposure during the year preceding birth was associated with ORs for NO2 of 0.87 (95%CI: 0.77-0.97) per 10 µg/m3 and for organic carbon of 0.84 (95%CI: 0.72-0.98) per 1 µg/m3. Exposure during the first 10 years of life was associated with ORs for organic carbon of 0.79 (95%CI: 0.67-0.93) per 1 µg/m3, for O3 of 1.20 (95%CI: 1.07-1.34) per 10 µg/m3 and for secondary inorganic aerosols of 1.07 (95%CI: 1.00-1.15) per 1 µg/m3.

CONCLUSIONS

Early-life exposure to NO2 and OC was associated with lower risk for testicular cancer whereas early-life exposure to O3 and SIA was associated with higher risk.

IMPACT

We report both positive and negative associations between ambient air pollutants and risk of testicular, dependent on pollutant, exposure time window and age at diagnosis. This is the first study to investigate such associations.

Age-related histomorphometric and ultrastructural changes in the Sertoli cells of Japanese quail (Coturnix Coturnix japonica)

Prepared sections from pre-pubertal, pubertal, adult, and aged Japanese quail testes were examined by light microscopy and transmission electron microscopy (TEM) and measurements of seminiferous tubular diameter (STD), luminal diameter (SLD), epithelial height (SEH) and cross-sectional area of the seminiferous tubules (AST) were taken using an image analyzer. Apoptotic Sertoli cells with features such as cell shrinkage and chromatin condensation were observed in pre-pubertal and aged quail. There was a significant difference between the mean Sertoli cell number (SCN), SLD, SEH, STD and AST among the four age groups (P < 0.001). The highest SCN (mean ± standard error) was recorded in the adult (30.53 ± 0.42), with the aged group displaying the lowest mean (11.80 ± 0.27) SCN. Spearman's rho correlation coefficients demonstrated a strong relationship between the SCN and SEH in the pubertal (ρ=0.915; P < 0.001), adult (ρ=0.878; P < 0.001), and aged (ρ=0.858; P < 0.001) groups, while a significant moderate correlation was observed in the pre-pubertal (ρ=0.606; P < 0.001) group. There were significant moderate correlations between the SCN and STD in the pre-pubertal (ρ=0.445; P < 0.001), pubertal (ρ=0.653; P < 0.001), adult (ρ=0.440; P < 0.001), and aged (ρ=0.514; P < 0.001) groups. Furthermore, significant moderate correlations were estimated between the SCN and AST in the pre-pubertal (ρ=0.453; P < 0.001), pubertal (ρ=0.661; P < 0.001), adult (ρ=0.393; P = 0.001), and aged (ρ=0.498; P < 0.001) groups. This study provides baseline data on the morphology and development of the Sertoli cell, as well as testicular morphometry in avian species during the pre-pubertal, pubertal, adult, and aged stages using the Japanese quail as a model.

Evaluation of Triclosan-induced reproductive impairments in the accessory reproductive organs and sperm indices in the mice

Highly effective antimicrobial properties of triclosan (TCS) make its use as a widely used preservative in different types of consumer products. TCS is reported as an emerging endocrine disruptor causing reproductive impairments in the males as well as in the females. The present study describes the adverse effects of various doses of TCS (40, 80, 160 and 320 mg/kg BW/day, for 42 consecutive days) on the weights and histopathology of the epididymis and seminal vesicle, sperm indices (motility, viability, count and morphology), concentrations of epididymal sialic acid and seminal vesicular fructose, along with TCS accumulated in these accessory reproductive organs of the laboratory mouse. TCS induced significant reductions in the weights of the epididymis and seminal vesicle along with noticeable histopathological alterations in these organs. TCS caused significant reductions in the count, percentage of motile and viable spermatozoa while a significant increase in the percentage of abnormal spermatozoa in the epididymis. Concentrations of epididymal sialic acid and seminal vesicular fructose declined significantly in the treated mice. A significant increase was noticed in the concentration of TCS, accumulated in the epididymis and seminal vesicle following TCS exposure at a high dose (320 mg/kg BW/day). The results thus suggest that the accessory sex organs are also affected deleteriously following TCS exposure, leading to impairment in the male reproductive health.

Protective Roles of Honey in Reproductive Health: A Review

Nowadays, most people who lead healthy lifestyles tend to use natural products as supplements, complementary medicine or alternative treatments. Honey is God's precious gift to mankind. Honey has been highly appreciated and extensively used since ancient history due to its high nutritional and therapeutic values. It is also known to enhance fertility. In the last few decades, the important role of honey in modern medicine has been acknowledged due to the large body of convincing evidence derived from extensive laboratory studies and clinical investigations. Honey has a highly complex chemical and biological composition that consists of various essential bioactive compounds, enzymes, amino and organic acids, acid phosphorylase, phytochemicals, carotenoid-like substances, vitamins and minerals. Reproductive health and fertility rates have declined in the last 30 years. Therefore, this review aimed to highlight the protective role of honey as a potential therapeutic in maintaining reproductive health. The main role of honey is to enhance fertility and treat infertility problems by acting as an alternative to hormone replacement therapy for protecting the vagina and uterus from atrophy, protecting against the toxic effects of xeno-oestrogenic agents on female reproductive functions and helping in the treatment of gynaecological disorders, such as vulvovaginal candidiasis infection, that affect women's lives.

Chronic Exposure to Environmental DDT/DDE in 2 Species of Small Rodents: Measures of Contaminant Load, Immune Dysfunction, and Oxidative Stress

Persistent contaminants are ubiquitous in our water and soil, and thus chronic exposure to environmentally relevant levels of these contaminants may pose a risk to humans and wildlife. Two species of small mammals (deer mouse, Peromyscus maniculatus and cotton rat, Sigmodon hispidus) were collected from historically dichlorodiphenyltrichloroethane (DDT)-contaminated and reference areas at the Redstone Arsenal (Huntsville, AL, USA), a US Environmental Protection Agency (USEPA)-designated Superfund site. Soil samples taken concurrently with mammal collection from the DDT abatement site exhibited DDT and dichlorodiphenyldichloroethylene (DDE) levels >1 ppm (USEPA total threshold limit concentration for DDT and DDE <1 ppm), whereas soil samples from the reference area had undetectable levels. Liver samples from individuals of both species collected in the contaminated areas also had significantly elevated DDT/DDE levels, with P. maniculatus averaging an approximately 20× greater load than that documented for S. hispidus. Both rodent species collected from the contaminated site had significantly lower total leukocyte counts and total differential blood cell counts (p = 0.01 and p = 0.04, respectively) than those collected from the nearby (~7000-m) reference site. Cellular stress indices also trended higher in both species, suggesting a potential for chronic exposure to DDT to act as a mediator of oxidative damage. The present study provides support to the idea that environmental exposure to low levels of contaminants can cause physiological consequences that may influence immune responsiveness and initiate cellular stress in resident mammals. Environ Toxicol Chem 2021;40:1619-1629. © 2021 SETAC.

Turmeric and vitamin C mitigate testicular atrophy induced by lead diacetate via regulation of GRP-78/17β-HSD pathways in rat's model

Occupational and ecological contacts to lead persist as a universal concern. Lead alters most of the physiological processes via enhancing oxidative stress. Thus, this study was purposed to assess the influence of turmeric (TMRC) and/or vitamin C (VIT-C) on Lead diacetate (Lead diAC)-induced testicular atrophy with an emphasis on oxidative stress, inflammation, BAX/STAR and GRP-78/17β-HSD signalling. Rats were injected with Lead diAC and then treated with TMRC and/or VIT-C orally for 1 week. Lead diAC decreased serum testosterone and testicular glutathione levels. It also decreased superoxide dismutase activity. On the contrary, levels of malondialdehyde, tumour necrosis factor-α, IL-1β and caspase-3 were increased. mRNA levels and protein expressions of GRP-78 and BAX were upregulated, while the expression of both steroidogenic acute regulatory protein and 17β-HSD were downregulated. DNA fragmentation was increased as well. These changes were further confirmed by histopathological findings. Supplementation with TMRC and/or VIT-C ameliorated all of the above parameters. In Conclusion: TMRC or VIT-C specially in combination group prevents Lead diAC testicular damage via reduction of oxidative injury as well as inflammation, downregulation of GRP-78/BAX and upregulation of 17β-HSD and STAR expression as well as improvement in the histological architecture of the testis.

Endocrine Disruptors Acting on Estrogen and Androgen Pathways Cause Reproductive Disorders through Multiple Mechanisms: A Review

Increasing contamination of the environment by toxic compounds such as endocrine disrupting chemicals (EDCs) is one of the major causes of reproductive defects in both sexes. Estrogen/androgen pathways are of utmost importance in gonadal development, determination of secondary sex characteristics and gametogenesis. Most of the EDCs mediate their action through respective receptors and/or downstream signaling. The purpose of this review is to highlight the mechanism by which EDCs can trigger antagonistic or agonistic response, acting through estrogen/androgen receptors causing reproductive defects that lead to infertility. In vitro, in vivo and in silico studies focusing on the impact of EDCs on estrogen/androgen pathways and related proteins published in the last decade were considered for the review. PUBMED and PUBCHEM were used for literature search. EDCs can bind to estrogen receptors (ERα and ERβ) and androgen receptors or activate alternative receptors such as G protein-coupled receptors (GPCR), GPR30, estrogen-related receptor (ERRγ) to activate estrogen signaling via downstream kinases. Bisphenol A, dichlorodiphenyltrichloroethane, dichlorodiphenyldichloroethylene, polychlorinated biphenyls and phthalates are major toxicants that interfere with the normal estrogen/androgen pathways leading to infertility in both sexes through many ways, including DNA damage in spermatozoids, altered methylation pattern, histone modifications and miRNA expression.

Endocrine Disrupting Chemicals and Reproductive Health in Boys and Men

Male reproductive health has declined as indicated by increasing rates of cryptorchidism, i.e., undescended testis, poor semen quality, low serum testosterone level, and testicular cancer. Exposure to endocrine disrupting chemicals (EDCs) has been proposed to have a role in this finding. In utero exposure to antiandrogenic EDCs, particularly at a sensitive period of fetal testicular development, the so-called 'masculinization programming window (MPW)', can disturb testicular development and function. Low androgen effect during the MPW can cause both short- and long-term reproductive disorders. A concurrent exposure to EDCs may also affect testicular function or damage testicular cells. Evidence from animal studies supports the role of endocrine disrupting chemicals in development of male reproductive disorders. However, evidence from epidemiological studies is relatively mixed. In this article, we review the current literature that evaluated relationship between prenatal EDC exposures and anogenital distance, cryptorchidism, and congenital penile abnormality called hypospadias. We review also studies on the association between early life and postnatal EDC exposure and semen quality, hypothalamic-pituitary-gonadal axis hormone levels and testicular cancer.

Climate change and declining fertility rate in Malaysia: the possible connexions

Climate change is an incessant global phenomenon and has turned contentious in the present century. Malaysia, a developing Asian country, has also undergone significant vicissitudes in climate, which has been projected with significant deviations in forthcoming decades. As per the available studies, climate changes may impact on the fertility, either via direct effects on the gonadal functions and neuroendocrine regulations or via several indirect effects on health, socioeconomic status, demeaning the quality of food and water. Malaysia is already observing a declining trend in the Total fertility rate (TFR) over the past few decades and is currently recorded below the replacement level of 2.1 which is insufficient to replace the present population. Moreover, climate changes reportedly play a role in the emergence and cessation of various infectious diseases. Besides its immediate effects, the long-term effects on health and fertility await to be unveiled. Despite the huge magnitude of the repercussion of climate changes in Malaysia, research that can explain the exact cause of the present reduction in fertility parameters in Malaysia or any measures to preserve the national population is surprisingly very scarce. Thus, the present review aims to elucidate the possible missing links by which climate changes are impairing fertility status in Malaysia.

The Effect of Lead Acetate and Quercetin on the Tight and Gap Junctions in the Mouse Testis

Environmental pollutant effects on fertility sometime are irretrievable. The aim of this study was to investigate the effect of lead acetate and quercetin on tight (claudin 11 and occludin) and gap junctional (connexin 43) proteins and the integrity of the blood-testis barrier status. Experimental groups, including the lead acetate (Pb), quercetin (QE), lead acetate with quercetin (Pb + QE), and control mice, were treated at least one spermatogenic cycle. Gene expression of claudin 11 and occludin decreased in Pb + QE, Pb, and QE compared with the control group. Connexin 43 (Cx43) expression in the control and Pb groups was lower than in Pb + QE and QE. The immunohistochemical data were generally in line with these findings. In conclusion, the results showed that Pb exposure led to disorders in cellular interactions that affect testicular function; however, simultaneous treatment with quercetin did not alleviate these effects. Graphical Abstract.

The impact of endocrine-disrupting chemical exposure in the mammalian hypothalamic-pituitary axis

The hypothalamic-pituitary axis (HP axis) plays a critical and integrative role in the endocrine system control to maintain homeostasis. The HP axis is responsible for the hormonal events necessary to regulate the thyroid, adrenal glands, gonads, somatic growth, among other functions. Endocrine-disrupting chemicals (EDCs) are a worldwide public health concern. There is growing evidence that exposure to EDCs such as bisphenol A (BPA), some phthalates, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and biphenyls (PBBs), dichlorodiphenyltrichloroethane (DDT), tributyltin (TBT), and atrazine (ATR), is associated with HP axis abnormalities. EDCs act on hormone receptors and their downstream signaling pathways and can interfere with hormone synthesis, metabolism, and actions. Because the HP axis function is particularly sensitive to endogenous hormonal changes, disruptions by EDCs can alter HP axis proper function, leading to important endocrine irregularities. Here, we review the evidence that EDCs could directly affect the mammalian HP axis function.

Antioxidant pretreatment for male partner before ART for male factor subfertility: a randomized controlled trial

STUDY QUESTION

Does oral antioxidant pretreatment for the male partner improve clinical pregnancy rate in couples undergoing ART for male factor subfertility?

SUMMARY ANSWER

There was no significant difference in clinical pregnancy rate following oral antioxidant pretreatment for male partner in couples undergoing ART for male factor subfertility compared to no pretreatment.

WHAT IS KNOWN ALREADY

Damage to sperm mediated by reactive oxygen species (ROS) contributes significantly to male factor infertility. The ROS-related injury reduces fertilization potential and adversely affects the sperm DNA integrity. Antioxidants act as free radical scavengers to protect spermatozoa against ROS induced damage. During ART, use of sperms which have been exposed to ROS-mediated damage may affect the treatment outcome. Pretreatment with antioxidants may reduce the ROS-mediated sperm DNA damage. Currently, antioxidants are commonly prescribed to men who require ART for male factor subfertility but there is ambiguity regarding their role.

STUDY DESIGN, SIZE, DURATION

This was an open label, randomized controlled trial conducted at a tertiary level infertility clinic between February 2013 and October 2019. The trial included 200 subfertile couples who were undergoing ART treatment for male factor subfertility.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Couples were randomized into treatment arm (n = 100) and control arm (n = 100). In the treatment arm, the male partner received oral antioxidants (Vitamin C, Vitamin E and Zinc) for 3 months just prior to the ART cycle. In the control arm, no antioxidant was given to the male partner. The primary outcome was clinical pregnancy rate, while live birth rate (LBR), miscarriage rate and changes in semen parameters were the secondary outcomes.

MAIN RESULTS AND THE ROLE OF CHANCE

Out of 200 women randomized, 135 underwent embryo transfer as per protocol. Following intention to treat analysis, no significant difference was noted in clinical pregnancy (36/100, 36% vs 26/100, 26%; odds ratio (OR) 1.60, 95% CI 0.87 to 2.93) and LBR (25/100, 25% vs 22/100, 22%; OR 1.18, 95% CI 0.61 to 2.27) between antioxidant and no pretreatment arms. The clinical pregnancy rate per embryo transfer was significantly higher following antioxidant pretreatment (35/64, 54.7% vs 26/71, 36.6%; OR 2.09, 95% CI 1.05 to 4.16) compared to no pretreatment. There was no significant difference in LBR per embryo transfer (25/64, 39.1%, vs 22/71, 31.0%; OR 1.43, 95% CI 0.70 to 2.91) after antioxidant pretreatment versus no pretreatment. The semen parameters of sperm concentration (median, interquartile range, IQR) (18.2, 8.6 to 37.5 vs 20.5, 8.0 to 52.5, million/ml; P = 0.97), motility (median, IQR) (34, 20 to 45 vs 31, 18 to 45%; P = 0.38) and morphology (mean ± SD) (2.0 ± 1.4 vs 2.2 ± 1.5%; P = 0.69) did not show any significant improvement after intake of antioxidant compared to no treatment, respectively.

LIMITATIONS, REASONS FOR CAUTION

The objective assessment of sperm DNA damage was not carried out before and after the antioxidant pretreatment. Since the clinicians were aware of the group allotment, performance bias cannot be ruled out.

WIDER IMPLICATIONS OF THE FINDINGS

The current study did not show any significant difference in clinical pregnancy and LBR following antioxidant pretreatment for the male partner in couples undergoing ART for male subfertility. The findings need further validation in a larger placebo-controlled randomized trial.

STUDY FUNDING/COMPETING INTEREST(S)

This trial has been funded by Fluid Research grant of Christian Medical College, Vellore (internal funding). The authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

CTRI/2013/02/003431

TRIAL REGISTRATION DATE

26 February 2013

DATE OF FIRST PATIENT’S ENROLMENT

11 February 2013

Antioxidant, anti-inflammatory and anti-apoptotic effects of hydro-ethanolic extract of Cyperus esculentus L. (tigernut) on lead acetate-induced testicular dysfunction in Wistar rats

AIM

Lead acetate impairs testicular function by enhancing testicular oxidative stress and apoptosis. Cyperus esculentus possesses antioxidants and has shown great improvement of testicular function. This study investigated the protective effect of hydro-ethanolic extract of Cyperus esculentus on lead acetate-induced testicular dysfunction in Wistar rats.

MATERIALS AND METHODS

Twenty-five male Wistar rats (180-195 g) were randomly divided into 5 groups (n = 5) namely: Normal control (NC), Lead control (PbC) (20 mg/kg b.w. i.p.), C. esculentus-treated (CE) (500 mg/kg b.w p.o.), Pb + CE(500) (20 mg/kg of lead and 500 mg/kg of extract) and Pb + CE(1000) (20 mg/kg of lead and 1000 mg/kg of extract). Administration lasted for 21 days.

RESULTS

Sperm count, motility, viability, serum testosterone and follicle stimulating hormone, Johnsen's score, Leydig cell count, Sertoli cell count, testicular testosterone, B-cell lymphoma protein-2 (Bcl-2), steroidogenic acute regulatory protein, cytochrome P450 A1, 3β-hydroxysteroid dehydrogenase (HSD), 17β-HSD, enzymatic antioxidant activities and total antioxidant capacity were significantly (p < 0.05) decreased in PbC compared with NC. These parameters however increased significantly (p < 0.05) in Pb + CE(500) and Pb + CE(1000) compared with PbC. Lead acetate upregulated (p < 0.05) testicular malondialdehyde, nitric oxide, glucose, lactate, lactate dehydrogenase, C-reactive protein, tumor necrosis factor-α, interleukin (IL)-6, IL-1β, Bcl-2 associated X (Bax), Bax/Bcl-2 and cleaved caspase-3 levels. All these parameters were downregulated (p < 0.05) in Pb + CE(500) and Pb + CE(1000) in comparison with PbC.

CONCLUSION

C. esculentus exhibited a dose-dependent mitigation of lead acetate-induced testicular dysfunction in Wistar rats via its antioxidant, anti-inflammatory and anti-apoptotic effects.

Integrated probabilistic risk assessment in sites contaminated with arsenic and lead by long-term mining liabilities in San Luis Potosi, Mexico

Mining environmental liabilities (MEL) in San Luis Potosi are the result of more than 450 years of mining activity, which has contaminated the soil mainly with arsenic (As) and lead (Pb) in several areas. Risk assessments are used to estimate the possibility of the occurrence of adverse effects on human health or on ecological receptors; and the most accessible way of performing them is through probabilistic estimates such as the Latin Hypercube Sampling (LHS) model. Therefore, the aim of this study was to carry out an Integrated Probabilistic Environmental Risk Assessment (IPERA) for the estimation of health risks in infants and rodents. The mean concentrations of As and Pb in soil were significantly higher (p<0.05) in all contaminated sites than in their respective reference sites. Villa de la Paz was the site with the highest mean concentration of As (1374 mg/kg), while Charcas was the one with the highest level of Pb (12,929 mg/kg). The Hazard Quotient (HQ) was calculated and Villa de la Paz had the highest values of As in both rodents (11.994) and children (39.32), and Charcas showed the highest values of Pb in both (24.971 and 31.668 for rodents and children respectively). The cumulative hazard Index (HI) reveals there is a very significant health risk due to As and Pb exposure for both rodents and children in contaminated areas of these mining communities.

More pesticides-less children?

A previously presented study investigated the impact of recent pesticide exposure on cytological signs of genotoxicity and on symptoms of intoxication in 71 male coffee workers in the Dominican Republic. An unexpected finding of this study was that conventional farming workers, among other symptoms, reported fewer children than controls working in organic farms without pesticide use. This study set out to investigate possible reasons for the latter difference. One statistical problem of this analysis is that the age of the workers is a strong predictor for the number of children and available data on the exposure determinants "duration of pesticide exposure" as well as "age at first pesticide exposure" are correlated with age. To correctly control statistics for these confounding parameters, different approaches to best control for age were explored. After careful elimination of the age-related confounding factors, a reduced number of children was still observed in exposed workers. The clearest effect is seen in those workers that reported first exposure before the age of 20 years. Socioeconomic factors could still confound that finding, but a direct effect of early life pesticide exposure is the most likely explanation of the observation.

The association between anogenital distance, reproductive and general health in adult females- a prospective cohort of 17 years

BACKGROUND

Studies have suggested an association between prenatal hormonal environment and anogenital distance (AGD). We aimed to study the association between AGD and health characteristics in adult women.

METHODS

In this prospective cohort AGD was measured in 300 parturients during the years 2000-2001. In December 2017, study participants` hospital records were abstracted and medical diagnoses grouped into major categories, including gynecological, cardiovascular, and other. Associations between AGD and the morbidities categories were evaluated using multivariable survival models, which adjusted for confounding variables.

RESULTS

Participants were 44.3 ± 5.4 years old with mean AGD 40.3 mm (±10.7 mm). Women with below vs. above mean AGD were more likely to develop gynecological morbidities (39.9% vs. 27.1%, adjusted Hazard ratio 1.82; 95%CI 1.08-3.06).

CONCLUSIONS

Women with short AGD are at increased risk for gynecological morbidities. AGD should be studied further, and may possibly be used for screening of women at risk for these conditions.

Effect of endocrine disruptors on the ratio of X and Y chromosome-bearing live spermatozoa

Although equal numbers of X and Y spermatozoa are produced during spermatogenesis, the sex chromosome ratio in ejaculated spermatozoa can be altered by exposure to endocrine-disrupting chemicals (EDCs), which can be reflected by altered sex ratios at birth. Here, we hypothesized EDCs affect sperm functions and viability of X and Y chromosome-bearing human spermatozoa. After exposure to genistein (Gen), bisphenol A (BPA), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), dibromochloropropane (DBCP), and diazinon (Diaz), we evaluated motility, viability, capacitation, and differential viability of X and Y spermatozoa. All EDCs tested altered sperm viability, motility, and capacitation. Interestingly, the Y/X ratio of live spermatozoa was significantly lower in sperm treated with TCDD, DBCP, and Diaz than control spermatozoa. Our results suggest that some of EDCs have larger effects on the viability of Y spermatozoa than X spermatozoa, implicating that a reduction in Y sperm viability may result in a female-biased sex ratio of offspring at birth.

Melatonin prevents and ameliorates lead-induced gonadotoxicity through antioxidative and hormonal mechanisms

We investigated the effects of melatonin on sperm parameters and some biochemical markers in lead-exposed male Wistar rats. Lead (50 mg/kg bw/day) and/or melatonin (4 mg/kg or 10 mg/kg bw/day) was administered for 4 weeks, while 2-week lead exposure was preceded by or followed by 2-week treatment with both doses of melatonin in other groups. Lead reduced glutathione, catalase, adjusted testes weight, semen parameters but did not change malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase, and total antioxidant capacity. Though independent of prolactin, lead-induced gonadotoxicity was both centrally and peripherally mediated, as it reduced gonadotropin-releasing hormone and testosterone levels, while gonadotropin levels did not change significantly probably due to negative feedback by elevated estradiol. However, pre-, simultaneous, or posttreatment of lead-exposed rats with melatonin reduced MDA, SOD, and estradiol but dose-dependently increased other parameters. Conclusively, lead causes male gonadotoxicity through oxidative stress and endocrine mechanisms, and these could be dose-dependently prevented and ameliorated by melatonin.

Novel Epigenomic Biomarkers of Male Infertility Identified by Methylation Patterns of CpG Sites Within Imprinting Control Regions of H19 and SNRPN Genes

Male infertility is an important global health burden that can benefit from novel biomarkers and diagnostics innovation. Aberrant methylation of the imprinted genes H19 and SNRPN (small nuclear ribonucleoprotein polypeptide N) in sperm DNA has been implicated in abnormal sperm parameters and male infertility. However, whether certain methylation patterns of one or multiple CpG sites within an imprinted gene are pathological for multiple sperm defects remains poorly understood. To examine the diagnostic potential of certain methylation patterns of CpG sites for multiphenotype defects in human sperm, the sperm DNA methylation patterns of individual CpG sites within imprinting control regions (ICRs) of imprinted genes H19 and SNRPN were measured by bisulfite pyrosequencing in a Han Chinese population sample: 39 oligoasthenozoospermia (OA) patients, 36 asthenoteratozoospermia (AT) patients, and 50 normozoospermia (N) controls. A partial least squares discriminant analysis model was built with the CpG sites as independent variables. Among the 16 CpG sites screened, the methylation patterns of eight CpG sites within H19-ICR (CpG sites 1, 6-9, 12 and 15-16), and eight CpG sites within SNRPN-ICR (CpG sites 2, 5-6, 8-10, 13, and 16) correctly classified 74.4% and 72.0% of the samples in terms of male fertile status, respectively. Furthermore, by combination of these 16 selected CpG sites within ICRs of H19 and SNRPN, 88.0% of the samples could be successfully classified. Our study demonstrates that methylation profiles of CpG sites within ICRs of imprinted genes H19 and SNRPN may potentially serve as epigenomic biomarkers for assessment of infertility in men with multiple sperm defects. Further studies in independent population samples are called for diagnostic significance of methylation patterns of CpG sites within imprinted genes.

Impact of chromium and boron compounds on the reproductive function in rats

The purpose of this research is to study the process of mutagenesis and the reproductive function in male rats under separate and combined exposure to chromium and boron compounds. The experiment was conducted on two groups of animals. The first group was used to assess the ability of potassium dichromate and boric acid to induce mutation in germ and somatic cells under isolated and combined administration with the use of the dominant lethal mutations test and the micronuclei test in the polychromatophilic erythrocytes of the bone marrow. The second group was used to test the combined and separate effect of the compounds under consideration on the reproductive function of male rats during the spermatogenesis cycle. When used in specific doses, boron compounds are a promising means of preventing and correcting chromium-induced effects in chromium production facility workers and people who live in ecologically adverse regions.

2,3,7,8-Tetrachlorodibenzo-p-dioxin can alter the sex ratio of embryos with decreased viability of Y spermatozoa in mice

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a reproductive and developmental toxicant that can alter the sex ratio of offspring (proportion of male offspring). We hypothesized that the alteration of sex ratio is associated with sex chromosome ratio of live spermatozoa affected by exposure to TCDD. After exposure to TCDD we analyzed simultaneously sperm sex chromosome constitution and viability, and evaluated sperm sex chromosome ratio association with embryo sex ratio in mice. Short-term exposure to TCDD affects the decreased sperm motility and viability, and the increased acrosome reaction. Interestingly, Y spermatozoa survived shorter than X spermatozoa at high concentrations of TCDD. Moreover, the decreased sex ratio of embryos was associated with the short lifespan of Y spermatozoa. Our results suggest that TCDD may affect the fertility of Y spermatozoa more than X spermatozoa. Further studies are needed to compare the difference of fertilizing capability between X and Y spermatozoa by the effect of TCDD.

Developing a deeper insight into reproductive biomarkers

The development of biomarkers of reproductive medicine is still in its infancy because many black boxes are still present in reproductive medicine. Novel approaches to human infertility diagnostics and treatment must be developed because reproductive medicine has lagged behind in the implementation of biomarkers in clinical medicine. Despite the dearth of the available literature, the current rapid pace of publications suggests that this gap will soon be filled therefore; this review is a précis of the research that has been done so far and will provide a basis for the development of biomarkers in reproductive medicine.

Scientometric study of the effects of exposure to non-ionizing electromagnetic fields on fertility: A contribution to understanding the reasons of partial failure

The exposure to Non-Ionizing-Electromagnetic Fields (NI-EMFs) is often indicated as a cofactor responsible for the fertility reduction, which has been described in recent years. Despite the great interest in this topic and the research effort in exploring it, to date, there are no reliable data. Therefore, we carried out a scientometric analysis of the scientific literature published in peer reviewed Journals concerning this topic to better understand the reasons of this partial failure. To this aim, we identified and analysed 104 papers, published in last 26 years in peer-reviewed Journals, present in ISI Web of Knowledge Core Collection. Then, we analysed the impact of the Journals in which the papers were published as well as that of the single papers, the paper citation dynamics, the keywords citation busts, the geographical localization of citations and the co-authorship dynamics of the Authors. As a result, we found that different animal models (rodent, rabbit, guinea pig, and swine) and different experimental approaches (epidemiological vs. experimental studies) have the same impact, highlighting the lack of universally adopted standard in research activity. The analysis of the temporal trend in keywords and the high differences in citations between the different countries (also in those belonging to the same geographical and socio-economical area) pointed out the difficulties in approaching this branch of study. Lastly, it was evident that the Authors did not behave as a connected community, but as unconnected clusters of very small size. In conclusion, based on the results of our analysis, we think that important efforts must be undertaken to adopt more standardized models and to improve the research quality and the information exchange within the scientific community, with the aim of improving the reliability and usefulness of the results of research regarding the effect of NI-EMFs on fertility.

A robust high-throughput fungal biosensor assay for the detection of estrogen activity

Estrogenic active compounds are present in a variety of sources and may alter biological functions in vertebrates. Therefore, it is crucial to develop innovative analytical systems that allow us to screen a broad spectrum of matrices and deliver fast and reliable results. We present the adaptation and validation of a fungal biosensor for the detection of estrogen activity in cow derived samples and tested the clinical applicability for pregnancy diagnosis in 140 mares and 120 cows. As biosensor we used a previously engineered genetically modified strain of the filamentous fungus Aspergillus nidulans, which contains the human estrogen receptor alpha and a reporter construct, in which β-galactosidase gene expression is controlled by an estrogen-responsive-element. The estrogen response of the fungal biosensor was validated with blood, urine, feces, milk and saliva. All matrices were screened for estrogenic activity prior to and after chemical extraction and the results were compared to an enzyme immunoassay (EIA). The biosensor showed consistent results in milk, urine and feces, which were comparable to those of the EIA. In contrast to the EIA, no sample pre-treatment by chemical extraction was needed. For 17β-estradiol, the biosensor showed a limit of detection of 1ng/L. The validation of the biosensor for pregnancy diagnosis revealed a specificity of 100% and a sensitivity of more than 97%. In conclusion, we developed and validated a highly robust fungal biosensor for detection of estrogen activity, which is highly sensitive and economic as it allows analyzing in high-throughput formats without the necessity for organic solvents.

Chlorinated biphenyls effect on estrogen-related receptor expression, steroid secretion, mitochondria ultrastructure but not on mitochondrial membrane potential in Leydig cells

To characterize polychlorinated biphenyls (PCBs) action on Leydig cells, PCBs congeners, low-chlorinated (delor 103; d103) and high-chlorinated ones (delor 106; d106) were selected. The cells were treated according to PCBs dose (d103 or d106 0.2 ng/ml in low doses:, or 2 ng/ml in high doses) and type (d103 + d106 in low doses or 103 + 106 in high doses). After 24 h treatment with PCBs, a distinct increase in estrogen-related receptors (ERRs type α, β and γ) expression was revealed. However, the dose- and type-dependent PCBs effect was mostly exerted on ERRα expression. A similar increase in ERRs expression was demonstrated by estradiol but not testosterone, which was without an effect on ERRs. PCBs caused no decrease in the membrane potential status of Leydig cells (either in dose or type schedule) but had severe effects on the mitochondria number and structure. Moreover, PCBs markedly increased calcium (Ca2+) concentration and sex steroid secretion (both androgens and estrogens were elevated). These findings suggest a similar estrogenic action of PCBs congeners (d103 and d106) on Leydig cell function. We report dose- and type-specific effects of PCBs only on Leydig cell ERRs expression. Both delors showed common effects on the mitochondria ultrastructural and functional status. Based on our results, ERRα seems to be the most sensitive to hormonal modulation. The increases in Ca2+ and sex steroid secretion may be due to the activation of ERRs by PCBs binding and/or direct effect of PCBs on ERRs mRNA/protein expression. Nevertheless, to confirm the existence of possible relationships between ERRs signaling (including PCBs as ligands) and mitochondria function in Leydig cells, further intensive studies are needed.

Effect of Air Pollution on Menstrual Cycle Length-A Prognostic Factor of Women's Reproductive Health

Air pollution can influence women's reproductive health, specifically menstrual cycle characteristics, oocyte quality, and risk of miscarriage. The aim of the study was to assess whether air pollution can affect the length of the overall menstrual cycle and the length of its phases (follicular and luteal). Municipal ecological monitoring data was used to assess the air pollution exposure during the monitored menstrual cycle of each of 133 woman of reproductive age. Principal component analyses were used to group pollutants (PM10, SO₂, CO, and NOx) to represent a source-related mixture. PM10 and SO₂ assessed separately negatively affected the length of the luteal phase after standardization (b = -0.02; p = 0.03; b = -0.06; p = 0.02, respectively). Representing a fossil fuel combustion emission, they were also associated with luteal phase shortening (b = -0.32; p = 0.02). These pollutants did not affect the follicular phase length and overall cycle length, neither in single- nor in multi-pollutant models. CO and NOx assessed either separately or together as a traffic emission were not associated with overall cycle length or the length of cycle phases. Luteal phase shortening, a possible manifestation of luteal phase deficiency, can result from fossil fuel combustion. This suggests that air pollution may contribute to fertility problems in women.

The effect of Tributyltin on thyroid follicular cells of adult male albino rats and the possible protective role of green tea: a toxicological, histological and biochemical study

Introduction

Tributyltin is one of the important and wide-spread persistent organic contaminants that accumulate in the food chain. It is suspected to cause endocrine-disrupting effects in mammals, due in part to its possible transfer through marine food chains and to the consumption of contaminated seafood.

Aim of the work

Was to study the possible toxic effect of Tributyltin on thyroid follicular cells of adult male albino rats and to evaluate the possible protective role of green tea.

Material and methods

Forty-five adult male albino rats were included and randomly divided into 3 equal groups: a control group (Group I); Group II: received tributyltin chloride (TBT) dissolved in corn oil orally in a dose of 5 mg/kg for 30 days. Group III: received tributyltin chloride in the same dose with concomitant oral administration of green tea extract for 30 days. At the end of the experiment, the animals were sacrificed and blood samples were subjected to hormonal assay for T3, T4 and TSH levels. Malondialdehyde and reduced glutathione were assessed. The thyroid tissue was processed for histological and ultrastructure examination. The colloid area of thyroid follicles was evaluated morphometrically and statistically analyzed.

Results

A significant decrease in T3 and T4 levels and serum reduced glutathione in the group II when compared with the other groups. Furthermore, a significant increase in serum Malondialdehyde and TSH levels was recorded in group II treated group by comparison to the other two groups. Histopathological and ultrastructural changes of thyroid gland follicles were detected in tributyltin treated rats; the follicular cells appeared swollen and vacuolated. Epithelial stratification was noticed in some foci with excessive vacuolation of the colloid. Dilated rough endoplasmic reticulum filled with flocculent material and increased number of lysosomes were also detected together with variation in shape and size of the nuclei. A marked improvement in the histological features of thyroid follicles was noticed in group III.

Conclusion

Tributyltin induces oxidative stress in rats as well as anti-thyroid effect. The green tea extract is useful in combating tissue injury that is a result of tributyltin toxicity.

Aroclor1254 disrupts the blood-testis barrier by promoting endocytosis and degradation of junction proteins via p38 MAPK pathway

The blood–testis barrier (BTB) constituted by coexisting junction apparatus between Sertoli cells (SCs) plays an important role in spermatogenesis, which is a known target of various environmental toxicants. The commercial polychlorinated biphenyls mixture, Aroclor1254, has been shown to impair male reproduction by decreasing sperm count and affecting SC metabolism. This study was designed to investigate the effects of Aroclor1254 on the BTB integrity and elucidate the underlying mechanisms. We found that Aroclor1254 treatment in rats (1 or 3 mg/kg per day for 21 consecutive days) and in primary cultured SCs (5 or 10 μg/ml for 48 h) could induce BTB disruption via p38 MAPK pathway, concurrently with increments in junction proteins (JAM-A, N-cadherin, and β-catenin) endocytosis, and occludin ubiquitination. Either inhibition of caveolin-dependent membrane protein internalization by cholesterol oxidase or silencing E3 ubiquitine ligase Itch by small interfering RNA could partially counteract the effects of Aroclor1254 on the barrier function of cultured SCs. These results demonstrate that Aroclor1254 disrupts the BTB function by promoting the caveolin-dependent endocytosis and ubiquitine–proteasome degradation of junction proteins through the p38 MAPK pathway, which might be the potential reasons for its negative effects on spermatogenesis and male reproduction.

Endocrine-disrupting chemicals-Mechanisms of action on male reproductive system

Endocrine-disrupting chemicals (EDCs) are exogenous compounds that can cause disturbances in the endocrine system and have multiple harmful effects on health by targeting different organs and systems in the human body. Mass industrial production and widespread use of EDCs have resulted in worldwide contamination. Accumulating evidence suggest that human exposure to EDCs is related to the impairment of male reproductive function and can interrupt other hormonally regulated metabolic processes, particularly if exposure occurs during early development. Investigation of studies absent in previous reviews and meta-analysis of adverse effects of EDCs on functioning of the male reproductive system is the core of this work. Four main modes of action of EDCs on male fertility have been summarized in this review. First, studies describing estrogen- pathway disturbing chemicals are investigated. Second, androgen-signaling pathway alterations and influence on androgen sensitive tissues are examined. Third, evaluation of steroidogenesis dysfunction is discussed by focusing on the steroid hormone biosynthesis pathway, which is targeted by EDCs. Last, the reportedly destructive role of reactive oxygen species (ROS) on sperm function is discussed. Spermatogenesis is a remarkably complex process, hence multiple studies point out various dysfunctions depending on the development state at which the exposure occurred. Collected data show the need to account for critical windows of exposure such as fetal, perinatal and pubertal periods as well as effects of mixtures of several compounds in future research.