Endocrine disruptors of inhibiting testicular 3β-hydroxysteroid dehydrogenase

A Novel Organophosphate Ester, Tris(2,4-ditert-butylphenyl) Phosphate, Induced Reproductive Toxicity in Male Zebrafish at Environmentally Relevant Concentrations

As a novel organophosphate ester (NOPE), tris(2,4-ditert-butylphenyl) phosphate (TDtBPP) has attracted significant attention due to its unexpectedly high detection in natural environments. However, the ecological toxic effects of environmentally relevant concentrations of TDtBPP in organisms remain entirely unknown. In this study, 1 month old zebrafish were exposed to 0, 50, 500, or 5000 ng/L TDtBPP for 150 days, and the reproductive toxicity in male fish was evaluated. Results demonstrated that TDtBPP exposure significantly inhibited the maturation of spermatozoa and thus decreased spermatogenesis. Furthermore, abnormal sperm morphology and decreased sperm motility were also observed. The decrease in sperm quantity and quality eventually resulted in the declining fecundity. Moreover, TDtBPP exposure downregulated the expression of hsd3b1 in vivo and in vitro and subsequently inhibited the synthesis of androgens in zebrafish testes and Leydig cells. This inhibition of androgen synthesis appeared to be responsible for the observed reproductive toxicity in male fish. Molecular docking and dual-luciferase reporter gene experiments elucidated that TDtBPP inhibited the promotion of vitamin D on hsd3b1 transcription by the vitamin D receptor and thus downregulated the expression of hsd3b1. Our findings provide first time evidence that TDtBPP poses a risk to male fish reproduction at environmentally relevant levels.

Transcriptomic analysis of the HPT axis in a model of oligoasthenozoospermia induced by Adenine in rats

Male infertility is most commonly caused by oligozoospermia, and its pathogenesis is still poorly understood at the molecular level. This study used RNA sequencing (RNA-Seq) technology to identify candidate genes and regulatory pathways that regulate semen quality in the hypothalamic, pituitary, and testicular tissues of healthy rats and Adenine-induced oligozoospermia model rats. Semen quality testing and histological analysis of testicular tissues were performed on both groups of rats. We identified 627, 692, and 437 differentially expressed genes in the hypothalamus, pituitary gland, and testes, respectively. Functional analysis indicates that "neuronal projections," "positive regulation of hormone biosynthetic process," and "neuroactive ligand-receptor interaction pathways" are closely related to the hypothalamic-pituitary-testicular (HPT) axis hormone regulation and sperm production. Seven genes (Pomc, Rxfp1, Tac1, Npy, Insl3, Hsd3b3, Lhcgr) have been identified as key candidate genes responsible for regulating sperm quality within the HPT axis, potentially affecting rat reproductive function by influencing testicular development and testosterone secretion. These data provide a theoretical basis for further understanding the molecular mechanisms of reproductive performance in a rat model of oligoasthenozoospermia.

Reproductive toxicity of bisphenol A and nitro-bisphenol A in male zebrafish at environmentally relevant concentrations

Bisphenol A (BPA) is a well-known endocrine-disrupting pollutant that poses significant environmental challenges globally. However, the toxicity of nitro-BPA (NBPA), the primary transformation product of BPA, remains poorly understood. This study employs a multi-omics approach, integrating in silico and bioinformatics analyses, to investigate and compare the male reproductive toxicity of BPA and NBPA in male zebrafish exposed to environmentally relevant concentrations. After 21 days of exposure, we observed a significant increase in cumulative egg production over five days in the NBPA 200 nM group compared to pre-exposure levels. Conversely, the gonadosomatic index of NBPA 200 nM group was significantly reduced by approximately 41.65 %. Our findings indicate that the activation of ESRRγ and inhibition of NR5A2 are critical molecular initiating events linked to male reproductive toxicity. Additionally, both BPA and NBPA were found to disrupt several key events within the steroid hormone biosynthesis pathway. This disruption includes the downregulation of genes encoding cytochrome P450 (CYP450) and hydroxysteroid dehydrogenase enzymes, as well as alterations in the levels of steroid hormones such as cholesterol and 25-hydroxycholesterol. Our study identifies biomolecular targets of BPA and NBPA at environmentally relevant concentrations that induce reproductive toxicity, enhancing our understanding of NBPA toxicity and are anticipated to inform the development of effective mitigation strategies.

Structural determinants of parabens in inhibiting human and rat gonadal 3β-hydroxysteroid dehydrogenase

This study delved into the impacts of 10 parabens on the activity of human and rat gonadal 3β-hydroxysteroid dehydrogenase (3β-HSD) within human KGN cell and rat testicular microsomes, as well as on the secretion of progesterone in KGN cells and the inhibitory potency was compared between human and rats. Intriguingly, the outcomes revealed that ethyl, propyl, butyl, hexyl, heptyl, nonyl, phenyl, and benzyl parabens displayed varying IC50 values for human 3β-HSD2, from 4.15 to 139.96 μM, demonstrating characteristics of mixed inhibitors. Notably, within KGN cells, all examined parabens, excluding nonyl and phenyl parabens, significantly inhibited progesterone secretion at 5-50 μM. In the case of rats, the IC50 values for these parabens on gonadal 3β-HSD1 fluctuated between 7.15 and 110.76 μM, likewise functioning as mixed inhibitors. Through docking analysis, it was proposed that most parabens effectively bind to NAD+ and/or steroid binding site. Moreover, bivariate correlation analysis unveiled an inverse correlation between IC50 values and structural characteristics such as LogP, molecular weight, heavy atom number, and carbon number within the alcohol moiety of parabens. 3D-QSAR elucidated pivotal regions, comprising hydrogen bond donor, hydrogen bond acceptor, and hydrophobic region, with the most potent inhibitor nonyl paraben engaging with all regions, while the weakest inhibitor ethyl paraben interacted with the regions except for the hydrophobic region. In conclusion, this investigation underscored the inhibitory effects imparted by several parabens on both human and rat gonadal 3β-HSD activity, with their inhibitory potency being modulated by aspects of hydrophobicity and carbon chain length.

Fine particulate matter (PM2.5) induces testosterone disruption by triggering ferroptosis through SIRT1/HIF-1α signaling pathway in male mice

Fine particulate matter (PM2.5), a significant component of air pollution particulate matter, is inevitable and closely associated with increasing male reproductive disorder. However, the testicular targets of PM2.5 and its toxicity related molecular mechanisms are still not fully understood. In this study, the conditional knockout (cKO) mice and primary Leydig cells were used to explore the testicular targets of PM2.5 and the related underlying mechanisms. First, apparent the structure impairment of seminiferous tubules, Leydig cells vacuolization, decline of serum testosterone and sperm quality reduction were found in male wild-type (WT) and Sirt1 knockout mice after exposure to PM2.5. Enrichment analyses revealed that differentially expressed genes (DEGs) were enriched in steroid hormone biosynthesis, ferroptosis, and HIF-1 signaling pathway in the mice testes after exposure to PM2.5, which were subsequently verified by the molecular biological analyses. Notably, similar enrichment analyses results were also observed in primary Leydig cells after treatment with PM2.5. In addition, Knockdown of Sirt1 significantly increased PM2.5-induced expression and activation of HIF-1α, which was in parallel to the changes of cellular iron levels, oxidative stress indicators and the ferroptosis markers. In conclusion, this highlights that PM2.5 triggers ferroptosis via SIRT1/HIF-1α signaling pathway to inhibit testosterone synthesis in males. These findings provide a novel research support for the study that PM2.5 causes male reproductive injury.

UV-filter benzophenones suppress human, pig, rat, and mouse 11β-hydroxysteroid dehydrogenase 1: Structure-activity relationship and in silico docking analysis

Benzophenone chemicals (BPs) have been developed to prevent the adverse effects of UV radiation and they are widely contaminated. 11β-Hydroxysteroid dehydrogenase 1 (11β-HSD1) catalyze the conversion of inactive glucocorticoid to active glucocorticoid, playing critical role in many physiological function. However, the direct effect of BPs on human, pig, rat, and mouse 11β-HSD1 remains unclear. In this study, we screened the inhibitory strength of 12 BPs on 4 species, and performed the structure-activity relationship (SAR) and in silico docking analysis. The inhibitory potency of BPs was: for human 11β-HSD1, BP6 (IC50 = 18.76 μM) > BP8 (40.84 μM) > BP (88.89 μM) > other BPs; for pig 11β-HSD1, BP8 (45.57 μM) > BP6 (59.44 μM) > BP2 (65.12 μM) > BP (135.56 μM) > other BPs; for rat 11β-HSD1, BP7 (67.17 μM) > BP (68.83 μM) > BP8 (133.04 μM) > other BPs; and for mouse 11β-HSD1, BP8 (41.41 μM) > BP (50.61 μM) > other BPs. These BP chemicals were mixed/competitive inhibitors of these 11β-HSD1 enzymes. The 2,2'-dihydroxy substitutions in two benzene rings play a key role in enhancing the effectiveness of inhibiting 11β-HSD1, possibly via increasing hydrogen bond interactions. Docking analysis shows that these BPs bind to NADPH/glucocorticoid binding sites and forms hydrogen bonds with catalytic residues Ser and/or Tyr. In conclusion, this study demonstrates that BP chemicals can inhibit 11β-HSD1 from 4 species, and there are subtle species-dependent difference in the inhibitory strength and structural variations of BPs.

Structure-activity relationship and mechanistic study of organotins as inhibitors of human, pig, and rat gonadal 3β-hydroxysteroid dehydrogenases

Organotins have been widely used in various industrial applications. This study investigated the structure-activity relationship as inhibitors of human, pig, and rat gonadal 3β-hydroxysteroid dehydrogenases (3β-HSD). Human KGN cell, pig, and rat testis microsomes were utilized to assess the inhibitory effects of 18 organotins on the conversion of pregnenolone to progesterone. Among them, diphenyltin, triethyltin, and triphenyltin exhibited significant inhibitory activity against human 3β-HSD2 with IC50 values of 114.79, 106.98, and 5.40 μM, respectively. For pig 3β-HSD, dipropyltin, diphenyltin, triethyltin, tributyltin, and triphenyltin demonstrated inhibitory effects with IC50 values of 172.00, 100.19, 87.00, 5.75, and 1.65 μM, respectively. Similarly, for rat 3β-HSD1, dipropyltin, diphenyltin, triethyltin, tributyltin, and triphenyltin displayed inhibitory activity with IC50 values of 81.35, 43.56, 55.55, 4.09, and 0.035 μM, respectively. They were mixed inhibitors of pig and rat 3β-HSD, while triphenyltin was identified as a competitive inhibitor of human 3β-HSD2. The mechanism underlying the inhibition of organotins on 3β-HSD was explored, revealing that they may disrupt the enzyme activity by binding to cysteine residues in the catalytic sites. This proposition was supported by the observation that the addition of dithiothreitol reversed the inhibition caused by all organotins except for triethyltin, which was partially reversed. In conclusion, this study provides valuable insights into the structure-activity relationship of organotins as inhibitors of human, pig, and rat gonadal 3β-HSD. The mechanistic investigation suggests that these compounds likely exert their inhibitory effects through binding to cysteine residues in the catalytic sites.

In vitro culture and tissue-derived specific expression of melanocytes from ovary of adult Silky Fowl

The presence of a significant number of melanocytes in the ovary and follicular membrane of Silky Fowl suggests their potential involvement in follicle development. Currently, there is a lack of available data regarding to the isolation of primary melanocytes from adult chickens. To date, primary melanocytes and their in vitro culture system have been successfully conducted in the peritoneum of chicken embryos. Herein, melanocytes from silky fowl ovaries were isolated and identified. Silky Fowl ovaries were obtained by mixed digestion of 0.1% collagenase II and 0.25% trypsin-EDTA. Melanocytes could be further purified and cultured up to 5 generations in vitro. RNA-seq analysis was used to investigate whether there were differences in the functional status of melanocytes in different tissues and developmental stages. Consequently, differential gene expressions between peritoneal and ovarian melanocytes were compared. These findings demonstrated that the Silky Fowl ovary had higher expression levels of genes involved in the production of sexual hormones and melanogenesis, while those of melanocytes derived from the peritoneum were involved in amino acid metabolism, lipid synthesis, and overall metabolic rates. This suggests that the role of melanocytes is dependent on the origin tissue and developmental stage, and is tightly connected to the function of the specific source tissue from which the cells were derived. This study provides a method for isolating adult melanocytes and serve as a basis for further investigate the effect of SFOM on germ cells.

Toxicological Effects of Naturally Occurring Endocrine Disruptors on Various Human Health Targets: A Rapid Review

Endocrine-disrupting compounds are chemicals that alter the normal functioning of the endocrine system of living organisms. They can be natural (N-EDCs) or synthetic compounds (S-EDCs). N-EDCs can belong to different groups, such as phytoestrogens (PEs), including flavonoids, or mycotoxins originating from plants or fungi, and cyanotoxins, derived from bacteria. Humans encounter these substances in their daily lives. The aim of this rapid review (RR) is to provide a fine mapping of N-EDCs and their toxicological effects on human health in terms of various medical conditions or adverse consequences. This work is based on an extensive literature search and follows a rigorous step-by-step approach (search strategy, analysis strategy and data extraction), to select eligible papers published between 2019 and 2023 in the PubMed database, and to define a set of aspects characterizing N-EDCs and the different human target systems. Of the N-EDCs identified in this RR, flavonoids are the most representative class. Male and female reproductive systems were the targets most affected by N-EDCs, followed by the endocrine, nervous, bone and cardiovascular systems. In addition, the perinatal, pubertal and pregnancy periods were found to be particularly susceptible to natural endocrine disruptors. Considering their current daily use, more toxicological research on N-EDCs is required.

Comparison of structure-activity relationship for bisphenol analogs in the inhibition of gonadal 3β-hydroxysteroid dehydrogenases among human, rat, and mouse

Bisphenol A (BPA) is a widely used plastic material and its potential endocrine disrupting effect has restricted its use and increasing use of BPA alternatives has raised health concerns. However, the effect of bisphenol alternatives on steroidogenesis remains unclear. The objective of this study was to compare inhibitory potencies of 10 BPA alternatives in the inhibition of gonadal 3β-hydroxysteroid dehydrogenase (3β-HSD) in three species (human, rat and mouse). The inhibitory potency for human 3β-HSD2, rat 3β-HSD1, and mouse 3β-HSD6 ranged from bisphenol FL (IC50, 3.32 μM for human, 5.19 μM for rat, and 3.26 μM for mouse) to bisphenol E, F, and thiodiphenol (ineffective at 100 μM). Most BPA alternatives were mixed inhibitors of gonadal 3β-HSD and they dose-dependently inhibited progesterone formation in KGN cells. Molecular docking analysis showed that all BPA analogs bind to steroid and NAD+ active sites. Lipophilicity of BPA alternatives was inversely correlated with IC50 values. In conclusion, BPA alternatives mostly can inhibit gonadal 3β-HSDs and lipophilicity determines their inhibitory strength.

Polymethoxylated flavonoids in citrus fruits: absorption, metabolism, and anticancer mechanisms against breast cancer

Polymethoxylated flavonoids (PMFs) are a subclass of flavonoids found in citrus fruits that have shown multifunctional biological activities and potential anticancer effects against breast cancer. We studied the absorption, metabolism, species source, toxicity, anti-cancer mechanisms, and molecular targets of PMFs to better utilize their anticancer activity against breast cancer. We discuss the absorption and metabolism of PMFs in the body, including the methylation, demethylation, and hydroxylation processes. The anticancer mechanisms of PMFs against breast cancer were also reviewed, including the estrogen activity, cytochrome P-450 enzyme system, and arylhydrocarbon receptor (AhR) inhibition, along with various molecular targets and potential anticancer effects. Although PMFs may be advantageous in the prevention and treatment for breast cancer, there is a lack of clinical evidence and data to support their efficacy. Despite their promise, there is still a long way to go before PMFs can be applied clinically.

Benzene ring bisphenol A substitutes potently inhibit human, rat, and mouse gonadal 3β-hydroxysteroid dehydrogenases: Structure-activity relationship and in silico docking analysis

Bisphenol A (BPA) is a chemical used in the production of certain plastics and resins. Recent research has found that BPA can inhibit the activity of 3β-hydroxysteroid dehydrogenase/Δ5,4-isomerases (3β-HSDs). Whether benzene ring BPA substitutes can inhibit human, rat, and mouse gonadal 3β-HSDs, the structure-activity relationship and the underlying mechanism remain unclear. In this study, we compared 6 benzene ring BPA substitutes to BPA in the inhibition of human, rat, and mouse gonadal 3β-HSDs and conducted structure-activity relationship and in silico docking analysis. The inhibitory activity (IC50) of human 3β-HSD2 in KGN cells ranged from about 0.02 μM for bisphenol H to 8.75 μM for BPA, that of rat 3β-HSD1 in testicular microsomes ranged from 0.099 μM for bisphenol H to 31.32 μM for BPA, and that of mouse 3β-HSD6 ranged from 0.021 μM for BPH to ineffectiveness for 100 μM BPA. These compounds acted as mixed inhibitors with LogP inversely correlated with IC50 and ΔG positively correlated with IC50 value. Docking analysis showed that these compounds bind to the steroid active site of the 3β-HSD enzymes. In conclusion, some benzene ring BPA substitutes potently inhibit gonadal 3β-HSD in various species, and lipophilicity and binding affinity determine their inhibitory strength.

Derivatized versus non-derivatized LC-MS/MS techniques for the analysis of estrogens and estrogen-like endocrine disruptors in human plasma

Bisphenols, parabens, alkylphenols and triclosan are anthropogenic substances with a phenolic group that have been introduced to the environment in recent decades. As they possess hormone-like effects, they have been termed endocrine disruptors (EDs), and can interfere with steroid pathways in organisms. To evaluate the potential impact of EDs on steroid biosynthesis and metabolism, sensitive and robust methods enabling the concurrent measurement of EDs and steroids in plasma are needed. Of crucial importance is the analysis of unconjugated EDs, which possess biological activity. The aim of the study was to develop and validate LC-MS/MS methods with and without a derivatization step for the analysis of unconjugated steroids (estrone-E1, estradiol-E2, estriol-E3, aldosterone-ALDO) and different groups of EDs (bisphenols, parabens, nonylphenol-NP and triclosan-TCS), and compare these methods on a set of 24 human plasma samples using Passing-Bablok regression analysis. Both methods were validated according to FDA and EMA guidelines. The method with dansyl chloride derivatization allowed 17 compounds to be measured: estrogens (E1, E2, E3), bisphenols (bisphenol A-BPA, BPS, BPF, BPAF, BPAP, BPZ, BPP), parabens (methylparaben-MP, ethylparaben-EP, propylparaben-PP, butylparaben-BP, benzylparaben-BenzylP), TCS and NP, with lower limits of quantification (LLOQs) between 4 and 125 pg/mL. The method without derivatization enabled 15 compounds to be analyzed: estrogens (E1, E2, E3), ALDO, bisphenols (BPA, BPS, BPF, BPAF, BPAP, BPZ), parabens (MP, EP, PP, BP, BenzylP) with LLOQs between 2 and 63 pg/mL, and NP and BPP in semiquantitative mode. Adding 6 mM ammonium fluoride post column into mobile phases in the method without derivatization achieved similar or even better LLOQs than the method with the derivatization step. The uniqueness of the methods lies in the simultaneous determination of different classes of unconjugated (bioactive) fraction of EDs together with selected steroids (estrogens + ALDO in the method without derivatization), which provides a useful tool for evaluating the relationships between EDs and steroid metabolism.

Oral administration of Turnera diffusa willd. ex Schult. extract ameliorates steroidogenesis and spermatogenesis impairment in the testes of rats with type-2 diabetes mellitus

ETHNOPHARMACOLOGICAL RELEVANCE

Turnera diffusa Willd. ex Schult. (T. diffusa) has traditionally been used to treat male reproductive dysfunction and have aphrodisiac properties.

AIMS OF THE STUDY

This study aims to investigate the ability of T. diffusa to ameliorate the impairment in testicular steroidogenesis and spermatogenesis in DM that might help to improve testicular function, and subsequently restore male fertility.

MATERIALS AND METHODS

DM-induced adult male rats were given 100 mg/kg/day and 200 mg/kg/day T. diffusa leaf extract orally for 28 consecutive days. Rats were then sacrificed; sperm and testes were harvested and sperm parameter analysis were performed. Histo-morphological changes in the testes were observed. Biochemical assays were performed to measure testosterone and testicular oxidative stress levels. Immunohistochemistry and double immunofluorescence were used to monitor oxidative stress and inflammation levels in testes as well as Sertoli and steroidogenic marker proteins' expression.

RESULTS

Treatment with T. diffusa restores sperm count, motility, and viability near normal and reduces sperm morphological abnormalities and sperm DNA fragmentation in diabetic rats. T. diffusa treatment also reduces testicular NOX-2 and lipid peroxidation levels, increases testicular antioxidant enzymes (SOD, CAT, and GPx) activities, ameliorates testicular inflammation via downregulating NF-ΚB, p-Ikkβ and TNF-α and upregulating IκBα expression. In diabetic rats, T. diffusa treatment increases testicular steroidogenic proteins (StAR, CYP11A1, SHBG, and ARA54, 3 and 17β-HSD) and plasma testosterone levels. Furthermore, in diabetic rats treated with T. diffusa, Sertoli cell marker proteins including Connexin 43, N-cadherin, and occludin levels in the testes were elevated.

CONCLUSION

T. diffusa treatment could help to ameliorate the detrimental effects of DM on the testes, thus this plant has potential to be used to restore male fertility.

Inhibition of Resveratrol Analogs on Human and Rat 3β-Hydroxysteroid Dehydrogenases: Structure-Activity Relationship and Docking Analysis

Resveratrol and its analogs are phytochemicals. Human 3β-hydroxysteroid dehydrogenase 1 (3β-HSD1) synthesizes steroid hormones for normal pregnancy or promoting cancer metastasis. Whether they inhibit 3β-HSD1 remains unclear. In this study, the inhibitory potency, mode of action, structure-activity relationship, and docking parameters of resveratrol and its analogs on 3β-HSD1 and rat homolog 3β-HSD4 were analyzed. The inhibitory potency of these chemicals on human 3β-HSD1 was 4,4'-dihydroxystilbene (IC₅₀, 3.68 μM) > pinostilbene (8.07 μM) > pinosylvin (10.60 μM) > lunularin (26.84 μM) > resveratrol (30.20 μM) > dihydroresveratrol (>100 μM) = oxyresveratrol (>100 μM) > dihydropinosylvin (ineffective at 100 μM). Resveratrol analogs and metabolites are mixed or competitive inhibitors of human 3β-HSD1. Resveratrol and 4,4'-dihydroxystilbene inhibited progesterone secretion by human JAr cells at ≥1 μM. Resveratrol (IC₅₀, 32.09 μM) and pinosylvin (34.71 μM) significantly inhibited rat placental 3β-HSD4 activity. Docking analysis shows that resveratrol analogs and metabolites bind the steroid-binding sites of human 3β-HSD1 and rat 3β-HSD4 and interact with the catalytic residues Ser125/Thr125 and Tyr155. The negative correlation of LogP and IC₅₀ values for human 3β-HSD1 indicates that lipophilicity of chemicals plays a critical role in the inhibitory effect of chemicals. In conclusion, 4,4'-dihydroxystilbene, pinostilbene, and pinosylvin effectively inhibit human 3β-HSD1 depending on their lipophilicity, thereby acting as potential therapeutic agents.

Expression characteristics of Hsd3b7 in the gonads of Paralichthys olivaceus

Steroidogenesis is an important biological process for gonadal differentiation and development. In mammals, 3β-hydroxysteroid dehydrogenase 7 (HSD3B7) could convert 3β-hydroxy of 7α-hydroxycholesterol into a ketone and form 7α-hydroxy-4-cholesten-3-one, which may affect steroidogenesis. However, in fish, the study of Hsd3b7 is still lacking. In this study, Hsd3b7 was identified in the olive flounder Paralichthys olivaceus, an important mariculture fish. According to bioinformatics analysis, Hsd3b7 belongs to a Rossmann-fold NAD(P)(+)-binding protein and can interact in a predictable manner with Hsd17b2, -3, and - 4, which play a role in steroidogenesis. In the adult flounder, Hsd3b7 was expressed in various tissues, at particularly high level in male muscle. The expression levels of Hsd3b7 at gonadal development stages I-V initially increased and then decreased, with an inflection point in the ovary at stage III and in the testis at stage IV. At stage III, the expression level of Hsd3b7 was significantly higher in the ovary than in the testis (P < 0.01). The results of in situ hybridization (ISH) revealed that it was mainly expressed in oocytes of phases I-IV or around oocytes of phases IV-V in the ovaries and around spermatid lobules at stages IV-V in the testes. Three regulatory sites of SRY-box transcription factor 9 (Sox9), a transcription factor involved in steroidogenesis and gonadal differentiation, were predicted in the promoter of Hsd3b7. After intraperitoneal injection with the recombination flounder Sox9a, the expression of Hsd3b7 was significantly up-regulated (P < 0.01). During the flounder gonadal differentiation, 17β-estradiol (E2, 5 μg/g feed) and 17α-methyltestosterone (T, 5 μg/g feed) were used to obtain the phenotypic female or male flounder, and the results showed that in the E2 group, Hsd3b7 expression was highest at 2 cm TL, the primordial gonad stage, which was significantly higher than that at 12 cm TL (P < 0.05). In the T group, Hsd3b7 expression level was also highest at 2 cm TL and significantly higher than at 10 and 12 cm TL (P < 0.05). Moreover, Hsd3b7 was detected to be localized mainly around oogonia and spermatogonia during the differentiated gonads with ISH. These findings first introduce the expression characteristics of Hsd3b7 and the effect of Sox9a on its expression, which contribute to our understanding of the function of Hsd3b7 in fish gonads.

Impact of Fetal Exposure to Endocrine Disrupting Chemical Mixtures on FOXA3 Gene and Protein Expression in Adult Rat Testes

Perinatal exposure to endocrine disrupting chemicals (EDCs) has been shown to affect male reproductive functions. However, the effects on male reproduction of exposure to EDC mixtures at doses relevant to humans have not been fully characterized. In previous studies, we found that in utero exposure to mixtures of the plasticizer di(2-ethylhexyl) phthalate (DEHP) and the soy-based phytoestrogen genistein (Gen) induced abnormal testis development in rats. In the present study, we investigated the molecular basis of these effects in adult testes from the offspring of pregnant SD rats gavaged with corn oil or Gen + DEHP mixtures at 0.1 or 10 mg/kg/day. Testicular transcriptomes were determined by microarray and RNA-seq analyses. A protein analysis was performed on paraffin and frozen testis sections, mainly by immunofluorescence. The transcription factor forkhead box protein 3 (FOXA3), a key regulator of Leydig cell function, was identified as the most significantly downregulated gene in testes from rats exposed in utero to Gen + DEHP mixtures. FOXA3 protein levels were decreased in testicular interstitium at a dose previously found to reduce testosterone levels, suggesting a primary effect of fetal exposure to Gen + DEHP on adult Leydig cells, rather than on spermatids and Sertoli cells, also expressing FOXA3. Thus, FOXA3 downregulation in adult testes following fetal exposure to Gen + DEHP may contribute to adverse male reproductive outcomes.

Physiological, biochemical, and hormonal changes in rats exposed to bottled water left in a hot car and the freezer

The aim of this study was to investigate the effects of bottled water left in the car and those left in the refrigerator on the physiological and biochemical parameters of male rats. Eighteen male albino rats were randomly divided into control, warmed bottled water (WBW), and cooled bottled water (CBW) groups. The concentrations of bisphenol A (BPA) and antimony (Sb) in the water samples were measured. Results showed that the levels of BPA and Sb were higher in bottled water left in the car and those kept at room temperature (control), relative to the bottled water samples kept in the fridge. Bodyweight, some metabolic indicators, cTnT and CRP levels, hematological parameters, testosterone level, and sperm quality were significantly affected by storage conditions. These results indicate that storage conditions can potentially affect the quality of bottled water, which in turn can affect the biological parameters of living organisms. Moreover, since the concentrations of BPA and Sb were least in bottled water kept in the refrigerator, we recommend that manufacturers and households should endeavor to keep bottled water under cold storage.

Transcriptomic responses to cytotoxic drug cisplatin in water flea Daphnia magna

Cytotoxic drugs have been recognized by the European Union as the potential threat in the aquatic environment. As a typical cytotoxic drug, effects of long-term exposure to cisplatin at the environmentally relevant concentrations on the crustacean health and its molecular mechanism remain undetermined. In this study, the growth and reproduction of Daphnia magna resulting from cisplatin exposure were initially assessed. While the phenotypes were not altered in 2 μg L^-1, 20 μg L^-1, and 200 μg L^-1 treatment groups, cisplatin at 500 µg L^-1 significantly reduced the offspring number to 8-13 neonates in each brood, which was lower than 13-27 neonates in the control group. In addition to the delay in the time of first pregnancy, the body length was decreased by approximate 12.13% at day 7. Meanwhile, all daphnids died after exposure to 500 µg L^-1 cisplatin for 17 days. Transcriptome profiling bioassays were performed for 10 days to explore the alternation at the molecular level. Briefly, 980 (257 up- and 723 down-regulated), 429 (182 up- and 247 down-regulated) and 1984 (616 up-regulated and 1368 down-regulated) genes were differentially expressed (adj p < 0.05) in low (2 μg L^-1), medium (200 μg L^-1) and high (500 μg L^-1) cisplatin treatment groups, respectively. Differentially expressed genes were primarily enriched in the digestion and absorption, nerve conduction, endocrine interference, and circulatory related pathways. Specifically, the down-regulated digestive secretion and nutrient absorption and neuronal conduction pathways may lead to insufficient energy supply involved in growth and reproduction, and hinder ovarian development and cell growth. Down-regulation of ovarian steroids and relaxin signaling pathways may be related to the reduction of offspring number and delayed pregnancy, and reduced body length of D. magna may attribute to the enrichment of insulin secretion pathway. In addition, the death of D. magna may result from the reduced expression of genes in cardiomyocyte contraction and apoptosome processes. Taken together, this study revealed the potential toxic mechanism of cisplatin in a model water flea.

Uptake, Transport, and Toxicity of Pristine and Weathered Micro- and Nanoplastics in Human Placenta Cells

BACKGROUND

The first evidence of micro- and nanoplastic (MNP) exposure in the human placenta is emerging. However, the toxicokinetics and toxicity of MNPs in the placenta, specifically environmentally relevant particles, remain unclear.

OBJECTIVES

We examined the transport, uptake, and toxicity of pristine and experimentally weathered MNPs in nonsyncytialized and syncytialized BeWo b30 choriocarcinoma cells.

METHODS

We performed untargeted chemical characterization of pristine and weathered MNPs using liquid chromatography high-resolution mass spectrometry to evaluate compositional differences following particle weathering. We investigated cellular internalization of pristine and weathered polystyrene (PS; 0.05-10μm) and high-density polyethylene (HDPE; 0-80μm) particles using high-resolution confocal imaging and three-dimensional rendering. We investigated the influence of particle coating with human plasma on the cellular transport of PS particles using a transwell setup and examined the influence of acute MNP exposure on cell viability, damage to the plasma membrane, and expression of genes involved in steroidogenesis.

RESULTS

Chemical characterization of MNPs showed a significantly higher number of unique features in pristine particles in comparison with weathered particles. Size-dependent placental uptake of pristine and weathered MNPs was observed in both placental cell types after 24 h exposure. Cellular transport was limited and size-dependent and was not influenced by particle coating with human plasma. None of the MNPs affected cell viability. Damage to the plasma membrane was observed only for 0.05μm PS particles in the nonsyncytialized cells at the highest concentration tested (100μg/mL). Modest down-regulation of hsd17b1 was observed in syncytialized cells exposed to pristine MNPs.

DISCUSSION

Our results suggest that pristine and weathered MNPs are internalized and translocated in placental cells in vitro. Effects on gene expression observed upon pristine PS and HDPE particle exposure warrant further examination. More in-depth investigations are needed to better understand the potential health risks of MNP and chemicals associated with them under environmentally relevant exposure scenarios. https://doi.org/10.1289/EHP10873.

Transcriptomic diversification of granulosa cells during follicular development between White Leghorn and Silky Fowl hens

Egg production rate in chicken is related to the continuity of follicle development. In this study, we found that the numbers of white prehierarchical, dominant, and yellow preovulatory follicles in the high-yielding layer breed, White Leghorn (WL), were significantly higher than those in the low egg-yielding variety, Silky Fowl (SF). The proliferation and differentiation of granulosa cells (GCs) play an important role in follicle maturation. Histological observation revealed a large number of melanocytes in the outer granulosa layer of follicles in SF but not in WL. Finally, RNA-sequencing was used to analyze the gene expression profiles and pathways of the GC layer in the follicles in both WL and SF hens. Transcriptome analysis of prehierarchical GCs (phGCs) and preovulatory GCs (poGCs) between WL and SF showed that steroid hormone-, oxytocin synthesis-, tight junction-, and endocytosis-related genes were expressed at higher levels in WL phGCs than in SF phGCs, whereas the insulin signaling pathway- and vascular smooth muscle contraction-related genes were upregulated in SF phGCs. Fatty acid synthesis, calcium signaling, and Wnt signaling pathway-related genes were expressed at higher levels in WL poGCs than in SF poGCs; however, adrenergic signaling, cGMP-PKG, and melanogenesis-related genes were upregulated in SF poGCs. These results indicate that genes that promote GC proliferation and secretion of various sex hormones are more active in WL than in SF hens. The upregulated signaling pathways in SF help in providing energy to GCs and for angiogenesis and melanogenesis. In vitro experiments confirmed that both the proliferation of poGCs and synthesis of reproductive hormones were higher in WL than in SF hens.

Bisphenol F blocks Leydig cell maturation and steroidogenesis in pubertal male rats through suppressing androgen receptor signaling and activating G-protein coupled estrogen receptor 1 (GPER1) signaling

Bisphenol F (BPF) is a new analog of bisphenol A (BPA). BPA has deleterious effects on the male reproductive system, but the effect of BPF has not been studied in detail. In this study we focus on the effect of BPF on Leydig cell maturation. Male Sprague-Dawley rats were gavaged with 0, 1, 10, or 100 mg/kg BPF from postnatal days 35-56. BPF significantly reduced serum testosterone levels and sperm count in cauda epididymis at dose ≥1 mg/kg. It significantly down-regulated the expression of steroidogenic enzymes, while increasing FSHR and SOX9 levels at 10 and 100 mg/kg. Further studies showed that BPF reduced NR3C4 expression in Leydig and Sertoli cells without affecting its levels in peritubular myoid cells. BPF markedly increased GPER1 in Leydig cells at 100 mg/kg, and it significantly reduced SIRT1 and PGC1α levels in the testes at 100 mg/kg. BPF significantly inhibited testosterone production by immature Leydig cells at 50 μM after 24 h of treatment, which was completely reversed by NR3C4 agonist 7α-methyl-19-nortestosterone and partially reversed by GPER1 antagonist G15 not by ESR1 antagonist ICI 182,780. In conclusion, BPF negatively affects Leydig cell maturation in pubertal male rats through NR3C4 antagonism and GPER1 agonism.

Characteristics of steroidogenesis-related factors in the musk gland of Chinese forest musk deer (Moschus berezovskii)

Musk secreted by Chinese forest musk deer (FMD; Moschus berezovskii) is a highly valuable ingredient in the fields of perfumery and medicine, and the main factor affecting the production of musk is the androgen level of male FMD. To clarify whether the musk gland of FMD can synthesize androgen, we compared and analyzed the expression patterns of steroid hormone biosynthesis-related genes in the musk gland and testis of FMD by RNA-seq and RT-qPCR. We obtained 33,308 and 38,602 unigenes from the musk gland and testis, respectively, and 26,780 co-expressed unigenes. Analysis of co-expressed genes revealed that 12,647 genes were annotated to 11,484 Gene Ontology terms and 10,941 genes were annotated to 6120 pathways, including several pathways important in metabolic and synthetic activity. Next, 21 steroid hormone synthesis-related genes were screened from the transcriptome of the musk gland of 4-month-old FMD. The expression levels of three key genes of steroid hormone biosynthesis (CYP11A1, CYP17A1, and HSD3B) in the musk gland differed from their expression levels in the testis based on RT-qPCR. Furthermore, immunohistochemistry indicated that CYP11A1, CYP17A1, and HSD3B were localized in the glandular tubular columnar cells of the musk gland. These results suggested that the musk gland of male FMD has the potential to locally synthesize steroid hormone and thus plays a critically important role in musk secretion.

Supplementing rabbit diets with butylated hydroxyanisole affects oxidative stress, growth performance, and meat quality

Butylated hydroxyanisole (BHA) is a synthetic antioxidant analogous of vitamin E. It is used as a preservative to prevent free radical-mediated oxidation in high-fat foods, and this study's objective was to investigate the effects of BHA on oxidative stress and apoptosis in addition to delineating its efficacy as a growth-promoting feed additive. 60 weaned male rabbits (V-line) were randomly divided into four equal groups: BHA0.0 (control), BHA50, BHA100, and BHA150, administered basal diets with 0.0, 50, 100, and 150 mg BHA/kg of feed for 60 days. Animals were examined for growth performance, markers of oxidative stress and apoptosis, and meat characteristics. Compared to the control group, rabbits receiving BHA-supplemented diets exhibited increases in BW and average daily gain (P < 0.01), where BHA50 and BHA100 groups showed increased muscle content of methionine aspartic acid, serine, and glutamine (P < 0.05). These two groups also exhibited elevated catalase and superoxide dismutase activities and diminished malondialdehyde levels in the liver. Butylated hydroxyanisole upregulated fatty acid synthase gene (FASN), especially in BHA100 animals. Bcl-2-associated X/B-celllymphoma-2 (Bax/Bcl-2) ratio significantly increased in animals receiving higher doses of BHA, and the weight of the liver significantly increased following BHA treatment. Supplementing growing rabbits with lower doses of dietary BHA may promote growth performance and meat quality via maintaining the redox balance. Hence, the 50-100 mg/kg may be recommended as a safe and still effective feed additive as well as an oxidative stress attenuator.

Isoflavones alter male and female fertility in different development windows

Isoflavones are a group of secondary metabolites found in plants belonging to the class of phytoestrogens. These, because they have a chemical structure similar to the endogenous hormone 17β-estradiol, act as endocrine disruptors over the different development window periods. This study aimed to evaluate male and female reproductive systems' responses when exposed to isoflavones during the development window. It is characterized as a bibliographic review, built after analyzing clinical and preclinical articles indexed in English, Portuguese, and Spanish published in the last ten years. The isoflavones, aglycone or glucosides, have essential therapeutic properties in the relief of postmenopausal symptoms in women, reduce the proliferation of cancers, in addition to being antioxidants. On the other hand, they can still behave in a similar way to 17β-estradiol, binding to hormone receptors and acting as endocrine disruptors over the gestational period until pre-puberty, negatively affecting the development of the reproductive system. The effects on reproduction are not dose-response but are influenced by the type of isoflavone and period. There are variations in the serum concentration of hormones and action on their negative feedback on the hypothalamic-pituitary-testicular axis in males. Reproductive functions are also affected by spermatogenesis, such as decreased sperm count, lower reproductive performance, reduced litter size, low sperm production, and reduced seminal vesicle size. In females, puberty is reached later, irregular estrous cycle, reduced weight of the ovary, uterus, lower serum levels of estradiol and progesterone, reduced fertility, or interrupted fertility. At the end of the analysis of the selected publications, it can be concluded that despite the beneficial therapeutic effects in the face of pathologies, the unknown consumption of doses and types of isoflavones in food can damage the development and reproduction of individuals. Therefore, further studies must be carried out to elucidate the usual safe doses of the analyzed phytoestrogen. Greater control over insertion in foods targeted at pediatric consumers should be implemented until we have adequate safety.

Perfluoroalkyl Chemicals and Male Reproductive Health: Do PFOA and PFOS Increase Risk for Male Infertility?

Poly- and perfluoroalkyl substances (PFAS) are manmade synthetic chemicals which have been in existence for over 70 years. Though they are currently being phased out, their persistence in the environment is widespread. There is increasing evidence linking PFAS exposure to health effects, an issue of concern since PFAS such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) bioaccumulate in humans, with a half-life of years. Many epidemiological studies suggest that, worldwide, semen quality has decreased over the past several decades. One of the most worrying effects of PFOS and PFOA is their associations with lower testosterone levels, similar to clinical observations in infertile men. This review thus focuses on PFOS/PFOA-associated effects on male reproductive health. The sources of PFAS in drinking water are listed. The current epidemiological studies linking increased exposure to PFAS with lowered testosterone and semen quality, and evidence from rodent studies supporting their function as endocrine disruptors on the reproductive system, exhibiting non-monotonic dose responses, are noted. Finally, their mechanisms of action and possible toxic effects on the Leydig, Sertoli, and germ cells are discussed. Future research efforts must consider utilizing better human model systems for exposure, using more accurate PFAS exposure susceptibility windows, and improvements in statistical modeling of data to account for the endocrine disruptor properties of PFAS.

An in silico approach to study the interaction of BHA with selected steroid hormone receptors and investigating it's agonistic and antagonistic properties

Antioxidant food additives were routinely used for increasing the keeping quality of packaged food items. Butylated Hydroxyanisole (BHA) is one of the most widely used synthetic phenolic antioxidants of such kind. Although quantity of antioxidants in packaged eatables and admissible daily intake (ADI) per person per day are limited by laws, the urbanisation and changes in lifestyle has cross these limits. Although studies on BHA has been carried out, there exists a great deal of uncertainty about the exact molecular mechanism of interaction of BHA with various receptors in the body. Since earlier reports suggested BHA plausibly interferes with reproductive system development, we opted docking of critical receptors of endogenous hormones controlling growth and development of reproductive system with BHA. Nuclear receptors of estrogen (ER), androgen (AR) and progesterone (PR) were selected for this purpose. This manuscript describes the comparison of binding pattern of BHA towards AR, ER and PR along with their agonists and antagonist. Lamarckian Genetic Algorithm of AutoDock 4.0 was used for analysing the mode of binding of ligands with the receptors. It is evident form the docking studies that, BHA exhibited similar binding pattern` with antagonists of AR and agonists of ER. But the interaction of BHA with PR was not compatible with either agonists or antagonists. The docking patterns produced could reliably demonstrate the interactions of BHA with selected receptors and also predict its possible agonistic and antagonistic action.

Testis Toxicants: Lesson from Traditional Chinese Medicine (TCM)

The testis is one of the organs in the mammalian body that is sensitive to toxicants. Accumulating evidence has shown that human exposure to toxic ingredients in Traditional Chinese Medicine (TCM), such as triptolide, gossypol, cannabidol, piperine, α-solanine, matrine, aristolochic acid, and emodin, lead to testis injury and reproductive dysfunction. The most obvious phenotype is reduced sperm counts due to defects in spermatogenesis. Studies have also shown that Sertoli cells in the seminiferous tubule, the functional unit of the testis that supports spermatogenesis, are the cell type that is most sensitive to the disruptive effects of toxicants. Since Sertoli cells are the "mother cells" that nurture germ cell development, Sertoli cell injury thus leads to failure in germ cell development in the seminiferous epithelium. Mounting evidence has shown that the Sertoli cell cytoskeletons, mitochondria function, Leydig cells steroidogenesis pathways and sperm ion channels are some of the prime targets of toxicants from TCM. We carefully evaluate recent findings in this area of research herein, and to provide a summary of these findings, including some insightful information regarding the underlying molecular basis of toxicant-induced testis injury that impede spermatogenesis.

ARe we there yet? Understanding androgen receptor signaling in breast cancer

The role of androgen receptor (AR) activation and expression is well understood in prostate cancer. In breast cancer, expression and activation of AR is increasingly recognized for its role in cancer development and its importance in promoting cell growth in the presence or absence of estrogen. As both prostate and breast cancers often share a reliance on nuclear hormone signaling, there is increasing appreciation of the overlap between activated cellular pathways in these cancers in response to androgen signaling. Targeting of the androgen receptor as a monotherapy or in combination with other conventional therapies has proven to be an effective clinical strategy for the treatment of patients with prostate cancer, and these therapeutic strategies are increasingly being investigated in breast cancer. This overlap suggests that targeting androgens and AR signaling in other cancer types may also be effective. This manuscript will review the role of AR in various cellular processes that promote tumorigenesis and metastasis, first in prostate cancer and then in breast cancer, as well as discuss ongoing efforts to target AR for the more effective treatment and prevention of cancer, especially breast cancer.

Endocrine Disruptors in Water and Their Effects on the Reproductive System

Anthropogenic contaminants in water can impose risks to reproductive health. Most of these compounds are known to be endocrine disrupting chemicals (EDCs). EDCs can impact the endocrine system and subsequently impair the development and fertility of non-human animals and humans. The source of chemical contamination in water is diverse, originating from byproducts formed during water disinfection processes, release from industry and livestock activity, or therapeutic drugs released into sewage. This review discusses the occurrence of EDCs in water such as disinfection byproducts, fluorinated compounds, bisphenol A, phthalates, pesticides, and estrogens, and it outlines their adverse reproductive effects in non-human animals and humans.