QSAR: Using the Past to Study the Present.

Quantitative structure-activity relationships (QSAR) is a method for predicting the physical and biological properties of small molecules; it is in use in industry and public services. However, as any scientific method, it is challenged by more and more requests, especially considering its possible role in assessing the safety of new chemicals. To answer the question whether QSAR, by exploiting available knowledge, can build new knowledge, the chapter reviews QSAR methods in search of a QSAR epistemology. QSAR stands on tree pillars, i.e., biological data, chemical knowledge, and modeling algorithms. Usually the biological data, resulting from good experimental practice, are taken as a true picture of the world; chemical knowledge has scientific bases; so if a QSAR model is not working, blame modeling. The role of modeling in developing scientific theories, and in producing knowledge, is so analyzed. QSAR is a mature technology and is part of a large body of in silico methods and other computational methods. The active debate about the acceptability of the QSAR models, about the way to communicate them, and the explanation to provide accompanies the development of today QSAR models. An example about predicting possible endocrine-disrupting chemicals (EDC) shows the many faces of modern QSAR methods.

Large scale screening and quantification of micropollutants in fish from the coastal waters of Cochin, India: Analytical method development and health risk assessment.

Urban estuarine and coastal water receive several micropollutants through industrial and agricultural influxes. The bioaccumulation of these micropollutants in fish and their entry into the coastal population's food chain raises significant food safety concerns. Hence, a comprehensive analytical method was developed for ultra-trace level quantification of 345 micropollutants in fish. The optimized sample preparation method could extract compounds suitable for both GC-MS/MS and LC-MS/MS analysis simultaneously. The target list of contaminants included 278 agricultural pesticides and also 102 endocrine disruptors covering polyaromatic hydrocarbons, polychlorinated biphenyls, organochlorines, and endocrine-disrupting pesticides. The GC-MS/MS with large volume injection (LVI) technique, and LC-MS/MS operating in MRM mode, achieved an LOQ of <2.00 ng/g for most of the analytes. The extraction strategy involved tri-phase partitioning between water, acidified acetonitrile, and hexane, followed by salting out. Dispersive solid phase cleanup (dSPE) with C18, Z-Sep+, CaCl2, and MgSO4 was able to reduce the matrix influence, and the method achieved satisfactory recovery in the range of 70.0-120.0 % for all the target analytes. The repeatability and reproducibility relative standard deviation values of the measured analytes were <20.0 %, and the Horwitz ratio values were well below 2. The method was used to accurately measure the target micropollutants in fish from the Cochin estuary, the highly urbanized portion of the Vembanad Lake, and an important Ramsar site. At least one or more of the 41 different micropollutants were identified and quantified in about 90.7 % of the 108 samples analyzed. The importance of large-scale screening and trace-level quantification methods in environmental monitoring and risk assessment is underscored by the results. The risk assessment showed a moderate risk of exposure to the nearby coastal population through the food chain.

COMBINED DEVELOPMENTAL EXPOSURE TO ESTROGENIC ENDOCRINE DISRUPTOR AND NUTRITIONAL IMBALANCE INDUCES LONG TERM ADULT PROSTATE INFLAMMATION THROUGH INFLAMMASOME ACTIVATION.

Increasing number of studies suggested that environmental deleterious impacts (such as estrogen-like endocrine disruptors, EDCs, unhealthy diet) during early human development affect the risk of developing non-communicable diseases including prostate cancer (PCa) later in life. To test if the combination of EDCs and unhealthy induces adult prostate lesions, we developed an experimental model of adult male Sprague Dawley rats exposed during gestation (from day 7) to weaning to high fat diet (HFD 60% fat), or to a xenoestrogen (estradiol benzoate, EB, 2.5µg/d) from post-natal days 1 to 5, or to a combination of both. EB and EB+HFD exposures induced decreased prostate weight in adult rats along with inflammatory status. A white blood cell infiltrate was observed after EB exposure and more dramatic lesions were observed with the combined exposure, along with a gland destruction. The lesions, following EB or EB+HFD exposure, are associated with elevated mRNA levels for TNFa, IL6 and CCL2/MCP1 pro-inflammatory cytokines while the levels of the anti-inflammatory IL10 cytokine remained unchanged. This activation of NLRP3 and elevated levels of CASP1 were observed following EB or EB+HFD exposures associated with elevated mRNA levels for IL1b, substrates for the NLRP3 complex. HFD exposure alone has mild if not pro-inflammatory effects in adult prostate. In conclusion, we showed that developmental combined exposure to EB and HFD programmed prostate inflammatory lesions in adult prostate. Since proliferative inflammatory atrophy and chronic inflammation of prostate may drive cell to become cancer cells, our model might be useful for study onset of PCa.

Exploring the association between urinary bisphenol A, S, and F levels and semen quality parameters: Findings from Led-Fertyl cross-sectional study.

Infertility is recognized as a multifaceted condition affecting approximately 15% of couples globally, influenced by various factors including genetic predisposition and environmental exposures. Among these environmental factors, bisphenol A (BPA) emerges as a prominent Endocrine-disrupting chemical (EDCs) widely distributed, leading to chronic human exposure in daily life. As regulations on BPA became more stringent, alternative substances such as bisphenol S (BPS) and bisphenol F (BPF) have emerged. Animal studies have demonstrated a dose-dependent decline in fertility and embryotoxicity following chronic exposure to BPA. However, literature data on human studies are limited and heterogeneous. Additionally, even less is known about the relationship between exposure to the BPA analogues (BPS and BPF) and sperm quality. Therefore, the present study aimed to examine the association between urinary concentrations of BPA, BPF, and BPS and semen quality parameters among 195 adult Spanish men from the Led-Fertyl study cohort using multiple linear regression models adjusted by potential confounding variables. Our results revealed an inverse association between log-transformed creatinine-adjusted concentration (ng/mg) of BPA and BPF levels and the percentage of sperm vitality (ß: 3.56 %; 95%CI: 6.48 to -0.63 and ß: 4.14 %; 95%CI: 6.97 to -1.31; respectively). Furthermore, participants in the highest quartile of BPA and BPF urinary concentration exhibited lower sperm vitality compared to those in the lowest quartile (ß: 6.90 %; 95%CI: 11.60 to -2.15 and ß: 9.68 %; 95%CI: 14.43 to -4.94; respectively). These results supply epidemiological evidence establishing a relationship between bisphenols urine exposure and sperm quality, suggesting that a re-evaluation of the overall safety of BPA alternatives is warranted.

Toxicokinetic Profiles and Potential Endocrine Disruption Effects at the Reproductive Level Promoted by Siloxanes Used in Consumer Products.

Siloxanes, commonly known as silicones, are polymeric compounds made up of silicon and oxygen atoms bonded together alternately. Within this group of substances are linear methyl-siloxanes and cyclic methyl-siloxanes, with octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5) being the most produced and used industrially. Due to their versatility, high production volume, stability, and local presence in environmental matrices and biological fluids such as breast milk, fat, and plasma, siloxanes have been considered persistent organic pollutants, representing a public health problem. This represents a public health concern, especially when different investigations have reported potential endocrine effects at the reproductive level in experimental animals exposed to D4 and D5. The objective of this study was to review the potential reproductive and endocrine effects derived from siloxanes present in personal care products (PCPs). The results of the literature review confirmed that D4 and D5 were the most used siloxanes as additives in PCP because they improve the emollient properties of the cosmetic and the physical appearance of hair and skin. Similarly the toxicological effects of siloxanes, particularly D4, D5, and D6 included significant endocrine disruption, reproductive toxicity, and liver toxicity. Studies in SD and F-344 rats, commonly used to assess these effects, have shown that D4 has low estrogenic activity, binding to ER-α receptors, whereas D5 does not bind to estrogen receptors. D4 exposure has been associated with increased uterine weight and estrous cycle alterations, leading to prolonged exposure to estrogens, which raises the risk of endometrial hyperproliferation and carcinogenesis. Recent research highlights that D5 exposure disrupts follicle growth, endometrial receptivity, and steroidogenesis, resulting in infertility and hormonal imbalances, potentially causing disorders like endometriosis and increased cancer risk. Chronic exposure to D5 has been linked to the development of uterine endometrial adenocarcinoma, with higher doses further elevating this risk.

Prenatal phthalate exposure and pubertal development in 16-year-old daughters: reproductive hormones and number of ovarian follicles.

STUDY QUESTION: Is there a possible association between prenatal phthalate exposure and late effects in teenage daughters with respect to reproductive hormone levels, uterine volume, and number of ovarian follicles? SUMMARY ANSWER: Our study showed subtle associations between phthalate metabolite concentrations in maternal serum from pregnancy or cord blood and LH and insulin-like growth factor 1 (IGF-1) levels as well as uterine volume in their daughters 16 years later. WHAT IS KNOWN ALREADY: Endocrine-disrupting environmental chemicals may adversely affect human reproductive health, and many societies have experienced a trend toward earlier puberty and an increasing prevalence of infertility in young couples. The scientific evidence of adverse effects of foetal exposure to a large range of chemicals, including phthalates, on male reproductive health is growing, but very few studies have explored effects on female reproduction. STUDY DESIGN, SIZE, DURATION: This follow-up study included 317 teenage daughters who were part of the Copenhagen Mother-Child Cohort, a population-based longitudinal birth cohort of 1210 females born between 1997 and 2002. PARTICIPANTS/MATERIALS, SETTING, METHODS: A total of 317 female participants (median age 16 years) were examined for weight, height, and menstrual pattern. A serum sample was analysed for concentrations of reproductive hormones, and trans-abdominal 3D ultrasonography was performed to obtain the number of ovarian follicles, ovarian and uterine size. Prenatal maternal serum samples were available for 115 females, and cord blood samples were available for 118 females. These were analysed for concentrations of 32 phthalate metabolites. Weighted quantile sum regression was used for modelling associations of combined prenatal phthalate exposure with the reproductive outcomes in post-menarcheal females. MAIN RESULTS AND THE ROLE OF CHANCE: In bivariate correlation analyses, negative significant associations were found between several prenatal phthalate metabolite concentrations and serum hormone concentrations (testosterone, 17-OH-progesterone, and IGF-1) as well as number of ovarian follicles in puberty. Positive significant correlations were found between prenatal phthalate exposure and FSH and sex hormone-binding globulin concentrations. Combined analyses of phthalate exposure (weighted quantile sums) showed significant negative associations with IGF-1 concentration and uterine volume as well as a significant positive association with LH concentration. LIMITATIONS, REASONS FOR CAUTION: Phthalate metabolites were measured in serum from single prenatal maternal blood samples and cord blood samples. Potential concomitant exposure to other endocrine-disrupting environmental chemicals before or after birth was not controlled for. The study population size was limited. WIDER IMPLICATIONS OF THE FINDINGS: Our results support the need for further research into possible adverse effects of environmental chemicals during foetal development of the female reproductive system. STUDY FUNDING/COMPETING INTEREST(S): The work was supported by The Center on Endocrine Disruptors (CeHoS) under The Danish Environmental Protection Agency and The Ministry of Environment and Food (grant number: MST-621-00 065). No conflicts of interest are declared. TRIAL REGISTRATION NUMBER: N/A.

Exploring the Hypothetical Links Between Environmental Pollutants, Diet, and the Gut-Testis Axis: The Potential Role of Microbes in Male Reproductive Health.

The gut system, commonly referred to as one of the principal organs of the human "superorganism," is a home to trillions of bacteria and serves an essential physiological function in male reproductive failures or infertility. The interaction of the endocrine-immune system and the microbiome facilitates reproduction as a multi-network system. Some recent studies that link gut microbiota to male infertility are questionable. Is the gut-testis axis (GTA) real, and does it affect male infertility? As a result, this review study emphasizes the interconnected links between gut health and male reproductive function via changes in gut microbiota. However, a variety of harmful (endocrine disruptors, heavy metals, pollutants, and antibiotics) and favorable (a healthy diet, supplements, and phytoconstituents) elements promote microbiota by causing dysbiosis and symbiosis, respectively, which eventually modify the activities of male reproductive organs and their hormones. The findings of preclinical and clinical studies on the direct and indirect effects of microbiota changes on testicular functions have revealed a viable strategy for exploring the GTA-axis. Although the GTA axis is poorly understood, it may have potential ties to reproductive issues that can be used for therapeutic purposes in the future.

Magnetic conjugated microporous polymer for rapid extraction and sensitive analysis of environmental endocrine disruptors in environmental waters and dairy products.

BACKGROUND: Environmental endocrine disruptors (EEDs) are a class of new pollutants that are diffusely used in the medical industry and animal husbandry. In view of toxicity concerns, elevated levels of EEDs in the environment and food, which cause potential harm to human beings and ecosystems, must be monitored. Determination of EEDs contaminants to ensure environment and food safety has became a major concern worldwide, it is also a challenging task because of their trace level and probable matrices interference. Thus, developing rapid adsorption and efficient analysis methods for EEDs is apparently necessary. RESULTS: A magnetic conjugated micro-porous polymer (Fe3O4@TbDt) was designed and synthesized, which was endowed with large specific surface area, rich functional groups and magnetic responsiveness. The material showed high extraction efficiency for EEDs via magnetic solid-phase extraction (MSPE). The quantum chemistry calculations showed the adsorption mechanism of Fe3O4@TbDt on EEDs mainly included electrostatic interactions, van der waals forces (N-H … π interaction, C-H … π interaction), and multiple hydrogen bonds. Finally, a trace analysis method for nine EEDs was established combined with HPLC-MS/MS under optimized MSPE conditions. The method showed a good linearity (R2 ≥ 0.996), low limits of detection (0.25-5.1 ng L-1), high precision (RSD of 1.1-8.2 %, n = 6). The applicability of this method was investigated by analyzing four water samples and two dairy products, and satisfactory recovery rates (82.1-100.7 %) were obtained. The proposed method showed the potential for the analysis of EEDs residues in food and environmental samples. SIGNIFICANCE: The developed MSPE method based on conjugated micro-porous polymers (CMPs) is simple, green, and efficient compared to existing techniques. The application of CMPs provides a new idea for preparing versatile sample pre-treatment materials. What's more, this work has certain reference value for addressing of EEDs residues in the environment and food.

Metabolic disrupting chemicals in the intestine: the need for biologically relevant models: Zebrafish: what can we learn from this small environment-sensitive fish?

Although the concept of endocrine disruptors first appeared almost 30 years ago, the relatively recent involvement of these substances in the etiology of metabolic pathologies (obesity, diabetes, hepatic steatosis, etc.) has given rise to the concept of Metabolic Disrupting Chemicals (MDCs). Organs such as the liver and adipose tissue have been well studied in the context of metabolic disruption by these substances. The intestine, however, has been relatively unexplored despite its close link with these organs. In vivo models are useful for the study of the effects of MDCs in the intestine and, in addition, allow investigations into interactions with the rest of the organism. In the latter respect, the zebrafish is an animal model which is used increasingly for the characterization of endocrine disruptors and its use as a model for assessing effects on the intestine will, no doubt, expand. This review aims to highlight the importance of the intestine in metabolism and present the zebrafish as a relevant alternative model for investigating the effect of pollutants in the intestine by focusing, in particular, on cytochrome P450 3A (CYP3A), one of the major molecular players in endogenous and MDCs metabolism in the gut.

Characterization of the C17.2 cell line as testing system for endocrine disruption-induced developmental neurotoxicity.

Hormone signaling plays an essential role during fetal life and is vital for brain development. Endocrine-disrupting chemicals can interfere with the hormonal milieu during this critical time-period, disrupting key neurodevelopmental processes. Hence, there is a need for the development of assays that evaluate developmental neurotoxicity (DNT) induced by an endocrine mode of action. Herein, we evaluated the applicability of the neural progenitor C17. 2 cell-line, as an in vitro test system to aid in the detection of endocrine disruption (ED) induced DNT. For this, C17.2 cells were exposed during 10 days of differentiation to agonists and antagonists of the thyroid hormone (Thr), glucocorticoid (Gr), retinoic acid (Rar), retinoic x (Rxr), oxysterols (Lxr), estrogen (Er), androgen (Ar), and peroxisome proliferator activated delta (Pparß/δ) receptors, as well as to the agonist of the vitamin D (Vdr) receptor. Upon exposure and differentiation, neuronal morphology (neurite outgrowth and branching), and the percentage of neurons in culture were assessed by immunofluorescence. For this, the cells were incubated with Hoechst (nuclear staining) and stained for ßIII-tubulin (neuronal marker). The C17.2 cells were responsive to the Rar, Rxr and Pparß/δ agonists which decreased neurite outgrowth and branching. Additionally, exposure to the Gr agonist increased the number of cells differentiating into neurons, while exposure to the Rxr agonist had the opposite effect. With this approach, we have identified that the C17.2 cells are responsive to Gr, Rar, Rxr, and Pparß/δ agonists, hence contributing to the development of test systems for hazard assessment of ED-induced DNT.

Endocrine disrupting chemicals (EDCs) interfere with hormonal signaling. As hormones play a vital role for an organism's development, EDC exposure is of high concern. In European regulations, the use of a chemical can be restricted if its toxicity is mediated by hormonal interference. A number of EDCs affect brain development. However, in animal tests, it is impossible to prove that a chemical induces developmental neurotoxicity (DNT) via endocrine disruption (ED). Furthermore, the regulatory DNT tests require large amounts of animals. Thus, there is an urgent need for in vitro test systems to identify ED-induced DNT. Herein we present the development of such a method based on the murine neural progenitor cell-line C17.2 with which neuronal differentiation processes can be mimicked. We show that differentiation of C17.2 cells are sensitive to retinoid, glucocorticoid, and peroxisome proliferator activated receptor signaling disruption, thus providing an alternative method for identifying ED-induced DNT.

In Utero and Lactational Exposure to an Environmentally Relevant Mixture of Phthalates Alters Hypothalamic Gene Expression and Sexual Preference in Rats.

Several phthalates, mainly used as plasticizers, are known for their adverse effects on the male genital system. Previously, we demonstrated that an environmentally relevant mixture of six antiandrogenic phthalates (PMix), derived from a biomonitoring study in pregnant Brazilian women, was able to disrupt the reproductive development in male rats. Experimental groups (control, 0.1, 0.5, and 500 mg PMix/kg/day) were established starting from the extrapolated human dose (0.1 mg/kg/day), followed by doses 5 times and 5000 times higher. Pregnant rats received daily oral gavage administration of either vehicle (control) or PMix from gestational day 13 to postnatal day 10. Here, we examined male and female offspring regarding changes in gene expression of key reproductive factors in the hypothalamus and pituitary gland at adulthood and conducted a battery of behavioral tests in males, including partner preference, sexual behavior, and male attractiveness tests. PMix induced some changes in mating-related behavior in males, as demonstrated by the absence of preference for females against males and a higher number of penetrations up to ejaculation in the 0.5 dose group. PMix decreased Esr2 expression in the male hypothalamus across all three doses, and in females at mid and high doses in both the hypothalamus and pituitary. In male hypothalamus, we also observed decreased Kiss1 transcripts in these groups and a reduction in AR at the 0.5 dose group. In summary, our results provide further evidence that phthalates in a mixture, even at low doses, may exert cumulative effects on the structures underlying sexual behavior, which seems to be more sensitive than reproductive endpoints for the same experimental design.

Prenatal exposure to environmentally relevant levels of PAHs inhibits spermatogenesis in adult mice and the mechanism involved.

Polycyclic aromatic hydrocarbons (PAHs) are a class of contaminants that cannot be banned. Exposure to PAHs has been reported to alter spermatogenesis in mammals, but little is known about prenatal exposure to a mixture of PAHs on the reproductive toxicity of adult offspring. In this study, we investigated the associations between prenatal exposure to environmentally relevant levels of PAHs in mice and testicular dysfunction, including impaired spermatogenesis and steroid hormone dysfunction in male offspring on postnatal day 180. The percentage of testicular apoptotic cells was significantly increased, which was further verified by the up-regulated BAX protein. The expression of Ar and the Leydig cell marker Cyp11a1 was down-regulated, suggesting an impairment in the synthesis of steroid hormones. DNA hypermethylation of the Tnp1 and Sohlh2 promoters suppresses transcriptional expression, consequently altering the sperm production process. This study shows that prenatal exposure to PAHs may induce long-term reproductive toxicity.

In vitro exposure to butylparaben impairs the integrity and size of ovarian follicles in a bovine model.

There is a growing regulatory and scientific interest in the studies of environmental substances that are capable of interfering with the reproductive system. Among them, parabens stand out due to their widespread use and frequent detection as contaminants in human tissues and biological fluids. Therefore, we evaluated the toxic effects of butylparaben on the viability and follicular staging of bovine ovarian follicles in vitro. Fragments of ovaries from five cyclic bovine females were cultured for 44 h in a minimal essential medium (MEM; control) or MEM supplemented with 50 µg/mL and 100 µg/mL of butylparaben (BP 50 and BP 100 groups, respectively). The ovarian fragments were subjected to follicular staging, morphological analysis, morphometric analysis, estradiol analysis and oxidative profiling. No significant changes were observed between the experimental groups in follicular staging, estradiol analysis and oxidative profile analysis. However, the BP 50 group showed a significant decrease in the number of intact ovarian follicles. Moreover, a decrease in the follicular and oocyte diameters was observed in the groups that were exposed to butylparaben. In conclusion, butylparaben impairs the integrity and size of ovarian follicles in an in vitro bovine model, but does not affect the oxidative profile and steroidogenesis.

Sub-acute bisphenol A exposure induces proteomic alterations and impairs male reproductive health in mice.

Bisphenol A (BPA) is one of the most prevalent endocrine disrupting chemicals (EDCs) and there is widespread concern about the adverse effects of EDCs on human health. However, the exact mechanism of these toxicities has still not been fully deciphered. Additionally, studies have reported the toxicological effects at far low doses to the generally considered no-observed-adverse-effect level (NOAEL) dose. The present study investigates the effects of a sub-acute (28 days) exposure to BPA (10, 50 and 100 mg/kg/day) in adult male mice on various hormones levels, sperm motility, sperm count, functional integrity of sperm plasma membrane, testicular histological changes, oxidative stress markers and DNA damage. The key proteome signatures were quantified by LC-MS/MS analysis using Orbitrap Fusion Lumos Tribrid Mass Spectrometer equipped with nano-LC Easy-nLC 1200. Data suggest that the BPA exposure in all doses (below/above NOAEL dose) have greatly impacted the hormone levels, sperm parameters (sperm count, motility and membrane integrity) and testicular histology. Mass spectrometry-based proteomics data suggested for 1352 differentially expressed proteins (DEPs; 368 upregulated, 984 downregulated) affecting biological process, cellular component, and molecular functions. Specifically searched male reproductive function related proteins suggested a complex network where 46 potential proteins regulating spermatogenesis, sperm structure, activity and membrane integrity while tackling oxidative stress responses were downregulated. These potential biomarkers could shed some more light on our current understanding of the reproductive toxicological effects of BPA and may lead to exploration of novel interventions strategies against these targets for male infertility.

Bisphenols in daily clothes from conventional and recycled material: evaluation of dermal exposure to potentially toxic substances.

Given the increasing concern about chemical exposure from textiles, our study examines the risks of dermal exposure to bisphenol A (BPA), bisphenol S (BPS), bisphenol B (BPB) and bisphenol F (BPF) from conventional and recycled textiles for adults, aiming to obtain new data, assess exposure, and evaluate the impact of washing on bisphenol levels. A total of 57 textile samples (33 from recycled and 24 from conventional material) were subjected to ultrasound-assisted extraction (UAE) followed by ultra-high performance liquid chromatography with tandem mass spectrometry analysis (UHPLC-MS/MS). The BPA and BPS concentrations varied widely (BPA: < 0.050 to 625 ng/g, BPS: 0.277-2,474 ng/g). The median BPA content in recycled textiles (13.5 ng/g) was almost twice as high as that of 7.66 ng/g in conventional textiles. BPS showed a median of 1.85 ng/g in recycled textiles and 3.42 ng/g in conventional textiles, indicating a shift from BPA to BPS in manufacturing practices. Simulated laundry experiments showed an overall reduction in bisphenols concentrations after washing. The study also assessed potential health implications via dermal exposure to dry and sweat-wet textiles compared to a tolerable daily intake (TDI) of 0.2 ng/kg bw/day for BPA set by the European Food Safety Authority (EFSA). Exposure from dry textiles remained below this threshold, while exposure from wet textiles often exceeded it, indicating an increased risk under conditions that simulate sweating or humidity. By finding the widespread presence of bisphenols in textiles, our study emphasises the importance of being aware of the potential risks associated with recycling materials as well as the benefits.

Muscle Damage and Immune-Endocrine Responses in 20-km Walking Race.

The objective of the study was to monitor exercise-induced muscle damage (EIMD), inflammatory responses (IL-6, TNFα, and IL-10), and immune-endocrine balance (testosterone, cortisol, and salivary SIgA) in official 20 km walking race competitions. Eight 20 km professional walking racers (n = 6 women), 27 ± 9 years, underwent blood and saliva sampling, evaluation of delayed-onset muscle soreness (DOMS), and squat (SJ) and countermovement (CMJ) jump tests 2 h before (Pre), immediately after (Post), and 24 and 48 h after the competition. The rate of perceived exertion (RPE) was recorded 20 minutes after the race ended. The race evoked high competitive load (948.3 ± 268.0 a.u.), increased creatine kinase levels at 24 h (p < 0.05), and DOMS at 48 h (p < 0.05), but no significant changes in SJ and CMJ after the race. No significant changes in cytokines were detected. No changes in salivary SIgA secretion rate and inflammatory cytokines were detected (p > 0.05). The race induced increased testosterone (p < 0.05), and cortisol (p < 0.01) levels immediately after the race. Despite the high competitive load, 20-km walking racer athletes presented mild EIMD without impairment in immune-endocrine markers.

Effects and risk assessment of halogenated bisphenol A derivatives on human follicle stimulating hormone receptor: An interdisciplinary study.

Halogenated bisphenol A (BPA) derivatives are produced during disinfection treatment of drinking water or are synthesized as flame retardants (TCBPA or TBBPA). BPA is considered as an endocrine disruptor especially on human follicle-stimulating hormone receptor (FSHR). Using a global experimental approach, we assessed the effect of halogenated BPA derivatives on FSHR activity and estimated the risk of halogenated BPA derivatives to the reproductive health of exposed populations. For the first time, we show that FSHR binds halogenated BPA derivatives, at 10 nM, a concentration lower than those requires to modulate the activity of nuclear receptors and/or steroidogenesis enzymes. Indeed, bioluminescence assays show that FSHR response is lowered up to 42.36 % in the presence of BPA, up to 32.79 % by chlorinated BPA derivatives and up to 27.04 % by brominated BPA derivatives, at non-cytotoxic concentrations and without modification of basal receptor activity. Moreover, molecular docking, molecular dynamics simulations, and site-directed mutagenesis experiments demonstrate that the halogenated BPA derivatives bind the FSHR transmembrane domain reducing the signal transduction efficiency which lowers the cellular cAMP production and in fine disrupts the physiological effect of FSH. The potential reproductive health risk of exposed individuals was estimated by comparing urinary concentrations (through a collection of human biomonitoring data) with the lowest effective concentrations derived from in vitro cell assays. Our results suggest a potentially high concern for the risk of inhibition of the FSHR pathway. This global approach based on FSHR activity could enable the rapid characterization of the toxicity of halogenated BPA derivatives (or other compounds) and assess the associated risk of exposure to these halogenated BPA derivatives.

Genetic and Environmental Factors Co-Contributing to Behavioral Abnormalities in adnp/adnp2 Mutant Zebrafish.

Human mutations of ADNP and ADNP2 are known to be associated with neural developmental disorders (NDDs), including autism spectrum disorders (ASDs) and schizophrenia (SZ). However, the underlying mechanisms remain elusive. In this study, using CRISPR/Cas9 gene editing technology, we generated adnp and adnp2 mutant zebrafish models, which exhibited developmental delays, brain deficits, and core behavioral features of NDDs. RNA sequencing analysis of adnpa-/-; adnpb-/- and adnp2a-/-; adnp2b-/- larval brains revealed altered gene expression profiles affecting synaptic transmission, autophagy, apoptosis, microtubule dynamics, hormone signaling, and circadian rhythm regulation. Validation using whole-mount in situ hybridization (WISH) and real-time quantitative PCR (qRT-PCR) corroborated these findings, supporting the RNA-seq results. Additionally, loss of adnp and adnp2 resulted in significant downregulation of pan-neuronal HuC and neuronal fiber network α-Tubulin signals. Importantly, prolonged low-dose exposure to environmental endocrine disruptors (EEDs) aggravated behavioral abnormalities in adnp and adnp2 mutants. This comprehensive approach enhances our understanding of the complex interplay between genetic mutations and environmental factors in NDDs. Our findings provide novel insights and experimental foundations into the roles of adnp and adnp2 in neurodevelopment and behavioral regulation, offering a framework for future preclinical drug screening aimed at elucidating the pathogenesis of NDDs and related conditions.

Extracellular vesicles as a potential source of biomarkers for endocrine disruptors in MASLD: A short review on the case of DEHP.

Metabolic dysfunction-Associated Steatotic Liver Disease (MASLD) is a chronic disease with increasing prevalence and for which non-invasive biomarkers are needed. Environmental endocrine disruptors (EDs) are known to be involved in the onset and progression of MASLD and assays to monitor their impact on the liver are being developed. Extracellular vesicles (EVs) mediate cell communication and their content reflects the pathophysiological state of the cells from which they are released. They can thus serve as biomarkers of the pathological state of the liver and of exposure to EDs. In this review, we present the relationships between DEHP (Di(2-ethylhexyl) phthalate) and MASLD and highlight the potential of EVs as biomarkers of DEHP exposure and the resulting progression of MASLD.