StAR protein and the regulation of steroid hormone biosynthesis

Bisphenol Z inhibits the function of Leydig cells via upregulation of METTL3 expression in adult male rats

The use of bisphenol A has been restricted due to its toxicity. However, the impact of its substitute, bisphenol Z (BPZ), on Leydig cell function remains uncertain. We aimed to examine the associations between BPZ exposure and the disruption of Leydig cell function via upregulating Mettl3 and inducing oxidative stress. To address this, in vivo, male adult Sprague-Dawley rats received BPZ (0, 1, 10, or 100mg/kg/d orally) for 7 days, and in vitro, purified Leydig cells were treated with BPZ (0-20μM, 24h). Leydig cell morphology and function were assessed. The results showed that BPZ did not alter Leydig cell quantity but notably decreased serum testosterone levels. Furthermore, it significantly downregulated the expression levels of genes and proteins (SCARB1, STAR, CYP17A1, HSD17B3, and INSL3) in Leydig cells. Concurrently, BPZ treatment led to diminished expression of antioxidant genes (Gpx1 and Cat), an upregulation in m6A related gene (Mettl3) subsequent to the enrichment of RNA methylation fragments in the testis. In vitro analysis of primary Leydig cells demonstrated that BPZ heightened oxidative stress and diminished testosterone production. In conclusion, BPZ reduces rat testosterone by downregulating steroidogenic genes (Star, Scarb1, Cyp17a1, and Hsd17b3) via METTL3-m6A-Camkk2 pathway, impairing Leydig cell function.

The mitochondrial LONP1 protease: molecular targets and role in pathophysiology

Lon peptidase 1 (LONP1), a member of the AAA + family, is essential for maintaining mitochondrial function. Recent studies have revealed that LONP1 serves as a multifunctional enzyme, acting not only as a protease but also as a molecular chaperone, interacting with mitochondrial DNA (mtDNA), and playing roles in mitochondrial dynamics, oxidative stress, cellular respiration, and energy metabolism. LONP1 is evolutionarily highly conserved, and mutations or dysfunctions in LONP1 can lead to diseases. There is growing evidence linking LONP1 to various human diseases, such as tumors, neurodegenerative diseases, and heart diseases. This review discusses the discovery, molecular structure, subcellular localization, tissue distribution, and mitochondrial function of LONP1. Furthermore, it summarizes the associations between LONP1 and tumors, neurodegenerative diseases, and heart diseases, exploring its role in different diseases and potential molecular mechanisms. It also analyzes the regulatory effects of related inhibitors and agonists on LONP1. Considering the pleiotropic effects of LONP1, the study of LONP1 is crucial to understanding the relevant pathophysiological processes and developing strategies to modulate and control these related diseases.

Exploring the epigenetic impacts of atrazine in zebrafish: Unveiling mechanisms of neurotoxicity, reproductive toxicity, and implications for human health

Atrazine (ATZ), a widely utilized herbicide, is notable for its long environmental half-life and high solubility, raising significant concerns regarding its ecological and health impacts. While debates continue over its role as an endocrine disruptor, increasing attention has been directed toward its potential epigenetic effects. Utilizing the zebrafish model, a vertebrate with considerable genetic similarity to humans, provides valuable insights into how ATZ exposure may translate into human health risks. This review systematically examines the differential DNA methylation induced by ATZ's non-competitive inhibition of DNA methyltransferases, miRNA dysregulation resulting from mutations in miRNA processing enzymes, and the complex epigenetic interactions affecting histone modifications. Additionally, potential epigenetic biomarkers for ATZ exposure are proposed, which could advance targeted treatment strategies and improve health risk assessments. This synthesis of current understanding identifies knowledge gaps and guides future research towards a more comprehensive understanding of ATZ's epigenetic mechanisms.

Prenatal bisphenol A exposure causes sperm quality and functional defects via Leydig cell impairment and meiosis arrest in mice offspring

Bisphenol A (BPA), widely used in plastic production, acts as an environmental endocrine disruptor which is harmful to male reproductive health. However, the specific mechanisms through which prenatal BPA exposure disrupts spermatogenesis in offspring, particularly in terms of Leydig cell dysfunction and meiotic progression, remain poorly understood. To address this gap, we constructed a mouse model with BPA lowest Observed Adverse Effect Level (LOAEL: 50 mg/kg bw/day) exposure from embryonic day (ED) 0.5 to 18.5. Our results demonstrated that prenatal BPA exposure significantly decreased serum testosterone levels, testis weight, sperm count, motility parameters, and acrosomal integrity. Furthermore, it arrested the meiotic transition from zygotene to pachytene spermatocytes, leading to reduced sperm fertility characterized by reduced sperm-egg binding capacity and abnormal early embryonic cleavage in the male offspring. Importantly, prenatal BPA exposure significantly reduced the expression of PCNA (a marker of germ cell proliferation), SYCP3 (a meiosis regulator), and Vimentin (a blood-testis barrier component), collectively indicating impaired spermatogenesis in offspring testes. Additionally, prenatal BPA exposure dramatically reduced Leydig cell numbers and increased apoptosis, marked by BAX/BCL2 up-regulation, which mechanistically explains the observed testosterone reduction. In vitro experiments corroborated these effects: BPA exposure concentration-dependently inhibited Leydig cell proliferation, induced G0/G1 phase arrest, and downregulated testosterone synthesis molecules (Hsd3b1, Hsd17b3, Star, Cyp11a1, Cyp17a1). Quantitative proteomics identified 234 differentially expressed proteins (97 downregulated, 137 upregulated) in BPA-exposed Leydig cells. Bioinformatics analysis revealed that down-regulated proteins were mainly related to steroid hormone receptor activity, estrogen response element binding, and centrosome duplication processes, while the up-regulated proteins were mainly involved in oxygen binding and ROS metabolic process. Conclusively, prenatal BPA exposure impaired offspring male fertility via multi-faceted mechanisms: sperm quality defects, steroidogenic disruption, and meiotic arrest. This study advances the understanding of BPA transgenerational reproductive toxicity and underscores the need to mitigate prenatal exposure risks.

Targeted gene silencing in mouse testicular Sertoli and Leydig cells using adeno-associated virus vectors

ABSTRACT

Researchers commonly use cyclization recombination enzyme/locus of X-over P1 (Cre/loxP) technology-based conditional gene knockouts of model mice to investigate the functional roles of genes of interest in Sertoli and Leydig cells within the testis. However, the shortcomings of these genetic tools include high costs, lengthy experimental periods, and limited accessibility for researchers. Therefore, exploring alternative gene silencing techniques is of great practical value. In this study, we employed adeno-associated virus (AAV) as a vector for gene silencing in Sertoli and Leydig cells. Our findings demonstrated that AAV serotypes 1, 8, and 9 exhibited high infection efficiency in both types of testis cells. Importantly, we discovered that all three AAV serotypes exhibited exquisite specificity in targeting Sertoli cells via tubular injection while demonstrating remarkable selectivity in targeting Leydig cells via interstitial injection. We achieved cell-specific knockouts of the steroidogenic acute regulatory (Star) and luteinizing hormone/human chorionic gonadotropin receptor (Lhcgr) genes in Leydig cells, but not in Sertoli cells, using AAV9-single guide RNA (sgRNA)-mediated gene editing in Rosa26-LSL-Cas9 mice. Knockdown of androgen receptor (Ar) gene expression in Sertoli cells of wild-type mice was achieved via tubular injection of AAV9-short hairpin RNA (shRNA)-mediated targeting. Our findings offer technical approaches for investigating gene function in Sertoli and Leydig cells through AAV9-mediated gene silencing.

Polydatin, a derivative of resveratrol, ameliorates busulfan-induced oligozoospermia in mice by inhibiting NF-κB pathway activation and suppressing ferroptosis

Polydatin (PD), a glucoside derivative of resveratrol (RES), is extracted as a monomer compound from the dried rhizome of Polygonum cuspidatum. Our laboratory synthesized PD via the biotransformation of resveratrol. To assess the reproductive protective effects of PD, an oligozoospermia mouse model was induced by administering 30 mg/kg busulfan (BUS) via intraperitoneal injection. Initially, mice were categorized into groups based on PD concentrations of 10, 50, and 100 mg/kg. Subsequently, the optimal concentration of 10 mg/kg was ascertained based on testis weight and spermatological parameters. Additionally, a 10 mg/kg resveratrol group was included as a control. The findings revealed that exposure to BUS resulted in a reduction of testicular weight, diminished spermatogenic cells and epididymal sperm counts, increased sperm deformity, disordered testicular cytoskeleton, compromised blood-testis barrier integrity, and a significant decrease in serum sex hormone levels, notably testosterone. This resulted in decreased expression of androgen receptors and other testosterone-related proteins, increased levels of malondialdehyde and reactive oxygen species, and promoted testicular ferroptosis. However, PD could successfully reverse these injuries. High-throughput sequencing data demonstrated that polydatin significantly downregulated the expression of inflammatory and metabolic genes, including PRKCQ and CARD11. These proteins are pivotal in the activation of the NF-κB pathway during the inflammatory response. Molecular docking studies showed that PD could interact with PRKCQ and CARD11 to reduce the level of inflammation. Additionally, PD was shown to interact with the ferroptosis-promoting gene ACSL4, modulating ferroptosis. In summary, PD facilitates the reversal of BUS-induced oligozoospermia through the mitigation of oxidative stress and inflammation, the inhibition of ferroptosis, and the modulation of hormonal levels.

Proteomic analysis reveals the alleviation of follicular development defects in offspring mice under DEHP exposure by melatonin

BACKGROUND

Environmental endocrine disruptor Di (2-ethylhexyl) phthalate (DEHP) widely affects the health of human and animals including the reproductive system. However, there are few studies on the protective strategies for the maternal DEHP exposure on follicular development of offspring. In the present study, we established a model of lactation female mice exposed to DEHP and reported the effects and potential mechanism of melatonin on the follicular development of offspring.

RESULTS

Our data showed that melatonin rescued the decrease of primordial follicles, antral follicles and oocyte number (increased by 74.2%) of offspring caused by maternal DEHP exposure from the primordial follicle formation stage. Proteomic analysis showed that melatonin altered the ovarian steroidogenesis, lipid metabolism, signal transduction, and DNA damage-related proteins. Melatonin reversed the disorder of lipid metabolism caused by DEHP and stabilized ovarian hormone secretase level. Molecular docking results indicated that DEHP/MEHP/melatonin binds to HSD17B2 to form a stable conformation, which may explain the reduction in 17β-estradiol induced by DEHP. Moreover, melatonin restored granulosa cell proliferation, reduced oxidative stress and DNA damage-related apoptosis, enhanced mitochondrial function, and protected ovarian cells. Besides, melatonin enhanced gap junction and promoted intercellular communication, which facilitate the formation of primordial follicles and the growth and development of antral follicles. In addition, melatonin rescued the oocyte defects of offspring caused by maternal DEHP exposure.

CONCLUSIONS

Taken together, our data showed that melatonin could alleviate the damage of follicular development and abnormal ovarian steroidogenesis of offspring caused by maternal DEHP exposure.

HIF1α controls steroidogenesis under acute hypoxic stress

BACKGROUND

Hypoxia is a critical physiological and pathological condition known to influence various cellular processes, including steroidogenesis. While previous studies, including our own, have highlighted the regulatory effects of Hypoxia-Inducible Factor 1α (HIF1α) on steroid production, the specific molecular mechanisms remain poorly understood. This study investigates the role of hypoxia and HIF1α in steroid biosynthesis across multiple experimental models during acute exposure to low oxygen levels.

METHODS

To assess the extent to which acute hypoxia modulates steroidogenesis, we employed several approaches, including the Y1 adrenocortical cell line, and a conditional HIF1α-deficient mouse line in the adrenal cortex. We focused on various regulatory patterns that may critically suppress steroidogenesis.

RESULTS

In Y1 cells, hypoxia upregulated specific microRNAs in a HIF1α-dependent manner, resulting in the suppression of mRNA levels of critical steroidogenic enzymes and a subsequent reduction in steroid hormone production. The hypoxia/HIF1α-dependent induction of these microRNAs and the consequent modulation of steroid production were confirmed in vivo. Notably, using our adrenocortical-specific HIF1α-deficient mouse line, we demonstrated that the increase in miRNA expression in vivo is also directly HIF1α-dependent, while the regulation of steroidogenic enzymes (e.g., StAR and Cyp11a1) and steroid production occurs at the level of protein translation, revealing an unexpected layer of control under hypoxic/HIF1 α conditions in vivo.

CONCLUSIONS

These findings elucidate the molecular mechanisms underlying acute hypoxia/HIF1α-induced changes in steroid biosynthesis and may also be useful in developing new strategies for various steroid hormone pathologies.

Increased Steroidogenic Acute Regulatory Protein Contributes to Cholesterol-induced β-Cell Dysfunction

Hypercholesterolemia is often observed in individuals with type 2 diabetes. Cholesterol accumulation in subcellular compartments within islet β-cells can result in insulin secretory dysfunction, which is a key pathological feature of diabetes. Previously, we demonstrated that expression of the mitochondrial cholesterol transport protein, steroidogenic acute regulatory protein (StAR), is induced in islets under conditions of β-cell dysfunction. However, whether it contributes to mitochondrial cholesterol accumulation in β-cells and cholesterol-induced β-cell dysfunction has not been determined. Thus, we sought to examine the role of StAR in isolated mouse islets under conditions of excess exogenous cholesterol. Cholesterol treatment of islets upregulated StAR expression, which was associated with cholesterol accumulation in mitochondria, decreased mitochondrial membrane potential and impaired mitochondrial oxidative phosphorylation. Impaired insulin secretion and reduced islet insulin content were also observed in cholesterol-laden islets. To determine the impact of StAR overexpression in β-cells per se, a lentivirus was used to increase StAR expression in INS-1 cells. Under these conditions, StAR overexpression was sufficient to increase mitochondrial cholesterol content, impair mitochondrial oxidative phosphorylation, and reduce insulin secretion. These findings suggest that elevated cholesterol in diabetes may contribute to β-cell dysfunction via increases in StAR-mediated mitochondrial cholesterol transport and accumulation.

Endogenous and fluorescent sterols reveal the molecular basis for ligand selectivity of human sterol transporters

Sterol transport proteins (STPs) play a pivotal role in cholesterol homeostasis and therefore are essential for healthy human physiology. Despite recent advances in dissecting functions of STPs in the human cell, there is still a significant knowledge gap regarding their specific biological functions and a lack of suitable selective probes for their study. Here, we profile fluorescent steroid-based probes across ten STPs, uncovering substantial differences in their selectivity, aiding the retrospective and prospective interpretation of biological results generated with those probes. These results guided the establishment of an STP screening panel combining diverse biophysical assays, enabling the evaluation of 42 steroid-based natural products and derivatives. Combining this with a thorough structural analysis revealed the molecular basis for STP-specific selectivity profiles, leading to the uncovering of several new potent and selective Aster-B inhibitors and supporting the role of this protein in steroidogenesis.

Mitochondrial Functioning: Front and Center in Defining Psychosomatic Mechanisms of Allostasis in Health and Disease

There is increased awareness among basic and clinical scientists that psychological and social stress can have detrimental effects on physical, cognitive, and mental health. Data have been published indicating that social, economic, psychological, and physical environmental stress can influence behavior that has biological and physiological consequences-yet there are major gaps in understanding the physiological and cellular processes that drive increased morbidity and mortality. The potential role of mitochondria has been highlighted in psychosomatic medicine, as their functionality in various biological and physiological processes has earned recognition. This review outlines the essential role of mitochondria by considering the numerous intracellular, extracellular, and physiological functions it regulates that position the organelle as a central mediator in responses to psychological stress. We then connect these functions to mitochondrial allostasis and allostatic load for further examination of the limitations of mitochondria to an adaptive psychological stress response where mitochondrial allostatic load may eventually lead to systemic pathophysiology. This review emphasizes how chronic social, economic, and psychological stress can contribute to mitochondrial dysfunction and predispose individuals to poorer health outcomes and death. Mitochondrial capacity, function, and activity may therefore serve as biomarkers for identifying individuals at high risk for developing comorbid conditions related to their psychosocial environment.

HSF1/HSP25 system protects mitochondria function from heat stress and assists steroidogenesis in MA-10 Leydig cells

Heat shock response is characterized by the induction of heat shock proteins (HSPs) or molecular chaperones that maintain protein homeostasis. Heat shock transcription factor 1 (HSF1) plays a central role in heat shock response in mammalian cells. To investigate the impact of the heat shock response mechanism on steroidogenesis, we generated MA-10 mouse Leydig tumor cells deficient in HSF1 using CRISPR-Cas9 genome editing. Under heat stress conditions, the levels of StAR protein, but not its mRNA, decreased more in HSF1-knockout cells than in wild-type cells, confirming that HSF1 stabilizes StAR protein. Simultaneously, HSP110, HSP70, and HSP25 were markedly upregulated in a manner dependent on HSF1. Mitochondrial membrane potential (MMP) and ATP synthesis were decreased in HSF1-knockout cells under heat stress conditions, and mitochondrial fragmentation was enhanced. Furthermore, treatment with carbonyl cyanide 3-chlorophenylhydrazone (CCCP), a disruptor of MMP, reduced the levels of StAR protein to a greater extent in HSF1-knockout cells than in wild-type cells, which was associated with decreased MMP and ATP synthesis. Unexpectedly, HSP25 expression was markedly increased in wild-type cells following CCCP treatment. HSP25 knockdown reduces MMP under heat stress conditions and decreases StAR protein levels and progesterone synthesis. HSP25 overexpression in HSF1KO cells restored StAR protein levels. These results show that the HSF1/HSP25 pathway protects mitochondrial function and maintains StAR synthesis.

Volatile organic compound exposure in relation to lung cancer: Insights into mechanisms of action through metabolomics

Volatile organic compounds (VOCs) have proven to be hazardous to the human respiratory system. However, the underlying biological mechanisms remain poorly understood. Therefore, targeted determination of eleven VOC metabolites (mVOCs) along with the nontargeted metabolomic analysis was performed on urine samples collected from lung cancer patients and healthy individuals. Nine mVOCs mainly derived from aldehydes, alkenes, amides, and aromatics were detected in > 90 % of the urine samples, suggesting that the participants were ubiquitously exposed to these typical VOCs. A molecular gatekeeper discovery workflow was employed to link the exposure biomarkers with correlated clusters of endogenous metabolites. As a result, multiple metabolic pathways, including amino acid metabolism, steroid hormone biosynthesis and metabolism, and fatty acid β-oxidation were connected with VOC exposure. Furthermore, 16 of 73 molecular gatekeepers were associated with lung cancer and pointed to a few disrupted metabolic pathways related to hydroxysteroids and acylcarnitine. The shift in molecular profiles was validated in rat model post VOC administration. Thereinto, the up-regulation of enzymes involved in acylcarnitine synthesis and transport in rat lung tissues highlighted that the mitochondrial dysfunction may be a potential carcinogenic mechanism. Our findings provide new insights into the mechanisms underlying lung cancer induced by VOC exposure.

Combined analyses of mRNA and miRNA transcriptome reveal the molecular mechanisms of theca cells physiological differences in geese follicular selection stage

In avian, follicular selection is a key molecular event that can determine avian egg production. Theca cells (TC) are the main components of follicles, the molecular mechanisms about TCs physiological differences during follicle selection stage are still unclear. This study revealed significant differences in proliferation, apoptosis, lipid synthesis, and steroid secretion levels between prehierarchical theca cells (phTC) and hierarchical theca cells (hTC) of Tianfu meat-type geese. A total of 1,559 differentially expressed genes (DEG) and 71 differentially expressed miRNAs (DEM) were identified between phTCs and hTCs, respectively. Functional enrichment analysis results showed that 143 DEGs were enriched in the pathways related to cell proliferation/apoptosis and lipid/steroid metabolism. Protein-protein interaction (PPI) network results indicated the 143 DEGs have functional interactions. Additionally, the predicted target genes of 71 DEMs were jointly analyzed with the above 143 DEGs, and the results showed that 15 DEMs and 17 DEGs with targeted relationships were found. Among them, miR-202-5p was significantly down-regulated both in hTCs and hierarchical theca layers, and target prediction results showed that miR-202-5p may affect TCs proliferation/apoptosis by targeting CHPT1 to regulate the expression levels of CCN1/FOXO3; meanwhile, may affect TCs lipid/steroid metabolism and proliferation/apoptosis by targeting CHPT1 to regulate the expression levels of p53/ABCA1/SREBP-2. This study provides new insights into the regulatory mechanisms of TCs physiological differences during goose follicle selection.

Multi-Omics Approaches Uncovered Critical mRNA-miRNA-lncRNA Networks Regulating Multiple Birth Traits in Goat Ovaries

The goat breeding industry on the Tibetan Plateau faces strong selection pressure to enhance fertility. Consequently, there is an urgent need to develop goat lines with higher fertility and adaptability. The ovary, as a key organ determining reproductive performance, is regulated by a complex transcriptional network involving numerous protein-coding and non-coding genes. However, the molecular mechanisms of the key mRNA-miRNA-lncRNA regulatory network in goat ovaries remain largely unknown. This study focused on the histology and differential mRNA/miRNA/lncRNA between Chuanzhong black goat (CBG, high productivity, multiple births) and Tibetan goat (TG, strong adaptability, single birth) ovaries. Histomorphological analysis showed that the medulla proportion in CBG ovaries was significantly reduced compared to TG. RNA-Seq and small RNA-Seq analysis identified 1218 differentially expressed (DE) mRNAs, 100 DE miRNAs, and 326 DE lncRNAs, which were mainly enriched in ovarian steroidogenesis, oocyte meiosis, biosynthesis of amino acids and protein digestion, and absorption signaling pathways. Additionally, five key mRNA-miRNA-lncRNA interaction networks regulating goat reproductive performance were identified, including TCL1B-novel68_mature-ENSCHIT00000010023, AKAP6-novel475_mature-ENSCHIT00000003176, GLI2-novel68_mature-XR_001919123.1, ITGB5-novel65_star-TCONS_00013850, and VWA2-novel71_mature-XR_001919911.1. Further analyses showed that these networks mainly affected ovarian function and reproductive performance by regulating biological processes such as germ cell development and oocyte development, which also affected the plateau adaptive capacity of the ovary by participating in the individual immune and metabolic capacities. In conclusion, we identified numerous mRNA-miRNA-lncRNA interaction networks involved in regulating ovarian function and reproductive performance in goats. This discovery offers new insights into the molecular breeding of Tibetan Plateau goats and provides a theoretical foundation for developing new goat lines with high reproductive capacity and strong adaptability to the plateau environment.

Impact of gonadotropin on certain testis-related genes identified through testicular transcriptome analysis in the Asian and the African catfish

Induction of spawning in catfish is well demonstrated in females while stimulation of spermiation in males seems difficult. This has led to least understanding of gene profile changes during testicular maturation. Expression of the factors after hormonal induction that control reproductive processes has become an intense research area in fish endocrinology. In view of this, de novo assemblies of testicular transcriptomes of the Asian catfish, Clarias batrachus and the African catfish, C. gariepinus, were performed to identify genes/factors involved in testicular maturation. For testicular induction, human chorionic gonadotropin (hCG) was administered in vivo to both the catfish species during active phase of reproduction. 1,68,071 and 1,26,232 assembled transcripts were obtained from C. batrachus and C. gariepinus testicular transcriptomes and were annotated using different databases. Further, in silico analysis suggested the presence of several transcripts that were involved in steroidogenesis and male reproduction. Comparison of transcriptomes of both species revealed the presence of certain unique genes related to reproduction differentially. Expression profiles after hCG induction in testis showed higher expression of certain steroidogenesis related genes such as star, cyp11b1, cyp17a and cyp21a in both the species. Further, expression levels of crucial factors related to testis, such as dmrt1/2/3, were also found to be significantly higher after gonadotropin induction. However, amh, tgfα and dmrt4/5 expression levels were significantly low. Factors related to male reproduction i.e., tekt1, tekt2, sox9, spag1, spata2 and spata7 were found to be differentially upregulated in hCG treated testicular tissues of both the species. Histology analysis indicated that the gonadotropin induction either short or long term is a better strategy to highlight expression profile changes during testicular maturation in teleost.

ZnO NPs Impair the Viability and Function of Porcine Granulosa Cells Through Autophagy Regulated by ROS Production

The zinc oxide nanoparticles (ZnO NPs) is one of the most extensively utilized metal oxide nanoparticles in biomedicine, human food, cosmetics and livestock farming. However, growing evidence suggests that there is a potential risk for humans and animals because of the accumulation of ZnO NPs in cells, which leads to cell death through several different pathways. Nevertheless, the effects of ZnO NPs on porcine granulosa cells (PGCs) and how ZnO NPs regulate the follicular cells are unknown. In this study, we aimed to elucidate the role of ZnO NPs in the porcine ovary by using PGCs. Firstly, we identified the characterization of ZnO NPs used in this study and the results showed that the size of ZnO NPs was 29.0 nm. The results also demonstrated that ZnO NPs impaired cell viability and decreased steroid hormone secretion in PGCs. In addition, ZnO NPs induced reactive oxygen species (ROS) production, leading to oxidative stress of PGCs. Meanwhile, ZnO NPs also triggered autophagy in PGCs by increasing the ratio of LC3-II/LC3-I, along with the expression of SQSTM1 and ATG7. Finally, the results from N-acetylcysteine (NAC) addition suggested that ZnO NPs promoted autophagy through the enhancement of ROS production. In summary, this study demonstrates that ZnO NPs impair the viability and function of PGCs through autophagy, which is regulated by ROS production.

Knockdown of type 2 orexin receptor in adult mouse testis potentiates testosterone production and germ cell proliferation

Orexins (OXs) are neuropeptides which regulate various physiological processes. OXs exist in two different forms, mainly orexin A (OXA) and orexin B (OXB) and their effects are mediated via OX1R and OX2R. Presence of OXB and OX2R in mouse testis is also reported. However, the role of OXB/OX2R in the male gonad remains unexplored. Herein we investigated the role of OXB/OX2R system in testicular physiology under in vivo and ex vivo conditions. Adult mice were given a single dose of bilateral intratesticular injection of siRNA targeting OX2R and were sacrificed 96 h post-injection. OX2R-knockdown potentiated serum and intratesticular testosterone levels with up-regulation in the expressions of major steroidogenic proteins. Germ cell proliferation also increased in siRNA-treated mice. Results of the ex vivo experiment also supported the findings of the in vivo study. In conclusion, OX2R may regulate testosterone production and thereby control the fine-tuning between steroidogenesis and germ cell dynamics.

Protective effect of afamin protein against oxidative stress related injury in human ovarian granulosa cells

BACKGROUND

Ovarian granulosa cells (GCs) play crucial roles in follicular growth and development. Their normal function is influenced by various factors, including oxidative stress, which is a significant factor. Afamin protein is a vitamin E-specific binding protein that acts as a vitamin E carrier in follicular fluid. Although the mechanism of the protective effect of afamin on human ovarian GCs is still unclear, there is evidence it has an antioxidant effect in neuronal cells.

METHODS

In this study, we investigated the protective effects of afamin proteins on testosterone propionate (TP)-induced ovarian GCs using a human ovarian tumor granulosa cell line (KGN).

RESULTS

The results showed that afamin reduced TP-induced oxidative stress in KGN cells by decreasing the levels of oxidative damage markers, enhancing the activity of antioxidant enzymes, and exerting a protective effect on GCs. Supplementation with afamin repaired mitochondrial dysfunction by improving mitochondrial membrane potential damage and ATP levels. It counteracted TP-induced apoptosis by decreasing the activity of Caspase-3 and upregulating the expression of the anti-apoptotic gene (BCL-2) while downregulating the expression of the pro-apoptotic gene BCL-2-associated X protein (BAX). In addition, afamin regulated the expression of genes related to ovarian steroid hormone synthesis, ameliorating the endocrine dysfunction observed in TP-induced KGN cells.

CONCLUSION

Therefore, Afamin proteins may serve as important complementary factors that protect GCs from other types of damage, such as oxidative stress, and may help improve ovarian follicle quality and female reproductive function.

Metabolomic and Transcriptomic Analyses Reveal the Potential Mechanisms of Dynamic Ovarian Development in Goats during Sexual Maturation

The ovary is a crucial reproductive organ in mammals, and its development directly influences an individual's sexual maturity and reproductive capacity. To comprehensively describe ovarian sexual maturation in goats, we integrated phenotypic, hormonal, metabolomic, and transcriptomic data from four specific time points: after birth (D1), at 2 months old (M2), at 4 months old (M4), and at 6 month old (M6). The study showed that during the early stage (D1-M2), ovarian growth was the most rapid, with weight and morphology increasing by 284% and 65%, respectively, and hormone levels rose significantly, with estradiol increasing by 57%. Metabolomic analysis identified 1231 metabolites, primarily lipids, lipid molecules, and organic acids, which can support hormone balance and follicle development by providing energy and participating in signaling transduction. Transcriptomic analysis identified 543 stage-specific differentially expressed genes, mainly enriched in steroid biosynthesis, amino acid metabolism, and the PI3K/AKT pathway, which are key factors influencing ovarian cell proliferation, apoptosis, hormone secretion, and metabolism. The integrated analysis revealed the key processes in the ovarian steroid hormone biosynthesis pathway and gene/metabolite networks associated with ovarian phenotypes and hormone levels, ultimately highlighting scavenger receptor class B type 1 (SCARB1), Cytochrome P450 Family 1 Subfamily A Member 1 (CYP11A1), 3beta-hydroxysteroid dehydrogenase (3BHSD), progesterone, estradiol, and L-phenylalanine as key regulators of ovarian morphological and functional changes at different developmental stages. This study is the first to reveal the metabolic changes and molecular regulatory mechanisms during ovarian sexual maturation in goats, providing valuable insights for understanding reproductive system development and optimizing reproductive performance and breeding efficiency.

A homozygous mutation of TWNK identified in premature ovarian insufficiency warns of late-onset perrault syndrome

BACKGROUND

Primary ovarian insufficiency (POI) is defined as cessation of ovarian function before the age of 40 years, which is characterized by amenorrhoea, infertility, elevated gonadotrophin level and sex-steroid deficiency. The phenotypes of POI are heterogeneous, including isolated and syndromic forms. Perrault syndrome (PS), characterized by sensorineural hearing loss (SNHL) and ovarian dysfunction before 40 years in females, is one type of syndromic POI. Genetic defects play a vital role in the pathogenesis of POI.

METHODS AND RESULTS

To illustrate the genetic causation of Perrault syndrome, we performed whole exome sequencing (WES) in one pedigree with the disease, and identified a novel homozygous mutation in TWNK (c.1388G > A, p.R463Q). TWNK encodes a hexameric DNA helicase in mitochondria and plays a critical role in mtDNA replication. In order to determine the effect of the novel mutation on the mitochondrial function, we generated immortalized cell lines by infecting lymphocytes from the family members with EB virus in vitro. Functional studies found that TWNK p.R463Q impaired mtDNA replication and the respiration potential of mitochondria, while the ROS level remains unaffected.

CONCLUSION

Our study provided evidence that TWNK mutation impaired the ovarian function by dysfunctional mitochondria. Moreover, considering the patients here presented POI onset earlier than SNHL, specific variants localizing in different locus of TWNK might induce heterogeneous phenotypes, indicating that the genetic screening of patients with POI would be useful for early recognition of other disease or other phenotypes of syndromic POI.

Endogenous and fluorescent sterols reveal the molecular basis for ligand selectivity of human sterol transporters

Sterol transport proteins (STPs) play a pivotal role in cholesterol homeostasis and therefore are essential for healthy human physiology. Despite recent advances in dissecting functions of STPs in the human cell, there is still a significant knowledge gap regarding their specific biological functions and a lack of suitable selective probes for their study. Here, we profile fluorescent steroid-based probes across ten STPs, uncovering substantial differences in their selectivity, aiding the retrospective and prospective interpretation of biological results generated with those probes. These results guided the establishment of an STP screening panel combining diverse biophysical assays, enabling the evaluation of 41 steroid-based natural products and derivatives. Combining this with a thorough structural analysis revealed the molecular basis for STP specific selectivity profiles, leading to the uncovering of several new potent and selective Aster-B inhibitors, and supporting the role of this protein in steroidogenesis.

Ferroptosis: First evidence in premature duck ovary induced by polyvinyl chloride microplastics

Ferroptosis is frequently observed in fibrosis and diseases related to iron metabolism disorders in various mammalian organs. However, research regarding the damage mechanism of ferroptosis in the female reproductive system of avian species remains unclear. In this study, Muscovy female ducks were divided into three groups which were given purified water, 1 mg/L polyvinyl chloride microplastics (PVC-MPs) and 10 mg/L PVC-MPs for two months respectively, to investigate the ferroptosis induced by PVC-MPs caused ovarian tissue fibrosis that lead to premature ovarian failure. The results showed that the high accumulation of PVC-MPs in ovarian tissue affected the morphology and functional activity of ovarian granulosa cells (GCs) and subsequently caused the follicular development disorders and down-regulated the immunosignaling of ovarian steroidogenesis proteins 3β-hydroxysteroid dehydrogenase (3β-HSD), 17β-hydroxysteroid dehydrogenase (17β-HSD), CYP11A1 cytochrome (P450-11A1) and CYP17A1 cytochrome (P450-17A1) suggested impaired ovarian function. In addition, PVC-MPs significantly up-regulated positive expression of collagen fibers, significantly increased lipid peroxidation and malondialdehyde (MDA) level, along with encouraged overload of iron contents in the ovarian tissue were the characteristics of ferroptosis. Further, immunohistochemistry results confirmed that immunosignaling of ferroptosis related proteins Acyl-CoA synthetase (ACSL4), Cyclooxygenase 2 (COX2) and ferritin heavy chain 1 (FTH1) were significantly increased, but solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase (GPX4) were decreased by PVC-MPs in the ovarian tissue. In conclusion, our study demonstrates that PVC-MPs induced ferroptosis in the ovarian GCs, leading to follicle development disorders and ovarian tissue fibrosis, and ultimately contributing to various female reproductive disorders through regulating the proteins expression of ferroptosis.

Artemisinins ameliorate polycystic ovarian syndrome by mediating LONP1-CYP11A1 interaction

Polycystic ovary syndrome (PCOS), a prevalent reproductive disorder in women of reproductive age, features androgen excess, ovulatory dysfunction, and polycystic ovaries. Despite its high prevalence, specific pharmacologic intervention for PCOS is challenging. In this study, we identified artemisinins as anti-PCOS agents. Our finding demonstrated the efficacy of artemisinin derivatives in alleviating PCOS symptoms in both rodent models and human patients, curbing hyperandrogenemia through suppression of ovarian androgen synthesis. Artemisinins promoted cytochrome P450 family 11 subfamily A member 1 (CYP11A1) protein degradation to block androgen overproduction. Mechanistically, artemisinins directly targeted lon peptidase 1 (LONP1), enhanced LONP1-CYP11A1 interaction, and facilitated LONP1-catalyzed CYP11A1 degradation. Overexpression of LONP1 replicated the androgen-lowering effect of artemisinins. Our data suggest that artemisinin application is a promising approach for treating PCOS and highlight the crucial role of the LONP1-CYP11A1 interaction in controlling hyperandrogenism and PCOS occurrence.

Impact of dioxins on reproductive health in female mammals

Extensive research has been conducted to investigate the toxicological impact of dioxins on mammals, revealing profound effects on the female reproductive system in both humans and animals. Dioxin exposure significantly disrupts the intricate functions of the ovary, a pivotal organ responsible for reproductive and endocrine processes. This disruption manifests as infertility, premature ovarian failure, and disturbances in sex steroid hormone levels. Comprehensive studies, encompassing accidental human exposure and experimental animal data, have raised a wealth of information with consistent yet varied conclusion influenced by experimental factors. This review begins by providing an overarching background on the ovary, emphasizing its fundamental role in reproductive health, particularly in ovarian steroidogenesis and hormone receptor regulation. Subsequently, a detailed examination of the Aryl hydrocarbon Receptor (AhR) and its role in governing ovarian function is presented. The review then outlines the sources and toxicity of dioxins, with a specific focus on AhR involvement in mediating reproductive toxicity in mammals. Within this context, the impact of dioxins, notably 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), on Folliculogenesis and Preimplantation embryos is discussed. Furthermore, the review delves into the disruptions of the female hormonal system caused by TCDD and their ramifications in endometriosis. Notably, variations in the effects of TCDD on the female reproductive and hormonal system are highlighted in relation to TCDD dose, animal species, and age. As a forward-looking perspective, questions arise regarding the potential involvement of molecular mechanisms beyond AhR in mediating the female reproductive toxicity of dioxins.

Altered luteal expression patterns of genomic and non-genomic progesterone receptors in bitches at different reproductive states

The binding of steroid hormones to their specific receptors is necessary to exert their effects on target cells. Progesterone (P4), a steroid hormone, carries out its effects through both genomic and non-genomic (the cell membrane-associated) receptors. This study aimed to ascertain luteal expression patterns of genomic and non-genomic progesterone receptors in bitches in physiological (early dioestrus and early pregnant) and pathological (pyometra) reproductive states. Luteal tissue was collected from the bitches at early dioestrus (ED, n = 5), early pregnant (EP, n = 5), and pyometra (PY, n = 5). The expression profiles of Steroidogenic Acute Regulator Protein (STAR), Progesterone Receptor (PGR), Membrane Progestin Receptors (PAQR5, PAQR7 and PAQR8), and Progesterone Membrane Components (PGMRC1 and PGMRC2) were examined at the mRNA levels using Real-Time Polymerase Chain Reaction (RT-PCR). Protein levels of PGR, PGMRC1 and PGMRC2 were detected by western blotting (WB). The STAR expression was found in all groups, with a statistical difference observed between EP and PY groups (P < 0.05). The protein level of PGR was determined to be highest in the EP group and lowest in the PY group. The expression of PAQR8 increased in the EP group (P < 0.05). The PAQR5 exhibited high expression in the EP group and low expression in the PY group (P < 0.05). PGRMC1 was more elevated in the EP group and lower in the PY group (P < 0.05). Protein levels of PGMRC1 and PGMRC2 were also observed at the highest expression in EP group. According to the altered expression profiles for examined receptors, we suggest that those progesterone receptors have roles in early pregnancy or pyometra in bitches.

Retinoic acid enhances ovarian steroidogenesis by regulating granulosa cell proliferation and MESP2/STAR/CYP11A1 pathway

INTRODUCTION

Ovarian steroidogenesis not only affects the embryonic development and pregnancy outcome, but also associates with many diseases in mammals and women. Exploring the nutrients and mechanisms influencing ovarian steroidogenesis is critical to maintaining the optimal reproductive performance, as well as guaranteeing body health.

OBJECTIVES

This research aimed to explore the effect of retinol metabolism on ovarian steroidogenesis and the underlying mechanisms.

METHODS

Comparative transcriptomic analysis of ovaries from normal and low reproductive performance sows were performed to identify the main causes leading to low fertility. The metabolites regulating steroid hormones synthesis were investigated in ovarian granulosa cells. Gene interference, overexpression, dual-luciferase reporter assays, chromatin immunoprecipitation and transcriptome analysis were further conducted to explore the underlying mechanisms of Aldh1a1 mediating ovarian steroidogenesis.

RESULTS

Transcriptome analysis of ovaries from normal and low reproductive performance sows showed the significant differences in both retinol metabolism and steroid hormones synthesis, indicating retinol metabolism probably influenced steroid hormones synthesis. The related metabolite retinoic acid was furtherly proven a highly active and potent substance strengthening estrogen and progesterone synthesis in ovarian granulosa cells. For the first time, we revealed that retinoic acid synthesis in porcine and human ovarian granulosa cells was dominated by Aldh1a1, and required the assistance of Aldh1a2. Importantly, we demonstrated that Aldh1a1 enhanced the proliferation of ovarian granulosa cells by activating PI3K-Akt-hedgehog signaling pathways. In addition, Aldh1a1 regulated the expression of transcription factor MESP2, which targeted the transcription of Star and Cyp11a1 through binding to corresponding promoter regions.

CONCLUSION

Our data identified Aldh1a1 modulates ovarian steroidogenesis through enhancing granulosa cell proliferation and MESP2/STAR/CYP11A1 pathway. These findings provide valuable clues for improving ovarian health in mammals.

Combined effects of copper and cadmium exposure on ovarian function and structure in Nile Tilapia (Oreochromis niloticus)

With the rapid development of industrialization and urbanization, the issue of copper (Cu) and cadmium (Cd) pollution in aquatic ecosystems has become increasingly severe, posing threats to the ovarian tissue and reproductive capacity of aquatic organisms. However, the combined effects of Cu and Cd on the ovarian development of fish and other aquatic species remain unclear. In this study, female Nile tilapia (Oreochromis niloticus) were individually or co-exposed to Cu and/or Cd in water. Ovarian and serum samples were collected at 15, 30, 60, 90, and 120 days, and the bioaccumulation, ovarian development, and hormone secretion were analyzed. Results showed that both single and combined exposure significantly reduced the gonadosomatic index and serum hormone levels, upregulated estrogen receptor (er) and progesterone receptor (pr) gene transcription levels, and markedly affected ovarian metabolite levels. Combined exposure led to more adverse effects than single exposure. The data demonstrate that the Cu and Cd exposure can impair ovarian function and structure, with more pronounced adverse effects under Cu and Cd co-exposure. The Cu and Cd affect the metabolic pathways of nucleotides and amino acids, leading to ovarian damage. This study highlights the importance of considering combined toxicant exposure in aquatic toxicology research and provides insights into the potential mechanisms underlying heavy metal-induced reproductive toxicity in fish.

Stay in touch with the endoplasmic reticulum

The endoplasmic reticulum (ER), which is composed of a continuous network of tubules and sheets, forms the most widely distributed membrane system in eukaryotic cells. As a result, it engages a variety of organelles by establishing membrane contact sites (MCSs). These contacts regulate organelle positioning and remodeling, including fusion and fission, facilitate precise lipid exchange, and couple vital signaling events. Here, we systematically review recent advances and converging themes on ER-involved organellar contact. The molecular basis, cellular influence, and potential physiological functions for ER/nuclear envelope contacts with mitochondria, Golgi, endosomes, lysosomes, lipid droplets, autophagosomes, and plasma membrane are summarized.

Effect of quercetin on granulosa cells development from hierarchical follicles in chicken

1. The bioflavonoid quercetin is a biologically active component, but its functional regulation of granulosa cells (GCs) during chicken follicular development is little studied. To investigate the effect of quercetin on follicular development in laying hens, an in vitro study was conducted on granulosa cells from hierarchical follicles treated with quercetin.2. The effect of quercetin on cell activity, proliferation and apoptosis of granulosa cells was detected by CCK-8, EdU and apoptosis assays. The effect on progesterone secretion from granulosa cells was investigated by enzyme-linked immunosorbent assay (ELISA). Expression of proliferating cell nuclear antigen (PCNA) mRNA and oestrogen receptors (ERs), as well as the expression of steroid acute regulatory protein (StAR), cytochrome P450 cholesterol side chain cleavage enzyme (P450scc) and 3β-hydroxysteroid dehydrogenase (3β-HSD) mRNA during progesterone synthesis, were measured by real-time quantitative polymerase chain reaction (RT-qPCR). PCNA, StAR and CYP11A1 protein expression levels were detected using Western blotting (WB).3. The results showed that treatment with quercetin in granulosa cells significantly enhanced cell vitality and proliferation, reduced apoptosis and promoted the expression of gene and protein levels of PCNA. The levels of progesterone secretion increased significantly following quercetin treatment, as did the expression levels of StAR and CYP11A1 using the Western Blot (WB) method.4. The mRNA expression levels of ERα were significantly upregulated in the 100 ng/ml and 1000 ng/ml quercetin-treated groups, while there was no significant difference in expression levels of ERβ mRNA.

Fluctuating and Stable High Temperatures Differentially Affect Reproductive Endocrinology of Female Pupfish

For many fishes, reproductive function is thermally constrained such that exposure to temperatures above some upper threshold has detrimental effects on gametic development and maturation, spawning frequency, and mating behavior. Such impairment of reproductive performance at elevated temperatures involves changes to hypothalamic-pituitary-gonadal (HPG) axis signaling and diminished gonadal steroidogenesis. However, how HPG pathways respond to consistently high versus temporally elevated temperatures is not clear. Here, sexually mature Amargosa River Pupfish (Cyprinodon nevadensis amargosae) were maintained under thermal regimes of either stable ∼25°C (low temperature), diurnal cycling temperatures between ∼27 and 35°C (fluctuating temperature), or stable ∼35°C (high temperature) conditions for 50 days to examine effects of these conditions on HPG endocrine signaling components in the pituitary gland and gonad, ovarian and testicular gametogenesis status, and liver gene expression relating to oogenesis. Female pupfish maintained under stable high and fluctuating temperature treatments showed reduced gonadosomatic index values as well as a lower proportion of oocytes in the lipid droplet and vitellogenic stages. Females in both fluctuating and stable 35°C conditions exhibited reduced ovarian mRNAs for steroid acute regulatory protein (star), cholesterol side chain-cleavage enzyme, P450scc (cyp11a1), and 3β-hydroxysteroid dehydrogenase (3bhsd), while ovarian transcripts encoding 11β-hydroxysteroid dehydrogenase (11bhsd) and sex hormone-binding globulin (shbg) were elevated in females at constant 35°C only. Ovarian aromatase (cyp19a1a) mRNA levels were unaffected, but circulating 17β-estradiol (E2) was lower in females at 35°C compared to the fluctuating temperature condition. In the liver, mRNA levels for choriogenins and vitellogenin were downregulated in both the fluctuating and 35°C conditions, while hepatic estrogen receptor 2a (esr2a) and shbg mRNAs were elevated in 35°C females. Taken together, these results demonstrate the potential for elevated temperatures to impair ovarian steroidogenesis and reduce egg envelope and vitellogenin protein production in female C. n. amargosae pupfish, while also shedding light on how thermal regimes that only intermittently reach the upper thermal range for reproduction have differential impacts on reproductive endocrine pathways than constantly warm conditions.

Reaction thermodynamics as a constraint on piscine steroidogenesis flux distributions

While a considerable amount is known of the dynamics of piscine steroidogenesis during reproduction, the influence of thermodynamics constraints on its control has not been studied. In this manuscript, Gibbs free energy change of reactions was calculated for piscine steroidogenesis using the in silico eQuilibrator thermodynamics calculator. The analysis identified cytochrome P450 (cyp450) oxidoreductase reactions to have more negative Gibbs free energy changes relative to hydroxysteroid (HSD) and transferase reactions. In addition, a more favorable Gibbs free energy change was predicted for the Δ5 (cyp450 catalyzed) vs. Δ4 (HSD catalyzed) steroidogenesis branch-point, which converts pregnenolone to 17α-hydroxypregnenolone or progesterone respectively. Comparison of in silico predictions with in vivo experimentally measured flux across the Δ5 vs. Δ4 branch-point showed higher flux through the thermodynamically more favorable Δ5 pathway in reproducing or spawning vs. non-spawning fathead minnows (Pimephales promelas). However, the exposure of fish to endocrine stressors such as hypoxia or the synthetic estrogen 17α-ethinylestradiol (EE2), resulted in increased flux through both Δ5 and Δ4 pathways, indicating an adaptive response to increase steroidogenic redundancy. The correspondence of elevated flux through the Δ5 branch-point in spawning fish indicated the use of a thermodynamically favorable pathway to optimize steroid hormone productions during reproduction. We hypothesize that such selective use of a thermodynamically favorable steroidogenesis pathway may conserve reduced equivalents or transcriptional costs for investment to other biosynthetic or catabolic reactions to support reproduction. If generalizable, such an approach can provide novel insights into the structural principles and regulation of steroidogenesis or other metabolic pathways.

Effects of sub-chronic exposure to microcystin-LR on the endocrine system of male rats

Microcystins (MCs) can cause reproductive and developmental toxicity and disrupt endocrine homeostasis in mammals. In the present study, male, Sprague-Dawley (SD) rats were administrated 3 or 30 μg MC-LR/kg, body mass (bm) per day via intraperitoneal (i.p.) injections for 6 weeks. Effects of MC-LR on histology, hormone concentrations, gene transcriptional profiles and protein expressions along the hypothalamic-pituitary-adrenal (HPA), -gonad (HPG) and -thyroid (HPT) axes were assessed. Sub-chronic administration with MC-LR caused histological damage to hypothalamus, pituitary, adrenal, testes and thyroid and affected relative masses of pituitary, adrenal and testes. The HPA axis was activated and serum concentrations of corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH) and corticosterone (CORT) were significantly augmented. Along the HPG axis, serum concentrations of gonadotropin-releasing hormone (GnRH) and dihydrotestosterone (DHT) were diminished, while concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone (T) and estradiol (E2) were augmented. For the HPT axis, only concentrations of free tetra-iodothyronine (fT4) were significantly diminished, while concentrations of thyrotropin-releasing hormone (TRH), thyroid-stimulating hormone (TSH) or free tri-iodothyronine (fT3) were not significantly changed. Also, several genes and proteins related to synthesis of steroid hormones were significantly altered. Findings of the present study illustrate that MC-LR can cause endocrine-disrupting effects through the disruption of synthesis and secretion of hormones along the HPA, HPG and HPT axes and negative feedback regulation. Also, there could be crosstalk among HPA, HPG and HPT axes. These findings elucidate mechanisms of endocrine-disrupting effects of MCs.

A comprehensive review on the decabromodiphenyl ether (BDE-209)-induced male reproductive toxicity: Evidences from rodent studies

Polybrominated diphenyl ethers (PBDEs), a class of brominated flame retardants (BFRs), are employed in various manufactured products to prevent fires, slow down their spread and reduce the resulting damages. Decabromodiphenyl ether (BDE-209), an example of PBDEs, accounts for approximately 82 % of the total production of PBDEs. BDE-209 is a thyroid hormone (TH)-disrupting chemical owing to its structural similarity with TH. Currently, increase in the level of BDE-209 in biological samples has become a major issue because of its widespread use. BDE-209 causes male reproductive toxicity mainly via impairment of steroidogenesis, generation of oxidative stress (OS) and interference with germ cell dynamics. Further, exposure to this chemical can affect metabolic status, sperm concentration, epigenetic regulation of various developmental genes and integrity of blood-testis barrier in murine testis. However, the possible adverse effects of BDE-209 and its mechanism of action on the male reproductive health have not yet been critically evaluated. Hence, the present review article, with the help of available literature, aims to elucidate the reproductive toxicity of BDE-209 in relation to thyroid dysfunction in rodents. Further, several crucial pathways have been also highlighted in order to strengthen our knowledge on BDE-209-induced male reproductive toxicity. Data were extracted from scientific articles available in PubMed, Web of Science, and other databases. A thorough understanding of the risk assessment of BDE-209 exposure and mechanisms of its action is crucial for greater awareness of the potential threat of this BFR to preserve male fertility.

MicroRNA regulation of adrenal glucocorticoid and androgen biosynthesis

Steroid hormones are derived from a common precursor molecule, cholesterol, and regulate a wide range of physiologic function including reproduction, salt balance, maintenance of secondary sexual characteristics, response to stress, neuronal function, and various metabolic processes. Among the steroids synthesized by the adrenal and gonadal tissues, adrenal mineralocorticoids, and glucocorticoids are essential for life. The process of steroidogenesis is regulated at multiple levels largely by transcriptional, posttranscriptional, translational, and posttranslational regulation of the steroidogenic enzymes (i.e., cytochrome P450s and hydroxysteroid dehydrogenases), cellular compartmentalization of the steroidogenic enzymes, and cholesterol processing and transport proteins. In recent years, small noncoding RNAs, termed microRNAs (miRNAs) have been recognized as major post-transcriptional regulators of gene expression with essential roles in numerous biological processes and disease pathologies. Although their role in the regulation of steroidogenesis is still emerging, several recent studies have contributed significantly to our understanding of the role miRNAs play in the regulation of the steroidogenic process. This chapter focuses on the recent developments in miRNA regulation of adrenal glucocorticoid and androgen production in humans and rodents.

Exposure to 4-nonylphenol compromises Leydig cell development in pubertal male mice

Exposure to 4-nonyl phenol (4-NP) on Leydig cell (LC) development and function remains poorly understood. We explored the effects of 4-NP on LC development and elucidate the underlying mechanisms. Male (28-day-old) mice received orally 4-NP (0.125, 0.25, and 0.5 mg/kg/day) for 28 days. We found that 4-NP at ≥ 0.125 mg/kg markedly compromised serum testosterone levels and LC numbers. Gene and protein expression analysis demonstrated downregulation of key genes and their proteins involved in LC steroidogenesis, including Star, Cyp11a1, Cyp17a1, Hsd17b3, Hsd3b6, and Scarb1. Furthermore, exposure to 4-NP induced oxidative stress, as evidenced by elevated reactive oxygen species (ROS) and malondialdehyde (MDA), as well as reduced superoxide dismutase 1/2 and catalase (CAT). Apoptosis was also observed in LCs following exposure to 4-NP, as shown by an increased BAX/BCL2 ratio and caspase-3. A TM3 mouse LC line further confirmed that 4-NP induced ROS and the expression of apoptosis-related genes and proteins. In conclusion, this study demonstrates that 4-NP exposure compromises LC development through multiple mechanisms.

Sex steroid metabolism and action in colon health and disease

The colon is the largest hormonally active tissue in the human body. It has been known for over a hundred years that various hormones and bioactive peptides play important roles in colon function. More recently there is a growing interest in the role the sex steroids, oestrogens and androgens, may play in both normal colon physiology and colon pathophysiology. In this review, we examine the potential role oestrogens and androgens play in the colon. The metabolism and subsequent action of sex steroids in colonic tissue is discussed and how these hormones impact colon motility is investigated. Furthermore, we also determine how oestrogens and androgens influence colorectal cancer incidence and development and highlight potential new therapeutic targets for this malignancy. This review also examines how sex steroids potentially impact the severity and progression of other colon disease, such as diverticulitis, irritable bowel syndrome, and polyp formation.

De novo assembly, characterization and comparative transcriptome analysis of gonads reveals sex-biased genes in Coreoperca whiteheadi

The wild Coreoperca whiteheadi is considered as the primordial species in sinipercine fish, which has valuable genetic information. Unfortunately, C. whiteheadi was listed as a near-threatened species because of the environmental pollution, over-exploitation and species invasion. Therefore, more genetic information is needed to have a better understanding of gonadal development in C. whiteheadi. Here, the first gonadal transcriptomes analysis of C. whiteheadi was conducted and 277.14 million clean reads were generated. A total of 96,753 unigenes were successfully annotated. By comparing ovary and testis transcriptomes, a total of 21,741 differentially expressed genes (DEGs) were identified, of which 12,057 were upregulated and 9684 were downregulated in testes. Among them, we also identified about 53 differentially expressed sex-biased genes. Subsequently, the expression of twenty-four DEGs were confirmed by real-time fluorescence quantitative PCR. Furthermore, the histological analysis was conducted on ovaries and testes of one-year-old C. whiteheadi. Our results provided basic support for further studies on the function of sex-biased genes and the molecular mechanism of sex determination and reproduction in C. whiteheadi.

Zonal expression of StARD1 and oxidative stress in alcoholic-related liver disease

Alcoholic-related liver disease (ALD) is one of the leading causes of chronic liver disease and morbidity. Unfortunately, the pathogenesis of ALD is still incompletely understood. StARD1 has emerged as a key player in other etiologies of chronic liver disease, and alcohol-induced liver injury exhibits zonal distribution. Here, we report that StARD1 is predominantly expressed in perivenous (PV) zone of liver sections from mice-fed chronic and acute-on-chronic ALD models compared to periportal (PP) area and is observed as early as 10 days of alcohol feeding. Ethanol and chemical hypoxia induced the expression of StARD1 in isolated primary mouse hepatocytes. The zonal-dependent expression of StARD1 resulted in the accumulation of cholesterol in mitochondria and increased lipid peroxidation in PV hepatocytes compared to PP hepatocytes, effects that were abrogated in PV hepatocytes upon hepatocyte-specific Stard1 KO mice. Transmission electron microscopy indicated differential glycogen and lipid droplets content between PP and PV areas, and alcohol feeding decreased glycogen content in both areas while increased lipid droplets content preferentially in PV zone. Moreover, transmission electron microscopy revealed that mitochondria from PV zone exhibited reduced length with respect to PP area, and alcohol feeding increased mitochondrial number, particularly, in PV zone. Extracellular flux analysis indicated lower maximal respiration and spared respiratory capacity in control PV hepatocytes that were reversed upon alcohol feeding. These findings reveal a differential morphology and functional activity of mitochondria between PP and PV hepatocytes following alcohol feeding and that StARD1 may play a key role in the zonal-dependent liver injury characteristic of ALD.

Classification of Cushing's syndrome PKAc mutants based upon their ability to bind PKI

Cushing's syndrome is an endocrine disorder caused by excess production of the stress hormone cortisol. Precision medicine strategies have identified single allele mutations within the PRKACA gene that drive adrenal Cushing's syndrome. These mutations promote perturbations in the catalytic core of protein kinase A (PKAc) that impair autoinhibition by regulatory subunits and compartmentalization via recruitment into AKAP signaling islands. PKAcL205R is found in ∼45% of patients, whereas PKAcE31V, PKAcW196R, and L198insW and C199insV insertion mutants are less prevalent. Mass spectrometry, cellular, and biochemical data indicate that Cushing's PKAc variants fall into two categories: those that interact with the heat-stable protein kinase inhibitor PKI, and those that do not. In vitro activity measurements show that wild-type PKAc and W196R activities are strongly inhibited by PKI (IC50 < 1 nM). In contrast, PKAcL205R activity is not blocked by the inhibitor. Immunofluorescent analyses show that the PKI-binding variants wild-type PKAc, E31V, and W196R are excluded from the nucleus and protected against proteolytic processing. Thermal stability measurements reveal that upon co-incubation with PKI and metal-bound nucleotide, the W196R variant tolerates melting temperatures 10°C higher than PKAcL205. Structural modeling maps PKI-interfering mutations to a ∼20 Å diameter area at the active site of the catalytic domain that interfaces with the pseudosubstrate of PKI. Thus, Cushing's kinases are individually controlled, compartmentalized, and processed through their differential association with PKI.

Leydig cell development in pubertal male rats is blocked by perfluorotetradecanoic acid through decreasing AMPK-mTOR-autophagy pathway

Perfluorotetradecanoic acid (PFTeDA) is a type of perfluoroalkyl acid that has been linked to various health effects in animals and humans. The study aimed to investigate the potential impact of PFTeDA exposure on Leydig cell development in rats during puberty. Understanding the effects of PFTeDA on Leydig cells is crucial as these cells play a significant role in male reproductive function. Male Sprague-Dawley rats were gavaged with PFTeDA at doses of 0, 1, 5, and 10mg/kg/day from postnatal day 35 to 56. The serum hormone levels were measured and testicular transcriptome changes were analyzed by RNA-seq and verified by qPCR, and the levels of steroidogenesis-related proteins and energy regulators were measured. PFTeDA significantly reduced serum testosterone levels while slightly increasing LH levels. RNA-seq and qPCR analysis showed that genes responsive to oxidative phosphorylation (Naufa1 and Ndufs6) and steroidogenesis (Ldlr, Star, Cyp11a1) were markedly downregulated at ≥5mg/kg, while those related to ferroptosis (Alox15) and cell senescence (Map2k3 and RT1-CE3) were significantly upregulated. PFTeDA markedly reduced SIRT1 (silent information regulator 1) /PGC-1α (peroxisome proliferator-activated receptor gamma coactivator-1α) and AMPKA (AMP activated kinase A), LC3B and Beclin1 (biomarkers for autophagy) levels while increasing phosphorylated mTOR. In vitro treatment of PFTeDA at 5 μM significantly reduced androgen output of Leydig cells from 35-day-old male rats while ferrostatin 1 (10 μM) reversed PFTeDA-mediated inhibition. In conclusion, the inhibitory effects of PFTeDA on pubertal rat Leydig cell development are possibly regulated by inducing ferroptosis thereby downregulating SIRT1/AMPKA/ autophagy pathways, eventually resulting in reduced steroidogenesis.

Expression Analysis of Lipocalin 2 (LCN2) in Reproductive and Non-Reproductive Tissues of Esr1-Deficient Mice

Estrogen receptor alpha (ERα) is widely expressed in reproductive organs, but also in non-reproductive tissues of females and males. There is evidence that lipocalin 2 (LCN2), which has diverse immunological and metabolic functions, is regulated by ERα in adipose tissue. However, in many other tissues, the impact of ERα on LCN2 expression has not been studied yet. Therefore, we used an Esr1-deficient mouse strain and analyzed LCN2 expression in reproductive (ovary, testes) and non-reproductive tissues (kidney, spleen, liver, lung) of both sexes. Tissues collected from adult wild-type (WT) and Esr1-deficient animals were analyzed by immunohistochemistry, Western blot analysis, and RT-qPCR for Lcn2 expression. In non-reproductive tissues, only minor genotype- or sex-specific differences in LCN2 expression were detected. In contrast, significant differences in LCN2 expression were observed in reproductive tissues. Particularly, there was a strong increase in LCN2 in Esr1-deficient ovaries when compared to WTs. In summary, we found an inverse correlation between the presence of ERα and the expression of LCN2 in testes and ovaries. Our results provide an important basis to better understand LCN2 regulation in the context of hormones and in health and disease.

Testicular hypoplasia in Nellore Cattle: Genetic analysis and functional analysis of genome-wide association study results

Characterized by the incomplete development of the germinal epithelium of the seminiferous tubules, Testicular hypoplasia (TH) leads to decreased sperm concentration, increased morphological changes in sperm and azoospermia. Economic losses resulting from the disposal of affected bulls reduce the efficiency of meat production systems. A genome-wide association study and functional analysis were performed to identify genomic windows and the underlying positional candidate genes associated with TH in Nellore cattle. Phenotypic and pedigree data from 207,195 animals and genotypes (461,057 single nucleotide polymorphism, SNP) from 17,326 sires were used in this study. TH was evaluated as a binary trait measured at 18 months of age. A possible correlated response on TH resulting from the selection for scrotal circumference was evaluated by using a two-trait analysis. Thus, estimated breeding values were calculated by fitting a linear-threshold animal model in a Bayesian approach. The SNP effects were estimated using the weighted single-step genomic BLUP method. Twelve non-overlapping windows of 20 adjacent SNP that explained more than 1% of the additive genetic variance were selected for candidate gene annotation. Functional and gene prioritization analysis of the candidate genes identified genes (KHDRBS3, GPX5, STAR, ERLIN2), which might play an important role in the expression of TH due to their known roles in the spermatogenesis process, synthesis of steroids and lipid metabolism.

Common and female-specific roles of protein tyrosine phosphatase receptors N and N2 in mice reproduction

Simultaneous knockout of the neuroendocrine marker genes Ptprn and Ptprn2, which encode the protein tyrosine phosphatase receptors N and N2, causes infertility in female mice while males are fertile. To elucidate the mechanism of the sex-specific roles of Ptprn and Ptprn2 in mouse reproduction, we analyzed the effects of their double knockout (DKO) on the hypothalamic-pituitary-gonadal axis. In DKO females, delayed puberty and lack of ovulation were observed, complemented by changes in ovarian gene expression and steroidogenesis. In contrast, testicular gene expression, steroidogenesis, and reproductive organs development were not significantly affected in DKO males. However, in both sexes, pituitary luteinizing hormone (LH) beta gene expression and LH levels were reduced, as well as follicle-stimulating hormone beta gene and gonadotropin-releasing hormone (GnRH) gene, while the calcium-mobilizing and LH secretory actions of GnRH were preserved. Hypothalamic Gnrh1 and Kiss1 gene expression was also reduced in DKO females and males. In parallel, a significant decrease in the density of immunoreactive GnRH and kisspeptin fibers was detected in the hypothalamic arcuate nucleus of DKO females and males. The female-specific kisspeptin immunoreactivity in the rostral periventricular region of the third ventricle was also reduced in DKO females, but not in DKO males. These data indicate a critical role of Ptprn and Ptprn2 in kisspeptin-GnRH neuronal function and sexual dimorphism in the threshold levels of GnRH required to preserve reproductive functions.

Sex steroid hormone synthesis, metabolism, and the effects on the mammalian olfactory system

Sex steroid hormones influence olfactory-mediated social behaviors, and it is generally hypothesized that these effects result from circulating hormones and/or neurosteroids synthesized in the brain. However, it is unclear whether sex steroid hormones are synthesized in the olfactory epithelium or the olfactory bulb, and if they can modulate the activity of the olfactory sensory neurons. Here, we review important discoveries related to the metabolism of sex steroids in the mouse olfactory epithelium and olfactory bulb, along with potential areas of future research. We summarize current knowledge regarding the expression, neuroanatomical distribution, and biological activity of the steroidogenic enzymes, sex steroid receptors, and proteins that are important to the metabolism of these hormones and reflect on their potential to influence early olfactory processing. We also review evidence related to the effects of sex steroid hormones on the development and activity of olfactory sensory neurons. By better understanding how these hormones are metabolized and how they act both at the periphery and olfactory bulb level, we can better appreciate the complexity of the olfactory system and discover potential similarities and differences in early olfactory processing between sexes.

Ca2+ and Annexins - Emerging Players for Sensing and Transferring Cholesterol and Phosphoinositides via Membrane Contact Sites

Maintaining lipid composition diversity in membranes from different organelles is critical for numerous cellular processes. However, many lipids are synthesized in the endoplasmic reticulum (ER) and require delivery to other organelles. In this scenario, formation of membrane contact sites (MCS) between neighbouring organelles has emerged as a novel non-vesicular lipid transport mechanism. Dissecting the molecular composition of MCS identified phosphoinositides (PIs), cholesterol, scaffolding/tethering proteins as well as Ca²⁺ and Ca²⁺-binding proteins contributing to MCS functioning. Compelling evidence now exists for the shuttling of PIs and cholesterol across MCS, affecting their concentrations in distinct membrane domains and diverse roles in membrane trafficking. Phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) at the plasma membrane (PM) not only controls endo-/exocytic membrane dynamics but is also critical in autophagy. Cholesterol is highly concentrated at the PM and enriched in recycling endosomes and Golgi membranes. MCS-mediated cholesterol transfer is intensely researched, identifying MCS dysfunction or altered MCS partnerships to correlate with de-regulated cellular cholesterol homeostasis and pathologies. Annexins, a conserved family of Ca²⁺-dependent phospholipid binding proteins, contribute to tethering and untethering events at MCS. In this chapter, we will discuss how Ca²⁺ homeostasis and annexins in the endocytic compartment affect the sensing and transfer of cholesterol and PIs across MCS.

The START domain mediates Arabidopsis GLABRA2 dimerization and turnover independently of homeodomain DNA binding

Class IV homeodomain leucine-zipper transcription factors (HD-Zip IV TFs) are key regulators of epidermal differentiation that are characterized by a DNA-binding HD in conjunction with a lipid-binding domain termed steroidogenic acute regulatory-related lipid transfer (START). Previous work established that the START domain of GLABRA2 (GL2), a HD-Zip IV member from Arabidopsis (Arabidopsis thaliana), is required for TF activity. Here, we addressed the functions and possible interactions of START and the HD in DNA binding, dimerization, and protein turnover. Deletion analysis of the HD and missense mutations of a conserved lysine (K146) resulted in phenotypic defects in leaf trichomes, root hairs, and seed mucilage, similar to those observed for START domain mutants, despite nuclear localization of the respective proteins. In vitro and in vivo experiments demonstrated that while HD mutations impair binding to target DNA, the START domain is dispensable for DNA binding. Vice versa, protein interaction assays revealed impaired GL2 dimerization for multiple alleles of START mutants, but not HD mutants. Using in vivo cycloheximide chase experiments, we provided evidence for the role of START, but not HD, in maintaining protein stability. This work advances our mechanistic understanding of HD-Zip TFs as multidomain regulators of epidermal development in plants.

Measurement of hair thyroid and steroid hormone concentrations in the rat evidence endocrine disrupting potential of a low dose mixture of polycyclic aromatic hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs) have been shown to influence endogenous hormones levels in animal models, but little is known about the effects of their mixtures. For hormone measurements, hair analysis is a promising approach to provide information on long-term status of hormones. Herein we used hair analysis to assess the combined effects of 13 PAHs on steroid and thyroid hormones levels in a rat model. The PAH mixture was administered orally three times per week to female rats at doses of 0, 10, 20, 40, 80, 200, 400 and 800 μg/kg of body weight for each compound over a 90-day exposure period. Fourteen out of 36 analyzed hormones were detected in rat hair, including pregnenolone (P5), 17α-hydroxyprogesterone (17-OHP4), corticosterone (CORT), dehydroepiandrosterone (DHEA), androstenedione (AD), 3,3'-diiodo-L-thyronine (T2), 3,3',5-triiodo-L-thyronine (T3), and 3,5,3',5'-triiodo-L-thyronine (T4). The PAH mixture significantly elevated P5 and DHEA levels at the doses of 200 and 400 μg/kg but reduced T2 and T3 levels at the highest dose as compared to the control. While P5, DHEA, 17-OHP4 and AD concentrations exhibited inverted U-shaped dose responses, T2, T3 and T4 concentrations exhibited inverse linear dose responses, which are further confirmed by their relationships with hair hydroxylated PAHs (OH-PAHs) concentrations. Likewise, there were significant nonmonotonic relationships of hormone molar ratios (e.g., AD/17-OHP4 and DHEA/CORT ratios) with exposure intensity and OH-PAHs. Overall, our results demonstrate the capability of PAH mixtures to interfere with steroid and thyroid hormones in female rats.

Transcriptome analysis of flathead grey mullet (Mugil cephalus) ovarian development induced by recombinant gonadotropin hormones

Background: Treatment with recombinant gonadotropin hormones (rGths), follicle-stimulating hormone (rFsh) and luteinizing hormone (rLh), was shown to induce and complete vitellogenesis to finally obtain viable eggs and larvae in the flathead grey mullet (Mugil cephalus), a teleost arrested at early stages of gametogenesis in intensive captivity conditions. This study aimed to investigate the transcriptomic changes that occur in the ovary of females during the rGths-induced vitellogenesis. Methods: Ovarian samples were collected through biopsies from the same five females at four stages of ovarian development. RNASeq libraries were constructed for all stages studied, sequenced on an Illumina HiSeq4000, and a de novo transcriptome was constructed. Differentially expressed genes (DEGs) were identified between stages and the functional properties of DEGs were characterized by comparison with the gene ontology and Kyoto Encyclopedia. An enrichment analysis of molecular pathways was performed. Results: The de novo transcriptome comprised 287,089 transcripts after filtering. As vitellogenesis progressed, more genes were significantly upregulated than downregulated. The rFsh application induced ovarian development from previtellogenesis to early-to-mid-vitellogenesis with associated pathways enriched from upregulated DEGs related to ovarian steroidogenesis and reproductive development, cholesterol metabolism, ovarian growth and differentiation, lipid accumulation, and cell-to-cell adhesion pathways. The application of rFsh and rLh at early-to-mid-vitellogenesis induced the growth of oocytes to late-vitellogenesis and, with it, the enrichment of pathways from upregulated DEGs related to the production of energy, such as the lysosomes activity. The application of rLh at late-vitellogenesis induced the completion of vitellogenesis with the enrichment of pathways linked with the switch from vitellogenesis to oocyte maturation. Conclusion: The DEGs and enriched molecular pathways described during the induced vitellogenesis of flathead grey mullet with rGths were typical of natural oogenesis reported for other fish species. Present results add new knowledge to the rGths action to further raise the possibility of using rGths in species that present similar reproductive disorders in aquaculture, the aquarium industry as well as the conservation of endangered species.

Testicular Expression of Antioxidant Enzymes and Changes in Response to a Slow-Release Deslorelin Implant (Suprelorin® 4.7 mg) in the Dog

Spermatogenesis takes place in a hypoxic environment, and antioxidant enzymes protect germ and somatic cells from free radical-mediated damage. Expression of the antioxidant enzyme system in the canine testis has not yet been investigated. We hypothesized that the slow-release GnRH superagonist deslorelin 4.7 mg implant, which induces temporary reversible suppression of endocrine and germinative testicular function, would affect the testicular expression of antioxidant enzymes compared to untreated adult and prepubertal dogs. The goal of this study was to investigate and compare gene (by qPCR, in whole-tissue homogenates) and protein expression (by immunohistochemistry) of superoxide dismutase (SOD1, SOD2), catalase (CAT), glutathione peroxidase (GPx1), and glutathione disulfide reductase (GSR) in the testes of untreated adult (CON, n = 7), prepubertal (PRE, n = 8), and deslorelin-treated (DES, n = 5, 16 weeks after implantation) dogs. We found that in DES dogs, the gene expression of SOD1 was significantly (p < 0.05) lower and GPx1 was higher than in CON, and SOD2 was higher than in PRE. Expression of all, except for the SOD2 mRNA, differed between the CON and PRE dogs. Immunohistochemistry showed distinct cell-specific localization and expression patterns for the antioxidant enzymes in each experimental group. Additionally, in the CON animals, cell-specific SOD1, CAT, and GSR expression was dependent on the stage of the seminiferous epithelium cycle. These findings confirm that members of the antioxidant enzyme system are present in normal adult and prepubertal testis as well as in the deslorelin-treated downregulated adult canine testis, and that this local antioxidant system protects developing germ cells and somatic cells from oxidative damage. Different expression patterns of antioxidant enzymes in various germ cell populations and stages of the seminiferous epithelium cycle may indicate differences in their susceptibility to oxidative stress depending on their developmental and maturation stage. The continued presence of the antioxidant enzymes in the testis of DES dogs offers protection to spermatogonia as well as Sertoli and Leydig cells from oxidative stress during temporary infertility, potentially contributing to ensure the reversibility of suppression and the return of normal spermatogenesis and steroidogenesis after the end of deslorelin treatment.