Protein kinase B (Akt) blockade inhibits LH/hCG-mediated 17,20-lyase, but not 17α-hydroxylase activity of Cyp17a1 in mouse Leydig cell steroidogenesis

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.

Reproductive and developmental implications of micro- and nanoplastic internalization: Recent advances and perspectives

A growing body of evidence exhibits the ubiquitous presence and accumulation of micro- and nanoplastics (MNPs) in the air, drinking water, food, and even inside the body, which has raised concerns about their potential impact on reproductive and developmental health. To comprehensively examine the current state of knowledge regarding MNPs-induced reproductive and developmental toxicity, we conducted this systematic review by focusing on the prevalence of MNPs determined in reproductive tissues and their influences on parental reproduction and offspring development. Our findings demonstrate the detection of MNPs in various human reproductive tissues, including semen, placenta, and ovarian follicular fluid, as well as in reproductive tissues of diverse animal species. We show a potential relationship between MNP exposure and increased prevalence of infertility and adverse pregnancy outcomes based on the fact that MNPs exert detrimental effects on reproductive parameters, including sperm quality, ovarian function, and steroidogenesis. In male reproductive systems, MNPs disrupt testicular tissue structure, impair reproductive endocrinology, and reduce sperm quality. In females, MNPs affect ovarian tissue structure and function, interfere with hormone secretion, and impact the endometrium and embryo implantation. Additionally, MNPs cause developmental toxicity in animal models, affecting embryonic development and offspring health, and produce transgenerational effects. Notably, in-depth literature study suggests a crucial role for oxidative stress, inflammation, and epigenetic modification in MNPs-induced toxicity. In conclusion, we integrated systematic knowledge on MNPs-induced reproductive and developmental toxicity, and the systematic finding underscores future study to fully elucidate the risks posed by MNPs to reproductive and developmental health and to inform policy decisions and public health interventions aimed at mitigating their harmful effects.

Prognosis significance and potential association between ALDOA and AKT expression in colorectal cancer

Colorectal cancer (CRC) is one of the most common malignant tumors of the digestive tract and a leading cause of cancer-related death worldwide. Since many CRC patients are diagnosed already in the advanced stage, and traditional chemoradiotherapy is prone to drug resistance, it is important to find new therapeutic targets. In this study, the expression levels of ALDOA and p-AKT were detected in cancer tissues and paired normal tissues, and it was found that they were significantly increased in CRC tissues, and their high expression indicated poor prognosis. Moreover, a positive correlation between the expression of ALDOA and p-AKT was found in CRC tissues and paired normal tissues. In addition, the Kaplan-Meier analysis revealed that the group with both negative of ALDOA/p-AKT expression had longer five-year survival rates compared with the other group. Besides, the group with both high expression of ALDOA/p-AKT had a worse prognosis compared with the other group. Based on the expression of ALDOA and p-AKT in tumor tissues, we can effectively distinguish tumor tissues from normal tissues through cluster analysis. Furthermore, we constructed nomograms to predict 3-year and 5-year overall survival, showing that the expression of ALDOA/p-AKT plays a crucial role in predicting the prognosis of CRC patients. Therefore, ALDOA/p-AKT may act as a crucial role in CRC, which may provide new horizons for targeted therapies for CRC.

Benzo[a]pyrene disrupts LH/hCG-dependent mouse Leydig cell steroidogenesis through receptor/Gαs protein targeting

Steroidogenesis of gonadal cells is tightly regulated by gonadotropins. However, certain polycyclic aromatic hydrocarbons, including Benzo[a]pyrene (BaP), induce reproductive toxicity. Several existing studies have considered higher than environmentally relevant concentrations of BaP on male and female steroidogenesis following long-term exposure. Also, the impact of short-term exposure to BaP on gonadotropin-stimulated cells is understudied. Therefore, we evaluated the effect of 1 nM and 1 µM BaP on luteinizing hormone/choriogonadotropin (LH/hCG)-mediated signalling in two steroidogenic cell models, i.e. the mouse tumor Leydig cell line mLTC1, and the human primary granulosa lutein cells (hGLC) post 8- and 24-h exposure. Cell signalling studies were performed by homogeneous time-resolved fluorescence (HTRF) assay, bioluminescence energy transfer (BRET) and Western blotting, while immunostainings and immunoassays were used for intracellular protein expression and steroidogenesis analyses, respectively. BaP decreased cAMP production in gonadotropin-stimulated mLTC1 interfering with Gαs activation. Therefore, decrease in gonadotropin-mediated CREB phosphorylation in mLTC1 treated with 1 μM BaP was observed, while StAR protein levels in gonadotropin-stimulated mLTC1 cells were unaffected by BaP. Further, BaP decreased LH- and hCG-mediated progesterone production in mLTC1. Contrastingly, BaP failed to mediate any change in cAMP, genes and proteins of steroidogenic machinery and steroidogenesis of gonadotropin-treated hGLC. Our results indicate that short-term exposure to BaP significantly impairs steroidogenic signalling in mLTC1 interfering with Gαs. These findings could have a significant impact on our understanding of the mechanism of reproductive toxicity by endocrine disruptors.