Prenatal exposure to atrazine induces cryptorchidism and hypospadias in F1 male mouse offspring

The adverse role of endocrine disrupting chemicals in the reproductive system

Reproductive system diseases pose prominent threats to human physical and mental well-being. Besides being influenced by genetic material regulation and changes in lifestyle, the occurrence of these diseases is closely connected to exposure to harmful substances in the environment. Endocrine disrupting chemicals (EDCs), characterized by hormone-like effects, have a wide range of influences on the reproductive system. EDCs are ubiquitous in the natural environment and are present in a wide range of industrial and everyday products. Currently, thousands of chemicals have been reported to exhibit endocrine effects, and this number is likely to increase as the testing for potential EDCs has not been consistently required, and obtaining data has been limited, partly due to the long latency of many diseases. The ability to avoid exposure to EDCs, especially those of artificially synthesized origin, is increasingly challenging. While EDCs can be divided into persistent and non-persistent depending on their degree of degradation, due to the recent uptick in research studies in this area, we have chosen to focus on the research pertaining to the detrimental effects on reproductive health of exposure to several EDCs that are widely encountered in daily life over the past six years, specifically bisphenol A (BPA), phthalates (PAEs), polychlorinated biphenyls (PCBs), parabens, pesticides, heavy metals, and so on. By focusing on the impact of EDCs on the hypothalamic-pituitary-gonadal (HPG) axis, which leads to the occurrence and development of reproductive system diseases, this review aims to provide new insights into the molecular mechanisms of EDCs' damage to human health and to encourage further in-depth research to clarify the potentially harmful effects of EDC exposure through various other mechanisms. Ultimately, it offers a scientific basis to enhance EDCs risk management, an endeavor of significant scientific and societal importance for safeguarding reproductive health.

Atrazine Toxicity: The Possible Role of Natural Products for Effective Treatment

There are various herbicides which were used in the agriculture industry. Atrazine (ATZ) is a chlorinated triazine herbicide that consists of a ring structure, known as the triazine ring, along with a chlorine atom and five nitrogen atoms. ATZ is a water-soluble herbicide, which makes it capable of easily infiltrating into majority of the aquatic ecosystems. There are reports of toxic effects of ATZ on different systems of the body but, unfortunately, majority of these scientific reports were documented in animals. The herbicide was reported to enter the body through various routes. The toxicity of the herbicide can cause deleterious effects on the respiratory, reproductive, endocrine, central nervous system, gastrointestinal, and urinary systems of the human body. Alarmingly, few studies in industrial workers showed ATZ exposure leading to cancer. We embarked on the present review to discuss the mechanism of action of ATZ toxicity for which there is no specific antidote or drug. Evidence-based published literature on the effective use of natural products such as lycopene, curcumin, Panax ginseng, Spirulina platensis, Fucoidans, vitamin C, soyabeans, quercetin, L-carnitine, Telfairia occidentalis, vitamin E, Garcinia kola, melatonin, selenium, Isatis indigotica, polyphenols, Acacia nilotica, and Zingiber officinale were discussed in detail. In the absence of any particular allopathic drug, the present review may open the doors for future drug design involving the natural products and their active compounds.

Prolonged exposure to the herbicide atrazine promotes kidney fibrosis by activating Wnt/β-catenin signaling in rats

Exposure to atrazine (ATR), a widely-used herbicide, is a potential harmful to human health due to its long-term environmental persistence and bioaccumulation. The effects of chronic exposure to ATR on renal function in rats were evaluated in this research. Female Sprague-Dawley rats at 4 weeks of age were treated with different concentrations of ATR for 6 months. No significant differences  in terms of renal functions were observed after ATR treatment. In histopathological examination of the kidney, Hematoxylin-Eosin staining indicated the development of degenerative changes in a dose-dependent manner. The results revealed that ATR exposure leads to renal fibrosis and that activation of the Wnt/β-catenin pathway plays a potential role in ATR-related renal fibrosis. Levels of transforming growth factor (TGF)-β and TGF-β1 levels and the reactive oxygen species were significantly upregulated after ATR treatment. In conclusion, long-term exposure to ATR could cause kidney fibrosis, which is the result of epithelial-mesenchymal transition caused by inflammation and oxidative stress.

Current perspectives in hypospadias research: A scoping review of articles published in 2021 (Review)

Hundreds of papers are written about hypospadias every year referring to all aspects of the pathology, being one of the most common congenital malformations. The present study conducted a scoping review of articles published in 2021 to present the main issues and summarize current perspectives and achievements in the field. It searched for the keyword 'hypospadias' in the three most popular databases (PubMed, Scopus and Web of Science). After the analysis of the publications, they were categorized into different domains. The present review was performed respecting the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA ScR) guidelines. A total of 284 articles were included. These were published in 142 different journals. The most accessed was the Journal of Paediatric Urology with 54 articles. The main identified domains were related to surgical techniques, postoperative care, complications, anesthesia, anatomical factors, genetics, environmental factors, endocrinology, associated malformations, questionnaires and recommendations, management, biological materials, animal models, retrospective studies of centers, social media, bibliometrics, small gestational age, neoplasm, or fertility. Promising modifications of existing surgical techniques were presented with improved outcomes for both the proximal and distal types of hypospadias. Relevant anatomical and etiological, and also genetic factors were clarified. Aspects of the peri- and postoperative management referring to the antibiotherapy, analgesia, dressing techniques, and the future use of novel bioengineering agents to prevent, reduce or treat the occurring complications were discussed.

Impact of Chronic Multi-Generational Exposure to an Environmentally Relevant Atrazine Concentration on Testicular Development and Function in Mice

A common herbicide, atrazine, is associated with poor health. Atrazine acts as an endocrine disruptor at supra-environmental levels. Little research, however, has been conducted regarding chronic exposure to environmental atrazine concentrations across generations. This study utilized comprehensive endpoint measures to investigate the effects of chronic exposure to a conservative atrazine concentration (0.02 ng/mL), measured in Australian waterways, on male mice fertility across two generations. Mice were exposed through the maternal line, from the pre-conception period and through the F1 and F2 generations until three or six months of age. Atrazine did not impact sperm function, testicular morphology nor germ cell parameters but did alter the expression of steroidogenic genes in the F1, down-regulating the expression of Cyp17a1 (Cytochrome P450 family 17, subfamily A member 1; p = 0.0008) and Ddx4 (DEAD-box helicase 4; p = 0.007), and up-regulating the expression of Star (Steroidogenic acute regulatory protein; p = 0.017). In the F2, atrazine induced up-regulation in the expression of Star (p = 0.016). The current study demonstrates that chronic exposure to an environmentally relevant atrazine concentration perturbs testicular steroid-associated gene expression that varies across generations. Future studies through the paternal and combined parental lineages should be undertaken to further elucidate the multigenerational effects of atrazine on male fertility.

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

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

Exposure to Atrazine through gestation and lactation period led to impaired sexual maturation and subfertility in F1 male rats with congenital deformities in F2 progeny

Several scientific reports suggest perturbed reproductive and developmental defects associated with environmental exposure to Atrazine (ATR). ATR has been associated with altered endocrine and reproductive functioning in-vivo exposed during the critical window of development. Thus, the present study investigates the effect of ATR exposure on F1-F2 male progeny exposed through gestation and lactation. F0 dams administered with ATR at doses 2, 10, 70, and 100 mg/kg b. wt/day from gestation day 6 to postnatal day 21. The F1 male rats were monitored for sexual maturation and subjected to fertility assessment on PND75. Delayed testicular descent was observed in 10, 70, and 100 mg/kg b. wt/day ATR dose with significantly lower serum testosterone, sperm count, and motility with testicular defects in F1 male. Expression of Androgen receptor (AR), Estrogen receptors (ER α and ER β), StAR, Aromatase, and INSL-3 were upregulated at all doses indicating estrogenic/anti-androgenic activity of ATR. Fertility assessment revealed subfertility in F1 males with high (%) pre- and post-implantation loss at 10, 70, and 100 mg/kg b. wt/day dose as compared to control. Further, F2 fetuses exhibited congenital disabilities viz. decreased weight, crown-rump length, and anogenital distance with several other morphological deformities. To conclude, ATR exerted estrogenic and/or anti-androgenic activity with fetotoxic effects through the male germline.

Prenatal exposure to atrazine induces cryptorchidism and hypospadias in F1 male mouse offspring

The main objective of the present study was to determine whether prenatal exposure to atrazine could affect testicle descent and penile masculinization. Atrazine has been demonstrated with a variety of endocrine disrupting activities and reproductive toxicities. However, the effects of prenatal atrazine exposure on male offspring's genital malformation, such as hypospadias and cryptorchidism, remain poorly understood. In this study, pregnant ICR mice were gavaged from gestational day 12.5-16.5 with different doses of atrazine. Although no sign of systemic toxicity was observed in F1 male pups, prenatal exposure to 100 mg/kg/day atrazine affected penile morphology, urethral meatus position and descent of testis, and reduced anogenital distance and penile size in postnatal day 21 F1 male pups. The comparative study with an androgen receptor (AR) antagonist vinclozolin suggested that these effects of atrazine on male genital development may not be through antagonism of AR. The results also revealed that atrazine exposure significantly reduced maternal serum testosterone levels, decreased AR nuclear translocation, and altered the expression levels of developmental gene networks in developing penis of mice. Atrazine exposure also affected the expression of insulin-like 3 (Insl3) and steroidogenic gene expression in developing reproductive tract. Therefore, our data indicate that prenatal atrazine exposure can induce hypospadias in F1 mice, likely through disruption of testosterone production, decreasing genomic androgen action, and then altering expression of developmental genes during sexual differentiation. Our data also suggest that prenatal atrazine exposure can induce cryptorchidism in F1 mice, possibly through down regulation of Insl3.