Atrazine induces penis abnormalities including hypospadias in mice

Effects of Atrazine exposure on human bone marrow-derived mesenchymal stromal cells assessed by combinatorial assay matrix

Introduction

Mesenchymal Stromal/Stem cells (MSCs) are an essential component of the regenerative and immunoregulatory stem cell compartment of the human body and thus of major importance in human physiology. The MSCs elicit their beneficial properties through a multitude of complementary mechanisms, which makes it challenging to assess their phenotype and function in environmental toxicity screening. We here employed the novel combinatorial assays matrix approach/technology to profile the MSC response to the herbicide Atrazine, which is a common environmental xenobiotic, that is in widespread agricultural use in the US and other countries, but banned in the EU. Our here presented approach is representative for screening the impact of environmental xenobiotics and toxins on MSCs as an essential representative component of human physiology and well-being.

Methods

We here employed the combinatorial assay matrix approach, including a panel of well standardized assays, such as flow cytometry, multiplex secretome analysis, and metabolic assays, to define the phenotype and functionality of human-donor-derived primary MSCs exposed to the representative xenobiotic Atrazine. This assay matrix approach is now also endorsed for characterization of cell therapies by leading regulatory agencies, such as FDA and EMA.

Results

Our results show that the exposure to Atrazine modulates the metabolic activity, size, and granularity of MSCs in a dose and time dependent manner. Intriguingly, Atrazine exposure leads to a broad modulation of the MSCs secretome (both upregulation and downmodulation of certain factors) with the identification of Interleukin-8 as the topmost upregulated representative secretory molecule. Interestingly, Atrazine attenuates IFNγ-induced upregulation of MHC-class-II, but not MHC-class-I, and early phosphorylation signals on MSCs. Furthermore, Atrazine exposure attenuates IFNγ responsive secretome of MSCs. Mechanistic knockdown analysis identified that the Atrazine-induced effector molecule Interleukin-8 affects only certain but not all the related angiogenic secretome of MSCs.

Discussion

The here described Combinatorial Assay Matrix Technology identified that Atrazine affects both the innate/resting and cytokine-induced/stimulated assay matrix functionality of human MSCs, as identified through the modulation of selective, but not all effector molecules, thus vouching for the great usefulness of this approach to study the impact of xenobiotics on this important human cellular subset involved in the regenerative healing responses in humans.

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.

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.

Plantain-based diet decreases oxidative stress and inflammatory markers in the testes of rats exposed to atrazine

Exposure to the herbicide atrazine (ATZ) has deleterious effects on male fertility. This fact underscores the need for measures to protect against the detrimental impact of atrazine exposure on male fertility. The study assessed the protective effects of plantain-based diet (PBD) on rat testes exposed to ATZ by exploring oxid-inflammatory homeostasis. The study evaluated the preventive and therapeutic effects of PBD in a two-phased experiment. Male rats were randomized into seven groups for therapeutic model (Control, ATZ only, ATZ recovery, ATZ + 50% PBD, ATZ + 25% PBD, ATZ + 12.5% PBD and ATZ + quercetin-QUE) while the preventive model had ten groups (Control, ATZ, 50% PBD + ATZ, 25% PBD + ATZ, 12.5% PBD + ATZ and QUE + ATZ). The oxidative stress parameters (DNA fragmentation and MDA level), purinergic activity (ATPase), acetylcholine esterase, and inflammatory markers (NO level, MPO activity, and TNF-α) were increased while the Nrf2 levels were decreased by the ATZ treatment. However, the PBD was able to restore the oxido-inflammatory parameters in the rat testes. The chemical fingerprint of the diet revealed that the diets contained 16 bioactive compounds with quercetin being the most prominent compound. Overall, treatment with PBD was able to protect and prevent the toxicity caused by ATZ by modulating the redox and inflammatory status as well as purinergic activity in the rat testes.

Meta-analysis and experimental validation identified atrazine as a toxicant in the male reproductive system

Atrazine (ATZ), as a widely used triazine herbicide, is an environmental endocrine disruptor (EDC) that can cause many health problems. Therefore, we conducted this study based on the evidence of rats and mice to figure out the characteristics of ATZ damage to the reproductive system and further evaluate its health effects on the human. PRISMA's guidelines were followed according to the principles recommended by the Cochrane Handbook for Systematic Review. Health assessment was performed using the OHAT approach. Our new data were obtained from randomized controlled trials in rats designed in accordance with toxicological guidelines. Exposure to ATZ was significantly associated with decreased testosterone production (SMD = - 0.90, 95% CI - 1.27 to - 0.53), and reduced absolute weights of testis (SMD = - 0.41, 95% CI - 0.61 to - 0.22) and other reproductive organs. The damaging effect of sperm quality was also observed clearly, which included reduction of sperm count both in epididymis (SMD = - 2.32, 95% CI - 2.83 to - 1.81) and testis (SMD = - 1.01, 95% CI - 1.37 to - 0.64), decrease in sperm motility (SMD = - 8.86, 95% CI - 10.88 to - 6.83), and increase in sperm abnormality. Subgroup analysis revealed consistency across different species, life stage, and dosage. In addition, we found that ATZ exposure at a daily dose of 120 mg/kg during adolescence could cause decrease in weight gain and histological damage to the testis. The gene expression levels of Nrf2/HO-1 and Bcl-2/caspase signaling pathways in testis tissues were changed significantly. The results of this SR indicated that exposure to ATZ was associated with impairment of male reproductive system in rodents regardless of species, exposure life stage, and dosage. It is believed that ATZ exposure may have similar effects on male reproductive system of human beings. Pathways related to oxidative stress and apoptosis may be the mechanism leading to testicular damage in rats treated with ATZ.

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.

Endocrine disrupting chemicals in the pathogenesis of hypospadias; developmental and toxicological perspectives

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Penis development is regulated by a tight balance of androgens and estrogens.

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EDCs that impact androgen/estrogen balance during development cause hypospadias.

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Cross-disciplinary collaborations are needed to define a mechanistic link.

Hypospadias is a defect in penile urethral closure that occurs in approximately 1/150 live male births in developed nations, making it one of the most common congenital abnormalities worldwide. Alarmingly, the frequency of hypospadias has increased rapidly over recent decades and is continuing to rise. Recent research reviewed herein suggests that the rise in hypospadias rates can be directly linked to our increasing exposure to endocrine disrupting chemicals (EDCs), especially those that affect estrogen and androgen signalling. Understanding the mechanistic links between endocrine disruptors and hypospadias requires toxicologists and developmental biologists to define exposures and biological impacts on penis development. In this review we examine recent insights from toxicological, developmental and epidemiological studies on the hormonal control of normal penis development and describe the rationale and evidence for EDC exposures that impact these pathways to cause hypospadias. Continued collaboration across these fields is imperative to understand the full impact of endocrine disrupting chemicals on the increasing rates of hypospadias.