Postnatal exposure to a glyphosate-based herbicide interferes with the development and growth of the mammary gland of pre-pubertal Ewe lambs

Exploring the link: DNA methylation and kidney injury markers in farmers exposed to glyphosate-surfactant herbicides

Glyphosate-surfactant herbicides (GSH), widely used herbicides, have raised concerns about their potential nephrotoxic effects. Despite extensive studies, the safety of GSH remains debatable. This study aimed to determine if occupational exposure to GSH causes detectable changes in renal injury biomarkers-specifically DNA methylation, KIM-1, TIMP2, and IGFBP7-in farmers regularly exposed to these chemicals. Two urine samples, pre-task (0-h) and post-task (24-h), were collected to analyze these biomarkers. No significant immediate changes were observed post-exposure, possibly due to personal protective equipment use. Moderate positive correlations were found between IGFBP7 and KIM-1, and IGFBP7 and TIMP2, suggesting early kidney injury. About 50% of subjects had a biomarker ratio greater than 1, indicating increased levels of IGFBP7, TIMP2, and KIM-1 after GSH exposure. This indicates that farmers who regularly spray GSH are at high risk of exposure, potentially leading to significant renal injury. Further long-term studies are needed to assess the chronic effects and validate these biomarkers for monitoring renal health in populations exposed to glyphosate.

Estrogen promotes autophagy in the mammary epithelial cells of dairy sheep via the CXCL12/CXCR4 axis

Mammary gland development and lactation in dairy sheep are regulated by hormones and autophagy; however, the role of estrogen-mediated autophagy remains unclear. This study determined that estrogen enhances autophagy, promotes CXCR4 and CXCL12 gene expression, and increases the number of autolysosomes in sheep mammary epithelial cells. Co-treatment with a CXCR4 overexpression vector and the small-molecule alternative of CXCL12, NUCC-390, significantly upregulated ATG5 and LC3 gene expression, increased the abundance of the autophagy-associated protein ATG5 and the LC3II/I ratio, and increased the consumption of the autophagy substrate P62. These results suggest that CXCR4 and CXCL12 signaling promotes autophagy in mammary epithelial cells. Conversely, co-treatment with a CXCR4-specific blocker and estrogen inhibited autophagic changes in ATG5, P62, and LC3 levels, reducing the number of autophagosomes and autolysosomes. Overall, this study demonstrated that estrogen promotes autophagy in sheep mammary epithelial cells through the CXCL12/CXCR4 signaling axis, revealing the underlying mechanisms behind estrogen-mediated autophagy.

Pubertal glyphosate-based herbicide exposure aggravates high-fat diet-induced obesity in female mice

Glyphosate-based herbicides (GBH) are the most widely used pesticides globally. Studies have indicated that they may increase the risk of various organic dysfunctions. Herein, we verified whether exposure to GBH during puberty increases the susceptibility of male and female mice to obesity when they are fed a high-fat diet (HFD) in adulthood. From the 4th-7th weeks of age, male and female C57Bl/6 mice received water (CTL group) or 50 mg GBH /kg body weight (BW; GBH group). From the 8th-21st weeks of age, the mice were fed a standard diet or a HFD. It was found that pubertal GBH exposure exacerbated BW gains and hyperphagia induced by HFD, but only in female GBH-HFD mice. These female mice also exhibited high accumulation of perigonadal and subcutaneous fat, as well as reduced lean body mass. Both male and female GBH-HFD displayed hypertrophic white adipocytes. However, only in females, pubertal GBH exposure aggravated HFD-induced fat accumulation in brown adipocytes. Furthermore, GBH increased plasma cortisol levels by 80% in GBH-HFD males, and 180% in GBH-HFD females. In conclusion, pubertal GBH exposure aggravated HFD-induced obesity, particularly in adult female mice. This study provides novel evidence that GBH misprograms lipid metabolism, accelerating the development of obesity when individuals are challenged by a second metabolic stressor, such as an obesogenic diet.

Effects of glyphosate-based herbicides and glyphosate exposure on sex hormones and the reproductive system: From epidemiological evidence to mechanistic insights

Glyphosate-based herbicides (GBHs) containing glyphosate as the active component are extensively used worldwide. Concerns have arisen about their potential risk to human, as glyphosate has been detected in human body fluids. Current controversies surround the endocrine-disrupting properties and transgenerational inheritance of diseases and germline epimutations resulting from exposure to GBHs and glyphosate. This review discusses evidence from in vitro, in vivo, and clinical studies on their impact on sex hormone regulation and reproductive system. Evidence suggests that they act as endocrine-disrupting chemicals, which altering sex hormone levels. Mechanistically, they interfere with hormone signaling pathways by disrupting proteins involved in hormone transport and metabolism. Pathological changes have been observed in male and female reproductive systems, potentially leading to reproductive toxicity. Prenatal exposure may lead to transgenerational inheritance of pathologies and sperm epimutations. However, due to the complexity of glyphosate formulations containing adjuvants identifying higher risk components in environmental exposure becomes challenging.

Mammary Gland Development in Male Rats Perinatally Exposed to Propiconazole, Glyphosate, or their Mixture

This study aimed to assess whether perinatal exposure to propiconazole (PRO), glyphosate (GLY) or their mixture (PROGLY) alters key endocrine pathways and the development of the male rat mammary gland. To this end, pregnant rats were orally exposed to vehicle, PRO, GLY, or a mixture of PRO and GLY from gestation day 9 until weaning. Male offspring were euthanized on postnatal day (PND) 21 and PND60. On PND21, GLY-exposed rats showed reduced mammary epithelial cell proliferation, whereas PRO-exposed ones showed increased ductal p-Erk1/2 expression without histomorphological alterations. On PND60, GLY-exposed rats showed reduced mammary gland area and estrogen receptor alpha expression and increased aromatase expression, whereas PRO-exposed ones showed enhanced lobuloalveolar development and increased lobular hyperplasia. However, PROGLY did not modify any of the endpoints evaluated. In summary, PRO and GLY modified the expression of key molecules and the development of the male mammary gland individually but not together.