Hematological effects of glyphosate in mice revealed by traditional toxicology and transcriptome sequencing

Transcriptomic implications of low herbicide concentrations in hepatic cells: Insights into the individual and combined effects of 2,4-D, glyphosate, and AMPA

Glyphosate and 2,4-D are among the most widely used herbicides globally, leading to environmental presence, food contamination, and human contact. Investigations based on current toxicological limits or populational-based herbicide exposures are warranted, and in vitro bioassays provide useful tools for toxicological screening. Thus, this study evaluated the transcriptomic implications of non-cytotoxic exposures to glyphosate, its metabolite aminomethylphosphonic acid (AMPA), or 2,4-D - or to their mixes - on hepatic cells. The half maximal effective concentration (IC50) of each herbicide was calculated (cell viability) in human hepatic C3A cells and 1000-fold lower concentrations were used for transcriptomic analysis (RNA-Seq) after 48 h exposure, resembling current toxicological limits and considering herbicide water levels (glyphosate: 0.95 µg/mL; AMPA: 3.7 µg/mL; 2,4-D: 0.56 µg/mL). Glyphosate exposure enriched MAPK-related biological processes (upregulated TNF, FOS, IGF1, and PDGFB), and downregulated genes associated with lipid metabolism (CD36 and PPARA). Many AMPA exposure-related differentially expressed genes (DEGs, such as PFKFB3, HK2, and ALDOA) were associated with glucose metabolic pathways. Glyphosate and its metabolite yielded a common molecular signature, as illustrated by principal component analysis and the function of 212 shared DEGs. The exposure to 2,4-D was associated with the JNK cascade and the solute carrier family annotations. The herbicide mixtures had a discrete effect on enhancing the impact of individual herbicides, although important epithelial-mesenchymal transition genes were exclusively modified by the mixes (COL11A2, LOXL3, SNAI1). Altogether, our data reveals new perspectives on the short-term molecular effects of herbicide exposure in liver cells, emphasizing potential avenues for further exploration.

Glyphosate exposure exacerbates neuroinflammation and Alzheimer's disease-like pathology despite a 6-month recovery period in mice

BACKGROUND

Glyphosate use in the United States (US) has increased each year since the introduction of glyphosate-tolerant crops in 1996, yet little is known about its effects on the brain. We recently found that C57BL/6J mice dosed with glyphosate for 14 days showed glyphosate and its major metabolite aminomethylphosphonic acid present in brain tissue, with corresponding increases in pro-inflammatory cytokine tumor necrosis factor-⍺ (TNF-⍺) in the brain and peripheral blood plasma. Since TNF-⍺ is elevated in neurodegenerative disorders such as Alzheimer's Disease (AD), in this study, we asked whether glyphosate exposure serves as an accelerant of AD pathogenesis. Additionally, whether glyphosate and aminomethylphosphonic acid remain in the brain after a recovery period has yet to be examined.

METHODS

We hypothesized that glyphosate exposure would induce neuroinflammation in control mice, while exacerbating neuroinflammation in AD mice, causing elevated Amyloid-β and tau pathology and worsening spatial cognition after recovery. We dosed 4.5-month-old 3xTg-AD and non-transgenic (NonTg) control mice with either 0, 50 or 500 mg/kg of glyphosate daily for 13 weeks followed by a 6-month recovery period.

RESULTS

We found that aminomethylphosphonic acid was detectable in the brains of 3xTg-AD and NonTg glyphosate-dosed mice despite the 6-month recovery. Glyphosate-dosed 3xTg-AD mice showed reduced survival, increased thigmotaxia in the Morris water maze, significant increases in the beta secretase enzyme (BACE-1) of amyloidogenic processing, amyloid-β (Aβ) 42 insoluble fractions, Aβ 42 plaque load and plaque size, and phosphorylated tau (pTau) at epitopes Threonine 181, Serine 396, and AT8 (Serine 202, Threonine 205). Notably, we found increased pro- and anti-inflammatory cytokines and chemokines persisting in both 3xTg-AD and NonTg brain tissue and in 3xTg-AD peripheral blood plasma.

CONCLUSION

Taken together, our results are the first to demonstrate that despite an extended recovery period, exposure to glyphosate elicits long-lasting pathological consequences. As glyphosate use continues to rise, more research is needed to elucidate the impact of this herbicide and its metabolites on the human brain, and their potential to contribute to dysfunctions observed in neurodegenerative diseases.

Clarification of the molecular mechanisms underlying glyphosate-induced major depressive disorder: a network toxicology approach

Major depressive disorder (MDD) is predicted to become the second most common cause of disability in the near future. Exposure to glyphosate (Gly)-based herbicides has been linked to the onset of MDD. However, the underlying mechanisms remain unclear. The aim of this study was to investigate the potential molecular mechanisms of MDD induced by Gly using network toxicology approach. The MDD dataset GSE76826 from the Gene Expression Omnibus database was referenced to identify differentially expressed genes (DEGs) in peripheral blood leukocytes of MDD patients and controls. The potential intersection targets of Gly-induced MDD were screened by network toxicology. The intersection targets were used for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis and to construct protein-protein interaction networks. The binding potentials of hub targets with Gly were validated by molecular docking. In total, 1216 DEGs associated with Gly-induced MDD were identified. Subsequent network pharmacology further refined the search to 43 targets. GO and KEGG enrichment analyses revealed multiple signaling pathways involved in GLY-induced MDD. Six potential core targets (CD40, FOXO3, FOS, IL6, TP53, and VEGFA) were identified. Finally, molecular docking demonstrated that Gly exhibited strong binding affinity to the core targets. The results of this study identified potential molecular mechanisms underlying Gly induced MDD and provided new insights for prevention and treatment.

Occupational Exposure to Pesticides Affects Pivotal Immunologic Anti-Tumor Responses in Breast Cancer Women from the Intermediate Risk of Recurrence and Death

Simple Summary

This study presents information regarding the immunological changes induced by pesticide exposure in patients diagnosed with breast cancer occupationally exposed to pesticides. Such changes are helpful to understand tumor behavior under pesticide exposure and can be beneficial to re-stratify breast cancer patients occupationally exposed concerning their risk of disease recurrence and death.

Abstract

Breast cancer risk stratification is a strategy based using on clinical parameters to predict patients’ risk of recurrence or death, categorized as low, intermediate, or high risk. Both low and high risk are based on well-defined clinical parameters. However, the intermediate risk depends on more malleable parameters. It means an increased possibility for either suboptimal treatment, leading to disease recurrence, or systemic damage due to drug overload toxicity. Therefore, identifying new factors that help to characterize better the intermediate-risk stratification, such as environmental exposures, is necessary. For this purpose, we evaluated the impact of occupational exposure to pesticides on the systemic profile of cytokines (IL-12, IL-4, IL-17A, and TNF-α) and oxidative stress (hydroperoxides, total antioxidants, and nitric oxide metabolites), as well as TGF-β1, CTLA-4, CD8, and CD4 expression, investigated in tumor cells. Occupational exposure to pesticides decreased the levels of IL-12 and significantly increased the expression of TGF-β1 and CTLA-4 in the immune infiltrate. Nevertheless, we observed a decrease in CTLA-4 in tumor samples and CD8 in infiltrating cells of intermediate overweight or obese patients with at least one metastatic lymph node at the diagnosis. These findings indicate that occupational exposure to pesticides changes the molecular behavior of disease and should be considered for intermediate-risk stratification assessment in breast cancer patients.