Toxicity mechanism of peri-implantation pesticide beta-cypermethrin exposure on endometrial remodeling in early pregnant mice

Parental exposure to Cypermethrin causes intergenerational toxicity in zebrafish offspring

Cypermethrin (CYP), a synthetic pyrethroid pesticide, has been detected in agriculture and aquaculture. However, there is limited knowledge about the transgenerational impacts. This study aimed to investigate the developmental toxicity of CYP on F1 larvae offspring of adult zebrafish exposed to various CYP concentrations (5, 10, and 20 μg/L) for 28 days. The results indicated that CYP accumulated in parental zebrafish, and CYP was below the limit of quantification in offspring. Paternal exposure impacted the hatching rate and heart rate of the F1 generation. Furthermore, CYP significantly impacted the development of swim bladders in progeny and dysregulated the genes relevant to swim bladder development. The neutrophil migrated to the swim bladder. The mRNA levels of the inflammatory factors were also significantly elevated. According to network toxicology, PI3-AKT may be the signaling pathway for CYP-influenced bladder development. Subsequent molecular docking and Western blot analysis showed CYP affected the PI3-AKT signaling pathway. Notably, MK-2206, a specific Akt inhibitor, rescued the CYP-induced damage of swim bladder development in offspring. The present study highlights the potential risks of CYP on the development of offspring and lasting impact in aquatic environments.

Effect of beta-cypermethrin on the reproductive capacity of female mice in advanced age

The aim of the present study was to investigate whether exposure to pesticides beta-cypermethrin (β-CYP) harms the reproductive capacity of advanced-age female mice. The results evidenced that peri-implantation β-CYP exposure significantly reduced the number of fetuses per advanced-age female in the first litter, and the number and weight of implantation sites. The levels of decidualization markers were significantly reduced in β-CYP-administered advanced-age mice. Lower expression of Pcna, Cdk6, Foxo1, Ki67, and p62 protein and mRNA was found in the decidua of β-CYP-treated advanced-age mice. The levels of Bax, cleaved caspase-3, Lc3a/b, Atg, mTOR, and p-mTOR protein, and the ratio of p-mTOR/mTOR protein expression were clearly downregulated by peri-implantation β-CYP exposure. These results indicated that peri-implantation β-CYP exposure may elevate the decline in reproductive capacity of early pregnant mice in advanced age.

Pyridaben impaired cell cycle progression through perturbation of calcium homeostasis and PI3K/Akt pathway in zebrafish hepatocytes

Environmental pollution caused by pesticides is a growing concern. Pyridaben, a widely used organochlorine insecticide, is a representative water pollutant. Owing to its extensive usage, it has been detected in various aquatic ecosystems, including rivers and oceans. Pyridaben is highly toxic to aquatic organisms; however, the mechanism of its toxicity in the liver, which is important in toxicant metabolism, has not been studied. Therefore, we employed zebrafish and its well-characterized liver cell line, ZFL to assess pyridaben hepatotoxicity and explore its potential mechanisms of action. Pyridaben led to reduction of the liver size and fluorescence intensity of dsRed-labeled Tg (fabp10a:dsRed) zebrafish. It reduced the viability and proliferation of ZFL cells in vitro by inducing apoptosis and cell cycle arrest. These changes might be primarily linked to uncontrolled intracellular calcium flow in ZFL cells exposed to pyridaben. Additionally, it also downregulates the PI3K/Akt signaling cascade, leading to the inactivation of Gsk3β and nuclear translocation of β-catenin. Taken together, our findings suggest that pyridaben could have hepatotoxic effects on aquatic organisms. This study is the first to provide insight into the hepatotoxic mechanism of pyridaben using both in vivo and in vitro models.