Action of the insecticide cyfluthrin on Ca2+ signal transduction and cytotoxicity in human osteosarcoma cells

Effects of Cyfluthrin Exposure on Neurobehaviour, Hippocampal Tissue and Synaptic Plasticity in Wistar Rats

This experiment was conducted to study the effects of Cyfluthrin (Cy) exposure on neurobehaviour, hippocampal tissue and synaptic plasticity in Wistar rats. First, it was found that high-dose Cy exposure could cause nerve injury, resulting in symptoms such as deficits in learning and memory ability, spatial exploration and autonomic motor function. Moreover, it was found that medium- and high-dose Cy exposure could cause an abnormal release of the neurotransmitter Glu. Second, brain tissue pathology showed that the middle and high doses of Cy caused tissue deformation, reduced the number of hippocampal puramidal cells, caused a disorder of these cells, decreased the number of Nissl bodies, and caused pyknosis of the hippocampal cell nuclear membrane and serious damage to organelles, indicating that exposure to these doses of Cy may cause hippocampal tissue damage in rats. Third, as the exposure dose increased, morphological changes in hippocampal synapses, including blurred synaptic spaces, a decreased number of synaptic vesicles and a decreased number of synapses, became more obvious. Moreover, the expression levels of the key synaptic proteins PSD-95 and SYP also decreased in a dose-dependent manner, indicating obvious synaptic damage. Finally, the study found that medium and high doses of Cy could upregulate the expression of A2AR in the hippocampus and that the expression levels of inflammatory factors and apoptosis-related proteins increased in a dose-dependent manner. Moreover, the expression of A2AR mRNA was correlated with neurobehavioural indicators and the levels of inflammatory factors, synaptic plasticity-related factors and apoptosis-related factors, suggesting that Cy may cause nerve damage in rats and that this effect is closely related to A2AR.

The Role of G3BP1 Gene Mediates P38 MAPK/JNK Pathway in Testicular Spermatogenic Dysfunction Caused by Cyfluthrin

In recent years, male infertility has received global attention and seriously affected the quality of human fertility, and pyrethroids (type II pyrethroids), as recognized environmental endocrine disruptors, may threaten male reproductive health. Therefore, in this study, we established an in vivo model for the development of testicular and germ cell toxicity induced by cyfluthrin and explored the role and mechanism of the G3BP1 gene-mediated P38 MAPK/JNK pathway in testicular and germ cell damage caused by cyfluthrin to find early and sensitive indicators and new therapeutic targets for the development of testicular damage. Firstly, 40 male Wistar rats (about 260 g) were divided into a control group (corn oil), low dose group (6.25 mg/kg), middle dose group (12.5 mg/kg) and high dose group (25 mg/kg). The rats were anesthetized and executed after 28 days of poisoning on alternate days. Then, HE staining, transmission electron microscopy, ELISA, q-PCR, Western blot, immunohistochemistry, double-immunofluorescence and TUNEL were used to observe the pathology, androgen levels, oxidative damage and altered expression of the key factors of the G3BP1 and MAPK pathways in rat testes. The results showed that, compared with the control group, the testicular tissue and spermatocytes were superficially damaged with an increasing dose of cyfluthrin; furthermore, it could interfere with the normal secretion of the hypothalamic-pituitary-gonadal axis (serum GnRH, FSH, T and LH levels) and cause hypergonadal dysfunction. A dose-dependent increase in MDA and a dose-dependent decrease in T-AOC indicated that the oxidative-antioxidative homeostatic balance was disrupted. The Western blot and qPCR analysis revealed that G3BP1, p-JNK1/2/3, P38 MAPK, p-ERK, COX1 and COX4 proteins and mRNA expression were decreased, and p-JNK1/2/3, p-P38MAPK, caspase 3/8/9 proteins and mRNA expression were significantly increased. The double-immunofluorescence and immunohistochemistry results showed that the protein expression of G3BP1 decreased with an increasing dose of staining, while the expression of JNK1/2/3 and P38 MAPK were increased significantly. The positive expressions of G3BP1 were mainly located in the testicular germinal epithelium and germ cell layer, and the positive expressions of JNK1/2/3 were mainly located in the testicular germinal epithelium and sperm cells, while the positive expressions of P38 MAPK were located in all levels of the germ cells and spermatozoa. Our results demonstrated that exposure to cyfluthrin caused testicular and spermatocyte damage in rats, which could cause pathomorphology, altered androgen levels and a decreased antioxidant capacity. When the intracellular antioxidant capacity was impaired, G3BP1 expression and activity were inhibited, causing activation of the P38 MAPK/JNK pathway and activation of the intracellular apoptotic pathway, which, in turn, led to germ cell apoptosis.

The role of stimulator of interferon genes-mediated AMPK/mTOR/P70S6K autophagy pathway in cyfluthrin-induced testicular injury

Cyfluthrin is widely used in the field of sanitary pest control by its wide insecticidal spectrum, high efficiency and low toxicity, low residue, and good biodegradability. But, as a double-edged sword, a large amount of cyfluthrin remains are still in the environment. The residual cyfluthrin is absorbed into the food chain through vegetation and then poses a risk to soil organisms and human health. Several studies have suggested that cyfluthrin is one of the main factors causing testicular damage, but the mechanism remains unclear. In this study, we established in vivo and in vitro models of testicular injury in rats and GC-2 cells exposed to cyfluthrin to explore whether stimulator of interferon genes (STING) gene mediates the regulation of AMPK/mTOR/p70S6K autophagy pathway, which lays a foundation for further study of the mechanism of testicular injury induced by cyfluthrin. The results showed that the activity of super oxide dismutase in testis decreased and the activity of malonic dialdehyde increased with the increase of concentration in vivo and in vitro. At the same time, the levels of mitochondrial damage and inflammation in the testis also increased, which further activated autophagy. In this process, the increased level of inflammation is related to the increased expression of STING gene, and AMPK/mTOR/p70S6K autophagy pathway is also involved. To sum up, cyfluthrin has certain reproductive toxicity, and long-term exposure can induce testicular cell damage. STING gene can participate in cyfluthrin-induced testicular injury through AMPK/mTOR/P70S6K autophagy pathway.