RESUMEN
Organophosphates, a widely used group of pesticides, can cause severe toxicity in human beings and other non-target organisms. Liver, being the primary site for xenobiotic metabolism, is extremely vulnerable to xenobiotic-induced toxicity. Considering the numerous vital functions performed by the liver, including xenobiotic detoxification, protecting this organ from the ubiquitous pesticides in our food and environment is essential for maintaining homeostasis. In this study, we have investigated the impact of the organophosphate pesticide, Chlorpyrifos (CPF), on zebrafish liver at a concentration (300 µg/L) which is environmentally realistic. We have also demonstrated the role of dietary supplementation of α-tocopherol or Vitamin E (Vit E) (500 mg/kg feed) in mitigating pesticide-induced liver toxicity. Mechanistically, we showed that Vit E resulted in significant elevation of the Nrf2 and its downstream antioxidant enzyme activities and gene expressions, especially that of GST and GPx, resulting in reduction of CPF-induced intracellular lipid ROS and hepatic LPO. Further interrogation, such as analysis of GSH: GSSG ratio, intracellular iron concentration, iron metabolizing genes, mitochondrial dysfunction etc. revealed that CPF induces ferroptosis which can be reversed by Vit E supplementation. Ultimately, reduced concentration of CPF in zebrafish serum and flesh highlighted the role of Vit E in ameliorating CPF toxicity.
Asunto(s)
Cloropirifos , Ferroptosis , Glutatión , Hepatocitos , Hierro , Peroxidación de Lípido , Vitamina E , Pez Cebra , Animales , Cloropirifos/toxicidad , Vitamina E/farmacología , Vitamina E/metabolismo , Hierro/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Ferroptosis/efectos de los fármacos , Glutatión/metabolismo , Hígado/efectos de los fármacos , Hígado/metabolismo , Antioxidantes/metabolismo , Factor 2 Relacionado con NF-E2/metabolismoRESUMEN
Cytotoxic chemotherapy dominates the field of cancer treatment. Consequently, anticancer phytochemicals are largely screened on the basis of their cytotoxicity towards cancer cells which are achieved at higher doses, leading to various toxic side effects. Some phytochemicals also showed pro-carcinogenic effects at certain doses. The concept of hormesis has taught us to look into biphasic responses of phytochemicals in a more systematic way. Interestingly, the monoterpenoid alcohol, linalool, also has been reported to display both anti-oxidant and pro-oxidant properties, which prompted us to explore a probable biphasic effect on cancer cells. Cytotoxicity of various concentrations of linalool (0.1-4 mM) was tested on B16F10 murine melanoma cell line, and two sub-lethal concentrations (0.4 and 0.8 mM) were selected for further experiments. 0.4 mM linalool inhibited angiogenesis and metastasis, while 0.8 mM increased them. Similarly, B16F10 cell migration, invasion, and epithelial-mesenchymal transition markers also showed inhibition and induction with lower and higher linalool concentrations, respectively. Chorioallantoic membrane assay, scratch wound assay, and Boyden's chamber were used to analyze angiogenesis and metastasis. Expression of molecular markers such as vascular endothelial growth factor (VEGF) and its receptor phosphorylated VEGF receptor II (p-VEGFRII or p-Flk-1), Hypoxia-inducible factor-1 α (HIF-1α), E-cadherin, and vimentin were detected using Western blot, ELISA, PCR, qPCR, and immunofluorescence. Finally, ChIP assay was performed to evaluate HIF-1α association with VEGF promoter. Interestingly, measurement of intracellular reactive oxygen species at the selected concentrations of linalool using DCFDA in a flow cytometer showed that the phytochemical induced significant amount of ROS at 0.8 mM. This work sheds light on bimodal dose-response relationship exhibited by dietary phytochemicals like linalool, and it should be taken into consideration to elicit a desirable therapeutic effect.
Asunto(s)
Monoterpenos Acíclicos/farmacología , Melanoma Experimental , Neovascularización Patológica , Animales , Embrión de Pollo , Células HEK293 , Humanos , Melanoma Experimental/sangre , Melanoma Experimental/tratamiento farmacológico , Melanoma Experimental/metabolismo , Melanoma Experimental/patología , Ratones , Metástasis de la Neoplasia , Neovascularización Patológica/tratamiento farmacológico , Neovascularización Patológica/metabolismo , Neovascularización Patológica/patologíaRESUMEN
Transforming growth factor ß (TGFß) is a prominent cytokine that promotes tumor progression by activating epithelial-to-mesenchymal transition (EMT). This study indicated that TGFß exerted metastasis by inducing zinc finger E-box binding homeobox 1 (ZEB1) and a long noncoding RNA, LINC00273, expressions in A549 cells. Knocking down LINC00273 diminished TGFß induced ZEB1 expression as well as metastasis. Mechanistically, LINC00273 acted as a molecular sponge of microRNA (miR)-200a-3p which liberate ZEB1 to perform its prometastatic functions. LINC00273 knockdown and miR200a3p mimic transfection of A549 cells were used for validating the link between TGFß and LINC00273 induced metastasis. RNA pulldown and luciferase assay were performed to establish mir200a-3p-LINC00273 interaction. High expressions of LINC00273, TGFß, and ZEB1 with concurrent low miR200a-3p expression had been verified in vivo and in patient samples. Overall, LINC00273 promoted TGFß-induced lung cancer EMT through miR-200a-3p/ZEB1 feedback loop and may serve as a potential target for therapeutic intervention in lung cancer metastasis.