Effects of the environmental contaminants terbacil and bromacil in prosteatotic lipid metabolism in hepatic cell culture and correlations with the uracil metabolism and epigenetic process followed by the translational studies in Drosophila melanogaster

Abstract

Nowadays, non-alcoholic fat liver diseases (NAFLD) are considered a serious health problem worldwide. Those diseases are described by an excessive fat storage in the liver caused by several different etiologies, which may progress to more severe clinical conditions. In the world, the policy of using large-scale chemical products result in their accumulation in the environment, which may be toxic. In Brazil, and in different regions of the world, environmental contaminants as the pesticides are used on large scale base, some of them presenting high half-life as the uracil-based-pesticides (terbacil and bromacil). These in turn, accumulate in the environment and, directly or indirectly, affect man and other non-target animals, which collaborates with the establishment and the development of liver diseases. However, studies are required to elucidate mechanisms of action of those environmental contaminants in metabolic processes and in the regulation of cell signaling that lead to the establishment of pathogenesis. These studies may collaborate with biotechnological innovations, by the characterization of molecules to be potentially use as molecular markers to screen the liver disease's progression, for example. In a previous proposal supported by FAPESP, we established models of liver cell cocultures, responsive to chemical agents and able to simulate a pro-steatotic environment. Thus, the present proposal aims to use our cellular model to investigate the mechanistic action of the terbacil and bromacil contaminants in cellular behavior and in the possible effect on the pro-steatotic environment establishment, correlating to the epigenetic mechanisms and pyrimidine biosynthesis. For this, biochemical, cellular and molecular assays will be performed aiming at the construction of a panel of the modulatory effects of the compounds in cellular health. Based on the integration of the results, we aim to identify relevant common molecules in the cellular signaling induced by the two contaminants, potentially correlated to the pro-steatotic metabolism in cells; those molecules will be silenced or overexpressed in cell culture to have their function validate. Next, in attempt to set up the alternative animal model of Drosophila melanogaster as a translational model for the study of liver disease, the effects of environmental contaminants will be investigated in this animal in biochemical, cellular and molecular assays, as described for the cell analysis, to evaluate the parallelism between the models. Combined, the results from the two models (cell culture and fly) will guide genetic modifications to be performed in fruit flies, using the GAL4/UAS binary system to validate the cellular analyses in a systemic manner. (AU)