Investigations into the Molecular Mechanisms of Trichloroethylene Cardiotoxicity in vivo and in vitro

Abstract

Trichloroethylene (TCE) is among the most common water contaminant in the United States and around the world. It is estimated that between 9% and 34% of all drinking water sources contain some TCE. The EPA set a drinking water standard for TCE at 5 parts per billion (ppb) in 1989, however since this date, many studies have shown TCE is dangerous to the health of adults and unborn children, even at low-level exposures. These studies reveal exposure to TCE can cause multi-organ damage, especially for the kidney, liver, reproductive and development systems. We investigated how TCE can effect embryonic heart development by identifing possible target mechanisms changing after exposure. Acute and chronic exposure to rat cardiomyocytes produced altered calcium flow and significant changes with TCE doses as low as 10ppb. Embryonic carcinoma cells, rat cardiomyocytes and fetal heart tissue all showed global changes in gene expression after low-dose TCE exposure, including critical ion channels that drive calcium flux. High levels of folic acid supplementation in combination with 10ppb TCE exposure in maternal diets caused significant genetic modifications in mRNA expression levels of Day 10 embryonic mouse cardiac tissue. We also found both high and low folate maternal diets leads to similar phenotypic outcomes in embryo development.