Endothelial Progenitor Cells for Assessing Toxicological Response Variability in Humans

DESCRIPTION provided by applicant Toxicological risk assessment lacks direct estimation of the magnitude and variability of human responses to environmental toxicants Specifically there is very little data on the effects of low dose toxicants on human developmental processes including cellular differentiation That is because the current basis of toxicological assessment animals and immortalized cell lines cannot adequately model the impact of low level toxicant exposure on human populations An alternative detection platform should enable incorporation of human variability in screening of a large number of toxicants in a high throughput manner To establish such a platform we propose using human donor specific cells that can be a isolated in a non invasive manner b easily expanded in culture and c cryopreserved without loss of viability Our preliminary data suggest that human endothelial progenitor cells or endothelial colony forming cells ECFCs a population of CD CD pluripotent cells found in circulating blood would fulfill these requirements ECFCs are highly proliferative in vitro and ca differentiate into mature endothelial cells ECs The overall goal of this research is to evaluate the effect of chemical toxicants on viability proliferation and differentiation of ECFCs derived from different individuals Prior to our recent and successful completion of a Phase I program we established cell culture parameters for ECFCs using a proprietary cell growth media supplement and completed initial toxicological risk assessment studies using low dose ionizing radiation LDIR These studies confirmed the utility of ECFCs in toxicological risk assessment screening as well as their ability to broadly represent varying responses expected in human populations Phase I studies successfully expanded these findings by performing ECFC toxicology assays using Bisphenol A BPA perfluorooctanoic acid PFOA and cadmium Cd ECFCs were found to be sensitive to BPA and Cd and less sensitive to PFOA exhibiting donor specific variability in proliferation rates BPA and Cd also induced reactive oxygen species ROS production in a donor specific manner ECFCs were shown to experience oxidative stress and cell cycle arrest after exposure to toxicants Elevated ROS production was shown to correlate with cell death after longer incubation times with toxicants We found that the toxicants we analyzed also affected expression of endothelial specific cell markers at a protein level in a newly developed differentiation assay Phase II will focus on the continued development of this screening platform toward a validated quantitative high content imaging based screen Commercialization of the platform as a service will also be pursued as well as the production of kits for ECFC culture and subsequent toxicological analysis Finally the screen will be expanded to include toxicant induced effects on ECFC differentiation into mature endothelial cells PUBLIC HEALTH RELEVANCE Toxicological assays currently rely on a range of cell lines and in vivo models as well as assays for viability and proliferation Here employing a primary human cell type endothelial colony forming cells ECFCs Brite Bio and Creative Scientist have collaborated to develop a quantitative high content imaging based platform not only suited to environmental agent induced cell death but also differentiation disruption Data derived from this screen is likely to be incorporated into toxicology forecasting algorithms providing novel insights into differentiation disruption in a cell type critical to vascular development and maintenance