Development of a high-throughput screening assay for chemical effects on proliferation and viability of immortalized human neural progenitor cells

There is considerable public concern that the majority of commercial chemicals have not been evaluated for their potential to cause developmental neurotoxicity. Although several chemicals are assessed annually under the current developmental neurotoxicity guidelines, time, resource, and animal constraints prevent testing of large numbers of chemicals using this approach. Thus, incentive is mounting to develop in vitro methods to screen chemicals for their potential to harm the developing human nervous system. As an initial step toward this end, the present studies evaluated an automated, high-throughput method for screening chemical effects on proliferation and viability using ReNcell CX cells, a human neural progenitor cell (hNPC) line. ReNcell CX cells doubled in similar to 36 h and expressed the neural progenitor markers nestin and SOX2. High-throughput assays for cell proliferation (5-bromo-2'-deoxyuridine incorporation) and viability (propidium iodide exclusion) were optimized and tested using known antiproliferative compounds. The utility of this in vitro screen was evaluated further using a set of compounds containing eight known to cause developmental neurotoxicity and eight presumably nontoxic compounds. Six out of eight developmental neurotoxicants significantly inhibited ReNcell CX cell proliferation and/or viability, whereas two out of eight nontoxic chemicals caused only minimal effects. These results demonstrate that chemical effects on cell proliferation and viability can be assessed via high-throughput methods using hNPCs. Further development of this approach as part of a strategy to screen compounds for potential effects on nervous system development is warranted.