Non-invasive evaluation of developmental neurotoxicity using hPSCs

Point

The effects of chemicals on cells can only be studied using a cell-based model system, and over an appropriately long evaluation period as the effects of chemicals change over time. It is not enough to measure the endpoint alone.

Overview

Human pluripotent stem cells (hPSCs), such as human embryonic stem cells (hESCs), and human induced pluripotent stem cells (hiPSCs), have high potential as new tools for the in vitro evaluation of developmental neurotoxicity (DNT).An in vitro DNT test using hPSCs has been proposed, and would be in the spirit of "The 3Rs"* principles for the more ethical treatment of animals. Here, we introduce a new assay using live cell imaging technology to accurately monitor cell response to chemicals in vitro.
* The 3Rs
refers to the use of Replacement (use of alternative methods), Reduction (reduction in the number used), and Refinement (reduction of pain) as the basic guiding principles for the more ethical treatment of animals in experiments.
W.M.S. Russell & R.L. Burch (1959): Proposed by The Principles of Humane Experimental Technique.
In the 2005 revision of the Animal Welfare Management Act, the principles of the 3Rs were described in Article 41.

Current

Issue-1
Conventional in vivo toxicity assays using lab animals alone cannot accurately predict the effects on humans.

In most drug development processes, conventional reproductive and developmental toxicity predictions are verified using lab animals. However, the effects of chemicals often differ between humans and other animals, making it difficult to accurately predict toxicity. In vitro assays using hPSCs have been attracting attention in recent years as a potential solution to this problem.

Issue-2
In order to study their effects on reproduction and development, it is necessary to examine the degree to which chemical compounds affect cell differentiation, in addition to conventional cytotoxicity assays.

In considering the effects of chemicals on human development, it is necessary to assess not only cytotoxicity, but also effects on cellular differentiation. Therefore, it is necessary to carefully monitor for differentiation and other effects over a sufficiently long observation period and to record the timing of appearance of the effects.

Solution

The observation of live cells with added chemical over time allows for the effects on differentiation to be accurately detected.Live cell imaging and analysis allows for the effects of chemicals on differentiation to be evaluated over time. It also allows for the evaluation of cytotoxicity, including the timing of the appearance of cytotoxicity indicators.Cell image analysis software Cell Analysis Module

The effect of VPA (0.1-2.4 mM) on the differentiation of hiPSCs into neural stem cells was examined. Morphological evaluation was performed for 69 hours following cell seeding.

Reference

PLoS One. 2013;8(1):e54122
(Results obtained from work consigned by collaboration with NIBIOHN is partially quoted.)