[Development of alternatives to animal experiments using pluripotent stem cells]

Area of Science:

• Toxicology
• Stem Cell Biology
• Biotechnology

Background:

• Animal testing is crucial for chemical safety assessment but faces ethical challenges and bans, particularly in cosmetics.
• The development of in vitro alternatives is essential due to increasing animal welfare concerns.
• Existing in vitro tests primarily address local toxicity, necessitating alternatives for systemic toxicities like chronic and developmental effects.

Purpose of the Study:

• To develop and validate in vitro alternative methods for assessing chemical toxicity, focusing on developmental and neurotoxicity.
• To utilize pluripotent stem cells, including embryonic stem (ES) and induced pluripotent stem (iPS) cells, for creating these alternative tests.
• To establish reliable methods for predicting systemic toxicity without animal use.

Main Methods:

• Development of luciferase reporter gene assays (ESTs) for developmental toxicity, such as Hand 1-Luc EST (cardiomyocyte differentiation) and Tubb 3- and Reln-Luc ESTs (nerve differentiation).
• Application of high-content imaging for neurite outgrowth evaluation and multi-electrode arrays for neural function assessment in in vitro neurotoxicity testing.
• Differentiation of human ES/iPS cells into retinal tissues for developing in vitro phototoxicity tests using retinal pigment epithelial cells (RPE).

Main Results:

• The combined use of Hand 1-Luc EST and Tubb 3-/Reln-Luc ESTs demonstrated improved prediction of developmental toxicity.
• Established high-content imaging and multi-electrode array methods for robust in vitro neurotoxicity assessment.
• Successfully differentiated retinal tissues from human ES/iPS cells, paving the way for in vitro phototoxicity testing.

Conclusions:

• Pluripotent stem cell-based in vitro assays are promising alternatives to animal testing for developmental and neurotoxicity.
• These novel methods enhance the accuracy and efficiency of chemical safety assessments.
• Further development and validation of these assays will support ethical and scientifically sound chemical safety evaluations.