The utility of animal models in hiPSC-based studies of autism spectrum disorder: a systematic review

ABSTRACT Introduction Autism spectrum disorder is a highly prevalent and heritable neurodevelopmental condition. To investigate its pathogenesis, genetic and non-genetic animal models have been developed. However, no animal model can fully capture the human-specific characteristics and genetic complexity of autism spectrum disorder. In this context, human induced pluripotent stem cell (hiPSC) derived models have emerged as powerful tools in autism spectrum disorder research, offering the potential to reduce or replace animal experiments. Despite this potential, many hiPSC-based studies still incorporate animal use. Objective To analyze the use of animals in hiPSC-based studies of autism spectrum disorder, with the aim of assessing the necessity of their inclusion and their contribution to our understanding of disease mechanisms. Methods Following the PRISMA guidelines, we searched PubMed, Scopus, and Web of Science for articles published between 2009 and 2024 using the search terms “autism”, “ASD”, and “autism spectrum disorder” combined with “iPSC”, “induced pluripotent stem cells and “organoid*”. Results A total of 207 studies using hiPSCs to investigate Autism spectrum disorder were identified. Of these, 79 studies (38.16%) also involved animals or animal-derived cells. While nearly half of these studies used autism spectrum disorder animal models to explore neurobiological mechanisms of the disorder, the remaining studies employed animals for purposes not directly related to understanding autism spectrum disorder pathophysiology. These included teratoma formation assays to validate hiPSC pluripotency and the extraction of primary astrocytes for co-culture with hiPSC-derived neurons, an approach that may introduce confounding variables. Conclusion Our review highlights the frequent and, in some cases, unnecessary use of animals in hiPSC-based studies of autism spectrum disorder.