Investigating neurodevelopmental toxicity of perfluoroalkyl acids and their derivatives in human brain organoids models

SUMMARY Per- and polyfluoroalkyl substances and their derivatives (PFAS) are industrial chemicals that are wide- spread in the environment, including blood serum of wildlife and humans. Their pervasiveness and long half-life raises the questions about their toxicity, especially with regards to the effect on the developing fetus. Several studies have demonstrated that these compounds cross the placenta, are found in the umbilical cord blood, and can cause neurodevelopmental abnormalities in the offspring of the exposed mothers, including early pregnancy loss, low birth weight, hyperactivity, decreased head circumference and behavior problems. However, the molecular mechanisms following PFAS exposure, such as dysregulated genes and pathways, especially in the context of human brain development, remain unexplored. Here, we are proposing to use human induced pluripotent stem cell (iPSC) derived models such as neural progenitor cells (NPCs), spheroids and brain cortical organoids, to fill in this knowledge gap. We hypothesize that PFAS impact early brain development by dysregulating transcriptional programs of NPCs that are involved in proliferation, cell cycle and survival. We also hypothesize that these early alterations will have significant impact on the formation of cortical networks. We are proposing the following Specific Aims to test these hypotheses: (1) Investigate dose- dependent impact of PFAS on neural progenitor cell cycle, cell viability and proliferation; (2) Perform genome- wide pooled genetic screens with CRISPRi/a sgRNA libraries to identify modifier genes and pathways upon PFAS treatment; (3) Validate the impact of PFAS on long-term neurodevelopment in cortical organoids models and identify cell populations impacted by PFAS. Our study will identify genes, molecular and cellular pathways dysregulated by PFAS exposure across various stages of brain development, modeled in vitro. It has a potential to uncover new mechanisms behind PFAS exposure, and to predict the impact of PFAS on developing human brain network function.