Identifying NRXN1 Function during Neural Differentiation of iPSC
- To use induced pluripotent stem cells (iPSC) as an in vitro system to recapitulate the regulatory interactions underlying the transition from pluripotency to neural competence in humans.
- To capture the early molecular differences of neurotypical and NRXN1 mutated iPSC lines as they undergo during neuronal differentiation.
Methods: We used iPSC lines derived from 3 neurotypical and 3 autistic individuals with NRXN1 deletions and induced neural differentiation by dual SMAD inhibition (2i). RNA was extracted at 6 time points during the initial 12 days of neural induction and cDNA was synthesized to obtain transcriptome data. The expression patterns of NRXN1a, NRXN1b and genes that have been associated with NRXN1 was analysed in control and NRXN1 mutated lines trough real time PCR
Results: NRXN1 is expressed during early neural induction, suggesting a potential role during neural development. We identify a number of genes that are expressed during this stage that might interact with NRXN1 including neuroligins and other adhesion molecules. We detect systematic changes in the expression levels of genes that have been related with NRXN1 in the mutated cell lines compared with control lines undergoing neuronal differentiation. We identify potential cell biological functions regulated by these sets of genes including cell adhesion and neural rosettes formation.
Conclusions: iPSCs provide a novel approach to study the impact of NRXN1 mutations during neural differentiation in humans, highlighting the utility of iPSC model in understanding the functional role of specific mutations that are associated with autism risk. We show that NRXN1 gene mutations can impact biological networks that are important for neural differentiation.