Neurofibromatosis 1 mutation impairs human induced pluripotent stem cell-derived microglia function

Neurofibromatosis type 1 (NF1) is autosomal dominant condition caused by germline mutations in the NF1 gene on chromosome 17. Children with NF1 are prone to the development of multiple nervous system abnormalities, including autism and brain tumors, which could result from the effect of NF1 mutation on microglia function. Using Nf1-mutant mice, we previously identified impaired microglia process extension and phagocytosis resulting from defects in purinergic signaling. To determine whether these abnormalities are also observed in human microglia, we leveraged human induced pluripotent stem cell engineering to generate human microglia-like (hiMGL) cells harboring three different NF1 patient-derived NF1 gene mutations. Both NF1-mutant and isogenic control hiMGL cells express classical microglial markers and exhibit similar transcriptomes and cytokine/chemokine release profiles, NF1-mutant hiMGL cells have defects in P2X receptor activation, phagocytosis and motility. We conclude that NF1 mutation impairs some aspects of microglia function in humans, which could contribute to a subset of the neurological abnormalities seen in children with NF1. Overall design: To determine whether NF1 mutation had a dramatic effect on human microglia gene expression, we generated at least three independent cultures of CTL and NF1-mutant hiMGL cells (M1 and M3) for bulk RNA sequencing analysis. To determine whether NF1 mutation had a dramatic effect on human microglia gene expression, we generated at least three independent cultures of CTL and NF1-mutant hiMGL cells (M1 and M3) for bulk RNA sequencing analysis.