Mutation in NADPH oxidase 3 (NOX3) impairs SHH signaling and increases cerebellar neural stem/progenitor cell proliferation.

Abnormalities in cerebellar structure and function may cause ataxia, a neurological dysfunction of motor coordination. In the course of the present study, we characterized a mutant mouse lineage with an ataxia-like phenotype. We localized the mutation on chromosome 17 and mapped it to position 1534 of the Nox3 gene, resulting in p.Asn64Tyr change. The primary defect observed in Nox3 mice was increased proliferation of cerebellar granule cell precursors (GCPs). cDNA microarray comparing Nox3 and BALB/c neonatal cerebellum revealed changes in the expression of genes involved in the control of cell proliferation. Nox3 GCPs and NSC produce higher amounts of reactive oxygen species (ROS) and upregulate the expression of SHH target genes, such as Gli1-3 and Ccnd1 (CyclinD1). We hypothesize that this new mutation is responsible for an increase in proliferation via stimulation of the SHH pathway. We suggest this mutant mouse lineage as a new model to investigate the role of ROS in neuronal precursor cell proliferation.