Norrie disease protein is essential for cochlear hair cell maturation
Yushi Hayashi, Hao Chiang, Chunjie Tian, Artur A. Indzhykulian, Albert S.B. Edge
Abstract
Significance Norrie disease causes deafness, blindness, and intellectual disability. By analyzing gene expression downstream of Norrie disease protein (Ndp), we show that Ndp controls a network of transcriptional regulators required for maturation and maintenance of cochlear hair cells. We demonstrate that Ndp secretion, after forced expression of the gene in cochlear supporting cells of Ndp-deficient mice, prevents the hearing-loss phenotype exhibited by these mice. Moreover, forced activation of the canonical Wnt pathway mediator, β-catenin, in hair cells is sufficient to rescue hearing, demonstrating that Ndp secreted from supporting cells acts on adjacent hair cells and is required for the maturation and continued functioning of these cells.