NACS Seminar: Andrew Griffith (NIH/NIDCD)

Salt, Water and the Developing Inner Ear: Unraveling a Common Genetic Cause of Childhood Hearing Loss

Mutations of the SLC26A4 gene are a common cause of hearing loss associated with enlargement of the endolymphatic sac and duct and vestibular aqueduct (EVA). SLC26A4 encodes a transmembrane anion exchanger, called pendrin, which is expressed in a subset of nonsensory epithelial cells in the cochlea, vestibular organs and endolymphatic sac (ES). The physiological function of the ES is poorly understood but thought to involve homeostasis of endolymph. We have used mouse models of EVA to elucidate the molecular and cellular mechanisms of normal and disordered development of auditory system structure and function. Comparison with the results of clinical studies of patients with EVA confirm the utility and validity of our model. We most recently used single-cell RNA sequencing of ES epithelia to demonstrate the molecular and cellular architecture of the ES. This architecture underlies a model for inner ear development dependent upon absorption of NaCl and water by the ES for morphogenesis of the developing ear. 

https://nacs.umd.edu/sites/nacs.umd.edu/files/griffith_flyer.pdf