title: The WFS1 gene, responsible for low frequency sensorineural hearing loss and Wolfram syndrome, is expressed in a variety of inner ear cells.
abstract: Heterozygous mutations in the WFS1 gene are responsible for autosomal dominant low frequency hearing loss at the DFNA6/14 locus, while homozygous or compound heterozygous mutations underlie Wolfram syndrome. In this study we examine expression of wolframin, the WFS1-gene product, in mouse inner ear at different developmental stages using immunohistochemistry and in situ hybridization. Both techniques showed compatible results and indicated a clear expression in different cell types of the inner ear. Although there were observable developmental differences, no differences in staining pattern or gradients of expression were observed between the basal and apical parts of the cochlea. Double immunostaining with an endoplasmic reticulum marker confirmed that wolframin localizes to this organelle. A remarkable similarity was observed between cells expressing wolframin and the presence of canalicular reticulum, a specialized form of endoplasmic reticulum. The canalicular reticulum is believed to be involved in the transcellular movements of ions, an important process in the physiology of the inner ear. Although there is nothing currently known about the function of wolframin, our results suggest that it may play a role in inner ear ion homeostasis as maintained by the canalicular reticulum.
authors.affiliation: Department of Medical Genetics, University of Antwerp, Universiteitsplein 1, 2610, Antwerp, Belgium.
authors.forename: Kim
authors.initials: K
authors.lastname: Cryns
authors.forename: Sofie
authors.initials: S
authors.lastname: Thys
authors.forename: Lut
authors.initials: L
authors.lastname: Van Laer
authors.forename: Yoshitomo
authors.initials: Y
authors.lastname: Oka
authors.forename: Markus
authors.initials: M
authors.lastname: Pfister
authors.forename: Luc
authors.initials: L
authors.lastname: Van Nassauw
authors.forename: Richard J H
authors.initials: RJ
authors.lastname: Smith
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Timmermans
authors.forename: Guy
authors.initials: G
authors.lastname: Van Camp
mesh_terms: D000818:Animals; D003051:Cochlea; D007758:Ear, Inner / Q000166:cytology* / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D006319:Hearing Loss, Sensorineural / Q000209:etiology; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008565:Membrane Proteins / Q000096:biosynthesis / Q000235:genetics*; D051379:Mice; D014929:Wolfram Syndrome / Q000209:etiology
chemical_list: D008565:Membrane Proteins; C114987:wolframin protein