First Author | MacLennan AJ | Year | 2006 |
Journal | Hear Res | Volume | 220 |
Issue | 1-2 | Pages | 38-48 |
PubMed ID | 16945494 | Mgi Jnum | J:112371 |
Mgi Id | MGI:3656173 | Doi | 10.1016/j.heares.2006.06.016 |
Citation | Maclennan AJ, et al. (2006) The S1P(2) sphingosine 1-phosphate receptor is essential for auditory and vestibular function. Hear Res 220(1-2):38-48 |
abstractText | Sphingosine 1-phosphate (S1P) is an endogenous growth factor with potent effects on many different cell types. Most of these effects are produced by activation of one or more of a family of G-protein coupled receptors. The S1P(2) receptor can mediate S1P-induced proliferation, differentiation and survival in a wide variety of cells in culture. However, identifying essential in vivo functions for S1P(2) has been hampered by its ubiquitous expression and the failure to detect any anatomical abnormalities in initial analyses of S1P(2) knockout mice. We report here that all S1P(2) knockout mice are profoundly deaf from postnatal day 22 and approximately half display a progressive loss of vestibular function with aging. Anatomically, both the auditory and vestibular systems appear to develop normally but then degrade. Morphological defects associated with hearing are first detected at 3 weeks postnatal as deformations of the organ of Corti/Nuel's space. By one year of age structures within the scala media are dramatically altered. The S1P(2) knockout mice also display a loss of otoconia consistent with the vestibular impairment. The present data are the first to indicate that S1P signaling plays critical roles, in vivo, in auditory and vestibular functions. The data further establish that the S1P signaling occurs through the S1P(2) receptor and makes an essential contribution to the structural maintenance of these systems, raising the possibility that properly targeted enhancement of this signaling may prove to be clinically beneficial. |