Noncoding Microdeletion in Mouse Hgf Disrupts Neural Crest Migration into the Stria Vascularis, Reduces the Endocochlear Potential, and Suggests the Neuropathology for Human Nonsyndromic Deafness DFNB39
| Autor: | Elizabeth J. Thomason, Julie M. Schultz, Matthew F. Starost, Takahiro Ohyama, Michael Hoa, Rafal Olszewski, Risa Tona, Robert J. Morell, Thomas L. Saunders, Talah T Wafa, Samuel Leitess, Tracy S. Fitzgerald, Thomas B. Friedman, Ian Taukulis, Elizabeth T. Wilson, Brittany N. Whitley, Keri Richards, Connor Hill |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
0301 basic medicine
Male Endocochlear potential Hearing Loss Sensorineural Cell Count Biology medicine.disease_cause 03 medical and health sciences Mice 0302 clinical medicine Hair Cells Auditory medicine otorhinolaryngologic diseases Evoked Potentials Auditory Brain Stem Animals Homeostasis Humans Inner ear Nonsyndromic deafness Cochlea Research Articles Mice Knockout Mutation Hepatocyte Growth Factor General Neuroscience Neural crest Stria Vascularis RNA Probes medicine.disease Cell biology Mice Inbred C57BL 030104 developmental biology Ion homeostasis medicine.anatomical_structure Neural Crest Ear Inner Hepatocyte growth factor Female 030217 neurology & neurosurgery medicine.drug |
| Zdroj: | J Neurosci |
| Popis: | Hepatocyte growth factor (HGF) is a multifunctional protein that signals through the MET receptor. HGF stimulates cell proliferation, cell dispersion, neuronal survival, and wound healing. In the inner ear, levels of HGF must be fine-tuned for normal hearing. In mice, a deficiency of HGF expression limited to the auditory system, or an overexpression of HGF, causes neurosensory deafness. In humans, noncoding variants inHGFare associated with nonsyndromic deafnessDFNB39. However, the mechanism by which these noncoding variants causes deafness was unknown. Here, we reveal the cause of this deafness using a mouse model engineered with a noncoding intronic 10 bp deletion (del10) inHgf. Male and female mice homozygous for del10 exhibit moderate-to-profound hearing loss at 4 weeks of age as measured by tone burst auditory brainstem responses. The wild type (WT) 80 mV endocochlear potential was significantly reduced in homozygous del10 mice compared with WT littermates. In normal cochlea, endocochlear potentials are dependent on ion homeostasis mediated by the stria vascularis (SV). Previous studies showed that developmental incorporation of neural crest cells into the SV depends on signaling from HGF/MET. We show by immunohistochemistry that, in del10 homozygotes, neural crest cells fail to infiltrate the developing SV intermediate layer. Phenotyping and RNAseq analyses reveal no other significant abnormalities in other tissues. We conclude that, in the inner ear, the noncoding del10 mutation inHgfleads to developmental defects of the SV and consequently dysfunctional ion homeostasis and a reduction in the EP, recapitulating human DFNB39 nonsyndromic deafness.SIGNIFICANCE STATEMENTHereditary deafness is a common, clinically and genetically heterogeneous neurosensory disorder. Previously, we reported that human deafness DFNB39 is associated with noncoding variants in the 3′UTR of a short isoform ofHGFencoding hepatocyte growth factor. For normal hearing, HGF levels must be fine-tuned as an excess or deficiency of HGF cause deafness in mouse. Using aHgfmutant mouse with a small 10 bp deletion recapitulating a humanDFNB39noncoding variant, we demonstrate that neural crest cells fail to migrate into the stria vascularis intermediate layer, resulting in a significantly reduced endocochlear potential, the driving force for sound transduction by inner ear hair cells. HGF-associated deafness is a neurocristopathy but, unlike many other neurocristopathies, it is not syndromic. |
| Databáze: | OpenAIRE |
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