Deterioration of the Medial Olivocochlear Efferent System Accelerates Age-Related Hearing Loss in Pax2-Isl1 Transgenic Mice

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F86652036%3A_____%2F16%3A00454012" target="_blank" >RIV/86652036:_____/16:00454012 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/68378041:_____/16:00454012

Výsledek na webu

<a href="http://dx.doi.org/10.1007/s12035-015-9215-1" target="_blank" >http://dx.doi.org/10.1007/s12035-015-9215-1</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s12035-015-9215-1" target="_blank" >10.1007/s12035-015-9215-1</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Deterioration of the Medial Olivocochlear Efferent System Accelerates Age-Related Hearing Loss in Pax2-Isl1 Transgenic Mice

Popis výsledku v původním jazyce

The development, maturation, and maintenance of the inner ear are governed by temporal and spatial expression cascades of transcription factors that form a gene regulatory network. ISLET1 (ISL1) may be one of the major players in this cascade, and in order to study its role in the regulation of inner ear development, we produced a transgenic mouse overexpressing Isl1 under the Pax2 promoter. Pax2-regulated ISL1 overexpression increases the embryonic ISL1+ domain and induces accelerated nerve fiber extension and branching in E12.5 embryos. Despite these gains in early development, the overexpression of ISL1 impairs the maintenance and function of hair cells of the organ of Corti. Mutant mice exhibit hyperactivity, circling behavior, and progressive age-related decline in hearing functions, which is reflected in reduced otoacoustic emissions (DPOAEs) followed by elevated hearing thresholds. The reduction of the amplitude of DPOAEs in transgenic mice was first detected at 1 month of age. By 6-9 months of age, DPOAEs completely disappeared, suggesting a functional inefficiency of outer hair cells (OHCs). The timing of DPOAE reduction coincides with the onset of the deterioration of cochlear efferent terminals. In contrast to these effects on efferents, we only found a moderate loss of OHCs and spiral ganglion neurons. For the first time, our results show that the genetic alteration of the medial olivocochlear (MOC) efferent system induces an early onset of age-related hearing loss. Thus, the neurodegeneration of the MOC system could be a contributing factor to the pathology of age-related hearing loss.

Název v anglickém jazyce

Deterioration of the Medial Olivocochlear Efferent System Accelerates Age-Related Hearing Loss in Pax2-Isl1 Transgenic Mice

Popis výsledku anglicky

The development, maturation, and maintenance of the inner ear are governed by temporal and spatial expression cascades of transcription factors that form a gene regulatory network. ISLET1 (ISL1) may be one of the major players in this cascade, and in order to study its role in the regulation of inner ear development, we produced a transgenic mouse overexpressing Isl1 under the Pax2 promoter. Pax2-regulated ISL1 overexpression increases the embryonic ISL1+ domain and induces accelerated nerve fiber extension and branching in E12.5 embryos. Despite these gains in early development, the overexpression of ISL1 impairs the maintenance and function of hair cells of the organ of Corti. Mutant mice exhibit hyperactivity, circling behavior, and progressive age-related decline in hearing functions, which is reflected in reduced otoacoustic emissions (DPOAEs) followed by elevated hearing thresholds. The reduction of the amplitude of DPOAEs in transgenic mice was first detected at 1 month of age. By 6-9 months of age, DPOAEs completely disappeared, suggesting a functional inefficiency of outer hair cells (OHCs). The timing of DPOAE reduction coincides with the onset of the deterioration of cochlear efferent terminals. In contrast to these effects on efferents, we only found a moderate loss of OHCs and spiral ganglion neurons. For the first time, our results show that the genetic alteration of the medial olivocochlear (MOC) efferent system induces an early onset of age-related hearing loss. Thus, the neurodegeneration of the MOC system could be a contributing factor to the pathology of age-related hearing loss.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

EB - Genetika a molekulární biologie

OECD FORD obor

—

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2016

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Molecular Neurobiology

ISSN

0893-7648

e-ISSN

—

Svazek periodika

53

Číslo periodika v rámci svazku

4

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

16

Strana od-do

2368-2383

Kód UT WoS článku

000373641500027

EID výsledku v databázi Scopus

2-s2.0-84929689126