title: Reduction in noise-induced functional loss of the cochleae in mice with pre-existing cochlear dysfunction due to genetic interference of prestin.
abstract: Various cochlear pathologies, such as acoustic trauma, ototoxicity and age-related degeneration, cause hearing loss. These pre-existing hearing losses can alter cochlear responses to subsequent acoustic overstimulation. So far, the knowledge on the impacts of pre-existing hearing loss caused by genetic alteration of cochlear genes is limited. Prestin is the motor protein expressed exclusively in outer hair cells in the mammalian cochlea. This motor protein contributes to outer hair cell motility. At present, it is not clear how the interference of prestin function affects cochlear responses to acoustic overstimulation. To address this question, a genetic model of prestin dysfunction in mice was created by inserting an internal ribosome entry site (IRES)-CreERT2-FRT-Neo-FRT cassette into the prestin locus after the stop codon. Homozygous mice exhibit a threshold elevation of auditory brainstem responses with large individual variation. These mice also display a threshold elevation and a shift of the input/output function of the distortion product otoacoustic emission, suggesting a reduction in outer hair cell function. The disruption of prestin function reduces the threshold shifts caused by exposure to a loud noise at 120 dB (sound pressure level) for 1 h. This reduction is positively correlated with the level of pre-noise cochlear dysfunction and is accompanied by a reduced change in Cdh1 expression, suggesting a reduction in molecular responses to the acoustic overstimulation. Together, these results suggest that prestin interference reduces cochlear stress responses to acoustic overstimulation.
authors.affiliation: Center for Hearing and Deafness, University at Buffalo, Buffalo, New York, United States of America.
authors.forename: Qunfeng
authors.initials: Q
authors.lastname: Cai
authors.affiliation: Department of Otolaryngology and Head & Neck Surgery, Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Wang
authors.affiliation: Center for Hearing and Deafness, University at Buffalo, Buffalo, New York, United States of America.
authors.forename: Donald
authors.initials: D
authors.lastname: Coling
authors.affiliation: Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America.
authors.forename: Jian
authors.initials: J
authors.lastname: Zuo
authors.affiliation: Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America.
authors.forename: Jie
authors.initials: J
authors.lastname: Fang
authors.affiliation: Department of Otolaryngology and Head & Neck Surgery, Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China.
authors.forename: Shiming
authors.initials: S
authors.lastname: Yang
authors.affiliation: Center for Hearing and Deafness, University at Buffalo, Buffalo, New York, United States of America.
authors.forename: Krystal
authors.initials: K
authors.lastname: Vera
authors.affiliation: Center for Hearing and Deafness, University at Buffalo, Buffalo, New York, United States of America.
authors.forename: Bo Hua
authors.initials: BH
authors.lastname: Hu
mesh_terms: D000818:Animals; D001309:Auditory Threshold; D003051:Cochlea / Q000378:metabolism* / Q000503:physiopathology*; D004195:Disease Models, Animal; D005260:Female; D015870:Gene Expression; D034381:Hearing Loss / Q000209:etiology / Q000503:physiopathology; D006720:Homozygote; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D020409:Molecular Motor Proteins / Q000235:genetics*; D009622:Noise / Q000009:adverse effects*; D009925:Organ of Corti / Q000378:metabolism / Q000503:physiopathology; D013997:Time Factors
chemical_list: D020409:Molecular Motor Proteins; C498720:Pres protein, mouse