2011-08-012024-05-13https://scholars.lib.ntu.edu.tw/handle/123456789/654938摘要：中文摘要（一）研究背景及目的聽損是常見的疾病，孩童罹患遺傳性聽損對個人、家庭和醫療體系都是沈重的負擔。由於分子生物學的進步和人類基因體的解碼，最近數年來，醫界對於導致遺傳性聽損的成因有了顯著的進展。在多數會導致遺傳性聽損的基因當中，SLC26A4基因突變是相當常見的，也是國人特發性聽損人口中，盛行率數一數二的聽損基因。帶有SLC26A4基因突變之患者經常合併內耳內耳大前庭導水管，且臨床上常見急性波動性的聽力喪失，此種聽力的不穩定性，也一直都是耳科醫師必須經常面臨的難題。我們認為，若能培育出帶有SLC26A4基因突變之實驗動物，將有助於我們進行進一步之研究。晚近，吾人已成功培育出帶有國人最常見之SLC26A4基因c.919-2A>G突變的基因置換鼠Slc26a4tm1Dontuh/tm1Dontuh，同時，亦著手於培育帶有其他常見突變之基因置換鼠。初步研究結果顯示，Slc26a4tm1Dontuh/tm1Dontuh基因置換鼠之表現型，與臨床上病人之表現型大致類似，若能加以適當調整，應可作為研究人類疾病之動物模式。本計畫即擬利用此一動物模式，進行致病機制之研究與新型態治療(包括：藥物治療、基因治療及幹細胞治療)的研發，希望可為大前庭導水管症候群此一臨床上常見疾病之處理，找到解決之道。（二）研究方法本計畫之設計為前瞻性動物研究，共分為兩大部分、6個子題：1. 致病機制之釐清(1) SLC26A4突變基因置換鼠之平衡功能研究：藉由比較基因置換鼠外表型「circling」及「non-circling」兩組間之差異，釐清病人臨床上發生之眩暈之原因。(2) SLC26A4突變之表現型與基因型關連研究：比較不同基因型之置換鼠間表現型之差異。(3) SLC26A4突變之演化優勢：分析SLC26A4突變與氣喘/高血壓之關連性、是否具保護作用，並進一步釐清pendrin蛋白質之生理功能。2. 新型態治療之研發(1) 藥物治療：研究質離子幫浦阻斷劑SCH28080是否可用以治療SLC26A4突變之聽損。(2) 基因治療：研究基因治療是否可用以治療SLC26A4突變之聽損，及其理想之投與方式。(3) 幹細胞治療：研究幹細胞治療是否可用以治療SLC26A4突變之聽損，及其理想之投與方式。（三）預期成果1. 釐清SLC26A4基因突變導致聽損和前庭功能異常之致病機制。2. 培育並比較帶有各種不同Slc26a4基因突變基因置換鼠之表現型，以找出最適合研究往後新型治療的動物模式。3. 釐清SLC26A4基因突變之演化上角色，以及與其他疾病之相關性，以更進一步瞭解pendrin蛋白質之生理功能。4. 藉由此研究，發展與建立大前庭導水管症候群的新型態治療方法，以期日後可以應用於臨床上治療。5. 所有研究人員可以從中習得基因轉殖鼠培育、動物內耳解剖生理研究、基因治療、幹細胞治療等相關技術知識和研究方法。6. 此研究成果具有高度原創性以及臨床實用價值，預期可以發表於國際知名期刊。<br> Abstract: 英文摘要Background and Objectives:Hereditary hearing loss is the most common inherited sensory defect, affecting about 3-10 per 1000 children. With the advances in molecular genetics, the nature of hereditary hearing loss has started to be unraveled. Among a plethora of deafness genes discovered in the past decade, certain genes are more important than others from an epidemiologic perspective, including the SLC26A4 gene. Clinically, patients with SLC26A4 mutations are characterized by inner ear malformations and fluctuating hearing loss. For decades, the latter has constituted a treatment difficulty for otologists, because traditional regimens (e.g. steroid) usually could not achieve satisfactory and predictable outcomes. To elucidate the pathogenesis of the deafness-associated genetic mutations, we tried to establish animal models which harbor the same mutations as the humans.Recently, we have successfully established a knock-in mouse model, Slc26a4tm1Dontuh/ tm1Dontuh, which was homozygous for the c.919A>G mutation, the most common SLC26A4 mutation in Han Chinese. Preliminary characterization of the Slc26a4tm1Dontuh / tm1Dontuh mice revealed phenotypes reminiscent of those observed in the human counterpart. We are also trying to establish another knock-in mouse model with the SLC26A4 p.H723R mutation. The purposes of the present project are to clarify the pathogenetic mechanisms of SLC26A4 mutations and to develop novel therapeutic strategies by using these animal models.Materials and Methods:This project is composed of 2 parts, including 6 sub-studies:1. The clarification of pathogenetic mechanisms:(1) We will compare the anatomic and physiologic differences between mice with and without the “circling” phenotype to clarify the pathogenesis of vertigo in humans.(2) The phenotype-genotype correlations will be analyzed in mice.(3) The evolutionary advantages of common SLC26A4 mutations will be investigated.2. The development of novel therapeutic strategies:(1) Pharmacogenetic study (with SCH28080) will be performed.(2) Gene therapy will be applied to the treatment of hearing loss in mice with Slc26a4 mutations.(3) Stem cell therapy will be applied to the treatment of hearing loss in mice with Slc26a4 mutations.Anticipated Results:1. The pathogenetic mechanisms of SLC26A4 mutations will be elucidated.2. By comparing knock-in mice with different SLC26A4 mutations, an animal model which can simulate the human phenotype will be identified.3. The physiologic function of pendrin will be investigated.4. Novel therapeutic strategies for SLC26A4 mutations-associated hearing loss, including pharmacogenetic therapy, gene therapy and stem cell therapy, may be developed.遺傳性聽損SLC26A4基因Pendrin基因置換鼠大前庭導水管症候群Hereditary hearing lossSLC26A4PendrinKnock-in miceEnlarged vestibular aqueduct syndrome