Restoration of hearing in connexin mutant mice

连接蛋白突变小鼠的听力恢复

• 批准号: 7305428
• 负责人: WENXUE TANG
• 金额: $ 22.95万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7305428
• 关键词: Alleles; Amino Acid Sequence; Apoptosis; Applications Grants; Area; Auditory Brainstem Responses; Bacterial Artificial Chromosomes; Bacterial Chromosomes; Cell Death; Child; Cochlea; Cochlear Implants; Code; Condition; Connexins; DNA; Data; Europe; Figs - dietary; Gap Junctions; Gene Expression; Genes; Genetic screening method; Genome; Goals; Grant; Hearing; Hearing Impaired Persons; Intervention; Investigation; Knockout Mice; Lead; Link; Measures; Mediating; Medical; Medical center; Messenger RNA; Methods; Molecular; Monitor; Morphology; Mouse Strains; Mus; Mutant Strains Mice; Mutation; Names; Neonatal Screening; Numbers; Oocytes; Organ of Corti; Outcome; Patients; Pattern; Placenta; Population; Prevention; Process; Property; Reporting; Research; Research Personnel; Role playing therapy; Screening procedure; Southern Blotting; Testing; Therapeutic; Today; Transgenic Organisms; United States; Work; base; deafness; enhanced green fluorescent protein; forging; gene therapy; hearing impairment; homologous recombination; improved; innovation; mouse genome; mutant; mutant mouse model; prevent; protein expression; research study; response; restoration

DESCRIPTION (provided by applicant): Among many genes linked to deafness, mutations in connexin26 (Cx26) gene (GJB2) are the most common genetic defects found in children with autosomal recessive and dominant nonsyndromic hearing loss. Studies in many ethnic populations have linked Cx26 mutations to about one-half of patients with prelingual severe-to-profound nonsyndromic hearing loss. Screening for mutations in the Cx26 and Cx30 genes is now a routine genetic test offered by many medical centers in the United States and Europe. Since the role played by Cx26 in the cochlea is unclear, no mechanism-based therapeutic strategy exists for developing effective prevention and treatment today. The investigators' long-term goal is to understand the molecular mechanisms of gap junction (GJ) mediated functions in the mammalian cochlea and to explore mechanism-based molecular approaches to restore hearing in Cx26 and Cx30 mutant mouse models that are applicable to patients. Preliminary studies demonstrated that the hearing of deaf Cx30-/- mice was completely restored to normal by transgenically over-expressing Cx26 gene from a modified bacterial artificial chromosome (BAC) incorporated in the Cx30-/- mouse genome. These results indicated that heteromeric GJs consisting of Cx26 and Cx30 were not essential for normal hearing. Since amino acid sequences of Cx26 and Cx30 are 80% identical and they co-assemble to form heteromeric GJs in the cochlea, the preliminary data also raised the possibility that up-regulating the expression of Cx30 gene may restore hearing of conditional Cx26-/- mice as well. This application, in response to PA-06-342, is initiated to test this hypothesis. In contrast to introducing foreign DNA materials to correct the dysfunctional gene by traditional gene therapy approaches, the investigators' new idea relies on up-regulating the expression of a gene already exist in the genome of the Cx26-mutant mice or patients. Successful outcome of their experiments may form the basis for pursuing innovative and mechanism-based therapeutic strategy for preventing and/or treating patients suffering from Cx26 mutation-linked deafness. Investigations about the mechanisms up-regulating the Cx26 gene expressions and slowing down the degradation of Cx26 may become therapeutically relevant, therefore may lead to new research directions for studying the prevention and treatment of connexin-related deafness.

描述（由申请人提供）：在与耳聋相关的许多基因中，Connexin26（CX26）基因（GJB2）中的突变是在常染色体隐性和主体非同伴听力损失的儿童中发现的最常见的遗传缺陷。 在许多种族人群中的研究将CX26突变与大约一半的初步严重至可靠的非综合性听力损失联系在一起。 现在，在美国和欧洲许多医疗中心提供了常规的基因检测，在CX26和CX30基因中筛选突变。 由于CX26在耳蜗中所扮演的角色尚不清楚，因此目前没有基于机制的治疗策略来开发有效的预防和治疗。 研究者的长期目标是了解哺乳动物耳蜗中GAP连接（GJ）介导的功能的分子机制，并探索基于机制的分子方法，以恢复适用于患者的CX26和CX33和CX30突变小鼠模型中的听力。 初步研究表明，通过从CX30 - / - 小鼠基因组中掺入的改良细菌人造染色体（BAC）的转基因过度表达CX26基因的转基因过表达CX26基因通过转基因过表达的CX26基因完全恢复到正常状态。 这些结果表明，由CX26和CX30组成的杂体GJ对于正常听力并不是必需的。 由于CX26和CX30的氨基酸序列是80％相同的，并且它们在耳蜗中共组装以形成异源GJ，因此初步数据也提出了一个可能性，即在上调CX30基因的表达可能会恢复有条件CX26 - / - 小鼠的听力。 该应用程序响应于PA-06-342，以检验该假设。 与引入外源DNA材料以通过传统基因治疗方法纠正功能失调的基因相反，研究者的新想法依赖于上调在CX26突变小鼠或患者的基因组中已经存在基因的表达。 他们的实验的成功结果可能是追求创新和基于机制的治疗策略的基础，以防止和/或治疗患有CX26突变连接耳聋的患者。 关于上调CX26基因表达和减慢CX26降解的机制的研究可能会在治疗上具有相关性，因此可能会导致研究预防和治疗连接蛋白相关的耳聋的新研究方向。