Characterization of mechanosensitive channels in a genetic model

遗传模型中机械敏感通道的表征

• 批准号: 8313268
• 负责人: Seth Alexander Wescott
• 金额: $ 3.25万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8313268
• 关键词: Address; Air; Anatomy; Beryllium; Biochemical; Biological Assay; Caenorhabditis elegans; Caring; Cations; Conflict (Psychology); Cytoskeleton; Data; Dominant-Negative Mutation; Ear; Economics; Emotional; Extracellular Matrix; Family; Figs - dietary; Genes; Genetic Models; Goals; Hearing; Hearing problem; Homologous Gene; Human; In Vitro; Individual; Invertebrates; Investigation; Ion Channel; Ions; Label; Life; Mammals; Mechanics; Mechanoreceptors; Mediating; Modeling; Molecular; Molecular Genetics; Neurons; Organism; Physiological; Physiology; Point Mutation; Property; Proteins; Protocols documentation; Regulation; Reporting; Role; Sensory; Series; Site-Directed Mutagenesis; Stimulus; System; TRPV channel; Testing; Time; Touch sensation; Vertebrates; Whole-Cell Recordings; Work; deafness; hearing impairment; human disease; in vivo; insight; member; mutant; novel; null mutation; receptor; sound; tool; vibration

DESCRIPTION (provided by applicant): Hearing is a sensory percept that is triggered by mechanical stimuli. Mechanosensitive channels, a type of ion channel that converts mechanical force into an electrical impulse, are central to hearing in both vertebrates and invertebrates. However, the identity of mechanosensitive channels responsible for hearing remains a mystery. While a wealth of circumstantial evidence implicates transient receptor potential (TRP) channel proteins in mammalian hearing, other studies argue against this model. The controversy mainly arises from the fact that most studies were carried out in heterologous systems; yet the proper function of mechanosensitive channels require the channel to be anchored to the extracellular matrix and intracellular cytoskeleton, a physiological setting that is difficult to recapitulate in heterologous expression systems. This suggests that it is necessary to investigate the function of these channels in an in vivo setting. Recently, our lab has developed an electrophysiological recording protocol to characterize mechanosensitive TRP channels in vivo. Using this approach, we have recently reported that the C. elegans TRPN protein TRP-4 is a pore-forming subunit of a native mechanosensitive channel, showing for the first time that TRP channels can function as mechanosensitive channels in vivo. This has also raised the possibility that other TRP channels may form mechanosensitive channels. While the TRPN channel family is conserved throughout invertebrates and lower vertebrates, they are not found in mammals, indicating that other mechanosensitive channels must underlie mechanotransduction in mammals. Notably, TRPV channels are well conserved from worms to humans. Our preliminary data indicate that C. elegans TRPV channels are required for mechanosensitive channel activity in a mechanosensory neuron in vivo, suggesting that TRPV channels may function as mechanosensitive channels. Here we propose that TRPV channels can function as mechanosensitive channels in vivo. To test this hypothesis, we will dissect the function and regulation of TRPV channels in mechanosensation in C. elegans using our newly developed in vivo electrophysiological recording protocol in conjunction with molecular genetic tools. As TRPV channels are well conserved from worms to humans, this work will provide novel insights into the molecular identity of the elusive mechanosensitive channels mediating hearing in humans. PUBLIC HEALTH RELEVANCE: Deafness and hearing deficits significantly reduce the quality of human life and caring for individuals with hearing disorders is a major economic and emotional burden for families. We know that our ears are mechanosensitive, detecting vibrations in the air as sound waves, but we have not identified the molecules responsible for detecting those sound waves. This application examines the role of a type of mechanosensitive protein, which will provide novel insights into the understanding of hearing loss and related human diseases.

描述（由申请人提供）：听力是由机械刺激触发的感官感知。机械敏感的通道是一种将机械力转换为电脉冲的离子通道，对于脊椎动物和无脊椎动物的听力至关重要。但是，负责听力的机械敏感渠道的身份仍然是一个谜。尽管大量的间接证据暗示了哺乳动物听力中的瞬时受体电位（TRP）通道蛋白，但其他研究则反对该模型。争议主要源于以下事实：大多数研究都是在异源系统中进行的。然而，机械敏感的通道的正确功能要求将通道锚定在细胞外基质和细胞内细胞骨架上，这是一种生理环境，很难在 异源表达系统。这表明有必要在体内环境中研究这些通道的功能。最近，我们的实验室开发了一种电生理记录方案，以表征体内机械敏感的TRP通道。使用这种方法，我们最近报道说，秀丽隐杆线虫TRPN蛋白TRP-4是天然机械敏感通道的孔形成亚基，这首先显示了TRP通道可以在体内充当机械敏感的通道。这也提高了其他TRP通道可能形成机械敏感通道的可能性。虽然TRPN通道家族在整个无脊椎动物和较低的脊椎动物中都保守，但在哺乳动物中未发现它们，这表明其他机械敏感的通道必须是哺乳动物中的机械转导的基础。值得注意的是，从蠕虫到人类，TRPV通道是充分保守的。我们的初步数据表明，秀丽隐杆线虫TRPV通道是体内机械感应神经元中机械敏感的通道活动所必需的，这表明TRPV通道可能起作用。在这里，我们建议TRPV通道可以在体内充当机械敏感的通道。为了检验这一假设，我们将使用我们新开发的体内电生理记录方案与分子遗传工具一起研究秀丽隐杆线虫中TRPV通道的功能和调节。由于TRPV通道从蠕虫到人都很好地保守了，因此这项工作将提供有关介导人类听力的难以捉摸的机械敏感通道的分子身份的新见解。 公共卫生相关性：耳聋和听力赤字大大降低了人类生活的质量和照顾听力障碍的人是家庭的主要经济和情感负担。我们知道我们的耳朵是机械敏感的，可以检测空气中的振动为声波，但我们尚未确定负责检测这些声波的分子。该应用研究了一种机械敏感蛋白的作用，该蛋白将为理解听力丧失和相关人类疾病提供新的见解。