Analysis of Hair Cell Regeneration in Zebrafish

描述(由申请人提供)：耳聋的一个主要原因是由于年龄、噪音或抗生素治疗导致的毛细胞丢失。与哺乳动物的毛细胞不同，鱼类、鸟类和两栖动物的毛细胞在毛细胞死亡后不断翻转和再生。其目的是利用斑马鱼的侧线来定义和表征毛细胞再生过程中发生的分子和细胞相互作用，并以激活哺乳动物的这些途径为长期目标。为了揭示驱动毛细胞再生的机制，斑马鱼的侧线被选为实验范式，因为1)斑马鱼支持细胞再生的能力；2)侧线毛细胞与内耳毛细胞在功能和形态上的相似性；3)它可以在整个发育过程中直接观察和操纵；4)能够快速且经济高效地分离参与毛细胞再生的特定细胞类型，这些实验是在经典模型系统中难以执行的，如小鼠和鸡。这两个实验室正在实施以下策略，以确定毛细胞死亡后在支持细胞中转录的最早基因。首先，将确定干细胞和周围的壁龛细胞在正常和再生的神经肥大中的位置和种群动态，这对于确定干细胞维持和激活所需的信号至关重要。其次，将使用微阵列分析来确定纯化的支持细胞的转录组。为了系统地分析所有已确定的候选基因，将使用一种新颖而强大的生物信息学方法来识别由相同转录因子共同调控的基因。识别这些重要的转录因子对于我们理解低等脊椎动物的再生是如何触发的至关重要。这两种方法结合起来，将发现关键的毛细胞再生基因，并为系统剖析这一复杂问题奠定基础，为哺乳动物毛细胞再生疗法的发展提供信息。 与公共卫生相关：干细胞对成人组织的动态平衡和再生至关重要。斑马鱼侧线是阐明控制干细胞和感觉毛细胞再生的遗传途径的一个很好的模型。我们的研究结果将有助于鉴定哺乳动物耳朵中的干细胞，并有助于开发哺乳动物再生毛细胞的治疗策略。

DESCRIPTION (provided by applicant): A prominent cause of deafness is loss of hair cells due to age, noise or antibiotic treatments. In contrast to mammalian hair cells, fish, bird and amphibian hair cells are constantly turning over and regenerate following hair cell death. The aim is to take advantage of the lateral line of zebrafish to define and characterize the molecular and cellular interactions occurring during hair cell regeneration with the long-term goal of activating these pathways in mammals. To uncover the mechanisms driving hair cell regeneration, the lateral line of the zebrafish was chosen as an experimental paradigm because of 1) the ability of zebrafish support cells to regenerate hair cells; 2) the functional and morphological similarity between the lateral line hair cells and the hair cells of the inner ear; 3) its accessibility to direct observation and manipulation throughout development; and 4) the ability to rapidly and cost-effectively isolate specific cell types involved in hair cell regeneration, experiments that are difficult to perform in the classical model systems, e.g., mouse and chick. The two laboratories are pursuing the following strategy to identify the earliest genes that are transcribed in support cells subsequent to hair cell death. First, the location and population dynamics of stem cells and surrounding niche cells in normal and regenerating neuromasts will be determined, which is essential for determining the signals required for stem cell maintenance and activation. Secondly, the transcriptome of purified support cells will be defined using microarray analyses. To systematically analyze all candidate genes identified, a novel and powerful bioinformatics approach will be employed to identify genes co-regulated by the same transcription factors. Identifying these important transcription factors will be crucial for our understanding of how regeneration is triggered in lower vertebrates. Combined, these two approaches will discover key hair cell regeneration genes and set the stage for a systematic dissection of this complex problem to inform the development of therapeutics to regenerate hair cells in mammals. PUBLIC HEALTH RELEVANCE: Stem cells are crucial for adult tissue homeostasis and regeneration. The zebrafish lateral line is an excellent model to elucidate the genetic pathways controlling stem cells and sensory hair cell regeneration. Results from our studies will aid in the identification of stem cells in the mammalian ear and in the development of therapeutic strategies to regenerate hair cells in mammals.