Wnt pathway mutations alter hair cell regeneration in the zebrafish fish lateral line

摘要 使人衰弱的听力损失影响着世界上超过6%的人口，并可能导致严重的 患者的生活质量下降。听觉是由机械感觉毛发调节的 细胞位于内耳的耳蜗处。内耳中的另一群毛细胞 组成前庭系统，传递平衡和重力的感觉。毛细胞损伤 会导致感官缺陷。毛细胞损伤的原因包括年龄、噪音暴露、耳毒性。 毒品、疾病和伤害。在成年哺乳动物中，毛细胞一旦丢失，就不能再生， 导致永久性听力损失和平衡障碍。 除了调节听觉和平衡感之外，机械感觉毛细胞还 在水生脊椎动物的侧线系统中也需要近距离触觉。侧向 线状毛细胞在形态和基因上与内耳毛细胞非常相似。相比之下， 对于哺乳动物的内耳毛细胞，侧线系统的毛细胞是健壮的。 再生的。斑马鱼(Danio Rerio)，已成为研究斑马鱼 机械感觉毛细胞再生的机制。 使用经典Wnt途径的药理学操作的研究表明，它是 对调节毛细胞所需的细胞增殖和分化至关重要 再生。为了从基因上确认Wnt信号在再生过程中的作用，我们将使用 三个斑马鱼品系在Wnt途径的不同点上携带突变。在目标1中，我们将 Krm1nl10突变体中导致Wnt过度激活的毛细胞再生的特征 发信号。在目标2中，我们将表征lef1nl2突变系的再生，这导致 对Wnt活性的抑制。在目标3中，我们将检查第三行的再生，foxg1aa266， 该基因包含Wnt转录靶基因foxg1a的突变。共同努力，我们将利用 以确定细胞的增殖、分化和存活是如何通过 机械感觉毛细胞再生过程中的Wnt途径。这样做的长期目标是 这项工作是为了提供一种再生人类内耳毛细胞的机制。

Abstract Debilitating hear loss affects over 6% of the world’s population and can result in a profound decrease in the quality of life for those afflicted. Hearing is mediated by mechanosensory hair cells located in the cochlea of the inner ear. Another population of hair cells in the inner ear makes up the vestibular system to relay the sensation of balance and gravity. Hair cell damage results in sensory defects. The causes of hair cell damage include age, noise exposure, ototoxic drugs, disease, and injury. In adult mammals, once hair cells are lost, they do not regenerate, resulting in permanent hearing loss and balance disorders. In addition to mediating the sensations of hearing and balance, mechanosensory hair cells are also required for close touch sensation in the lateral line systems of aquatic vertebrates. Lateral line hair cells are morphologically and genetically very similar to inner ear hair cells. In contrast to the inner ear hair cell of mammals, the hair cells of the lateral line system are robustly regenerative. The zebrafish (Danio rerio), has emerged as a valuable model to study the mechanisms of mechanosensory hair cell regeneration. Research using pharmacological manipulation of the canonical Wnt pathway suggests that it is critical for regulating the cellular proliferation and differentiation required for hair cell regeneration. To genetically confirm a role for Wnt signaling during regeneration, we will use three zebrafish lines carrying mutations at different points in the Wnt pathway. In Aim 1, we will characterize hair cell regeneration in the krm1nl10 mutant, which results in overactivation of Wnt signaling. In Aim 2, we will characterize regeneration in the lef1nl2 mutant line, which results in an inhibition of Wnt activity. In Aim 3, we will examine regeneration in a third line, foxg1aa266, which contains a mutation in the Wnt transcriptional target gene foxg1a. Together, we will use these lines to determine how cellular proliferation, differentiation, and survival are regulated by the Wnt pathway during regeneration of mechanosensory hair cells. The long-term goal of this work is to provide a mechanism for regenerate hair cells in the human inner ear.