Study of non- and mammalian inner ear hair cell regeneration by time lapse imaging

哺乳动物内耳不能自我再生是导致听力损失和平衡障碍无法治愈的主要原因。相比之下，非哺乳动物脊椎动物一生中都会再生毛细胞。这种能力是由常驻干细胞通过两种不同的机制介导的，可能是前庭支持细胞和耳蜗支持细胞：跨分化和增殖。非哺乳动物毛细胞再生的潜在信号通路尚不清楚。目前尚不清楚哺乳动物无法再生毛细胞是因为缺乏再生信号，还是因为无法对再生诱导信号做出反应。我建议建立一种毛细胞再生的体外检测系统，通过对诱导毛细胞丢失后再生的鸡前庭感觉上皮进行时间推移成像。我将确定是否所有的椭圆囊支持细胞或不同的干细胞群体都可以作为体细胞干细胞。我将区分两种机制之间的特征、细胞命运和形态变化。此外，我计划通过获得和失去功能的方法来操纵能够再生毛细胞的细胞。此外，我还打算制作鼠毛、鸡毛和支持细胞的马赛克。我建议追踪单个小鼠支持细胞的命运，以调查是否接近或直接接触再生的鸡支持细胞会影响它们的再生能力。这项建议解决了内耳生物学的一个基本问题，成功的完成可能会导致治疗听力损失的新方法的开发。

The inability for inner ear self-regeneration in mammals is the main reason for incurability of hearing loss and balance disorders. In contrast, non-mammalian vertebrates regenerate hair cells throughout life. This ability is mediated by resident stem cells, likely vestibular and cochlear supporting cells via two different mechanisms: trans-differentiation and proliferation. The underlying signaling pathways for non-mammalian hair cell regeneration are unknown. It remains unclear whether the mammalian inability for hair cell regeneration results from the lack of regenerative signals or the inability to respond to regeneration-inducing signals. I propose to develop an in vitro assay system for hair cell regeneration by time lapse imaging of regenerating chicken vestibular sensory epithelia after inducing hair cell loss. I will determine whether all utricle supporting cells or distinct stem cell populations serve as somatic stem cells. I will discriminate characteristics, cell fates and morphological changes between the two mechanisms. Further, I plan to manipulate cells that are capable of regenerating hair cells by gain- and loss-of-function approaches. In addition, I intend to generate mosaics of murine and chicken hair and supporting cells. I propose to track the fate of individual murine supporting cells to investigate whether proximity or direct contact with regenerating chicken supporting cells affects their regenerative capacity. This proposal addresses a fundamental question of inner ear biology and successful completion could lead to the development of novel approaches for curing hearing loss.