Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, California 94315.
Institute of Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California 94315.
Cold Spring Harb Perspect Med. 2019 Apr 1;9(4):a033183. doi: 10.1101/cshperspect.a033183.
In sharp contrast to the adult mammalian cochlea, which lacks regenerative ability, the mature avian cochlea, or basilar papilla (BP) is capable of complete recovery from hearing loss after damage. Avian sensory hair cell regeneration relies on rousing quiescent supporting cells to proliferate or transdifferentiate after hair cell death. Unlike mammalian cochlear supporting cells, which have clearly defined subtypes, avian BP supporting cells are deceptively indistinguishable and molecular markers have yet to be identified. Despite the importance of supporting cells as the putative stem cells in avian regeneration, it is unknown whether all supporting cells possess equal capability to give rise to a hair cell or if a specialized subpopulation exists. In this perspective, we reinvigorate the concept of a stem cell in the BP, and form comparisons to other regenerating tissues that show cell-cycle reentry after damage. Special emphasis is given to the structure of the BP and how anatomy informs both the potential, intrinsic heterogeneity of the supporting cell layer as well as the choice between mitotic and nonmitotic regenerative strategies.
与缺乏再生能力的成年哺乳动物耳蜗形成鲜明对比的是，成熟的禽类耳蜗或基底乳头（BP）在受到损伤后能够从听力损失中完全恢复。禽类感觉毛细胞的再生依赖于激活静止的支持细胞，使其在毛细胞死亡后增殖或转分化。与具有明确亚类的哺乳动物耳蜗支持细胞不同，禽类 BP 支持细胞具有欺骗性的不可区分性，并且尚未鉴定出分子标记物。尽管支持细胞作为禽类再生中的潜在干细胞非常重要，但尚不清楚所有支持细胞是否具有同等能力产生毛细胞，或者是否存在专门的亚群。在这种观点中，我们重新激活了 BP 中的干细胞概念，并与其他表现出损伤后细胞周期再进入的再生组织进行了比较。特别强调了 BP 的结构，以及解剖结构如何告知支持细胞层的潜在内在异质性，以及有丝分裂和非有丝分裂再生策略之间的选择。
