Zhong Cuiping, Han Yu, Qiu Jianhua, Lu Lianjun, Chen Yang, Chen Jun, Hei Renyi, Mi Wenjuan
Department of Otolaryngology, Xijing Hospital, Fourth Military Medical University, Changlexilu 15, Xi'an 710032, Shanxi Province, China.
Int J Pediatr Otorhinolaryngol. 2010 Feb;74(2):192-7. doi: 10.1016/j.ijporl.2009.11.009. Epub 2009 Dec 5.
Recent reports have shown that multipotent stem cells/progenitor cells that are capable of proliferation and regeneration are present in mammalian cochleae. However, progenitor cells have not been isolated from the adult cochlea. We examined the proliferative potential of cells derived from neonatal rats of various ages. The determination of the differences between the proliferative cells from rats of different ages may provide clues to the mechanisms controlling the destiny of these cells.
Proliferative cells were isolated from the cochleae of 1-, 7-, and 14-day-old rats, and the proliferative capacity and ultrastructure of the cells from each age group were assessed using flow cytometry and transmission electron microscopy, respectively.
During the first two postnatal weeks, the number of proliferative cells gradually fell to zero. This decrease occurred in parallel with the impairment of the proliferative capacity of the cells and the accumulation of proliferative cells in G0/G1. In addition, some of the cells exited the cell cycle by means of gradual maturity and apoptosis.
Our study suggests that cochlear proliferative cells are remnants of the progenitor cells that originally gave rise to the sensory epithelium. The disappearance of the cochlear proliferative cells in adult mammalian cochleae may result from their differentiation and/or apoptosis.
近期报告显示，能够增殖和再生的多能干细胞/祖细胞存在于哺乳动物的耳蜗中。然而，成年耳蜗中的祖细胞尚未被分离出来。我们研究了不同年龄新生大鼠来源细胞的增殖潜能。确定不同年龄大鼠增殖细胞之间的差异可能为控制这些细胞命运的机制提供线索。
从1日龄、7日龄和14日龄大鼠的耳蜗中分离增殖细胞，分别使用流式细胞术和透射电子显微镜评估各年龄组细胞的增殖能力和超微结构。
在出生后的前两周内，增殖细胞数量逐渐降至零。这种减少与细胞增殖能力的受损以及增殖细胞在G0/G1期的积累同时发生。此外，一些细胞通过逐渐成熟和凋亡退出细胞周期。
我们的研究表明，耳蜗增殖细胞是最初产生感觉上皮的祖细胞的残余。成年哺乳动物耳蜗中增殖细胞的消失可能是由于它们的分化和/或凋亡。
