Hirai Shigeo, Harada Tamotsu
Department of Otorhinolaryngology, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama 701-0192, Japan.
Hear Res. 2004 Dec;198(1-2):41-7. doi: 10.1016/j.heares.2004.07.012.
Dying cells studied by the TdT-mediated dUTP nick end-labeling (TUNEL) method have been classified as "apoptotic" and "non-apoptotic" cells. In this study, in which 12-day-old mouse embryos were used because of a high frequency of "natural cell death" due to changing inner ear morphology [Kaufman, M.H., 1992. The Atlas of Mouse Development, first ed., Academic Press, London, p. 147], the percentages of "apoptotic" and "non-apoptotic" dying cells (ADC and NADC) among total dying cells in the inner ear were calculated. Observation of consecutive paraffin sections showed about 90% of the dying inner ear cells to be ADC and about 10% to be NADC. ADC and NADC TUNEL positive dying cells in resin sections observed by light microscopy were examined again by transmission electron microscopy using a re-embedding procedure. ADC and NADC were then analyzed based on the classification of dying cells (types 1, 2, 3A, and 3B) as described by Clarke [Anat. Embryol. 181 (1990) 195]. It was clear that ADC were the equivalent of type 1 (apoptotic) dying cells and NADC were the equivalent of type 2 (autophagic) dying cells. We consider these findings to be important baselines for determining the process underlying abnormal development of the inner ear and its functional disorders such as hearing loss.
通过末端脱氧核苷酸转移酶介导的dUTP缺口末端标记法（TUNEL）研究的死亡细胞已被分类为“凋亡”细胞和“非凋亡”细胞。在本研究中，由于内耳形态变化导致“自然细胞死亡”的频率较高，因此使用了12日龄的小鼠胚胎[考夫曼，M.H.，1992年。《小鼠发育图谱》，第一版，学术出版社，伦敦，第147页]，计算了内耳中总死亡细胞中“凋亡”和“非凋亡”死亡细胞（ADC和NADC）的百分比。连续石蜡切片观察显示，约90%的内耳死亡细胞为ADC，约10%为NADC。通过光镜观察树脂切片中TUNEL阳性的ADC和NADC死亡细胞，然后使用重新包埋程序通过透射电子显微镜再次检查。然后根据克拉克[《解剖学与胚胎学》181（1990）195]描述的死亡细胞分类（1型、2型、3A型和3B型）对ADC和NADC进行分析。很明显，ADC相当于1型（凋亡）死亡细胞，NADC相当于2型（自噬）死亡细胞。我们认为这些发现是确定内耳异常发育及其功能障碍（如听力损失）潜在过程的重要基线。
