Coles H S, Burne J F, Raff M C
Department of Biology, University College London, UK.
Development. 1993 Jul;118(3):777-84. doi: 10.1242/dev.118.3.777.
Although normal cell death is known to occur in many developing vertebrate organs, it has not been thought to play an important part in the development of the mammalian kidney. We show here that normal cell death is found in both the nephrogenic region and medullary papilla of the developing rat kidney and, in each of these areas, it follows a distinct developmental time course. As many as 3% of the cells in these areas have a typical apoptotic morphology and the dead cells seem to be cleared rapidly (within 1-2 hours) by phagocytosis by neighbouring parenchymal cells. These values are similar to those in vertebrate neural tissues where 50% or more of the cells die during normal development, suggesting that large-scale death is a normal feature of kidney development. We also show that in vivo treatment with epidermal growth factor inhibits cell death in the developing kidney, consistent with the possibility that the cells normally die because they lack sufficient survival factors. Our findings suggest that the extent of normal cell death in developing animals is still greatly underestimated and they raise the possibility that many of these cell deaths may reflect limiting amounts of survival factors.
虽然已知正常细胞死亡发生在许多发育中的脊椎动物器官中，但人们一直认为它在哺乳动物肾脏的发育中并不起重要作用。我们在此表明，在发育中的大鼠肾脏的肾发生区和髓质乳头中都发现了正常细胞死亡，并且在这些区域中的每一个，它都遵循一个独特的发育时间进程。这些区域中多达3%的细胞具有典型的凋亡形态，并且死亡细胞似乎在1至2小时内被邻近实质细胞通过吞噬作用迅速清除。这些数值与脊椎动物神经组织中的数值相似，在神经组织中，50%或更多的细胞在正常发育过程中死亡，这表明大规模细胞死亡是肾脏发育的一个正常特征。我们还表明，用表皮生长因子进行体内治疗可抑制发育中肾脏的细胞死亡，这与细胞通常因缺乏足够的存活因子而死亡的可能性一致。我们的发现表明，发育中动物正常细胞死亡的程度仍被大大低估，并且它们增加了许多这些细胞死亡可能反映存活因子数量有限的可能性。
