Programmed cell death in rat intestine: Effect of feeding and fasting
Programmed cell death in rat intestine: Effect of feeding and fasting
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DOI：
10.1080/00365520150218048
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发表时间：
2001-01-01
影响因子：
1.9
通讯作者：
Aw, TY
中科院分区：
文献类型：
--
作者：
Iwakiri, R;Gotoh, Y;Aw, TY
背景：人们对管腔因子对肠道细胞死亡的调节知之甚少。本研究的目的是确定肠道细胞凋亡是否存在昼夜节律，并确定进食和禁食在此过程中所起的作用。方法：通过 DNA 片段化和原位免疫组织化学染色 (TUNEL) 测量喂养和 24 小时禁食大鼠以及喂养后不同时间的粘膜凋亡死亡。结果：在 24 小时禁食的大鼠中，总粘膜 DNA 的 32% 发生片段化，而进食动物中这一比例为 9%。在空肠和回肠片段中，片段化的 DNA 在琼脂糖凝胶上均表现出特征性的凋亡 DNA 梯带。免疫组织化学染色显示凋亡细胞位于肠绒毛的上三分之一处。在十二指肠中，喂食后 6-12 小时的 DNA 断裂率为 20%，24 小时时降至 4%。相比之下，空肠和回肠中的 DNA 碎片在喂养后 0 至 6 小时内较低（2%-9%），并分别在 12 小时（18% 与 12%）和 24 小时（30% 与 32%）时显着增加。这些结果与 DNA 片段百分比和进食后时间之间的时间关系一致，在较长的禁食期间细胞死亡较多。空肠和回肠中存在明显的餐后 DNA 断裂节律，其中断裂在 0900 小时至 1200 小时之间达到峰值。结论：总的来说，数据表明顶端肠上皮细胞凋亡的启动与停止进食和开始禁食同时发生，并且与这些细胞中与进食和禁食的循环模式平行的程序性细胞死亡节律一致。
Background: The regulation of intestinal cell death by luminal factors is poorly understood. The objectives of this study were to determine whether a diurnal rhythm of intestinal apoptosis exists, and to determine the role that feeding and fasting play in this process. Methods: Mucosal apoptotic death was measured in fed and 24-h fasted rats and at various times after feeding by DNA fragmentation and in situ immunohistochemical staining (TUNEL). Results: In 24-h fasted rats, 32% of total mucosal DNA was fragmented as compared to 9% in fed animals. In both jejunal and ileal segments, the fragmented DNA exhibited characteristic apoptotic DNA ladders on agarose gels. Immunohistochemical staining revealed significant location of apoptotic cells at the upper third of the intestinal villus. In the duodenum, DNA fragmentation at 6-12h post feeding was 20% and decreased to 4% at 24 h. In comparison, DNA fragmentation in the jejunum and ileum was low from 0 to 6 h post feeding (2%-9%) and significantly increased at 12 h (18% versus 12%) and 24 h (30% versus 32%), respectively. These results are consistent with a temporal relationship between percent fragmented DNA and time after feeding with greater cell death at longer fasting period. A postprandial rhythm of DNA fragmentation was evident in the jejunum and ileum, in which fragmentation was at a peak between 0900 h and 1200 h. Conclusion: Collectively, the data show that initiation of apoptosis in apical enterocytes is coincident with cessation of feeding and commencement of fasting, and is consistent with a rhythm of programmed cell death in these cells that parallels the cyclical pattern of feeding and fasting.