Participation of autophagy in the degeneration process of rat hepatocytes after transplantation following prolonged cold preservation
Participation of autophagy in the degeneration process of rat hepatocytes after transplantation following prolonged cold preservation
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DOI：
10.1679/aohc.68.71
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发表时间：
2005-01-01
影响因子：
--
通讯作者：
Monden, M
中科院分区：
文献类型：
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作者：
Lu, ZH;Dono, K;Monden, M
移植肝冷缺血-热再灌注损伤已被广泛研究，但其机制尚不清楚。在这里，我们表明，自噬不仅涉及冷保存，但也在移植后的热再灌注。免疫组化使用的抗体对LC 3，微管相关蛋白I轻链3和自噬体的标记物，显示点样弱染色的大鼠肝移植肝细胞在冷保存。由于威斯康星州大学的移植物保存溶液缺乏氨基酸，肝细胞自噬的诱导与饥饿条件下相似。再灌注开始后30分钟，在肝细胞中检测到大量的免疫阳性点状结构。LC 3阳性颗粒往往共同定位在ED 2阳性枯否细胞在60分钟的再灌注阶段。LC 3的分子形式主要是LC 3-II，膜结合的形式，在再灌注期间，特别是在30分钟的阶段。电子显微镜检查显示，在30分钟的再灌注期肝细胞中的许多空泡结构，而一些肝细胞与这种空泡结构存在于窦腔。在再灌注后期，枯否细胞含有吞噬细胞，具有许多自噬空泡/自溶酶体和染色质浓缩的核。我们的研究结果表明，存在自噬空泡/自体溶酶体肝移植肝细胞再灌注开始后，表明，热再灌注作为一种应激刺激肝细胞。此外，肝细胞的应激反应可能参与其变性过程。
Cold ischemia-warm reperfusion injury of liver grafts has been investigated thoroughly, but its underlying mechanism remains poorly understood. Here we show that autophagy is involved not only during cold preservation but also during warm reperfusion following transplantation. Immunohistochemistry using an antibody against LC3, a microtubule associated protein I light chain 3 and a marker of autophagosomes, showed dot-like weak staining in hepatocytes of rat liver grafts during cold preservation. Since University of Wisconsin solution for graft preservation lacks amino acids, the induction of autophagy in hepatocytes was similar to that under starvation conditions. Intense immunopositive punctate structures were detected abundantly in the hepatocytes 30 min after the beginning of reperfusion. LC3-positive granules were often co-localized in ED2-positive Kupffer cells at 60 min of the reperfusion phase. The molecular form of LC3 was mainly LC3-II, a membrane-bound form, during reperfusion, especially at 30 min of the phase. Electron microscopic examination demonstrated numerous vacuolar structures in hepatocytes at 30 min of the reperfusion period, while some hepatocytes with such vacuolar structures were present in the sinusoidal lumen. At the late stage of the reperfusion period, Kupffer cells contained phagocytosed cells that possessed numerous autophagic vacuoles/autolysosomes and nuclei with condensed chromatin. Our results showing the presence of autophagic vacuoles/autolysosomes in hepatocytes of liver grafts after the start of reperfusion suggest that warm reperfusion acted as a stress stimulus to hepatocytes. Moreover, the stress response of hepatocytes may be involved in their degeneration process.