Ceramide-mediated macroautophagy involves inhibition of protein kinase B and up-regulation of beclin 1
Ceramide-mediated macroautophagy involves inhibition of protein kinase B and up-regulation of beclin 1
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DOI：
10.1074/jbc.m313561200
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发表时间：
2004-04-30
影响因子：
4.8
通讯作者：
Codogno, P
中科院分区：
文献类型：
--
作者：
Scarlatti, F;Bauvy, C;Codogno, P
鞘脂神经酰胺参与细胞应激反应。在这里，我们证明，神经酰胺控制宏自噬，一个主要的溶酶体分解代谢途径。外源性C-2-神经酰胺通过增加长链神经酰胺的内源性库来刺激人结肠癌HT-29细胞中的大自噬（蛋白水解和自噬空泡的积累），如通过使用神经酰胺合酶抑制剂伏马菌素B-1所证明的。神经酰胺通过干扰蛋白激酶B的活化，逆转了白细胞介素13依赖的大自噬抑制。此外，C-2-神经酰胺刺激自噬基因产物beclin 1的表达。神经酰胺也是人乳腺癌MCF-7细胞中自噬空泡的他莫昔芬依赖性积累的介质。单丹尸胺染色和电子显微镜显示，这种积累被废除myriocin，从头合成神经酰胺的抑制剂。他莫昔芬依赖性的空泡积累被1-苯基-2-癸酰氨基-3-吗啉代-1-丙醇（一种葡萄糖神经酰胺合酶抑制剂）模拟。1-苯基-2-癸酰氨基-3-吗啉代-1-丙醇、他莫昔芬和C-2-神经酰胺刺激beclin 1的表达，而多球壳菌素拮抗他莫昔芬依赖性上调。他莫昔芬和C-2-神经酰胺干扰蛋白激酶B的激活，而多球壳菌素解除他莫昔芬的抑制作用。总之，神经酰胺对宏自噬的控制为这种脂质介质在具有主要生物学结果的细胞过程中提供了一种新功能。
The sphingolipid ceramide is involved in the cellular stress response. Here we demonstrate that ceramide controls macroautophagy, a major lysosomal catabolic pathway. Exogenous C-2-ceramide stimulates macroautophagy (proteolysis and accumulation of autophagic vacuoles) in the human colon cancer HT-29 cells by increasing the endogenous pool of long chain ceramides as demonstrated by the use of the ceramide synthase inhibitor fumonisin B-1. Ceramide reverted the interleukin 13-dependent inhibition of macroautophagy by interfering with the activation of protein kinase B. In addition, C-2-ceramide stimulated the expression of the autophagy gene product beclin 1. Ceramide is also the mediator of the tamoxifen-dependent accumulation of autophagic vacuoles in the human breast cancer MCF-7 cells. Monodansylcadaverine staining and electron microscopy showed that this accumulation was abrogated by myriocin, an inhibitor of de novo synthesis ceramide. The tamoxifen-dependent accumulation of vacuoles was mimicked by 1-phenyl-2-decanoylamino-3-morpholino-1-propanol, an inhibitor of glucosylceramide synthase. 1-Phenyl-2-decanoylamino-3-morpholino-1-propanol, tamoxifen, and C-2-ceramide stimulated the expression of beclin 1, whereas myriocin antagonized the tamoxifen-dependent up-regulation. Tamoxifen and C-2-ceramide interfere with the activation of protein kinase B, whereas myriocin relieved the inhibitory effect of tamoxifen. In conclusion, the control of macroautophagy by ceramide provides a novel function for this lipid mediator in a cell process with major biological outcomes.