Palmitate-induced apoptosis can occur through a ceramide-independent pathway
Palmitate-induced apoptosis can occur through a ceramide-independent pathway
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DOI：
10.1074/jbc.m010286200
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发表时间：
2001-05-04
影响因子：
4.8
通讯作者：
Schaffer, JE
中科院分区：
文献类型：
--
作者：
Listenberger, LL;Ory, DS;Schaffer, JE
已提出长链脂肪酸的细胞毒性蓄积在糖尿病和心脏病的发病机制中起重要作用。为了探讨细胞脂毒性的机制，我们在添加脂肪酸的培养基中培养中国仓鼠卵巢细胞。饱和脂肪酸棕榈酸酯，但不是单不饱和脂肪酸油酸酯，诱导程序性细胞死亡，确定膜联蛋白V阳性，半胱天冬酶3活性，和DNA梯状。补充棕榈酸可使新生神经酰胺合成增加2.4倍;然而，这不是棕榈酸诱导的细胞凋亡所必需的。补充棕榈酸后，新生神经酰胺合成的生化或遗传抑制均不能阻止中国仓鼠卵巢细胞的细胞凋亡。相反，我们的数据表明，棕榈酸诱导的细胞凋亡发生通过产生活性氧。荧光的氧化剂敏感的探针增加了3.5倍，棕榈酸补充表明，生产的活性中间体增加。此外，棕榈酸酯诱导的细胞凋亡被阻断吡咯烷二硫代氨基甲酸酯和4，5-二羟基-1，3-苯二磺酸，两种化合物，抑制活性中间体。这些研究表明，活性氧的产生，独立于神经酰胺的合成，是重要的脂毒性反应，并可能有助于涉及细胞内脂质积累的疾病的发病机制。
Cytotoxic accumulation of long chain fatty acids has been proposed to play an important role in the pathogenesis of diabetes mellitus and heart disease. To explore the mechanism of cellular lipotoxicity, we cultured Chinese hamster ovary cells in the presence of media supplemented with fatty acid. The saturated fatty acid palmitate, but not the monounsaturated fatty acid oleate, induced programmed cell death as determined by annexin V positivity, caspase 3 activity, and DNA laddering. De novo ceramide synthesis increased 2.4-fold with palmitate supplementation; however, this was not required for palmitate-induced apoptosis, Neither biochemical nor genetic inhibition of de novo ceramide synthesis arrested apoptosis in Chinese hamster ovary cells in response to palmitate supplementation. Rather, our data suggest that palmitate-induced apoptosis occurs through the generation of reactive oxygen species. Fluorescence of an oxidant-sensitive probe was increased 3.5-fold with palmitate supplementation indicating that production of reactive intermediates increased. In addition, palmitate-induced apoptosis was blocked by pyrrolidine dithiocarbamate and 4,5-dihydroxy-1,3-benzene-disulfonic acid, two compounds that scavenge reactive intermediates. These studies suggest that generation of reactive oxygen species, independent of ceramide synthesis, is important for the lipotoxic response and may contribute to the pathogenesis of diseases involving intracellular lipid accumulation.