Sialic acids linked to glycoconjugates of Fas regulate the caspase-9-dependent and mitochondria-mediated pathway of Fas-induced apoptosis in Jurkat T cell lymphoma.
Sialic acids linked to glycoconjugates of Fas regulate the caspase-9-dependent and mitochondria-mediated pathway of Fas-induced apoptosis in Jurkat T cell lymphoma.
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与 Fas 糖缀合物相连的唾液酸调节 Jurkat T 细胞淋巴瘤中 Fas 诱导的细胞凋亡的 caspase-9 依赖性和线粒体介导途径。
DOI：
10.3892/ijo.23.3.769
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发表时间：
2003
影响因子：
5.2
通讯作者：
M. Abe
中科院分区：
文献类型：
--
作者：
Osamu Suzuki;Y. Nozawa;M. Abe
为了阐明与Fas糖缀合物相关的唾液酸在Fas诱导的细胞凋亡中的作用，我们用抗Fas单克隆抗体CH11孵育未处理和神经氨酸酶处理的Jurkat T细胞。经神经氨酸酶预处理后，CH11诱导的Jurkat T细胞凋亡增强。利用LFA凝集素在Jurkat T细胞表面检测到唾液酸化的糖缀合物，LFA凝集素与唾液酸发生特异性反应，而霍乱弧菌神经氨酸酶预处理导致Jurkat细胞表面糖缀合物去盐化。广泛的caspase抑制剂z-VAD-fmk和caspase-9抑制剂Ac-LEHD-CHO能抑制fas诱导的细胞凋亡，但caspase-8或6抑制剂Ac-IETD-CHO、酸性鞘磷脂酶抑制剂丙咪嗪、中性鞘磷脂酶抑制剂谷胱甘肽和神经酰胺合成酶抑制剂伏马菌素B1不能抑制fas诱导的细胞凋亡。线粒体膜电位（Deltapsim）测定试剂盒显示，神经氨酸酶预处理增强了参与fas诱导的细胞凋亡的Deltapsim的丢失。此外，使用针对Fas的多克隆抗体（C-20）进行Western blot分析，检测到Fas的分子量约为45 kDa，并且神经氨酸酶预处理导致Fas的分子量减少约8 kDa。这些数据表明，通过神经氨酸酶预处理Fas诱导的细胞凋亡的增强是通过与Deltapsim缺失密切相关的caspase-9依赖途径介导的，而不是通过激活caspase-8、-6或酸性和中性鞘磷脂酶，并且与Fas糖缀合物相关的唾液酸可能调节Fas诱导的人T细胞淋巴瘤细胞凋亡。
To clarify the functions of sialic acids linked to glycoconjugates of Fas in Fas-induced apoptosis, Jurkat T cells, untreated and treated with neuraminidase, were incubated with anti-Fas monoclonal antibody, CH11. Apoptosis of Jurkat T cells induced by incubation with CH11 was enhanced by the pre-treatment with neuraminidase. By flow cytometry sialylated glycoconjugates were detected on the cell surface of Jurkat T cells using LFA lectin, which specifically reacts with sialic acid, and pre-treatment with Vibrio Cholerae neuraminidase resulted in desialylation of Jurkat cell surface glycoconjugates. The enhancement of Fas-induced apoptosis by pre-treatment with neuraminidase was inhibited by z-VAD-fmk, a broad caspase inhibitor, and Ac-LEHD-CHO, an inhibitor of caspase-9, but not by Ac-IETD-CHO an inhibitor of caspase-8 or 6, imipramine, an inhibitor of acidic sphingomyelinase, glutathione, an inhibitor of neutral sphingomyelinase and Fumonisin B1, an inhibitor of ceramide synthase. Mitochondrial membrane potentials (Deltapsim) measured with a Mitocapture assay kit demonstrated that the loss of Deltapsim involved in Fas-induced apoptosis was enhanced by pre-treatment with neuraminidase. Furthermore, Western blot analysis using polyclonal antibody (C-20) against Fas detected Fas at about 45 kDa, and pre-treatment with neuraminidase resulted in a reduction of the molecular weight of Fas of about 8 kDa. These data suggest that the enhancement of Fas-induced apoptosis by pre-treatment with neuraminidase was mediated by a caspase-9 dependent pathway closely associated with the loss of Deltapsim, not by activation of caspase-8, -6 or acidic and neutral sphingomyelinases, and that sialic acid linked to glycoconjugates of Fas may regulate Fas-induced apoptosis in human T cell lymphoma.