Lactosylceramide-Induced Phosphorylation Signaling to Group IVA Phospholipase A2 via Reactive Oxygen Species in Tumor Necrosis Factor-α-Treated Cells
Lactosylceramide-Induced Phosphorylation Signaling to Group IVA Phospholipase A2 via Reactive Oxygen Species in Tumor Necrosis Factor-α-Treated Cells
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在肿瘤坏死因子-α 处理的细胞中，乳糖神经酰胺通过活性氧诱导 IVA 族磷脂酶 A2 的磷酸化信号传导
DOI：
10.1002/jcb.26091
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Murayama T
中科院分区：
文献类型：
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作者：
Nakamura H;Moriyama Y;Watanabe K;Tomizawa S;Yamazaki R;Takahashi H;Murayama T
释放花生四烯酸（AA）的α型胞质磷脂酶A2（cPLA 2 α，IVA PLA 2组）的活性主要受Ca 2+诱导的酶与底物膜的细胞内易位/附着及其磷酸化的调节。我们之前报道了肿瘤坏死因子-α（TNFα）刺激L929成纤维细胞中乳糖神经酰胺（LacCer）的形成，并且该脂质直接与cPLA 2 α结合并激活cPLA 2 α [中村等人[2013] J. Biol. Chem. 288：23264-23272]。我们在此研究了磷酸化信号在TNFα/LacCer诱导的细胞中cPLA 2 α活化中的作用。TNFα处理的L929细胞通过细胞外信号调节激酶1/2（ERK 1/2）和cPLA 2 α的磷酸化释放AA，而单独用LacCer处理以类似的方式释放AA。通过抑制LacCer合成，TNFα诱导的反应（包括AA释放）降低。TNFα和LacCer处理增加了活性氧（ROS）的水平，并且ROS的减少/清除减少了TNFα/LacCer处理的L929细胞中AA的磷酸化级联和释放。在细胞系CHO中，用LacCer处理通过ROS的形成刺激AA的磷酸化级联和释放。用抗LacCer抗体和4β-佛波醇12-肉豆蔻酸酯13-乙酸酯处理刺激磷酸化级联反应，但本身不释放AA。当与Ca 2+离子载体A23187组合时，用抗LacCer抗体和4β-佛波醇12-肉豆蔻酸酯13-乙酸酯处理释放AA。这些结果，包括我们之前的发现，表明单独的LacCer同时刺激两个过程来激活cPLA 2 α：磷酸化信号和酶与底物膜的附着。J.细胞。118：4370-4382，2017.© 2017威利期刊公司.
The activity of α‐type cytosolic phospholipase A2(cPLA2α, group IVA PLA2), which releases arachidonic acid (AA), is mainly regulated by the Ca2+‐induced intracellular translocation/attachment of the enzyme to substrate membranes and its phosphorylation. We previously reported that tumor necrosis factor‐α (TNFα) stimulated the formation of lactosylceramide (LacCer) in L929 fibroblast cells, and this lipid directly bound with and activated cPLA2α [Nakamura et al. [2013] J. Biol. Chem. 288:23264–23272]. We herein investigated the role of phosphorylation signaling in the TNFα/LacCer‐induced activation of cPLA2α in cells. TNFα‐treated L929 cells released AA via the phosphorylation of extracellular signal‐regulated kinase 1/2 (ERK1/2) and cPLA2α, while a treatment with LacCer alone released AA in a similar manner. The TNFα‐induced responses including release of AA were decreased by the inhibition of LacCer synthesis. The treatment with TNFα and LacCer increased the levels of reactive oxygen species (ROS), and the reduction/scavenging of ROS decreased the phosphorylation cascade and release of AA in TNFα/LacCer‐treated L929 cells. In the cell line CHO, the treatment with LacCer stimulated the phosphorylation cascade and release of AA via the formation of ROS. Treatments with the anti‐LacCer antibody and 4β‐phorbol 12‐myristate 13‐acetate stimulated the phosphorylation cascade, but did not release AA by itself. When combined with the Ca2+ionophore A23187, treatments with the anti‐LacCer antibody and 4β‐phorbol 12‐myristate 13‐acetate released AA. These results, including our previous findings, showed that LacCer alone simultaneously stimulates two processes to activate cPLA2α: a phosphorylation signal and attachment of the enzyme to substrate membranes. J. Cell. Biochem. 118: 4370–4382, 2017. © 2017 Wiley Periodicals, Inc.