Tumor necrosis factor-α-induced cyclooxygenase-2 expression via sequential activation of ceramide-dependent mitogen-activated protein kinases, and IκB kinase 1/2 in human alveolar epithelial cells
Tumor necrosis factor-α-induced cyclooxygenase-2 expression via sequential activation of ceramide-dependent mitogen-activated protein kinases, and IκB kinase 1/2 in human alveolar epithelial cells
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DOI：
10.1124/mol.59.3.493
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发表时间：
2001-03-01
影响因子：
3.6
通讯作者：
Chang, YJ
中科院分区：
文献类型：
--
作者：
Chen, CC;Sun, YT;Chang, YJ
在NCI-H292上皮细胞中研究了p44/42丝裂原活化蛋白激酶（MAPK）、p38和c-Jun氨基末端激酶（JNK）在肿瘤坏死因子（TNF）-α诱导的环氧合酶（考克斯）-2表达中的作用。MAPK激酶抑制剂PD98059或p38抑制剂SB 203580可抑制TNF-α介导的考克斯-2表达和考克斯-2启动子活性。用TNF-α处理细胞10分钟导致p44/42 MAPK、p38和JNK的激活。C2-神经酰胺（一种细胞渗透性神经酰胺类似物）、细菌中性鞘磷脂酶（Smase;一种将鞘磷脂降解为神经酰胺的酶）和N-油酰乙醇胺（一种神经酰胺酶抑制剂）均诱导MAPK活化、考克斯-2表达、核因子（NF）-kappaB DNA-蛋白结合和考克斯-2启动子活性。无活性的类似物二氢-C2-神经酰胺没有效果。SMase或C2-神经酰胺诱导的考克斯-2表达和考克斯-2启动子活性也被PD98059或SB 203580抑制。中性SMase抑制剂Glucose可减弱TNF-α或SMase诱导的MAPK活化、考克斯-2表达和考克斯-2启动子活性。TNF-α或C2-神经酰胺诱导的考克斯-2启动子活性被细胞外信号调节激酶2、p38、JNK、I κ B激酶（IKK）1或IKK 2的显性负突变体抑制。IKK活性被TNF-α或C2-神经酰胺刺激，这些作用被PD98059或SB 203580抑制。所有这些结果表明，在NCI-H292上皮细胞中，神经酰胺激活MAPK有助于中性SMase激活下游发生的TNF-α信号传导，并导致IKK 1/2和考克斯-2启动子中的NF-κ B的刺激，随后启动考克斯-2表达。
The role of p44/42 mitogen-activated protein kinase (MAPK), p38, and c-Jun NH2-terminal kinase (JNK) in tumor necrosis factor (TNF)-alpha -induced cyclooxygenase (COX)-2 expression was studied in NCl-H292 epithelial cells. TNF-alpha -mediated COX-2 expression and COX-2 promoter activity were inhibited by the MAPK kinase inhibitor PD98059 or the p38 inhibitor SB203580. Treatment of cells for 10 min with TNF-alpha resulted in activation of p44/42 MAPK, p38, and JNK. C2-ceramide (a cell-permeable ceramide analog), bacterial neutral sphingomyelinase (Smase; an enzyme that degrades sphingomyelin to ceramide), and N-oleoylethanolamine (a ceramidase inhibitor) all induced activation of MAPKs, COX-2 expression, nuclear factor (NF)-kappaB DNA-protein binding, and COX-2 promoter activity. The inactive analog, dihydro-C2-ceramide, had no effect. SMase- or C2-ceramide-induced COX-2 expression and COX-2 promoter activity were also inhibited by PD98059 or SB203580. Glutathione, a neutral SMase inhibitor, attenuated TNF-alpha- or SMase-induced activation of MAPKs, COX-2 expression, and COX-2 promoter activity. TNF-alpha- or C2- ceramide- induced COX-2 promoter activity was inhibited by the dominant negative mutant of extracellular signal-regulated kinase 2, p38, JNK, I kappaB kinase (IKK)1, or IKK2. IKK activity was stimulated by either TNF-alpha or C2- ceramide, and these effects were inhibited by PD98059 or SB203580. All these results suggest that, in NCl-H292 epithelial cells, activation of MAPKs by ceramide contributes to the TNF-alpha signaling that occurs downstream of neutral SMase activation and results in the stimulation of IKK1/2, and NF-kappaB in the COX-2 promoter, followed by initiation of COX-2 expression.