Role of the JAK/STAT pathway in the regulation of interleukin-8 transcription by oxidized phospholipids in vitro and in atherosclerosis in vivo
Role of the JAK/STAT pathway in the regulation of interleukin-8 transcription by oxidized phospholipids in vitro and in atherosclerosis in vivo
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DOI：
10.1074/jbc.m704267200
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发表时间：
2007-10-26
影响因子：
4.8
通讯作者：
Berliner, Judith A.
中科院分区：
文献类型：
--
作者：
Gharavi, Nima M.;Alva, Jackelyn A.;Berliner, Judith A.
氧化后的1-棕榈酰-2-花生四烯酰基- n-甘油-3-磷酸胆碱（Ox-PAPC）及其成分磷脂1-棕榈酰-2-环氧异前列腺素- n-甘油-3-磷酸胆碱可诱导内皮细胞（EC）合成白细胞介素8 （IL-8）等趋化因子。之前，我们证明了c-Src激酶激活在ox - papc诱导的IL-8转录中的作用。在本研究中，我们研究了c-Src下游Ox-PAPC调控IL-8转录的机制。我们的发现证明了JAK2在Ox-PAPC调控IL-8转录中的重要作用。用Ox-PAPC和1-棕榈酰-2-环氧异前列腺素- cn -甘油-3-磷酸胆碱治疗人主动脉EC诱导JAK2快速而持续的激活；Ox-PAPC对JAK2的激活依赖于c-Src激酶活性。此外，选择性JAK2抑制剂预处理显著降低ox - papc诱导的IL-8转录。在之前的研究中，我们也证实了Ox-PAPC可以激活STAT3。在这里，我们提供的证据表明，Ox-PAPC对STAT3的激活依赖于JAK2的激活，STAT3的激活调节了Ox-PAPC对人EC中IL-8的转录。用小干扰RNA转染STAT3显著降低ox - papc诱导的IL-8转录。利用染色质免疫沉淀试验，我们证实了激活的STAT3与IL-8启动子中一致γ -干扰素激活序列（GAS）两侧的序列结合；GAS的定点诱变抑制了Ox-PAPC对IL-8的转录。最后，这些研究证明了STAT3在体内动脉粥样硬化中的激活作用。我们发现，在人类动脉粥样硬化病变的炎症区域，活化的STAT3染色增加，在食用致动脉粥样硬化饮食的ec特异性STAT3敲除小鼠中，脂肪条纹的形成减少。综上所述，这些数据证明了JAK2/STAT3通路在ox - papc诱导的IL-8体外和体内动脉粥样硬化中的重要作用。
Oxidized 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphorylcholine (Ox-PAPC) and its component phospholipid, 1-palmitoyl-2- epoxyisoprostane-sn-glycero-3-phosphorylcholine, induce endothelial cells (EC) to synthesize chemotactic factors, such as interleukin 8 (IL-8). Previously, we demonstrated a role for c-Src kinase activation in Ox-PAPC-induced IL-8 transcription. In this study, we have examined the mechanism regulating IL-8 transcription by Ox-PAPC downstream of c-Src. Our findings demonstrate an important role for JAK2 in the regulation of IL-8 transcription by Ox-PAPC. Treatment of human aortic EC with Ox-PAPC and 1-palmitoyl-2-epoxyisoprostane-sn-glycero-3- phosphorylcholine induced a rapid yet sustained activation of JAK2; activation of JAK2 by Ox-PAPC was dependent on c-Src kinase activity. Furthermore, pretreatment with selective JAK2 inhibitors significantly reduced Ox-PAPC-induced IL-8 transcription. In previous studies, we also demonstrated activation of STAT3 by Ox-PAPC. Here we provide evidence that STAT3 activation by Ox-PAPC is dependent on JAK2 activation and that STAT3 activation regulates IL-8 transcription by Ox-PAPC in human EC. Transfection with small interfering RNA against STAT3 significantly reduced Ox-PAPC-induced IL-8 transcription. Using chromatin immunoprecipitation assays, we demonstrated binding of activated STAT3 to the sequence flanking the consensus gamma-interferon activation sequence (GAS) in the IL-8 promoter; site-directed mutagenesis of GAS inhibited IL-8 transcription by Ox-PAPC. Finally, these studies demonstrate a role for STAT3 activation in atherosclerosis in vivo. We found increased staining for activated STAT3 in the inflammatory regions of human atherosclerotic lesions and reduced fatty streak formation in EC-specific STAT3 knock-out mice on the atherogenic diet. Taken together, these data demonstrate an important role for the JAK2/STAT3 pathway in Ox-PAPC-induced IL-8 transcription in vitro and in atherosclerosis in vivo.