Glucocorticoid-mediated gene suppression of rat cytokine-induced neutrophil chemoattractant CINC gro, a member of the interleukin-8 family, through impairment of NF-kappa B activation
Glucocorticoid-mediated gene suppression of rat cytokine-induced neutrophil chemoattractant CINC gro, a member of the interleukin-8 family, through impairment of NF-kappa B activation
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DOI：
10.1074/jbc.271.3.1651
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发表时间：
1996-01-19
影响因子：
4.8
通讯作者：
Tsurufuji, S
中科院分区：
文献类型：
--
作者：
Ohtsuka, T;Kubota, A;Tsurufuji, S
糖皮质激素地塞米松可抑制用白细胞介素-1 β（IL-1 β）、脂多糖或肿瘤坏死因子α刺激的正常大鼠肾上皮细胞系NRK-52 E中大鼠肾上腺素诱导的中性粒细胞趋化因子CINC/gro的产生，CINC/gro是属于白细胞介素-8（IL-8）家族的人黑色素瘤生长刺激活性的对应物。地塞米松也能抑制IL-1 β诱导的CINC/gro mRNA的积累。细胞核连续实验表明，地塞米松能抑制IL-1 β诱导的CINC/gro基因转录，CINC/gro mRNA转录物的半衰期在地塞米松作用后无明显变化，提示地塞米松主要在转录水平起作用。用含有5 '缺失和突变的CINC/gro基因序列的荧光素酶表达载体转染证明，含有NF-κ B结合位点的5'侧翼区分别参与IL-1 β和地塞米松诱导的CINC/gro基因表达的激活和抑制。CINC/gro基因中NF-κ B序列的串联重复赋予IL-1 β的诱导作用和地塞米松对荧光素酶活性的抑制作用。在电泳迁移率变动分析中，地塞米松减少了IL-1 β诱导的NF-κ B复合物的形成，该复合物由p65和p50组成。Western blotting显示地塞米松抑制了IL-1 β诱导的p65从胞浆向胞核的移位，而NF-κ B p50的核水平几乎不变。此外，地塞米松不抑制IL-1 β诱导的I κ B-α降解。这些结果表明，糖皮质激素对CINC/gro基因转录的抑制是通过损害NF-κ B活化发生的，可能是通过干扰NF-κ B p65从细胞质易位到细胞核，从而抑制CINC/gro基因的反式活化。
The glucocorticoid dexamethasone inhibited the production of the rat cytokine-induced neutrophil chemoattractant CINC/gro, a counterpart of human melanoma growth-stimulating activity that belongs to the interleukin-8 (IL-8) family, in the normal rat kidney epithelial cell line NRK-52E stimulated with interleukin-1 beta (IL-1 beta), lipopolysaccharide, or tumor necrosis factor alpha. The accumulation of CINC/gro mRNA induced by these activators was also decreased comparably by dexamethasone, A nuclear run-on assay revealed that dexamethasone decreased the IL-1 beta-induced transcription of the CINC/gro gene, The half-life of CINC/gro mRNA transcripts did not change significantly after exposure to dexamethasone, suggesting that this glucocorticoid acts mainly at the transcriptional level, Transfection with luciferase expression vectors containing 5'-deleted and mutated CINC/gro gene sequences demonstrated that the 5'-flanking region containing the NF-kappa B binding site is involved in the IL-1 beta- and dexamethasone-induced activation and repression of the CINC/gro gene expression, respectively, Furthermore, a tandem repeat of the NF-kappa B sequence in the CINC/gro gene conferred the inducibility by IL-1 beta and suppression of luciferase activity by dexamethasone. In an electrophoretic mobility shift assay, dexamethasone diminished the IL-1 beta-induced formation of NF-kappa B complexes, which consisted of p65 and p50. Western blotting revealed that dexamethasone inhibited the IL-1 beta-induced translocation of p65 hom the cytoplasm into the nucleus, while the nuclear level of NF-kappa B p50 remained almost unchanged. In addition, the degradation of I kappa B-alpha induced by IL-1 beta was not inhibited by dexamethasone. These results indicated that the suppression of the CINC/gro gene transcription by glucocorticoid occurs through the impairment of NF-kappa B activation, possibly by interference with the translocation of NF-kappa B p65 from the cytoplasm into the nucleus, thereby suppressing transactivation of the CINC/gro gene.