Celecoxib inhibits interleukin-12 αβ and β2 folding and secretion by a novel COX2-independent mechanism involving chaperones of the endoplasmic reticulum
Celecoxib inhibits interleukin-12 αβ and β2 folding and secretion by a novel COX2-independent mechanism involving chaperones of the endoplasmic reticulum
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DOI：
10.1124/mol.105.020669
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发表时间：
2006-05-01
影响因子：
3.6
通讯作者：
Vandenbroeck, K
中科院分区：
文献类型：
--
作者：
Alloza, I;Baxter, A;Vandenbroeck, K
塞来昔布（CE）是一种非甾体抗炎药（NSAID），是环氧合酶2（COX 2）的特异性抑制剂。它适用于各种慢性炎症，包括类风湿性关节炎。在过去的几年里，不良心血管作用和心脏病发作的风险增加与这种药物有关。此外，对于COX 2非依赖性分子靶点的证据正在出现。CE已显示通过COX 2非依赖性机制诱导各种癌细胞系的凋亡，该机制似乎涉及蛋白激酶Akt的失活和内质网（ER）Ca 2 + ATP酶的抑制。在这项研究中，我们发现CE和缺乏COX 2抑制活性的类似物[1-（4-氨磺酰基苯基）-3-三氟甲基-5-（4-三氟甲基苯基）吡唑，CEA]均抑制二聚体白细胞介素-12（IL-12）α、β和β（2）形式的分泌，其IC 50值分别为20和30 μ M，而罗非昔布没有观察到这种作用。逆转录-聚合酶链反应分析表明，这种抑制不是由于阻断了α-和β-链表达盒的转录。β单体形式的分泌受到较弱的抑制，提示主要靶向ER中二聚体组装的机制。细胞内组分的分析表明，CE和CEA增加了IL-12与钙网蛋白的关联，钙网蛋白是一种内质网驻留伴侣，参与错误折叠的货物蛋白的保留，同时阻断与ERp 44的相互作用。我们的研究结果揭示了塞来昔布对内质网中寡聚体蛋白折叠和组装以及随后的分泌的先前未描述的影响，并表明塞来昔布驱动的分泌组改变可能涉及其一些临床副作用。
Celecoxib (CE) is a nonsteroidal anti-inflammatory drug ( NSAID) that is a specific inhibitor of cyclooxygenase 2 (COX2). It is indicated for a variety of chronic inflammatory conditions, including rheumatoid arthritis. Over the last few years, adverse cardiovascular effects and increased risk for heart attacks have been associated with this drug. In addition, evidence is emerging for COX2-independent molecular targets. CE has been shown to induce apoptosis in various cancer cells lines through a COX2-independent mechanism that seems to involve inactivation of protein kinase Akt and inhibition of endoplasmic reticulum (ER) Ca2+ ATPase. In this study, we show that both CE and an analog devoid of COX2 inhibitory activity [1-(4-sulfamoyl phenyl)-3-trifluoromethyl-5-(4-trifluoromethylphenyl)pyrazole, CEA] inhibit the secretion of the dimeric interleukin-12 (IL-12) alpha beta and beta(2) forms with identical IC50 values of 20 and 30 mu M, respectively, whereas no such effect was seen with rofecoxib. Reverse transcription-polymerase chain reaction analysis showed that this inhibition was not due to a blockage of transcription of the alpha- and beta-chain expression cassettes. Secretion of the beta monomer form was less strongly inhibited, suggestive for a mechanism primarily targeting dimer assembly in the ER. Analysis of intracellular fractions revealed that both CE and CEA increased the association of IL-12 with calreticulin, an endoplasmic reticulum-resident chaperone involved in the retention of misfolded cargo proteins while blocking interaction with ERp44. Our findings reveal a previously undescribed effect of celecoxib on oligomer protein folding and assembly in the endoplasmic reticulum and ensuing secretion and suggest that celecoxib-driven alteration of the secretome may be involved in some of its clinical side effects.