Inhibition of Kv channel expression by NSAIDs depolarizes membrane potential and inhibits cell migration by disrupting calpain signaling.
Inhibition of Kv channel expression by NSAIDs depolarizes membrane potential and inhibits cell migration by disrupting calpain signaling.
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DOI：
10.1016/j.bcp.2015.10.017
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发表时间：
2015-12-15
影响因子：
5.8
通讯作者：
Lillich JD
中科院分区：
文献类型：
--
作者：
Silver K;Littlejohn A;Thomas L;Marsh E;Lillich JD
众所周知，临床使用非甾体抗炎药（NSAID）可通过抑制上皮细胞迁移和粘膜恢复等多种机制导致胃肠道溃疡形成。尽管先前的研究表明NSAID降低膜电位并抑制钙蛋白酶蛋白酶和电压门控钾（Kv）通道亚基的表达，但对NSAID抑制迁移的药物影响信号通路知之甚少。Kv通道在细胞迁移中起重要作用，并且是白色血细胞中NSAID活性的靶点，但是在肠上皮细胞中NSAID诱导的Kv通道表达变化的特定功能效应，特别是对细胞迁移的影响尚不清楚。因此，我们研究了NSAID对体外和/或体内Kv 1.3、1.4和1.6表达的影响，并评估了Kv亚基表达丧失的功能意义。吲哚美辛或NS-398降低了培养的肠上皮细胞（IEC-6）中Kv1.3的总蛋白和质膜蛋白表达。此外，去极化的膜电位与margatoxin（MgTx），40 mM K+，或沉默的Kv通道表达的siRNA显着降低IEC-6细胞迁移和破坏钙蛋白酶活性。此外，在大鼠小肠上皮细胞中，吲哚美辛和NS-398对Kv1.3、1.4或1.6的基因和蛋白表达具有显著但不同的影响，表明这些可能是临床相关的靶点。我们的研究结果表明，抑制上皮细胞迁移的NSAID与Kv通道亚单位的表达减少，并提供了一种机制，通过NSAID抑制细胞迁移，并可能有助于NSAID诱导的胃肠道（GI）毒性。
Clinical use of non-steroidal anti-inflammatory drugs (NSAIDs) is well known to cause gastrointestinal ulcer formation via several mechanisms that include inhibiting epithelial cell migration and mucosal restitution. The drug-affected signaling pathways that contribute to inhibition of migration by NSAIDs are poorly understood, though previous studies have shown that NSAIDs depolarize membrane potential and suppress expression of calpain proteases and voltage-gated potassium (Kv) channel subunits. Kv channels play significant roles in cell migration and are targets of NSAID activity in white blood cells, but the specific functional effects of NSAID-induced changes in Kv channel expression, particularly on cell migration, are unknown in intestinal epithelial cells. Accordingly, we investigated the effects of NSAIDs on expression of Kv1.3, 1.4, and 1.6 in vitro and/or in vivo and evaluated the functional significance of loss of Kv subunit expression. Indomethacin or NS-398 reduced total and plasma membrane protein expression of Kv1.3 in cultured intestinal epithelial cells (IEC-6). Additionally, depolarization of membrane potential with margatoxin (MgTx), 40 mM K+, or silencing of Kv channel expression with siRNA significantly reduced IEC-6 cell migration and disrupted calpain activity. Furthermore, in rat small intestinal epithelia, indomethacin and NS-398 had significant, yet distinct, effects on gene and protein expression of Kv1.3, 1.4, or 1.6, suggesting that these may be clinically relevant targets. Our results show that inhibition of epithelial cell migration by NSAIDs is associated with decreased expression of Kv channel subunits, and provide a mechanism through which NSAIDs inhibit cell migration and may contribute to NSAID-induced gastrointestinal (GI) toxicity.