Tumor Necrosis Factor-α (TNF-α) Induces Upregulation of RhoA via NF-κB Activation in Cultured Human Bronchial Smooth Muscle Cells
Tumor Necrosis Factor-α (TNF-α) Induces Upregulation of RhoA via NF-κB Activation in Cultured Human Bronchial Smooth Muscle Cells
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DOI：
10.1254/jphs.09081fp
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发表时间：
2009-08-01
影响因子：
3.5
通讯作者：
Misawa, Miwa
中科院分区：
文献类型：
--
作者：
Goto, Kumiko;Chiba, Yoshihiko;Misawa, Miwa
RhoA在抗原诱导的气道高反应性（AHR）中对支气管平滑肌的Ca ~（2+）增敏中起重要作用。肿瘤坏死因子-α（TNF-α）是一种主要的促炎细胞因子，能够诱导AHR，但其机制尚不清楚。在本研究中，在培养的人支气管平滑肌细胞（hBSMC）中检查了TNF-α对RhoA蛋白表达的影响。为了研究NF-κ B在TNF-α诱导的RhoA上调中的作用，还测定了I κ B激酶（IKK）抑制剂BMS-345541的作用。免疫印迹和免疫细胞化学分析均显示，TNF-α孵育hBSMCs可激活NF-κ B（通过p65蛋白质向细胞核的易位确定）：当细胞与10 ng/mL TNF-α孵育30 min时观察到峰值反应。在与TNF-α孵育后12 - 24 h也观察到RhoA蛋白的上调（10 ng/mL）。通过与BMS-345541共孵育，NF-κ B的活化和RhoA的上调均受到浓度依赖性抑制。这些结果表明TNF-α诱导的RhoA上调可能是通过活化hBSMCs中的NF-κ B介导的。
RhoA plays an important role in Ca2+ sensitization of bronchial smooth muscle in antigen-induced airway hyperresponsiveness (AHR). Tumor necrosis factor-alpha (TNF-alpha), a major proinflammatory cytokine, is capable of inducing AHR, but the mechanisms for this are still unknown. In the present study, the effect of TNF-alpha on RhoA protein expression was examined in Cultured human bronchial smooth muscle cells (hBSMCs). To investigate the role of NF-kappa B in the TNF-alpha-induced upregulation of RhoA, the effects of an inhibitor of I kappa B kinase (IKK), BMS-345541, were also determined. Both immunoblot and immunocytochemical analyses revealed that incubation of the hBSMCs with TNF-alpha caused an activation of NF-kappa B (determined by a translocation of p65 proteins to nuclei): the peak response was observed when cells were incubated with 10 ng/mL of TNF-alpha for 30 min. An upregulation of RhoA protein was also observed at 12 - 24 h after the incubation with TNF-alpha (10 ng/mL). Both the activation of NF-kappa B and upregulation of RhoA were concentration-dependently inhibited by the co-incubation with BMS-345541. These results suggest that TNF-alpha-induced Upregulation of RhoA might be mediated by an activation of NF-kappa B in hBSMCs.