Fluid shear-induced NFκB translocation in osteoblasts is mediated by intracellular calcium release
Fluid shear-induced NFκB translocation in osteoblasts is mediated by intracellular calcium release
复制标题
DOI：
10.1016/s8756-3282(03)00159-5
复制
发表时间：
2003-09-01
期刊：
影响因子：
4.1
通讯作者：
Duncan, RL
中科院分区：
文献类型：
--
作者：
Chen, NX;Geist, DJ;Duncan, RL
响应外源机械负荷的骨形成取决于环加氧酶诱导型同种型的前列腺素合成。环氧化酶-2。虽然有几种转录因子以 COX-2 基因为靶标，但我们研究了核因子 kappa B (NFkappaB) 在成骨细胞中 COX-2 上调中的作用，以响应流体剪切，因为它参与其他细胞类型的免疫和炎症反应。将 12 dyn/cm(2) 层流应用于 MOT3-E1 成骨细胞样细胞，导致 NFkappaB 在剪切开始后 1 小时内易位至细胞核，连续流动 2 小时后 NFkappaB 返回细胞质。 NFkappaB 因剪切而发生的易位受到蛋白酶抑制剂、Nα-对甲苯磺酰基-L-赖氨酸氯甲基酮盐酸盐 (TLCK) 或阻断 NFkappaB 核定位序列 (NLS) 的细胞渗透肽的抑制。用这些抑制剂阻断 NFkappaB 易位可阻断剪切诱导的 COX-2 上调。我们发现用细胞松弛素 D 破坏肌动蛋白细胞骨架或用诺科多唑破坏微管不会改变 NFkappaB 响应剪切的易位。然而，细胞内 Ca2+ 螯合剂 BAPTA 的添加完全阻断了 NFkappaB 易位。虽然用通道阻滞剂阻断 Ca2+ 进入不能抑制 NFkappaB 易位，但用 PLC 抑制剂 U73122 抑制磷脂酶 C (PLC) 诱导的细胞内 Ca2+ 释放完全消除了 NFkappaB 对剪切的反应。这些数据表明 NFkappaB 易位至细胞核对于流体剪切诱导的 COX-2 增加至关重要。此外，这些研究表明细胞内 Ca2+ 释放，而不是细胞骨架结构，对 NFkappaB 易位很重要。 (C) 2003 年爱思唯尔科学（美国）。版权所有。
Bone formation in response to exogenous mechanical loading is dependent on prostaglandin synthesis by the inducible isoform of cyclooxygenase. COX-2. While several transcription factors target the COX-2 gene, we examined the role of nuclear factor kappa B (NFkappaB) on COX-2 upregulation in osteoblasts in response to fluid shear due to its involvement in immune and inflammatory responses in other cell types. Application of 12 dyn/cm(2) laminar flow to MOT3-E1 osteoblast-like cells resulted in translocation of NFkappaB to the nucleus within I h of the onset of shear, with NFkappaB returning to the cytoplasm after 2 h of continuous flow. NFkappaB translocation in response to shear was inhibited by the protease inhibitor, Nalpha-p-tosyl-L-lysine chloromethylketone hydrochloride (TLCK), or a cell-permeant peptide that blocks the nuclear localization sequence (NLS) on NFkappaB. Block of NFkappaB translocation with these inhibitors blocked the shear-induced upregulation of COX-2. We found that disruption of the actin cytoskeleton with cytochalasin D or microtubules with nocodozol did not alter NFkappaB translocation in response to shear. However, addition of the intracellular Ca2+ chelator BAPTA completely blocked NFkappaB translocation. While block of Ca2+ entry with channel blockers failed to inhibit NFkappaB translocation, inhibition of phospholipase C (PLC)-induced intracellular Ca2+ release with the PLC inhibitor U73122 completely abrogated the NFkappaB response to shear. These data indicate that NFkappaB translocation to the nucleus is essential for the fluid shear-induced increase in COX-2. Further, these studies suggest that intracellular Ca2+ release, but not the cytoskeletal architecture, is important to NFkappaB translocation. (C) 2003 Elsevier Science (USA). All rights reserved.