脂磷壁酸诱导RAW 264.7巨噬细胞中一氧化氮合酶表达是由环氧化酶-2、前列腺素E2、蛋白激酶A、p38丝裂原活化蛋白激酶和核因子-κB途径介导的。

Lipoteichoic acid-induced nitric oxide synthase expression in RAW 264.7 macrophages is mediated by cyclooxygenase-2, prostaglandin E2, protein kinase A, p38 MAPK, and nuclear factor-kappaB pathways.

作者信息

Chang Yau-Chong, Li Pei-Chih, Chen Bing-Chang, Chang Ming-Shyan, Wang Jui-Ling, Chiu Wen-Ta, Lin Chien-Huang

机构信息

Department of Cardiac Surgery, Taipei Medical University, Wang Fang Hospital, Taipei, Taiwan; Graduate Institute of Injury Prevention, College of Public Health and Nutrition, Taipei Medical University, Taipei, Taiwan.

出版信息

Cell Signal. 2006 Aug;18(8):1235-43. doi: 10.1016/j.cellsig.2005.10.005. Epub 2005 Nov 11.

DOI:10.1016/j.cellsig.2005.10.005

PMID:16289764

Abstract

We recently reported that lipoteichoic acid (LTA), a cell wall component of the gram-positive bacterium Staphylococcus aureus, stimulated inducible nitric oxide synthase (iNOS) expression, nitric oxide (NO) release, and cyclooxygenase-2 (COX-2) expression in RAW 264.7 macrophages. This study was carried out to further investigate the roles of COX-2 and prostaglandin E2 (PGE2) in LTA-induced iNOS expression and NO release in RAW 264.7 macrophages. Treatment of RAW 264.7 macrophages with LTA caused a time-dependent increase in PGE2 release. LTA-induced iNOS expression and NO release were inhibited by a non-selective COX inhibitor (indomethacin), a selective COX-2 inhibitor (NS-398), an adenylyl cyclase (AC) inhibitor (dideoxyadenosine, DDA), and a protein kinase A (PKA) inhibitor (KT-5720). Furthermore, both PGE2 and the direct PKA activator, dibutyryl-cAMP, also induced iNOS expression in a concentration-dependent manner. Stimulation of RAW 264.7 macrophages with LTA, PGE2, and dibutyryl-cAMP all caused p38 MAPK activation in a time-dependent manner. LTA-mediated p38 MAPK activation was inhibited by indomethacin, NS-398, and SB 203580, but not by PD 98059. The PGE2-mediated p38 MAPK activation was inhibited by DDA, KT-5720, and SB 203580, but not by PD 98059. LTA caused time-dependent activation of the nuclear factor-kappaB (NF-kappaB)-specific DNA-protein complex formation. The LTA-induced increase in kappaB-luciferase activity was inhibited by indomethacin, NS-398, KT-5720, and a dominant negative mutant of p38 alphaMAPK (p38 alphaMAPK DN). These results suggest that LTA-induced iNOS expression and NO release involve COX-2-generated PGE2 production, and AC, PKA, p38 MAPK, and NF-kappaB activation in RAW 264.7 macrophages.

摘要

我们最近报道，脂磷壁酸（LTA）作为革兰氏阳性菌金黄色葡萄球菌的细胞壁成分，可刺激RAW 264.7巨噬细胞中诱导型一氧化氮合酶（iNOS）的表达、一氧化氮（NO）的释放以及环氧合酶-2（COX-2）的表达。本研究旨在进一步探究COX-2和前列腺素E2（PGE2）在LTA诱导RAW 264.7巨噬细胞中iNOS表达和NO释放过程中的作用。用LTA处理RAW 264.7巨噬细胞会导致PGE2释放呈时间依赖性增加。LTA诱导的iNOS表达和NO释放受到非选择性COX抑制剂（吲哚美辛）、选择性COX-2抑制剂（NS-398）、腺苷酸环化酶（AC）抑制剂（双脱氧腺苷，DDA）以及蛋白激酶A（PKA）抑制剂（KT-5720）的抑制。此外，PGE2和直接的PKA激活剂二丁酰环磷腺苷（dibutyryl-cAMP）也以浓度依赖性方式诱导iNOS表达。用LTA、PGE2和二丁酰环磷腺苷刺激RAW 264.7巨噬细胞均会导致p38丝裂原活化蛋白激酶（p38 MAPK）呈时间依赖性激活。LTA介导的p38 MAPK激活受到吲哚美辛、NS-398和SB 203580的抑制，但不受PD 98059的抑制。PGE2介导的p38 MAPK激活受到DDA、KT-5720和SB 203580的抑制，但不受PD 98059的抑制。LTA导致核因子-κB（NF-κB）特异性DNA-蛋白质复合物形成呈时间依赖性激活。LTA诱导的κB-荧光素酶活性增加受到吲哚美辛、NS-398、KT-5720以及p38α丝裂原活化蛋白激酶的显性负突变体（p38αMAPK DN）的抑制。这些结果表明，LTA诱导的iNOS表达和NO释放涉及RAW 264.7巨噬细胞中COX-2生成PGE2的过程，以及AC、PKA、p38 MAPK和NF-κB的激活。