一氧化氮对香烟烟雾提取物诱导大鼠肺泡巨噬细胞核因子κB活化的影响

目的:探讨一氧化氮(NO)对香烟烟雾提取物(CSE)诱导的大鼠肺泡巨噬细胞(AM)中核因子κB(NF—κB)活化的影响及机 制。方法:将大鼠AM与不同浓度的NO前体左旋精氨酸(L-Arg)或iNOS特异性抑制剂N6-(1-亚氨乙基)赖氨酸(L-NIL)及CSE共同培养,用免疫细胞化学染色法检测NF-κB,用Western blot检测I-κB蛋白含量,用Griess法测定培养上清液中NO的水平。结果:CSE可使NF-κB活化细胞的百分率增加,I-κB的水平下降。加入CSE和低浓度L-Arg培养的AM,NF-κB活化细胞的百分率显著高于只加入CSE的AM;而I-κB的水平显著低于只加入CSE的AM。加入CSE和高浓度L-Arg培养的AM,NF-κB活化细胞的百分率显著低于只加入CSE的AM,而I-κB的水平无显著变化。加入CSE和不同浓度的L-NIL培养的AM,NF-κB活化细胞的百分率显著低于只加入CSE的AM;而I-κB的水平则显著高于只加入CSE的AM,并呈浓度依赖(P<0.01)。结论:内源性NO对香烟烟雾所致NF-κB的活化具有双向调控作用。

Effect of nitric oxide on NF-κB activation induced by cigarette smoke extract in rat alveolar macrophage

AIM; To explore the effect of nitric oxide on NF-KB activation in rat alveolar macrophage (AM) induced by cigarette smoke extract(CSE) and the involved mechanism. METHODS; AMs were co-cultured with NO precursor L-arginine (L-Arg) or inhibitor of inducible nitric oxide synthase L- N6-( 1-iminoeth-yl)lysine (L-NIL) and CSE. The expression of NF-KB was determined by immunocytochemistrical staining, the content of I-KB protein was detected by Western blot, the level of NO in supernatant was assayed by Griess reaction. RESULTS: CSE could induce NF-KB activation and decrease level of 1-KB. L-Arg augmented CSE-induced NF-KB activation and decreased I-KB content at low concentration while inhibited CSE-induced NF-KB activation at high concentration , but there was not any significant difference of the expression of 1-KB. The percentage of NF-KB nucleus dyeing-positive cells was lower and the expression of 1-KB was higher in response to CSE plus various concentrations of L-NIL as compared with that in response to CSE alone (P<0.01). The changes induced by L-NIL were concentration-dependent. CONCLUSION: NO may up-regulate and down-regulate the activation of NF-KB induced by CSE according to difference in NO concentration in AMs.