抗巨噬细胞移动抑制因子抗体在油酸致急性肺损伤发病中的干预作用

目的:探讨抗巨噬细胞移动抑制因子单克隆抗体(anti-MIFMAb)在油酸诱导的大鼠急性肺损伤(ALI)中的干预作用,及其对巨噬细胞移动抑制因子(MIF)和细胞间粘附分子-1(ICAM-1)表达的影响。方法:雄性Wistar大鼠静脉注射油酸复制ALI为油酸组,静脉注射生理盐水为对照组,大鼠先给予抗-MIF单抗腹腔注射后再给予油酸静脉注射为抗-MIF单抗干预组。静注后4h,3组大鼠分别测定动脉血氧分压(PaO₂),肺泡通透指数等肺损伤指标;用ELISA法测定支气管肺泡灌洗液(BALF)中可溶性细胞间粘附分子-1(sICAM-1)水平;用原位杂交检测MIF和ICAM-1mRNA表达水平;用免疫组化双重套染方法检测巨噬细胞浸润程度与MIF表达的关系。结果:油酸组PaO₂低于对照组和干预组,肺通透性指数高于对照组和干预组(P<0.01),BALF中sICAM-1水平显著高于对照组和干预组(P<0.01)。油酸组肺组织MIF和ICAM-1表达明显高于对照组和干预组(P<0.01),经抗-MIF单抗干预ICAM-1表达变化不明显,但MIF表达显著下调,巨噬细胞浸润减少且肺损伤指标改善。结论:MIF和ICAM-1在介导巨噬细胞对组织的粘附、浸润和ALI的发生发展中起重要作用,抗-MIF单抗主要通过阻断MIF表达,减少巨噬细胞浸润而起肺保护作用。

The protective effect of anti-macrophage migration inhibitory factor monoclonal antibody on oleic-acid-induced acute lung injury

AIM: To investigate the protective effect of anti-macrophage migration factor monoclonal antibody (anti-MIF MAb) on oleic-acid-induced acute lung injury (ALI) rats and its influence on the expression level of MIF and intercellular adhesion molecule-1(ICAM-1). METHODS: The rats were subjected to injection of oleic acid (oleic acid group) or saline solution (control group). One hours before administration of oleic acid, the rats were intraperitoneally injected with anti-MIF antibody (5 mg/kg) as the treatment group. After injecting oleic acid or saline for 4 hours, the PaO_2, lung permeability index (LPI), the number of macrophage and the level of soluble ICAM-1 (sICAM-1) in the bronchial alveolar lavage fluid (BALF) were measured. The expression level of MIF mRNA and ICAM-1 mRNA in the lung were detected by in situ hybridization, and the degree of macrophage infiltration and the expression of MIF were evaluated by double staining immunocytochemistry. RESULTS: The PaO_2 of the oleic acid group was far lower than those of the control and treatment group (P<0.01). The LPI of the oleic acid group was significantly higher than those of the control and treatment group (P<0.01). The sICAM-1 level in BALF were significantly higher than those of the control and treatment groups (P<0.01). There were marked up-regulation of MIF mRNA and ICAM-1 mRNA expression in ALI lung compared with the normal lung tissue. After pretreatment with anti-MIF antibody, the MIF expression was down-regulation in association with a marked reduction of macrophage infiltration. However, pretreatment with anti-MIF antibody did not interfere the expression level of ICAM-1. CONCLUSION: MIF and ICAM-1 may mediate the infiltration and adhesion of macrophage in injuried lung tissue, which play a pivotal role in the pathogenesis of progressive lung injuries induced by intravenous oleic acid. Pretreatment with anti-MIF antibody showed lung protective effect by blockage of MIF expression in association with reduction of macrophage infiltration and improvement in histological damage.