Functional characterization of recombinant rat macrophage inflammatory protein-1 alpha and mRNA expression in pulmonary inflammation.
Functional characterization of recombinant rat macrophage inflammatory protein-1 alpha and mRNA expression in pulmonary inflammation.
复制标题
重组大鼠巨噬细胞炎症蛋白-1α 和 mRNA 表达在肺部炎症中的功能特征。
DOI：
10.1023/a:1022391623063
复制
发表时间：
1998
期刊：
影响因子：
5.1
通讯作者：
Paulauskis,JD
中科院分区：
文献类型：
--
作者：
Shi,MM;Chong,IW;Long,NC;Love,JA;Godleski,JJ;Paulauskis,JD
趋化因子是重要的炎症介质，通过激活白细胞并将其招募到炎症组织中发挥作用。我们最近克隆了大鼠趋化因子巨噬细胞炎症蛋白-1α(α-1)(1)。在本研究中，我们鉴定了重组MIP-1α蛋白的生物学功能，并描述了其在体外和大鼠肺部炎症模型中的表达。在体外，大鼠rMIP-1α蛋白对多形核白细胞(PMN)和巨噬细胞均有趋化作用，在50 nM时活性最高。在体内研究中，我们发现气管内滴注1和5μg的rMIP-1α可导致细胞(主要是单核/巨噬细胞)在6小时后显著(P<；0.05)流入肺泡，但两种剂量的α均未显著增加PMN的平均数量(P<；0.05)。大鼠气管内注入细菌脂多糖(LPS)0.1 mg/kg作为炎症模型。3h后行支气管肺泡灌洗(BAL)。注射脂多糖可引起急性中性粒细胞增多，但对可吞噬的巨噬细胞无明显影响。对照组(生理盐水灌注组)和阳性对照组(对照组)BAL细胞均未见MIP1mRNA和α表达。而内毒素组大鼠肺泡灌洗液中MIP-1mRNA和MIP-2mRNA的α水平均显著升高。大鼠肺泡巨噬细胞株(NR8383)在脂多糖(10αg/ml)刺激下，MIP-1μα的表达也明显增加，6-8 h后最高，与抗氧化剂N-乙酰半胱氨酸和二甲基亚砜共同作用后，MIP-1α的表达减弱，提示脂多糖诱导肺泡巨噬细胞MIP-1 MIP-1mRNA的表达是通过产生活性氧来实现的。结论：巨噬细胞趋化因子MIP-1在体内对巨噬细胞具有很强的趋化作用，巨噬细胞和肺泡巨噬细胞对炎症刺激的α表达提示其在急性肺部炎症中起重要作用。
Chemokines are important inflammatory mediators that function by activating and recruiting leukocytes to an inflamed tissue. We have recently cDNA cloned the rat chemokine macrophage inflammatory protein–1α (MIP-1α) (1). In the present study, we characterize the biological function of recombinant MIP-1α protein and describe expression of its mRNA both in vitro and in a rat model of lung inflammation. In vitro rat rMIP-1α protein was chemotactic for both polymorphonuclear leukocytes (PMNs) and macrophages with maximal activity at 50 nM for both cell types. In in vivo studies, we found that intratracheal instillation of 1 and 5 μg of rMIP-1α resulted in a significant (P< 0.05) influx of cells, primarily monocytes/macrophages, into the airspace of the lungs after 6 h. Mean numbers of lavagable PMNs were not elevated significantly (P< 0.05) for either dose of MIP-1α. As a model of inflammation, rats were intratracheally instilled with 0.1 mg/kg bacterial lipopolysaccharide (LPS). Bronchoalveolar lavage (BAL) was performed 3 h later. Instillation of LPS resulted in an acute neutrophilia, but no significant change in lavagable macrophages. BAL cells from control animals (saline instilled) displayed no basal mRNA expression of either MIP-1α or MIP-2 (positive control). In contrast, both MIP-1α and MIP-2 mRNA levels increased markedly in BAL cells from rats instilled with LPS. The rat alveolar macrophage cell line (NR8383) also showed increased MIP-1α mRNA levels in response to LPS (10 μg/ml) with a maximal increase after 6–8 h. The induction of MIP-1α mRNA expression by LPS in NR8383 cells was attenuated by cotreatment with the antioxidants N-acetylcysteine and dimethylsulfoxide, suggesting that the induction of MIP-1α mRNA by LPS is mediated via the generation of reactive oxygen species. We conclude that MIP-1α is a potent chemoattractant for macrophages in vivo, and its mRNA expression in macrophages and BAL cells in response to inflammatory stimuli suggests a fundamental role in acute pulmonary inflammation.