Xu W B, Haddad E B, Tsukagoshi H, Adcock I, Barnes P J, Chung K F
Department of Thoracic Medicine, National Heart and Lung Institute, London, UK.
Thorax. 1995 Nov;50(11):1136-40. doi: 10.1136/thx.50.11.1136.
Recruitment of inflammatory cells in the lungs may contribute to tissue injury as a result of mediators released from these cells. Interleukin 1 beta (IL-1 beta) is a potent inducer of neutrophil accumulation, a process that may require local protein biosynthesis. Macrophage inflammatory protein 2 (MIP-2) is a approximately 6 kD heparin binding protein and is a member of the C-X-C superfamily that causes significant neutrophil chemotaxis and activation in vitro. A study was performed to determine whether IL-1 beta could induce the expression of MIP-2 in the lungs of Brown-Norway rats.
rhIL-1 beta (500 U) or 0.9% NaCl was injected intratracheally and bronchoalveolar lavage (BAL) cells and lung tissues were evaluated for MIP-2 mRNA expression after RNA extraction by Northern blot analysis. MIP-2 probe was prepared from cDNA obtained by reverse transcriptase-polymerase chain reaction (RT-PCR) of BAL cells obtained from a rat treated with lipopolysaccharide.
There was no detectable MIP-2 mRNA in the lungs of control rats but a marked enhancement of the expression at four hours with no expression at 12 hours and a slight expression at 24 hours. IL-1 beta induced a significant influx of neutrophils into BAL fluid with a transient increase in macrophages. In situ hybridisation of lungs using MIP-2 cDNA probe labelled with digoxigenin showed expression of MIP-2 mRNA in airway mononuclear cells and airway epithelium at four hours after IL-1 beta; at 24 hours the signal had nearly gone.
IL-1 beta induces the expression of MIP-2 mRNA in rat lung. MIP-2 may be one chemokine that could contribute to IL-1 beta induced neutrophil influx.
肺部炎症细胞的募集可能因这些细胞释放的介质而导致组织损伤。白细胞介素1β（IL-1β）是中性粒细胞聚集的强效诱导剂，这一过程可能需要局部蛋白质生物合成。巨噬细胞炎性蛋白2（MIP-2）是一种约6kD的肝素结合蛋白，是C-X-C超家族的成员，在体外可引起显著的中性粒细胞趋化和激活。进行了一项研究以确定IL-1β是否能诱导棕色挪威大鼠肺中MIP-2的表达。
经气管内注射重组人IL-1β（500U）或0.9%氯化钠，RNA提取后通过Northern印迹分析评估支气管肺泡灌洗（BAL）细胞和肺组织中MIP-2 mRNA的表达。MIP-2探针由经脂多糖处理的大鼠BAL细胞逆转录聚合酶链反应（RT-PCR）获得的cDNA制备。
对照大鼠肺中未检测到MIP-2 mRNA，但在4小时时表达显著增强，12小时时无表达，24小时时有轻微表达。IL-1β诱导大量中性粒细胞流入BAL液，巨噬细胞短暂增加。使用地高辛标记的MIP-2 cDNA探针进行肺原位杂交显示，IL-1β注射后4小时，气道单核细胞和气道上皮中有MIP-2 mRNA表达；24小时时信号几乎消失。
IL-1β诱导大鼠肺中MIP-2 mRNA的表达。MIP-2可能是一种有助于IL-1β诱导中性粒细胞流入的趋化因子。
