Schramm Rene, Schaefer Thilo, Menger Michael D, Thorlacius Henrik
Department of Surgery, Malmö University Hospital, Sweden.
J Leukoc Biol. 2002 Dec;72(6):1122-32.
This study examined adhesive and signaling pathways and anti-inflammatory mechanisms of dexamethasone in acute mast cell-dependent neutrophil recruitment in the skin in mice. Mast cell activation dose- and time-dependently triggered influx of predominately neutrophils and secretion of cytokine-induced neutrophil chemoattractant (KC). Neutralization of KC attenuated neutrophil recruitment upon mast cell activation. Mast cell activation- and KC-induced neutrophil responses were significantly decreased in lymphocyte function-associated antigen-1 (LFA-1)-deficient mice. Dexamethasone inhibited neutrophil accumulation elicited by mast cell activation. It is interesting that dexamethasone significantly reduced the mast cell-dependent secretion of KC, whereas neutrophil recruitment induced by exogenous KC was insensitive to dexamethasone treatment. Thus, KC is a fundamental mediator of neutrophil recruitment in acute mast cell-dependent skin inflammation, and mast cell activation- and KC-induced neutrophil responses are LFA-1-dependent. Moreover, dexamethasone inhibits mast cell-regulated skin infiltration of neutrophils mainly by attenuating KC secretion. Thus, this study elucidates important interactions between chemokines and adhesion molecules in mast cell-dependent neutrophil recruitment and provides new insight into mechanisms of dexamethasone in skin inflammation.
本研究检测了地塞米松在小鼠皮肤急性肥大细胞依赖性中性粒细胞募集中的黏附及信号通路和抗炎机制。肥大细胞活化呈剂量和时间依赖性地引发主要为中性粒细胞的流入以及细胞因子诱导的中性粒细胞趋化因子(KC)的分泌。中和KC可减弱肥大细胞活化后的中性粒细胞募集。在淋巴细胞功能相关抗原-1(LFA-1)缺陷小鼠中,肥大细胞活化和KC诱导的中性粒细胞反应显著降低。地塞米松抑制肥大细胞活化引起的中性粒细胞聚集。有趣的是,地塞米松显著降低了肥大细胞依赖性KC的分泌,而外源性KC诱导的中性粒细胞募集对地塞米松治疗不敏感。因此,KC是急性肥大细胞依赖性皮肤炎症中中性粒细胞募集的基本介质,且肥大细胞活化和KC诱导的中性粒细胞反应是LFA-1依赖性的。此外,地塞米松主要通过减弱KC分泌来抑制肥大细胞调节的中性粒细胞向皮肤浸润。因此,本研究阐明了趋化因子与黏附分子在肥大细胞依赖性中性粒细胞募集中的重要相互作用,并为地塞米松在皮肤炎症中的作用机制提供了新的见解。