Zaas David W, Duncan Mathew J, Li Guojie, Wright Jo Rae, Abraham Soman N
Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine Duke University Medical Center, Durham, North Carolina 27710, USA
J Biol Chem. 2005 Feb 11;280(6):4864-72. doi: 10.1074/jbc.M411702200. Epub 2004 Nov 15.
Pseudomonas aeruginosa is a major cause of pneumonia in patients with cystic fibrosis and other immuncompromising conditions. Here we showed that P. aeruginosa invades type I pneumocytes via a lipid raft-mediated mechanism. P. aeruginosa invasion of rat primary type I-like pneumocytes as well as a murine lung epithelial cell line 12 (MLE-12) is inhibited by drugs that remove membrane cholesterol and disrupt lipid rafts. Confocal microscopy demonstrated co-localization of intracellular P. aeruginosa with lipid raft components including caveolin-1 and -2. We generated caveolin-1 and -2 knockdowns in MLE-12 cells by using RNA interference techniques. Decreased expression of caveolin-2 significantly impaired the ability of P. aeruginosa to invade MLE-12 cells. In addition, the lipid raft-dependent tyrosine phosphorylation of caveolin-2 appeared to be a critical regulator of P. aeruginosa invasion.
铜绿假单胞菌是囊性纤维化患者和其他免疫功能低下患者肺炎的主要病因。在此我们表明，铜绿假单胞菌通过脂筏介导的机制侵入I型肺细胞。去除膜胆固醇并破坏脂筏的药物可抑制铜绿假单胞菌对大鼠原代I型样肺细胞以及小鼠肺上皮细胞系12（MLE-12）的侵袭。共聚焦显微镜显示细胞内铜绿假单胞菌与包括小窝蛋白-1和-2在内的脂筏成分共定位。我们通过RNA干扰技术在MLE-12细胞中敲低了小窝蛋白-1和-2。小窝蛋白-2表达的降低显著损害了铜绿假单胞菌侵袭MLE-12细胞的能力。此外，小窝蛋白-2依赖脂筏的酪氨酸磷酸化似乎是铜绿假单胞菌侵袭的关键调节因子。
