载脂蛋白A—I半胱氨酸突变体重组高密度脂蛋白对内毒素血症小鼠的作用

Effect of lipid-bound apoA- I cysteine mutants upon lipopolysaccharide-induced endotoxemia in mice

目的探讨载脂蛋白A．I及其半胱氨酸突变体重组高密度脂蛋白（rHDL）的抗炎作用。方法选择了前期构建的4种载脂蛋白A—I半胱氨酸突变体[A—I（N74C）、A—I（G129C）、A—I（K195C）、A．I（S228C）]及野生型A—I结合二棕榈酰磷脂酰胆碱（DPPC）构建rHDL（rHDL74、rHDI．129、rHDLl95、rHDL228、rHDLwt）干预组，用酶联免疫吸附实验（ELISA）方法验证5种rHDL干预后对肿瘤坏死因子（TNF）-α，自细胞介素1β（IL-1β）和白细胞介素6（IL-6）的影响。并分别设脂多糖（LPS）组，生理盐水组对照。结果LPS注射24h后，rHDL74组比rHDLwt组血清中TNF—α和IL-1β水平更低[TNF—α：（24±3）pg／ml比（135±12）pg／ml、IL-1[3（45±5）pg／ml比（82±8）pg／ml，P〈0．05]的水平，与LPS组比较只有rHDL74组能降低IL-6水平[（1936±58）pg／ml比（2022±73）pg／ml，P〈0．05]。同时组织切片HE染色显示，rHDL74组能明显抑制炎症细胞的浸润，肺泡壁的增厚。结论rHDL74拥有更强的抗炎能力，它可能会成为临床上极具潜力的抗炎药物之一。

Objective To determine the anti-inflammatory functions of different cysteine mutants of apolipoprotein A- I recombinant HDLs. Methods The authors reconstituted recombinant HDLs （namely rHDL74, rHDL129, rHDL195 and rHDL228 ） by mixing wild type or those mutants with dipalmitoyl phosphatidylcholine and examined their in vivo effects upon LPS-induced endotoxemia in mice. Results At 24 h post-injection, mice receiving rHDLT4 [TNF-α： （24 ±3） pg/ml; IL-113：（45 ±5） pg/ml] had a significant decrease of plasma tumor necrosis factor oL （TNF-ct） and interleukin-1β （ IL-1β） as compared with control mice receiving either saline or rHDLwt [ TNF-α ： （ 135 ± 12 ） pg/ml ; IL-1β： （ 82± 8 ） pg/ml, P 〈0. 051- Administration of rHDL74 to mice injected with LPS also led to a protection of lung against acute injury and attenuation of endotoxin-induced clinical symptoms in mice as compared with controls injected with LPS only. Conclusion Compared with rHDLwt, rHDL74 exhibits higher anti-inflammation capabilities. And it may be a potential clinical candidate for therapy for endotoxin-induced septic shock.