重组可溶性晚期糖基化终末产物受体对脂多糖致小鼠肺组织NF-κB活化的影响

Influence of recombinant soluble RAGE on LPS-induced NF-κB activation in lung tissue of mouse

目的探讨可溶性晚期糖基化终末产物受体(sRAGE)对脂多糖(LPS)致急性肺损伤(ALI)小鼠肺内核因子-kappaB(NF-κB)活化的影响及潜在意义。方法向小鼠左肺内滴注LPS建立ALI模型,于造模后1h腹腔注射100ugsRAGE,观察其对造模后4h左肺组织NF-κBP65DNA结合活性的影响,并检测造模后24h支气管肺泡灌洗液(BALF)中白细胞(WBC)及中性粒细胞(neutrophil,NEU)数量、蛋白(TP)浓度和肿瘤坏死因子(TNF)-α水平,同时对肺组织进行病理学评估。结果LPS滴注后4h,肺组织中NF-κBP65DNA结合活性显著增强(P<0.01),应用重组小鼠sRAGE减轻了LPS肺损伤早期肺内NF-κB活化(P<0.05),显著降低了LPS滴注后24hBALF中WBC及NEU数量、TP含量和TNF-κB水平(P均<0.05),减轻了LPS引起的肺组织病理改变。结论应用sRAGE阻止RAGE信号通过抑制LPS肺损伤早期肺内NF-κB活化减轻肺内失控的炎症反应,从而对ALI发挥保护作用。

[Objective] To investigate the influence of soluble receptor for advanced glycation end-preducts （sRAGE） on nuclear factor-kappaB （NF-κB） activation in lung tissue of mouse with lipopolysaccharide （LPS）-induced acute lung injury （ALI） and clarify the underlying significance. [Methods] Mice were intraperitoneally injected with 100 μg recombinant sRAGE 1h after ALI models were made by instillation of LPS into left lungs. Nuclear extracts were prepared from the lung tissue at 4 hours and DNA binding activity of NF-κB P65 in nuclear extract was determined using a BDTM TransFactor Chemilumineseent kit. Bronchoalveolar lavage fluid （BALF） were collected 24 hours after intratracheal instillation. The numbers of white blood cell （WBC） and neutrophils （NEU） in BALF were counted, the level of protein （TP） was detected and TNF-α concentration was assayed by ELISA. At the same time point left lungs were sampled for histopathology. [Results] 4 hours after LPS challenge, NF-κB p65 DNA binding in lung tissue was significantly increased （P 〈0.01）. Treatment with sRAGE obviously inhibitted LPS-induced NF-KB activation at early stage of ALI （P 〈0.05）. The numbers of both WBC and NEU,TP contents, TNF-α level in BALF collected 24 hours after LPS administration were all significantly lowered by sRAGE （P 〈0.05, respectively）. Attenuated pathological changes in the lung were also observed in sRAGE-treated mice. [Conclusion] Blockade of RAGE signal by sRAGE prevents exaggerated inflammatory response in LPS-challenged lung by inhibiting intrapulmonary NF-κB activation at early stage of ALI, thus plays protective roles against LPS-induced ALI.