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目的 探讨阳离子多肽MP -1对内毒素/脂多糖(LPS)攻击小鼠的作用及机制。方法将30只昆明小鼠随机分为MP- 1组(尾静脉注射3mg/kgMP- 1)、致伤组(尾静脉注射20mg/kgLPS)、保护组(先注射20mg/kgLPS, 20s内再注射3mg/kgMP- 1),每组10只。观察3组小鼠注射后3d内的存活情况。应用生物传感器及FASTfit作图,比较MP- 1、多黏菌素(PMB)与LPS的亲和力,以Kd值表示。通过动态比浊法和鲎试验定量,比较5、10、20、40μmol/LMP -1、PMB对2μg/LLPS的中和作用,以LPS中和0μmol/LMP -1、PMB为对照。采用逆转录聚合酶链反应法,观察MP- 1对LPS刺激的10只昆明小鼠腹腔巨噬细胞(PM)Toll样受体4(TLR4)mRNA、肿瘤坏死因子(TNF)αmRNA、白细胞介素(IL)6mRNA表达的影响。 结果 致伤组小鼠注射LPS后48h全部死亡。保护组小鼠精神状态一度萎靡但恢复较快,食欲、活动度在短时间内改善,存活率为90%。MP- 1组小鼠存活率为100%。MP -1对LPS具有高亲和力(Kd值为484. 0nmol/L)但弱于对LPS有极高亲和力的PMB(Kd值为18.9nmol/L). MP- 1具有中和LPS的能力但弱于PMB; 20、40μmol/LMP -1中和LPS的能力明显高于0μmol/LMP- 1(P<0. 01).MP- 1对LPS刺激的小鼠PM-TLR4mRNA、TNF- αmRNA和IL -6mRNA的表达均有显著的抑制作用。 结论 MP -1对L
Objective To investigate the effect and mechanism of cationic polypeptide MP-1 on mice challenged with lipopolysaccharide (LPS). Methods Thirty Kunming mice were randomly divided into MP-1 group (tail vein injection of 3mg / kg MP-1) and injury group (tail vein injection of 20mg / kg LPS) 3 mg / kg MP-1), 10 in each group. The survival of the three groups of mice after 3 days of injection was observed. Biosensors and FASTfit mapping were used to compare the affinity of MP-1, polymyxin (PMB) with LPS, expressed as Kd values. The turbidimetric method was used to quantify the neutralizing effect of PMB on 2μg / L LPS at 5, 10, 20 and 40μmol / LMP-1, and 0μmol / LMP-1 and PMB as controls. The effect of MP-1 on Toll-like receptor 4 (TLR4) mRNA, tumor necrosis factor (TNF) α mRNA, interleukin (IL) 6 mRNA expression. Results The mice in the injured group all died 48h after injection of LPS. In the protection group, the mental status of the mice was sluggish but recovered quickly. The appetite and activity of the mice in the protection group improved in a short time with a survival rate of 90%. The survival rate in MP-1 mice was 100%. MP-1 has a high affinity for LPS (Kd value of 484. 0nmol / L) but is weaker than PMB with a very high affinity for LPS (Kd value of 18.9nmol / L. MP-1 has the ability to neutralize LPS but weak The ability of PM-1 to neutralize LPS in LPS-stimulated mice was significantly higher than that of 0μmol / LMP-1 (P <0.01) at PMB; 20, 40μmol / LMP- -6 mRNA expression were significantly inhibited. Conclusion MP -1 to L