-
脓毒血症是指机体受到重大烧伤、创伤、严重感染后引起的剧烈的全身炎症反应,病程发展快,可引起发热、血压急剧下降等临床表现,随着病程进展,会造成肺、肝、心等脏器的进一步损伤,甚至导致病人因多器官功能障碍而死亡。在我国医院ICU中脓毒血症的发病率为28.7%,而病死率为33.5%[1],在美国每年因脓毒血症住院的病人病死率高达14%~29%[2]。在澳大利亚和新西兰入住ICU的病人脓毒血症发病率为7%~11%,同时医院病死率为18%~35%[3]。近年来,随着耐药菌株的逐年增多,治疗手段的局限性,脓毒血症的病死率居高不下。脓毒血症基础研究进展缓慢,与动物模型不稳定、无法很好模拟脓毒血症临床病理生理变化密切相关。研究[4]表明,肺脏结构及功能的病理生理学改变可以反映原始损伤与病理机制之间的动态平衡,急性肺损伤是脓毒血症的一个重要表现。肺损伤是脓毒血症病人死亡的主要原因,与脓毒血症的预后密切相关。本文就盲肠结扎穿刺建造的脓毒血症小鼠模型中肺组织损伤的相关机制作一探讨。
-
脓毒血症组小鼠脓毒血症情况评分较正常对照组、假手术明显升高(P<0.01),而假手术组脓毒血症情况评分较正常对照组明显升高(P<0.01)(见表 1)。正常对照组肺泡结构完整、清晰,肺间隔内无水肿,肺组织内无细胞碎片、充血、渗出,无炎性细胞浸润。假手术组肺损伤较轻,肺泡形态结构较完整,肺间隔轻微水肿、增厚,清晰可见并且连续,肺泡内细胞碎片、充血、渗出较少,肺炎症浸润较轻。脓毒血症组小鼠肺损伤重,肺泡结构破坏严重,形态结构不清晰,间隔水肿严重,肺泡内渗出、充血及各种细胞碎片较多,炎症细胞浸润多。假手术组肺组织考虑到小鼠全身麻醉、腹部创伤,因此也会出现轻微肺损伤(见图 2)。肺组织损伤评分差异有统计学意义(P<0.01)(见表 1),MPO免疫荧光显示肺组织浸润的炎性细胞主要为中性粒细胞(见图 3),脓毒血症组的炎性细胞较正常对照组、假手术组都有明显的增加(P<0.01)(见表 1),术后24 h脓毒血症组小鼠的肺组织中的TNF-α及IL-6水平均较正常对照组、假手术组明显升高(P<0.01)(见表 1)。
分组 n MSS 肺组织损伤评分 炎性细胞 TNF-α IL-6 正常对照组 14 — 0.67±0.21 1 080±188.0 1.000±0.000 1.000±0.000 假手术组 14 4.14±0.27** 3.50±0.22** 2 699±285.6** 2.070±0.383* 1.578±0.084** 脓毒血症组 14 20.50±0.68**△△ 11.00±0.45**△△ 16 948±401.9**△△ 9.300±1.107**△△ 451.000±36.760**△△ F — 659.90 290.49 686.50 44.53 149.70 P — <0.01 <0.01 <0.01 <0.01 <0.01 MS组内 — 1 645.000 0.098 1.906×108 120.300 404 414.000 q检验:与正常对照组比较*P<0.05;**P<0.01,与假手术组比较△△P<0.01 表 1 3组相关指标比较(x±s)
-
正常对照组小鼠、假手术组小鼠观察期间无小鼠死亡。而脓毒血症组小鼠16 h即出现第1例死亡,术后24 h脓毒血症组小鼠生存率为75.0%,而术后32 h小鼠生存率仅为37.5%,术后40 h小鼠生存率维持在25.0%,直至术后96 h,脓毒血症小鼠全部死亡。脓毒血症组小鼠32 h(χ2=12.62,P<0.01)、48 h(χ2=14.83,P<0.01)生存率较正常对照组、假手术组明显降低。
脓毒血症小鼠致肺损伤模型的研究
Study on the model of lung injury induced by sepsis in mice
-
摘要:
目的探讨盲肠结扎穿刺建造的脓毒血症小鼠模型中肺组织损伤的相关机制。 方法选取42只C57BL/6雄性小鼠,随机分为正常对照组、假手术组及脓毒血症组,各14只。正常对照组不做处理,假手术组行盲肠结扎,脓毒血症组予以盲肠结扎穿刺。24 h收集各组肺组织,观察脓毒血症情况评分(MSS)、生存率、肺组织形态改变情况、肺组织损伤评分、中性粒细胞以及肺组织中炎症因子肿瘤坏死因子α(TNF-α)和白细胞介素(IL)-6表达水平的差异。 结果脓毒血症组MSS评分、肺损伤评分、中性粒细胞数、TNF-α及IL-6表达水平均较正常对照组、假手术组升高(P < 0.01)。 结论脓毒血症可造成病理学层面的小鼠肺组织损伤,致炎症因子表达升高,降低小鼠的生存率。通过观察该模型中反映肺损伤程度的相关指标的变化,可评估脓毒血症严重程度和研究损伤相关机制。 Abstract:ObjectiveTo explore the related mechanism of the lung injury of in the mouse model of sepsis constructed by cecal ligation and puncture. MethodsA total of 42 healthy male C57BL/6 mice were randomly divided into the control group, sham operation group and sepsis group(14 mice each group).The control group was not treated, the sham group was treated with cecal ligation, and the sepsis group was treated with cecal ligation combined with puncture.The lung tissue in three groups was collected after 24 hours of treatment, and the MSS score, survival rate, morphological change of lung tissue, score of lung injury, number of neutrophils and expression levels of tumor necrosis factor α(TNF-α) and interleukin-6(IL-6) in lung tissues were analyzed in three groups. ResultsThe MSS score, score of lung injury, number of neutrophils and expression levels of TNF-α and IL-6 in sepsis group were higher than those in control group and sham operation group(P < 0.01). ConclusionsSepsis can lead to the acute lung injury and increasing expression level of inflammatory factors, and decrease the survival rate of mice.The related indicator of reflecting lung tissue injury change can reflect the severity of sepsis, and study its related mechanism. -
表 1 3组相关指标比较(x±s)
分组 n MSS 肺组织损伤评分 炎性细胞 TNF-α IL-6 正常对照组 14 — 0.67±0.21 1 080±188.0 1.000±0.000 1.000±0.000 假手术组 14 4.14±0.27** 3.50±0.22** 2 699±285.6** 2.070±0.383* 1.578±0.084** 脓毒血症组 14 20.50±0.68**△△ 11.00±0.45**△△ 16 948±401.9**△△ 9.300±1.107**△△ 451.000±36.760**△△ F — 659.90 290.49 686.50 44.53 149.70 P — <0.01 <0.01 <0.01 <0.01 <0.01 MS组内 — 1 645.000 0.098 1.906×108 120.300 404 414.000 q检验:与正常对照组比较*P<0.05;**P<0.01,与假手术组比较△△P<0.01 -
[1] CHARCHAFLIEH J, WEI J, LABAZE G, et al.The role of complement system in septic shock[J].Clin Dev Immnol, 2012, 2012(2):407. [2] GAIESKI DF, EDWARDS JM, KALLAN MJ, et al.Benchmarking the incidence and mortality of severe sepsis in the United States[J].Crit Care Med, 2013, 41(5):1167. doi: 10.1097/CCM.0b013e31827c09f8 [3] SINGER M, DEUTSCHMAN CS, SEYMOUR CW, et al.The third international concensus definitions for sepsis and septic shock (sepsis-3)[J].JAMA, 2006, 315(8):801. [4] 张婷, 王祥瑞.脓毒血症休克的液体治疗[J].上海医药, 2011, 34(10):796. [5] SHRUM B, ANANTHA RV, XU SX, et al.A robust scoring system to evaluate sepsis severity in an animal model[J].BMC Res Notes, 2014, 7(12):233. [6] SHEHABI Y, BELLOMO R, READE MC, et al.Early intensive care sedation predicts long-term mortality in wentilated critically ill patients[J].Am J Respir Crit Care Med, 2012, 186(8):724. doi: 10.1164/rccm.201203-0522OC [7] KRESS JP, POHLMAN AS, O'CONNOR MF, et al.Daily interruption of sedative infusions in critically ill patients undergoing mechanical ventilation[J].N Engl J Med, 2000, 342(20):1471. doi: 10.1056/NEJM200005183422002 [8] FINK MP, WARREN HS, Strategies to improve drug developmengts for sepsis[J].Nat Rev Drug Discov, 2014, 13(10):741. doi: 10.1038/nrd4368 [9] MARSHALL JC, Why have clinical trials in sepsis failed?[J].Trends Mol Med, 2014, 20(4):195. doi: 10.1016/j.molmed.2014.01.007 [10] RITTIRSCH D, HUBER LANG MS, FLIERL MA, et al.Immunodesign of experimental sepsis by cecal ligation and puncture[J].Nat Protoc, 2009, 4(1):31. doi: 10.1038/nprot.2008.214 [11] NOVOTNY AR, REIM D, ASSFALG V, et al.Mixed antagonist response and sepsis severity-dependent dysbalance of pro- and anti-inflammatory responses at the onset postoperative sepsis[J].Immunobiology, 2012, 217(6):616. doi: 10.1016/j.imbio.2011.10.019 [12] PRAKASH PS, CALDWELL CC, LENTSCH AB, et al.Human microparticles generated during sepsis in patients with critical illness are neutrophil-derived and modulate the immune response[J].J Trauma Acute Care Surg, 2012, 73(2):401. doi: 10.1097/TA.0b013e31825a776d [13] MADDUX AB, DOUGLAS IS.Is the developmentally immature immune response in paediatric sepsis a recapitulation of immune tolerance?[J].Immunology, 2015, 145(1):1. [14] CHEN XH, YIN YJ, ZHANG JX.Sepsis and immune response[J].World J Emerg Med, 2011, 2(2):88. doi: 10.5847/wjem.j.1920-8642.2011.02.002 [15] NAMATH AI, PATTERSON AJ.Genetic polymorphisms in sepsis[J].Crit Care Clin, 2009, 25(4):835. doi: 10.1016/j.ccc.2009.06.004 [16] MEDINA E.Murine model of polymicrobial septic peritonitis using cecal ligation and puncture (CLP)[J].Methods Mol Biol, 2010, 602(2):411. [17] SEVRANSKY JE, LEVY MM, MARINI JJ.Mechanical ventilation in sepsis-induced acute lung injury/acute respiratory distress syndrome:an evidence-based review[J].Crit Care Med, 2004, 32(11 Suppl):S548. [18] ZEMANS RL, COLGAN SP, DOWNEY GP.Transepithelial migration of neutrophils:mechanisms and implications for acute lung injuiy[J].Am J Respir Cell Mol Biol, 2009, 40(5):519. doi: 10.1165/rcmb.2008-0348TR [19] KABAY B, KOCAEFE C, BAYKAL A, et al.Interleukin-10 gene transfer:prevention of multiple organ injury in a murine cecalligation and puncture model of sepsis[J].World J Surg, 2007, 31(1):105. doi: 10.1007/s00268-006-0066-9 [20] SADOWITZ B, ROY S, GATTO LA, et al.Lung injury induced by sepsis:lessons learned from large animal models and future directions for treatment[J].Expert Rev Anti Infect Ther, 2011, 9(12):1169. doi: 10.1586/eri.11.141