Yoseph Benyam P, Klingensmith Nathan J, Liang Zhe, Breed Elise R, Burd Eileen M, Mittal Rohit, Dominguez Jessica A, Petrie Benjamin, Ford Mandy L, Coopersmith Craig M
*Department of Surgery and Emory Critical Care Center†Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia‡Department of Basic Sciences, Bastyr University California, San Diego, California§Department of Anesthesiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado||Department of Surgery and Emory Transplant Center, Emory University School of Medicine, Atlanta, Georgia.
Shock. 2016 Jul;46(1):52-9. doi: 10.1097/SHK.0000000000000565.
Intestinal barrier dysfunction is thought to contribute to the development of multiple organ dysfunction syndrome in sepsis. Although there are similarities in clinical course following sepsis, there are significant differences in the host response depending on the initiating organism and time course of the disease, and pathways of gut injury vary widely in different preclinical models of sepsis. The purpose of this study was to determine whether the timecourse and mechanisms of intestinal barrier dysfunction are similar in disparate mouse models of sepsis with similar mortalities. FVB/N mice were randomized to receive cecal ligation and puncture (CLP) or sham laparotomy, and permeability was measured to fluoresceinisothiocyanate conjugated-dextran (FD-4) six to 48 h later. Intestinal permeability was elevated following CLP at all timepoints measured, peaking at 6 to 12 h. Tight junction proteins claudin 1, 2, 3, 4, 5, 7, 8, 13, and 15, Junctional Adhesion Molecule-A (JAM-A), occludin, and ZO-1 were than assayed by Western blot, real-time polymerase chain reaction, and immunohistochemistry 12 h after CLP to determine potential mechanisms underlying increases in intestinal permeability. Claudin 2 and JAM-A were increased by sepsis, whereas claudin-5 and occludin were decreased by sepsis. All other tight junction proteins were unchanged. A further timecourse experiment demonstrated that alterations in claudin-2 and occludin were detectable as early as 1 h after the onset of sepsis. Similar experiments were then performed in a different group of mice subjected to Pseudomonas aeruginosa pneumonia. Mice with pneumonia had an increase in intestinal permeability similar in timecourse and magnitude to that seen in CLP. Similar changes in tight junction proteins were seen in both models of sepsis although mice subjected to pneumonia also had a marked decrease in ZO-1 not seen in CLP. These results indicate that two disparate, clinically relevant models of sepsis induce a significant increase in intestinal permeability mediated through a common pathway involving alterations in claudin 2, claudin 5, JAM-A, and occludin although model-specific differences in ZO-1 were also identified.
肠屏障功能障碍被认为与脓毒症中多器官功能障碍综合征的发生有关。尽管脓毒症后的临床病程存在相似之处，但根据引发疾病的病原体和病程不同，宿主反应存在显著差异，并且在不同的脓毒症临床前模型中，肠道损伤的途径差异很大。本研究的目的是确定在死亡率相似的不同脓毒症小鼠模型中，肠屏障功能障碍的时间进程和机制是否相似。将FVB/N小鼠随机分为接受盲肠结扎和穿刺（CLP）组或假手术组，并在6至48小时后测量对异硫氰酸荧光素偶联葡聚糖（FD-4）的通透性。在所有测量时间点，CLP后肠通透性均升高，在6至12小时达到峰值。在CLP后12小时，通过蛋白质免疫印迹、实时聚合酶链反应和免疫组织化学检测紧密连接蛋白claudin 1、2、3、4、5、7、8、13和15、连接粘附分子A（JAM-A）、闭合蛋白和ZO-1，以确定肠通透性增加的潜在机制。脓毒症使claudin 2和JAM-A增加，而使claudin-5和闭合蛋白减少。所有其他紧密连接蛋白均未改变。进一步的时间进程实验表明，早在脓毒症发作后1小时就可检测到claudin-2和闭合蛋白的改变。然后在另一组患有铜绿假单胞菌肺炎的小鼠中进行了类似实验。肺炎小鼠的肠通透性增加，其时间进程和幅度与CLP所见相似。在两种脓毒症模型中均观察到紧密连接蛋白的类似变化，尽管肺炎小鼠的ZO-1也有明显降低，而CLP小鼠中未见到这种情况。这些结果表明，两种不同的、具有临床相关性的脓毒症模型通过涉及claudin 2、claudin 5、JAM-A和闭合蛋白改变的共同途径，诱导肠通透性显著增加，尽管也发现了ZO-1的模型特异性差异。
