阻断白介素-3减轻脓毒血症小鼠的炎症反应

Blockade of IL-3 ameliorates sepsis-induced inflammation in mice

摘要:

目的  探究阻断白介素-3（IL-3）对脓毒性小鼠炎症反应的作用及其潜在机制。方法  小鼠盲肠结扎穿孔手术（CLP）后，分为野生型小鼠组和IL-3缺陷型小鼠组，每组13只，连续7 d观察和记录小鼠的死亡数。另取野生型小鼠和IL-3缺陷型小鼠，每组20只，分为3组进行实验：①组小鼠分别在CLP后0、12和24 h进行临床症状评分和体温测量；另在24 h测血压，采血，用于测定干扰素-α（IFN-α）、白介素-1β（IL-1β）和白介素-6（IL-6）水平；②组小鼠分别在CLP后0、6、12和24 h采血并在24 h取材（肝、肺），用于测定中性粒细胞、单核细胞总数及病理、免疫组织化学分析；③组小鼠分别在CLP后0和24 h采血并收集支气管肺泡灌洗液用于蛋白总量和生化指标[天冬氨酸转氨酶（AST）、丙氨酸转氨酶（ALT）]的测定。结果  与野生型小鼠组比较，CLP后IL-3缺陷型小鼠的存活率和体温升高（P <0.05），血压良好，临床症状评分下降（P <0.05）。此外，与野生型小鼠组比较，CLP后IL-3缺陷型小鼠炎症细胞因子IFN-α、IL-1β和IL-6水平降低（P <0.05）；肺和肝组织中的中性粒细胞和单核细胞总数降低（P <0.05）；支气管肺泡灌洗液中的总蛋白和血生化指标（AST、ALT）也降低（P <0.05）。结论 阻断IL-3能够减轻脓毒性小鼠的炎症反应，提高脓毒性小鼠的存活率。

Abstract:

Objective To investigate the effect of blockade of IL-3 on sepsis-induced inflammation in mice and explore its underlying mechanism. Methods Mice in WT group (n = 13) and IL-3-/- group (n = 13) were observed and mortality was recorded up to 7 days after cecal ligation and puncture (CLP). In addition, more mice were randomly assigned to WT group (n = 20) and IL-3-/- group (n = 20) after CLP, each group was divided into 3 subgroups for study. In the first subgroup, clinical score assessment and body temperature measurement were conducted at 0, 12 and 24 h after CLP; blood pressure was measured and blood was collected to determine the levels of IFN-α, IL-1β and IL-6 by ELISA at 24 h after CLP. In the second subgroup, blood was collected to determine the total number of neutrophils and monocytes at 0, 6, 12 and 24 h after CLP, and lungs and liver were harvested for histopathological analysis at 24 h after CLP. In the third subgroup, blood and bronchoalveolar lavage fluid (BALF) were collected to determine total protein content and enzyme activity (AST and ALT) at 0 h, 24 h after CLP. Results The survival, body temperature and blood pressure of septic mice in the IL-3-/- group were significantly improved after CLP compared with mice in the WT group (P < 0.05). The clinical score of the septic mice in the IL-3-/- group significantly decreased compared with the WT group (P < 0.05). In addition, the levels of IL-2 and IFN-γ in the IL-3-/- group significantly decreased compared with the WT group (P < 0.05). The total number of neutrophils and monocytes in the lung and liver tissues of the IL-3-/- group significantly decreased, and the total protein content of BALF and enzyme activity of serum AST and ALT also significantly decreased in the IL-3-/- group compared with the WT group (P < 0.05). Conclusions Blockade of IL-3 can improve survival of septic mice through alleviation of sepsis-induced inflammation.