敲除巨噬细胞移动抑制因子基因可减轻小鼠重症急性胰腺炎相关肺损伤

Knockout of MIF gene attenuates severe acute pancreatitis-associated lung injury in mice

目的探讨巨噬细胞移动抑制因子(macrophage migration inhibitory factor,MIF)在小鼠重症急性胰腺炎(severe acute pancreatitis,SAP)相关肺损伤中的作用。方法32只小鼠随机(随机数字法)分为4组(每组8只):野生型对照组(WT+CON组)、野生型SAP组(WT+SAP组)、MIF基因敲除对照组(KO+CON组)、MIF基因敲除SAP组(KO+SAP组)。通过腹腔注射L-精氨酸(4 mg/g)制备SAP模型。在末次注射后72 h取材,通过ELISA检测血清淀粉酶(AMY)、白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)、MIF表达,通过HE染色观察胰腺组织及肺组织病理变化,通过免疫组化检测肺组织中IL-6、TNF-α表达,通过Western blot检测肺组织核因子κB(NF-κB)表达。计量资料两组间比较采用t检验,多组比较采用单因素方差分析。结果与WT+CON组相比,WT+SAP组小鼠胰腺及肺组织损伤病理评分、AMY,血清及肺组织TNF-α、IL-6表达明显增高(P<0.05),而KO+SAP组以上指标水平明显减低(P<0.05)。此外,KO+SAP组肺组织中NF-κB蛋白表达较WT+SAP组显著降低(P<0.05)。结论敲除MIF基因可减轻小鼠SAP相关肺损伤,其作用机制可能与NF-κB有关。

Objective To investigate the role of macrophage migration inhibitory factor(MIF)in severe acute pancreatitis(SAP)associated lung injury in mice.Methods Totally 32 mice were randomly divided into 4 groups(n=8/per group):wild type control group(WT+CON group),wild type SAP group(WT+SAP group),MIF gene knockout control group(KO+CON group),and MIF gene knockout SAP group(KO+SAP group).SAP model was established by intraperitoneal injection of L-arginine(4 mg/g).The expression of serum amylase,IL-6,TNF-αand MIF were detected by ELISA.The pathological changes of pancreatic and lung tissues were observed by HE staining.The expression of IL-6 and TNF-αin lung tissue was detected by immunohistochemistry.The expression of NF-κB in lung tissue was detected by Western blot.For measurement data,t test was used for comparison between two groups,and one-way analysis of variance was used for comparison between multiple groups.Results Compared with the WT+CON group,pathological score of pancreatic and lung injury,serum amylase,TNF-αand IL-6 expression in serum and lung tissues were significantly increased in the WT+SAP group(P<0.05),while the above indexes were significantly decreased in the KO+SAP group(P<0.05).In addition,the expression of NF-κB protein in KO+SAP group was significantly lower than that in the WT+SAP group(P<0.05).Conclusions MIF gene knockout can alleviate severe acute pancreatitis associated acute lung injury in mice,and its mechanism may be related to NF-κB.