微小RNA-191抑制巨噬细胞EGR1介导小鼠巨噬细胞对脓毒症的影响

Effect of microRNA-191 on macrophage EGR1 in mice with sepsis

目的探讨微小RNA-191(miR-191)抑制巨噬细胞早期生长反应蛋白1(EGR1)介导小鼠巨噬细胞对脓毒症的影响。方法无特定病原级雌性BALB/c小鼠,构建脓毒症模型后分为对照组(n=10)和miR-191组(n=10)。对照组经腹腔注射10 mg/kg的0.9%氯化钠溶液,miR-191组经腹腔注射10 mg/kg的miR-191质粒。观察48 h记录小鼠生存情况,采用腹腔灌洗法收集腹腔灌洗液检测细菌负荷,苏木精伊红染色法观察肺脏组织变化。培养腹腔巨噬细胞并进行体外实验,分为A组和B组,A组加入miR-191质粒,B组加入等体积0.9%氯化钠溶液。检测A组和B组EGR1含量和细菌数目。结果miR-191组小鼠生存率高于对照组,腹腔和血液细菌负荷数小于对照组,差异有统计学意义(P<0.05)。对照组小鼠肺泡结构紊乱,肺泡间隔明显增宽,肺间质有明显充血水肿,部分肺不张,有大量中性粒细胞浸润;miR-191组小鼠肺泡结构基本完整,肺泡间隔增宽,肺间质充血水肿明显改善,中性粒细胞浸润明显减少。体外实验结果显示,A组小鼠巨噬细胞EGR1水平低于B组,细胞内细菌存活数低于B组,差异有统计学意义(P<0.05)。结论miR-191通过抑制EGR1表达,有效降低脓毒症小鼠氧化应激反应,减轻肺组织病理损伤,提高细菌清楚能力,这可为临床治疗脓毒症提供参考。

Objective To investigate the effect of microRNA-191(miR-191)on macrophage early growth response protein 1(EGR1)in mice with sepsis.Methods Specific pathogen free mice purchased from Beijing institute for medical Device testing were divided into control group and miR-191 group,each with 10 mice.The control group received intraperitoneal injection of 10 mg/kg 0.9%sodium chloride solution and miR-191 group received intraperitoneal injection of 10 mg/kg miR-191 plasmid.The survival condition of the mice was observed for 48 hours.The bacterial load was detected by abdominal lavage,and the changes of lung tissues were observed by HE staining.The peritoneal macrophages were cultured in vitro and divided into group A and group B.Group A was adding miR-191 plasmid,and group B was adding normal saline,then the content of EGR1 and the number of bacteria were detected.Results The survival rate of mice in miR-191 group was higher than that in control group,and the bacterial load in the abdominal cavity and blood was smaller than that in control group,the difference was statistically significant(P<0.05).In the control group,the alveolar structure was disordered,the alveolar septa was significantly widened,the interstitium of the lung was obviously congested and edema,and there were focal atelectasis and a large number of neutrophil infiltration.In miR-191 group,the alveolar structure was basically complete,the alveolar space was widened,the congestion and edema of pulmonary interstitium were significantly improved,and the infiltration of neutrophils was significantly reduced.In vitro experimental results showed that the level of EGR1 in macrophages in group A was lower than that in group B,the difference was statistically significant(P<0.05),and the number of intracellular bacteria survived in group A was lower than that in group B,the difference was statistically significant(P<0.05).Conclusion By inhibiting the expression of EGR1,miR-191 effectively reduces the oxidative stress response of sepsis mice,reduces the pathological damage of lung tissues,and improves the bacterial clearing ability,which can provide a reference for the clinical treatment of sepsis.