颗粒蛋白前体对脓毒症急性肺损伤小鼠肺组织核转录因子-κB的表达的影响

Effect of progranulin on the expression of nuclear factor-kappa B in lung tissue of mice with acute lung injury

摘要:

目的 探讨颗粒蛋白前体（progranulin，PGRN）对脓毒症急性肺损伤（acute lung injury，ALI）的影响及可能机制。方法 将C57BL/6小鼠随机分为对照组（Control组）、急性肺损伤组（CLP组）、颗粒蛋白前体治疗组（CLP+PGRN组）。采用盲肠结扎穿刺术（cecal ligation and puncture，CLP）构建小鼠脓毒症ALI模型，CLP+PGRN组在CLP处理半小时后使用PGRN腹腔注射。24 h后麻醉并处死小鼠，取小鼠肺HE染色观察肺组织病理损伤；TUNEL法检测肺部细胞凋亡情况；免疫荧光染色检测肺组织中核转录因子-κB（nuclear factor kappa B，NF-κB）水平；Western blot法检测NF-κB、总p65和磷酸化p65表达水平；RT-qPCR检测NF-κB和炎症细胞因子水平。结果 和Control组相比，CLP组和CLP+PGRN组肺损伤加重，促炎细胞因子升高，肺组织中细胞凋亡增加，NF-κB、p65和p-p65的表达水平明显增加；与CLP组相比，CLP+PGRN组肺组织损伤和凋亡减轻，促炎细胞因子降低，抑炎细胞因子升高，NF-κB、p65和p-p65的表达明显减少。结论 PGRN可以减轻脓毒症小鼠急性肺损伤，其机制可能与抑制NF-κB、p65表达和p65磷酸化有关。

Abstract:

Objective To investigate the effect and possible mechanisms of progranulin（PGRN） on acute lung injury（ALI） in sepsis.Methods C57BL/6 mice were randomly divided into normal control group（Control group），acute lung injury group（CLP group），and PGRN treatment group（CLP+PGRN group）. Cecal ligation and puncture（CLP） was used to establish a mouse model of septic ALI，and the mice in the CLP+PGRN group were given intraperitoneal injection of PGRN at half an hour after CLP treatment. The mice were anesthetized and sacrificed after 24 hours，and lung tissue was collected for HE staining to observe the pathological damage of lungs； the TUNEL method was used to observe cell apoptosis in lungs；immunofluorescent staining was used to measure the level of nuclear factor-kappa B（NF-κB） in lung tissue；Western blot was used to measure the expression levels of NF-κB，total p65，and phosphorylated p65（p-p65），and RT-qPCR was used to measure the levels of NF-κB and inflammatory factors.Results Compared with the Control group，the CLP group and the CLP+PGRN group had aggravated lung injury and significant increases in proinflammatory cytokines，cell apoptosis in lung tissue，and the expression levels of NF-κB，p65，and p-p65. Compared with the CLP group，the CLP+PGRN group had alleviation of lung injury and apoptosis，a reduction in proinflammatory cytokines，increases in anti-inflammatory cytokines，and significant reductions in the expression levels of NF-κB，p65，and p-p65.Conclusion PGRN can alleviate ALI in mice with sepsis，possibly by inhibiting the expression of NF-κB and p65 and the phosphorylation of p65.