甘草酸对急性肺损伤的防治作用研究

目的初步探讨甘草酸对急性肺损伤(acute lung injury, ALI)防治作用的相关机制。方法采集35例ALI病人和29例年龄性别相匹配的健康者血清样本,qPCR检测缺氧诱导因子(HIF-1α)、白介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)的表达、ELISA检测IL-6、TNF-α的含量;再脂多糖(LPS)处理肺上皮细胞株(A549)复制急性肺损伤模型,甘草酸干预治疗,ELISA、qPCR、WB的方法检测HIF-1α、IL-6、TNF-α的表达,CCK8检测细胞抑制率,然后干扰HIF-1α基因表达后再检测相关因子的表达。结果 ALI患者血清中HIF-1α、IL-6、TNF-α含量显著高于健康对照者,同时,体外LPS复制的ALI模型组细胞HIF-1α、TNF-α和IL-6的表达也较未处理的对照组显著升高,表明HIF-1α、TNF-α和IL-6和ALI发生发展有密切关系;CCK8结果显示LPS能显著抑制细胞生长,但甘草酸能明显改善LPS对细胞的生长抑制,同时,甘草酸干预细胞的HIF-1α、TNF-α和IL-6表达均显著低于ALI模型组,表明甘草酸通过降低炎症相关因子来发挥保护ALI的作用;干扰HIF-1α后,和阴性对照组相比,LPS诱导的TNF-α和IL-6的释放显著降低,说明HIF-1α在TNF-α和IL-6的释放中发挥关键作用;LPS诱导的模型细胞的四种处理中,甘草酸+shRNA-HIF-1α组TNF-α和IL-6的表达要显著低于对照组、shRNA-HIF-1α组和单纯加甘草酸组,表明甘草酸可能通过降低HIF-1α来抑制LPS诱导的TNF-α和IL-6的释放。结论 HIF-1α、TNF-α和IL-6参与到ALI的发生发展过程中,甘草酸可能通过降低HIF-1α表达来抑制TNF-α和IL-6的释放,从而起到保护ALI的作用。

Effect of Glycyrrhizic Acid on Prevention and Treatment of Acute Lung Injury

Objective To explore the mechanism of glycyrrhizic acid(GA) in the prevention and treatment of acute lung injury(ALI). Methods Serum samples were collected from 35 patients with ALI and 29 age-and sex-matched healthy persons. The expressions of HIF-1α, IL-6, TNF-α were detected by qPCR. The contents of IL-6 and TNF-α were detected by ELISA, and then the lung epithelial cell line(A549) was treated with LPS to replicate the model of ALI. The expressions of HIF-1α, IL-6 and TNF-α were detected by ELISA, qPCR and WB. The inhibition rate of HIF-1α, IL-6 and TNF-α was detected by CCK8, and the expression of related factors was detected after interfered with the HIF-1α. Results The levels of HIF-1α, IL-6 and TNF-α in serum of ALI patients were significantly higher than those in healthy controls. At the same time, the expressions of HIF-1α, TNF-α and IL-6 in ALI model cells duplicated by LPS in vitro were significantly higher than those in untreated control cells, indicating that HIF-1α, TNF-α and IL-6 were closely related to the occurrence and development of ALI. CCK8 results showed that LPS could significantly inhibit cell growth, but glycyrrhizic acid could significantly improve cell growth inhibition induced by LPS. At the same time, the expressions of HIF-1α, TNF-α and IL-6 in the cells treated with GA was significantly lower than that in the ALI model group, suggesting that GA played a protective role in ALI by reducing inflammation-related factors. After interfering with HIF-1α, the release of TNF-α and IL-6 induced by LPS was significantly lower than that of negative control group, suggesting that HIF-1α played a key role in the release of TNF-α and IL-6 in ALI model cells. The expressions of TNF-α and IL-6 in GA+shRNA-HIF-1α group was significantly lower than that in control group, shRNA-HIF-1α group and GA group alone, suggesting that GA may inhibit the release of TNF-α and IL-6 by reducing HIF-1α. Conclusion HIF-1α, TNF-α and IL-6 are involved in the development of ALI. GA may inhibit the release of TNF-α and IL-6 by reducing the expression of HIF-1α, and thus playing a role in protecting ALI.