甘草酸二胺通过上调水通道蛋白5减轻小鼠急性肺损伤肺水肿的实验研究

Diammonium Glycyrrhizinate Promotes Aquaporin-5 in LPS-induced Acute Lung Injury via Inactivation of NF-κB

目的探讨甘草酸二胺对于急性肺损伤状态下水通道蛋白5(AQP-5)的调节作用及相关机制。方法30只SPF级雄性BALB/c小鼠被随机分为3组,即Control组(对照组)、LPS组(模型组)和LPS+DG组(治疗组),每组10只。通过HE染色观察肺组织病理学改变,并进行肺损伤评分;使用湿/干比(W/D)分析肺水肿程度;RT-PCR和Western blot对AQP-5的表达进行测量;Western blot测定总核因子-κB p65(total NF-κB p65)和磷酸化-NF-κB p65(p-NF-κB p65)蛋白表达。结果小鼠气道内注射LPS 72h后,肺损伤评分和肺组织W/D比值增加,AQP-5表达水平下降,p-NF-κB p65水平增加,差异有统计学意义(P均<0.05)。同时发现,LPS+DG组小鼠肺损伤评分、W/D比值和p-NF-κB p65水平较LPS组降低,LPS+DG组AQP-5表达量较LPS组升高,差异均有统计学意义(P均<0.05)。结论甘草酸二胺可以有效的减轻LPS诱导的小鼠急性肺损伤(ALI)导致的肺水肿,其机制可能与甘草酸二胺抑制NF-κB p65的活化,上调AQP-5的表达有关。

Objective To determine the therapeutic value and associated mechanism of diammonium glycyrrhizinate （DG） on the expression of AQP-5 in lipapolysacchairides （LPS）-induced acute lung injury in mice. Methods Thirty male BALB/c mice were randomly divided into three groups equally： Control, LPS＋DG and LPS. HE staining and lung injury score system were used to evaluate the pathological changes in the lung tissues. Wet to dry ratio （W/D） was used to measure the degree of lung edema. RT-PCR and Western blot were obtained to measure AQP-5 expression. Total NF-κB p65 and phospho-NF-κB p65 （p-NF-κB p65） were evaluated by Western blot. Results After 3 days of LPS intratracheal injection, severe pathological changes, increased W/D, down-regulated AQP-5 expression and increased p-NF-κB p65/total NF-κB p65 were observed. Compared with mice in the LPS group, mice in the LPS＋DG group had more significantly ameliorated pathological changes and increased W/ D, up-regulated AQP-5 expression, and reduced p-NF-κB p65/total NF-κB p65. Conclusion DG up-regulates AQP- 5 in vivo, possibly resulting from inactivation of NF-κB.