NF-κB抑制剂通过逆转LPS诱导的BMPRⅡ下调改善肺血管重构

NF-κB inhibitor improves pulmonary vascular remodeling by reversing LPS-induced down-regulation of BMPRⅡ

动脉性肺动脉高压(pulmonary arterial hypertension,PAH)的发生、发展与骨形态发生蛋白受体II型(bone morphogeneticprotein receptor type II,BMPRII)编码基因的遗传突变和核因子κB(nuclear factorκB,NF-κB)通路介导的炎症反应密切相关。本文旨在研究NF-κB通路抑制剂对脂多糖(lipopolysaccharide,LPS)诱导的肺动脉内皮细胞损伤的作用。用1μg/mL的LPS处理人肺动脉内皮细胞,用免疫印迹和qPCR检测BMPRII和白介素8(interleukin-8,IL-8)的表达水平。腹腔注射野百合碱(monocrotaline,MCT)建立大鼠PAH模型,用免疫荧光染色法检测肺动脉内皮细胞BMPRII和IL-8的表达情况,检测模型大鼠心脏血流动力学变化和肺血管重构情况。结果显示,LPS可引起人肺动脉内皮细胞BMPRII的表达下调和IL-8的表达上调,NF-κB抑制剂BAY11-7082(10μmol/L)可逆转LPS的作用。在MCT-PAH大鼠模型中,肺动脉内皮细胞BMPRII表达下调,IL-8表达上调,右心室/(左心室+室间隔)重量比值[weight ratio of right ventricle to left ventricle plus septum,RV/(LV+S)]和右心室收缩压(rightventricular systolic pressure,RVSP)显著升高,心输出量(cardiac output,CO)和三尖瓣环收缩期位移(tricuspid annular plane systolicexcursion,TAPSE)明显降低,肺血管壁明显增厚,连续21天腹腔注射BAY11-7082(5 mg/kg)可逆转上述变化。以上结果提示,LPS通过NF-κB信号通路下调BMPRII的表达水平,促进PAH的发生、发展,因此NF-κB信号通路可作为PAH潜在治疗靶点。

The occurrence and development of pulmonary arterial hypertension(PAH) is closely related to the genetic mutation of bone morphogenetic protein receptor type II(BMPRII) encoding gene and the inflammatory response mediated by nuclear factor κB(NF-κB) pathway. This paper was aimed to investigate the effect of NF-κB pathway inhibitors on lipopolysaccharide(LPS)-induced pulmonary artery endothelial cell injury. Human pulmonary artery endothelial cells were treated with 1 μg/mL of LPS. The expression levels of BMPRII and interleukin-8(IL-8) were detected by Western blot and qPCR. The rat PAH model was established by intraperitoneal(i.p.) injection of monocrotaline(MCT). The expression levels of BMPRII and IL-8 in pulmonary artery endothelial cells were detected by immunofluorescence staining. Cardiac hemodynamic changes and pulmonary vascular remodeling were detected in the MCT-PAH model rats. The results showed that LPS caused down-regulation of BMPRII expression and up-regulation of IL-8 expression in human pulmonary artery endothelial cells. NF-κB inhibitor BAY11-7082(10 μmol/L) reversed the effect of LPS. In the pulmonary artery endothelial cells of MCT-PAH model, BMPRII expression was down-regulated, IL-8 expression was up-regulated, weight ratio of right ventricle to left ventricle plus septum [RV/(LV+S)] and right ventricular systolic pressure(RVSP) were significantly increased, cardiac output(CO) and tricuspid annular plane systolic excursion(TAPSE) were significantly reduced, and pulmonary vessel wall was significantly thickened. BAY11-7082(5 mg/kg, i.p., 21 consecutive days) reversed the above changes in the MCT-PAH model rats. These results suggest that LPS down-regulates the expression level of BMPRII through NF-κB signaling pathway, promoting the occurrence and development of PAH. Therefore, the NF-κB pathway can be used as a potential therapeutic target for PAH.