芒柄花素对肺动脉高压大鼠的治疗作用及机制研究

Effect of formononetin on monocrotaline-induced pulmonary arterial hypertension and its mechanism in rats

目的观察芒柄花素对野百合碱(MCT)诱导肺动脉高压(PAH)大鼠的治疗作用,并初步探讨其机制。方法将32只雄性SD大鼠随机分为对照组、MCT组、芒柄花素低剂量组和高剂量组,每组8只。除对照组外,其余各组大鼠皮下注射MCT建立大鼠PAH模型,芒柄花素低、高剂量组于MCT注射2周后分别予芒柄花素25、50mg/(kg·d)灌胃,持续14d,对照组等量橄榄油灌胃。造模4周后,测定大鼠右心室收缩压(RVSP)、右心重量(RVW)、右心室肥厚指数(RVHI);HE染色观察肺血管病理形态学变化;Western blot法测定各组肺组织α-平滑肌肌动蛋白(α-SMA)及含核苷酸结构域的Nod样受体家族3 (NLRP3)蛋白水平。RT-PCR法检测NLRP3以及ELISA检测TNF-α、IL-1和IL-6表达水平。结果与对照组比较,MCT组大鼠的RVSP、RVW和RVHI均明显升高,肺小动脉壁增厚,肺组织中α-SMA表达上调,肺组织NLRP3蛋白以及m RNA水平明显升高;TNF-α、IL-1和IL-6水平同样明显升高。与MCT组相比,芒柄花素低、高剂量组的RVSP、RVW和RVHI明显降低,肺小动脉壁增厚明显改善,肺组织α-SMA和NLRP3蛋白以及m RNA水平明显降低。TNF-α、IL-1和IL-6水平同样明显降低。结论芒柄花素可通过抑制炎症以及肺小动脉壁增厚来减轻PAH,部分作用通过NLRP3信号通路来实现。

Objective To investigate the effects of formononetin on monocrotaline(MCT)-induced pulmonary arterial hypertension(PAH)and its molecular mechanism in rats.Methods Male SD rats(n=32)were randomly divided into 4 groups with 8 rats in each group:control group,MCT group,formononetin low does group(25 mg/kg)and formononetin high does group(50 mg/kg).The PAH model was established by subcutaneous injection of MCT.After 2 weeks of modeling,formononetin 25 or 50 mg·kg-1·d-1 was given by gavage to rats in formononetin low or high dose groups for 14 d,respectively;the normal saline was given to rats in control group.After 4 weeks of modeling,right ventricular systolic pressure(RVSP),right ventricular weight(RVW)and right ventricular hypertrophy index(RVHI)were measured.The structural remodeling of pulmonary arteries was observed by HE staining.Western blot was used to detect the protein levels ofα-smooth muscle actin(α-SMA)and NLRP3(Nod-like receptor family,pyrin domain containing 3)in the lung tissue.The mRNA level of NLRP3 was detected by RT-PCR.The contents of TNF-α,IL-1 and IL-6 were measured by ELISA.Results Compared with the control group,the RVSP,RVW and RVHI increased significantly in the MCT group;the thickening of pulmonary artery wall was increased;the protein levels ofα-SMA and NLRP3 and mRNA levels of NLRP3 were up-regulated;the contents of TNF-α,IL-1 and IL-6 were also increased significantly.Compared with the MCT group,the RVSP,RVW and RVHI were significantly decreased in formononetin treatment groups;the pulmonary vascular wall thickening was reduced;the protein levels ofα-SMA and NLRP3 and mRNA levels of NLRP3,the contents of TNF-α,IL-1 and IL-6 were all decreased.Conclusion Formononetin ameliorates MCT-induced PAH by the inhibition of inflammation and pulmonary artery wall thickening,in which the NLRP3 signaling pathway may be involved.