木犀草素对变应性鼻炎大鼠PI3K/Akt/mTOR信号通路的影响

Effect of luteolin on the PI3K/Akt/mTOR signaling pathway in rats with allergic rhinitis

目的探讨木犀草素(Lut)对变应性鼻炎(AR)大鼠磷脂酰肌醇3-激酶(PI3K)/蛋白激酶B(Akt)/哺乳动物雷帕霉素靶蛋白(mTOR)信号通路的影响。方法SPF级雄性大鼠,随机取12只SD大鼠作为对照组,其余大鼠通过腹腔注射卵白蛋白抗原佐剂混悬液及卵白蛋白溶液滴鼻构建AR模型。将造模成功的大鼠随机平分为AR组、Lut组(1 mg/kg Lut)、740 Y-P组(10 mg/kg 740 Y-P)、Lut+740 Y-P组(1 mg/kg Lut+10 mg/kg 740 Y-P),每组12只。观察大鼠打喷嚏、抓鼻子以及流鼻涕情况;酶联免疫吸附(ELISA)检测炎性因子水平;流式细胞术检测Th1/Th2水平;HE染色检测鼻粘膜组织病理变化;Western blot检测T-bet、GATA-3以及PI3K/Akt/mTOR通路相关蛋白表达。结果对照组大鼠鼻粘膜组织结构正常,与对照组相比,AR组鼻黏膜组织上皮紊乱、细胞剥落、固有层嗜酸性粒细胞浸润、腺体肿胀和黏膜下血管充血,行为学评分、IL-4、IL-13和OVA-sIgE水平、Th2水平、GATA-3、p-PI3K/PI3K、p-AKT/AKT、mTOR蛋白水平显著增加(P<0.05),INF-γ水平、Th1水平、T-bet蛋白水平显著降低(P<0.05);与AR组相比,Lut组大鼠嗜酸性粒细胞浸润减少,上皮排列有序,鼻粘膜细胞剥落减少,行为学评分、IL-4、IL-13和OVA-sIgE水平、Th2水平、GATA-3、p-PI3K/PI3K、p-AKT/AKT、mTOR蛋白水平显著降低(P<0.05),INF-γ水平、Th1水平、T-bet蛋白水平显著升高(P<0.05),而740 Y-P组结果与Lut组趋势相反(P<0.05);740 Y-P减弱了Lut对AR大鼠的治疗效果。结论Lut可能通过下调PI3K/Akt/mTOR信号通路对AR大鼠起到改善作用。

Objective To investigate the effect of luteolin(Lut)on the phosphatidylinositol 3-kinase(PI3K)/protein kinase B(Akt)/mammalian target of rapamycin(mTOR)signaling pathway in rats with allergic rhinitis(AR).Methods A total of 12 SPF grade male SD rats were randomly selected as the control group,while the remaining rats were intraperitoneally injected with a suspension of ovalbumin antigen adjuvant and a nasal drop of ovalbumin solution to construct an AR model.The successfully modeled rats were randomly divided into AR group,Lut group(1mg/kg Lut),740 Y-P group(10mg/kg 740 Y-P),and Lut+740 Y-P group(1mg/kg Lut+10mg/kg 740 Y-P),with 12 rats in each group.The sneezing,nose scratching,and runny nose of rats were observed.Enzyme linked immunosorbent assay(ELISA)and flow cytometry were applied to detect the levels of inflammatory factors and T-helper 1(Th1)/Th2,respectively.The hematoxylin and eosin(H&E)staining was used to detect pathological changes in nasal mucosa tissue.Western blot was conducted to detect the expression of T-bet,GATA binding protein 3(GATA3),and PI3K/Akt/mTOR pathway related proteins.Results The nasal mucosa tissue structure of the control group was normal.Compared with the control group,the AR group showed epithelial disorder,cell exfoliation,infiltration of eosinophils in the lamina propria,glandular swelling,and submucosal vascular congestion in the nasal mucosa tissue.Behavioral scores,interleukin-4(IL-4),IL-13 and ovalbumin-specific immunoglobulin E(OVA-sIgE)levels,Th2 level,and protein expression of GATA-3,p-PI3K/PI3K,p-AKT/AKT and mTOR increased significantly(P<0.05),while the levels of interferon-gamma(INF-γ),Th1,and T-bet proteins decreased obviously(P<0.05).Compared with the AR group,the Lut group showed a decrease in eosinophil infiltration,orderly epithelial arrangement,and reduced nasal mucosal cell exfoliation.Behavioral scores,IL-4,IL-13 and OVA sIgE levels,Th2 level,and the expression of GATA-3,p-PI3K/PI3K,p-AKT/AKT and mTOR proteins decreased obviously(P<0.05),whereas the levels of INF-γ,Th1 and T-bet proteins increased significantly(P<0.05).The trend of the 740 Y-P group was opposite to that of the Lut group(P<0.05),and 740 Y-P weakened the therapeutic effect of Lut on AR rats.Conclusion Lut may improve AR rats by down-regulating the PI3K/Akt/mTOR signaling pathway.