PICK1经TGF-β/Nodal信号通路介导RSV感染小鼠的免疫抑制及气道高反应

PICK1 intervenes in immunosuppression and airway hyperresponsiveness in RSV-infected mouse by TGF-β/Nodal signaling pathway

目的探究蛋白激酶Cα相互作用蛋白1(protein interacting with Cαkinase 1,PICK1)通过TGF-β/Nodal信号通路干预呼吸道合胞病毒(respiratory syncytial virus,RSV)感染小鼠支气管哮喘(bronchial asthma,BA)模型中免疫抑制及气道高反应的机制研究。方法30只小鼠随机分为3组(n=10),分别为对照组、BA组和FSC231组。BA组和FSC231组通过RSV建立BA模型,FSC231组小鼠同时腹腔注射PICK1抑制剂FSC231干预。通过HE染色观察各组小鼠肺组织病理学变化。通过肺功能仪检测气道阻力,计数肺泡灌洗液中EOS数目。通过酶联免疫吸附法检测IL-17、IL-10和IgE水平。流式细胞术检测血液中Th17和Tregs水平。结果BA组肺泡结构紊乱,支气管狭窄,管壁增厚,出现炎性浸润。FSC231组支气管和肺泡结构严重损坏,并且支气管壁充血、增厚,支气管内阻塞,出现严重的炎性浸润现象。BA组的BALF中EOS计数、血清IgE水平、气道阻力、肺组织Nodal水平、Th17细胞比例和血清IL-17均高于对照组(P<0.05),而FSC231组的BALF中EOS计数、血清IgE水平、气道阻力、肺组织Nodal水平、Th17细胞比例和血清IL-17则高于BA组(P<0.05)。相反,BA组的Treg细胞和IL-10低于对照组(P<0.05),而FSC231组的Treg细胞和IL-10则低于BA组(P<0.05)。结论抑制PICK1可能通过促进TGF-β/Nodal信号通路引起Th17细胞升高和Treg的降低,从而加重免疫抑制,进一步提高BA小鼠气道高反应。

Objective To explore the mechanism by which PICK1(protein interacting with Cαkinase 1)interferes with immunosuppression and airway hyperresponsiveness in RSV(respiratory syncytial virus)-infected mice with bronchial asthma(BA)via TGF-β(transformation growth factor-beta)/Nodal signaling pathway.Methods Thirty mice were randomly divided into 3 groups(n=10),which were control group,BA group,intervention group and FSC231 group.The BA model was established by RSV in the BA group and the FSC231 group,and the mice in FSC231 group was also intraperitoneally injected with the PICK1 inhibitor FSC231.Hematoxylin-eosin(HE)staining was used to observe the lung histopathological changes of the three groups of mice.The number of eosinophilia(EOS)in the alveolar lavage fluid was counted by measuring the airway resistance by a pulmonary function meter.Serum levels of interleukin(IL)-17,IL-10 and immunoglobulin E(IgE)were measured by enzyme-linked immunosorbent assay.Flow cytometry was used to detect the levels of helper T cells 17(Th17)and regulatory T cells(Tregs)in the blood.Results The alveolar structure of the BA group was disordered,the bronchial stenosis,the wall thickening,and inflammatory infiltration.In the FSC231 group,the bronchial and alveolar structures were severely damaged,and the bronchial wall was congested,thickened,blocked in the bronchi,and severe inflammatory infiltration occurred.The EOS count in the BALF,serum IgE level,the airway resistance,the level of Nodal in lung tissue,the ratio of Th17 cells and serum IL-17 in the BA group were significantly higher than those of the control group(P<0.05).Moreover,the EOS count in the BALF,serum IgE level,the airway resistance,the level of Nodal in lung tissue,the ratio of Th17 cells and serum IL-17 in the FSC231 group were significantly higher than those of the BA group(P<0.05).Conversely,Treg cells and IL-10 in the BA group were significantly lower than those of the control group(P<0.05),and Treg cells and IL-10 in the FSC231 group were significantly lower than those of the BA group(P<0.05).Conclusion Inhibition of PICK1 may increase Th17 cells and decrease Treg cells by promoting TGF-β/Nodal signaling pathway,thereby aggravating immunosuppression and further improving airway hyperresponsiveness in BA mice.