Sunitinib对支气管哮喘气道重塑小鼠模型Erk通路和cyclin D1表达的影响

目的探讨sunitinib对支气管哮喘(简称哮喘)气道重塑的干预作用及可能的作用机制。方法 18只BALB/c小鼠随机分为对照组、哮喘组以及sunitinib组,每组6只;以卵清蛋白(OVA)致敏、激发,建立慢性哮喘气道重塑模型。Sunitinib组每次雾化吸入前半小时给予sunitinib(40mg/kg)灌胃给药。OVA末次激发结束后24h处死小鼠,HE染色观察气道炎症及形态学改变,采用ELISA法检测支气管肺泡灌洗液(BALF)中IL-4、IL-13和血清总IgE的表达,免疫组织化学法观察肺组织增殖细胞核抗原(proliferatingcell nuclear antigen,PCNA)、α平滑肌肌动蛋白(α-smooth muscle actin,α-SMA)表达水平。蛋白印记法(Westernblot)测定细胞外信号调节蛋白激酶(extracellular signal-regulated kinase,Erk)蛋白磷酸化水平及细胞周期蛋白D1(cyclin D1)的表达。结果 HE染色示哮喘组小鼠黏膜下层和平滑肌层增厚,管腔狭窄,大量炎性细胞浸润,sunitinib组上述改变较哮喘组为轻;sunitinib干预后哮喘小鼠BALF中Th2细胞因子IL-4、IL-13和血清总IgE以及肺组织羟脯氨酸含量显著降低(P0.01)。哮喘组小鼠气道PCNA阳性细胞百分比、α-SMA表达及肺组织Erk磷酸化水平、cyclin D1蛋白表达较对照组明显升高(P0.01),sunitinib干预后其表达均降低(P0.01)。结论 Sunitinib可能通过抑制Erk途径影响cyclin D1的表达,抑制了慢性哮喘模型中气道平滑肌的增殖,发挥抗气道重塑作用。

Effects of sunitinib on expression of Erk and cyclin D1 in asthmatic mice with airway remodeling

Objective To investigate the effects of sunitinib on asthmatic airway remodeling and its possible mechanisms.Methods 18 BALB/c mice were randomly divided into control group, asthma group and sunitinib intervention group,6 mice in each group. The mice were sensitized and challenged with ovalbumin (OVA) to establish the chronic asthmatic model. Sunitinib group mice were administered intragastrically with sunitinib at a dose of 40 mg/kg daily for 8 consecutive weeks before each airway challenge. The mice were sacrificed 24 h after last aerosol challenge. The sections were stained with hematoxylin & eosin(HE) to assess the inflammatory cell infiltrates. ELISA was used to measure interleukin (IL)-4 and IL-13 levels in bronchoalveolar lavage fluid (BALF) and total immunoglobulin E (IgE) levels in serum. Immunohistochemistry was used to detect the expression of PCNA and α-SMA in the mice lungs. Western blot was applied to examine the expression of p-Erk and cyclin D1 in the left lungs.Results There were bronchial airway remodeling and mass inflammatory cells infiltration in asthmatic group.Sunitinib intervention can ameliorate the above mentioned symptoms significantly. Meanwhile, administration of sunitinib decreased the levels of IL-4 and IL-13 in BLAF and total IgE levels in serum and attenuated the levels of hydroxyproline in lung tissues. The percentage of PCNA positive cells and expression levels of α-SMA, phosphorylated Erk and cyclin D1 proteins were significantly higher than those in control group (P<0.01), and they were all down-regulated after administration of sunitinib (P<0.01).Conclusions Sunitinib could inhibit airway smooth muscle proliferation and delay the process of airway remodeling, which might via inhibiting the expression of phosphorylated Erk and cyclin D1.