支气管哮喘大鼠肺组织中白血病抑制因子与神经激肽受体表达的相关性分析

The relationship between leukemia inhibitory factor and neurokinin receptors in a rat model of asthma

目的研究白血病抑制因子(LIF)和神经激肽受体(NKR)在支气管哮喘(简称哮喘)中的表达并分析两者的相关性,以探讨LIF与哮喘神经源性气道炎症的关系。方法24只W istar大鼠按随机数字表法分为对照组(A组)、哮喘组(B组)和地塞米松干预组(C组),每组8只。分别用10%卵白蛋白(OVA)腹腔注射与1%OVA雾化吸入制作致敏大鼠哮喘模型,在激发后2周通过逆转录-聚合酶链反应(RT-PCR)和免疫印迹检测肺组织中LIF、NK-1R和NK-2R mRNA及蛋白表达,并通过免疫组化观察大鼠肺组织中NK-1R表达分布。结果A、B、C组大鼠肺组织中LIF mRNA和蛋白表达分别为0.240±0.020、0.510±0.130、0.180±0.050,23 110±8 018、40 832±12 964、16 160±2 108;NK-1R mRNA和蛋白表达分别为0.240±0.020、1.040±0.480、0.170±0.040,16 538±4 342、32 292±4 564、15 018±1 488;B组大鼠肺组织LIF mRNA和NK-1R mRNA水平与A、C两组比较差异均有统计学意义(P均<0.01)。A、B(0.240±0.040、0.200±0.030)和C组(0.210±0.040)大鼠肺组织中NK-2R mRNA表达比较差异均无统计学意义(P均>0.05)。B组NK-1R mRNA、蛋白分别与LIF mRNA、蛋白表达水平呈显著正相关(r=0.850、0.868,P均<0.01)。免疫组化结果显示,NK-1R主要分布于支气管黏膜上皮细胞。结论哮喘气道存在LIF和NK-1R的过度表达,而且两者存在表达相关性,LIF可能参与了哮喘气道神经源性炎症的调控。

Objective To study the expression of leukemia inhibitory factor（LIF） and neurokinin receptors（NKR） in the lungs of asthmatic rats, and to evaluate the role of LIF in airway neurogenic inflammation. Methods Twenty-four Wistar rats were randomly divided into a control group （ group A, n = 8 ） , an asthma group （ group B, n = 8 ） and a dexamethasone treated group （ group C, n = 8 ）. The rat asthmatic model was made by intraperitoneal injection and nebulized aspiration of ovalbumin （OVA） at the concentrations of 10% and 1% respectively. Expression levels of lung LIF, NK-1R and NK-2R were detected by reverse transcription-polymerase chain reaction （RT-PCR） and Western blot two weeks after challenge, and the localization of NK-1R was determined by immunohistochemistry. Results After challenge, the expressions of lung LIF mRNA in group A,B and C were 0. 240 ±0. 020,0. 510 ±0. 130,0. 180 ±0. 050,and protein levels were 23 110 ± 8 018,40 832 ± 12 964,16 160 ± 2 108 respectively. The expressions of lung NK-1R mRNA in group A,B and C were 0. 240 ±0. 020,1. 040 ±0. 480,0. 170 ±0. 040,and protein levels were 16 538 ±4 342,32 292 ±4 564,15 018 ± 1 488 respectively. The mRNA and protein levels of LIF and NK-1R in group B were significantly elevated as compared with group A and C （all P 〈 0. 01 ）. The expressions of lung NK-2R mRNA in group A,B and C were 0. 240 ±0. 040,0. 200 ±0. 030 and 0. 210 ± 0. 040 ,and no difference was found among three groups （all P 〉 0. 05 ）. In group B, there was a positive correlation between LIF and NK-1R at mRNA （ r = 0. 850, P 〈 0. 01 ） and protein （ r = 0. 868, P 〈 0. 01 ） levels respectively. NK-1R immunoreactivity was observed primarily in bronchial epithelial cells. Conclusion LIF and NK-1R were excessively expressed and closely correlated in lungs of the rat asthmatic model, suggesting that LIF may be involved in modulating airway neurogenic inflammation.