白细胞介素13受体α2对变应性鼻炎大鼠鼻黏膜中杯状细胞凋亡的作用

摘要

目的 探讨白细胞介素13受体α2(sIL-13Rα2)对变应性鼻炎(AR)大鼠鼻黏膜组织中杯状细胞凋亡的诱导作用.方法 选取健康雄性Wistar大鼠40只,随机分为对照组(A组)、AR组(B组)、sIL-13Rα2治疗组(C组),曲安奈德治疗组(D组)4组,每组10只.采用卵清蛋白(OVA)、氢氧化铝建立大鼠AR模型.B、C、D组在建立AR模型后,分别于第4～10周于鼻腔滴入磷酸盐缓冲液(PBS)、sIL-13Rα2及曲安奈德;A组以生理盐水代替OVA进行操作.于最后一次滴鼻结束后24 h取各组大鼠鼻黏膜组织,应用过碘酸-雪夫(AB-PAS)法、免疫组织化学(免疫组化)法、末端转移酶标记法(TUNEL法)分别检测各组大鼠鼻黏膜组织中杯状细胞的数量及黏液分泌情况、Bax蛋白的表达情况及杯状细胞凋亡情况.应用ANOVA方差分析进行多组间比较,LSD-t检验进行两组间比较,Pearson相关分析进行杯状细胞Bax阳性细胞率与凋亡细胞率之间的相关性分析,设P＜0.05为差异有统计学意义.结果 与A组相比,B组大鼠鼻黏膜组织中杯状细胞比例明显增多,黏液分泌增加(0.956 7±0.980比0.0067±0.021,t=-6.853,P＜0.05),而C组黏液高分泌受抑制;C和D组杯状细胞比值明显低于B组(0.639 00±0.831比0.956 7±0.980,0.661 90±0.657比0.956 7±0.980,t值分别为2.748、2.767,P值均＜0.05).免疫组化结果显示C和D组杯状细胞Bax蛋白的阳性表达率明显高于B组(0.880 2±0.125比0.568 7±0.953,0.938 4±0.200比0.568 7±0.953,t值分别为-2.292、-2.685,P值均＜0.05).C和D组鼻黏膜组织中杯状细胞凋亡率明显高于B组(0.516 0±0.079比0.274 0±0.056,0.535 4±0.829比0.274 0±0.056,t值分别为-17.671、-2.225,P值均＜0.05).杯状细胞表达Bax阳性率与细胞凋亡率呈正相关(r=0.866,P＜0.05).结论 sIL-13Rα2能诱导AR大鼠鼻黏膜组织中杯状细胞的凋亡,其机制可能是通过抑制IL-13,上调促凋亡蛋白Bax的表达,从而导致了杯状细胞凋亡的发生.%Objective To investigate the effects of sIL-13Rα2 on the apoptosis of goblet cell in nasal mucosa of allergic rhinitis rats.Methods Forty healthy male Wistar rats were randomly divided into 4 groups (10 rats per group):control group (group A),AR group (group B),sIL-13Rαt2 group (group C) and triamcinolone acetonide group (group D).Ovalbumin (OVA) and aluminum hydroxide were used to establish the AR rat model.After the establishment of AR rat models,50 μ1 PBS,100 μg/50 μl IL-13Rα2 and 3.5 μg/50 μl triamcinolone acetonide were respectively dropped into each nasal cavity of every rat two times a week from 4 to 10 week in group B,group C and group D.Group A was operated with saline instead of OVA.The nasal mucosa tissues were collected at 24 h after the final administration.AB-PAS staining method was used to detect the quantity and secretion of goblet cells in the nasal mucosa tissue of all groups.Immunohistochemistry method was used to detect the expression of Bax proteins.Apoptosis was detected by TUNEL method.ANOVA analysis was used to compare multiple groups,and LSD-t test was used to compare the two groups.Pearson correlation analysis was used to analyze the correlation between the Bax positive cell rate of goblet cells and the rate of apoptotic cells.The difference was statistically significant with P ＜ 0.05.Results Compared with group A,there were more goblet cells and hypersecretion of mucus in the nasal mucosa tissue of rats in group B while fewer in group C.The goblet cells in group C and group D were significantly fewer than that in group B (0.639 00 ± 0.831 vs 0.956 7 ± 0.980,0.661 90 ± 0.657 vs 0.956 7 ± 0.980,t value was 2.748,2.767,respectively,all P ＜ 0.05).The immunohistochemistry results showed that the positive expression rates of Bax protein in goblet cells of group C and group D were significantly higher than that in group B (0.880 2 ± 0.125 vs 0.568 7 ± 0.953,0.938 4 ± 0.200 vs 0.568 7 ± 0.953,t value was-2.292,-2.685,respectively,all P ＜ 0.05).The apoptosis rates of goblet cell in nasal mucosa of group C and group D were also significantly higher than that in group B (0.516 0 ± 0.079 vs 0.274 0 ± 0.056,0.535 4 ± 0.829 vs 0.274 0 ± 0.056,t value was-17.671,-2.225,respectively,all P ＜ 0.05).The expression of Bax protein and apoptosis of goblet cells were positively correlated (r =0.859,P ＜ 0.01).Conclusion sIL-13Rot2 can induce apoptosis of the goblet cells in nasal mucosa of allergic rhinitis rats,by inhibiting IL-13 and up regulating Bax.