卵清蛋白诱导的特应性皮炎小鼠模型中白细胞介素-25的作用及其调控意义

The role and its regulatory significance of interleukin-25 in ovalbumin induced atopic dermatitis of mice

目的:探讨白细胞介素-25(interleukin-25,IL-25)对卵清蛋白(ovalbumin,OVA)诱导的特应性皮炎小鼠模型的影响,以及调控IL-25的意义。方法:将90只健康雄性6周龄无特定病原体(specific pathogen free,SPF)级BALB/c小鼠分为6组(每组15只),分别为:①皮下注射磷酸盐缓冲液(phosphate buffered saline,PBS)组(正常对照组);②皮下注射小鼠IL-25组(IL-25组);③皮下注射抗小鼠IL-25单克隆抗体组(anti-IL-25组),每日皮下注射1次×1周,间隔2周,重复每日皮下注射1次×1周,间隔2周,再重复每日皮下注射1次×1周,总共7周;④OVA致敏组(模型组);⑤OVA致敏及IL-25皮下注射组(IL-25干预致敏组);⑥OVA致敏及anti-IL-25注射组(anti-IL-25干预致敏组)。⑤⑥组在致敏过程中给予IL-25或anti-IL-25的方式同②③组。致敏期间观察比较小鼠的搔抓行为和皮肤表现,致敏结束24 h后由小鼠心脏取血,分离血清,采用酶联免疫吸附试验(enzyme linked immunosorbent assay,ELISA)检测总IgE、IL-4、IL-5、IL-13等。取致敏部位的皮肤进行苏木精-伊红(hematoxylin-eosin,HE)染色、免疫组织化学、实时PCR(real-time PCR)及Western blot检测。采用单因素(ANOVA)方差分析比较各组间各项指标的差异。结果:实验小鼠末次处理24 h后,IL-25干预致敏组的搔抓次数高于模型组,anti-IL-25干预致敏组的搔抓行为显著低于模型组;IL-25干预致敏组特应性皮炎表现、表皮增厚及真皮炎细胞浸润程度均明显重于模型组及anti-IL-25干预致敏组;IL-25干预致敏组血清IgE、IL-4、IL-5、IL-13水平显著高于模型组及anti-IL-25干预致敏组;IL-25干预致敏组CD4+T细胞在真皮层较anti-IL-25干预致敏组显著增多;IL-25干预致敏组的丝聚蛋白(filaggrin)及防御素β2(defensinβ2)蛋白水平明显低于模型组或anti-IL-25干预致敏组。结论:在OVA诱导的皮炎模型中,IL-25能够明显促进小鼠表皮屏障功能损害,加重OVA诱导的皮炎损害,拮抗IL-25可一定程度上缓解OVA诱导的皮炎损害。

Objective:To investigate the effect of interleukin-25(IL-25)on ovalbumin(OVA)induced atopic dermatitis of mice,and the significance of regulating IL-25.Methods:In this study,90 healthy male 6-week-old specific pathogen free(SPF)BALB/c mice were divided into 6 groups(15 in each group):①subcutaneous injection of phosphate buffered saline(PBS)group(normal control group);②subcutaneous injection of mouse IL-25 group(IL-25 group);③subcutaneous injection of anti-mouse IL-25 monoclonal antibody(anti-IL-25 group),each group received subcutaneous injection once a day for 1 week,2 weeks apart,repeated daily subcutaneous injections for 1 week,2 weeks apart,and repeated daily subcutaneous injections for 1 week,for a total of 7 weeks;④OVA treated group(model group);⑤OVA treated and IL-25 subcutaneous injection group(IL-25 treated dermatitis group);⑥OVA treated and anti-mouse IL-25 monoclonal antibody injection group(anti-IL-25 treated dermatitis group).The⑤and⑥groups in the process of treatment with OVA,IL-25 or anti-IL-25 antibody were given in the same way as the②and③groups.Scratching behavior and skin performance of the mice were recorded during the seven-week-treatment.Twenty four hours after the final treatment,blood was taken from the mouse heart,and the serum was separated to detect the total IgE,IL-4,IL-5,IL-13,etc.The skin samples of the treatment sites were used for hematoxylin-eosin(HE)staining,immunohistochemistry,real-time PCR and Western blot detections.A single factor(ANOVA)analysis of variance was used to compare the differences in various indicators between the groups.Results:The frequency of scratches in the IL-25 treated dermatitis group was higher than that in the model group,and the scratching behavior of the anti-IL-25 treated dermatitis group was significantly lower than that in the model group.The appearance of atopic dermatitis,thickening of the epidermis and the degree of dermal inflammation in the IL-25 treated dermatitis group were more serious than those in the model group and the anti-IL-25 treated dermatitis group.The levels of serum IgE,IL-4,IL-5,and IL-13 in the IL-25 treated dermatitis group were significantly higher than that in the model group and the anti-IL-25 treated dermatitis group.There were significantly more CD4+T cells in the dermis of IL-25 treated dermatitis group than that in the anti-IL-25 treated dermatitis group.The expression levels of filaggrin and defensinβ2 proteins in the IL-25 treated dermatitis group were significantly lower than those in the model group and the anti-IL-25 treated dermatitis group.Conclusion:In the OVA induced atopic dermatitis mice model,IL-25 can significantly promote the damage of the epidermal barrier function and aggravate the OVA-induced dermatitis.Antagonizing IL-25 can alleviate OVA induced dermatitis to a certain extent.