下丘脑-垂体-肾上腺轴紊乱对小鼠变应性鼻炎发病中免疫机制的影响

Effect of hypothalamic-pituitary-adrenal axis disorder on immune mechanism of allergic rhinitis in mice

目的探讨下丘脑-垂体-肾上腺轴(hypothalamic pituitary adrenal axis,HPA)紊乱对小鼠变应性鼻炎(allergic rhinitis,AR)发病中免疫机制的影响。方法将80只SPF级昆明小鼠随机分为4组:空白对照组,AR模型组,单侧肾上腺切除(adrenalectomy,ADX)/AR组,双侧ADX/AR组,每组20只。构建小鼠ADX或AR造模,采用量化叠加法计算症状评分,HE染色法观察鼻黏膜中炎性细胞的浸润情况,ELISA法检测卵清蛋白特异性IgE(ovalbumin-sIgE,OVA-sIgE)、促肾上腺皮质激素(adreno cortico tropic hormone,ACTH)和皮质酮(corticosterone,CORT)指标水平,qRT-PCR法检测鼻黏膜组织中IFN-γ、IL-4的mRNA表达,Western blot法检测鼻黏膜组织Foxp3、RORγt蛋白表达。结果空白对照组小鼠无明显打喷嚏、搔鼻及清鼻涕症状,鼻黏膜基底层细胞排列整齐,嗜酸粒细胞未见炎性细胞浸润。与空白对照组相比,AR模型组小鼠剧烈搔鼻,喷嚏及清鼻涕较多,症状评分、OVA-sIgE水平、鼻黏膜组织中IL-4 mRNA表达率和RORγt表达明显升高,差异有统计学意义(P<0.05),IFN-γmRNA和Foxp3蛋白表达明显降低ATCH、CORT水平无明显变化(P>0.05);与AR模型组相比,单、双侧ADX/AR组基底层细胞排列更为整齐,嗜酸粒细胞等炎性细胞浸润减少,症状评分、ATCH、CORT、OVA-sIgE水平、IL-4 mRNA表达率及Foxp3蛋白表达明显降低,IFN-γmRNA及RORγt表达明显升高,差异有统计学意义(P<0.05);与单侧ADX/AR组相比,双侧ADX/AR组变化更为显著(P<0.05)。结论 ADX导致小鼠HPA功能紊乱,可通过调节Th1/Th2和Treg/Th17细胞免疫反应平衡,抑制AR病情进展。

Objective To investigate the effect of hypothalamic-pituitary-adrenal axis(HPA) disorder on the immune mechanism of allergic rhinitis(AR) in mice. Methods Eighty SPF Kunming mice were randomly divided into 4 groups(n=20) blank control group, AR model group, unilateral adrenalectomy(ADX)/AR group and bilateral ADX/AR group. The mice of ADX or AR model were established according to the references, and the symptom score was calculated by quantitative superposition method. The infiltration of inflammatory cells in nasal mucosa was observed by HE staining. The levels of ovalbumin-sIgE, adrenocortical tropic hormone(ACTH) and CORT were measured by ELISA, the mRNA expression of IFN-γ and IL-4 in the nasal mucosa was measured by qRT-PCR, and the Foxp3 and RORγt protein expression was measured by Western blot. Results The mice in the blank control group had no obvious sneezing, scratching or snot clearing symptoms, the cells in the basal layer of the nasal mucosa were arranged neatly, and with no eosinophil infiltration. Compared with the blank group, the AR model group had more acute nose scratches, sneezing and nasal discharge, and the differences in symptom score, OVA-sIgE level, expression rate of IL-4 mRNA and expression rate of RORγt in nasal mucosa were statistically significant(P<0.05). The expression of IFN-γmRNA and Foxp3 protein was significantly reduced in AR group, but there was no significant changes in ATCH and CORT levels(P>0.05). After ADX, compared with the model group, basal cells in the single and bilateral ADX/AR groups were more neatly arranged, eosinophilic and other inflammatory cells infiltration was reduced, and symptom score, ATCH, CORT, OVA-sIgE level, IL-4 mRNA expression rate and Foxp3 protein expression were also significantly reduced, while IFN-γ mRNA and RORγt expression was significantly increased(P<0.05). Compared with the unilateral ADX/AR group, the changes in the bilateral ADX/AR group were more significant(P<0.05). Conclusion ADX causes HPA dysfunction in mice, which can inhibit the progression of AR by regulating the balance of Th1/Th2 and Treg/Th17.