基于NF-κB/MAPK 通路探讨微量元素锌对变应性鼻炎免疫反应的保护作用和机制研究

Allergic rhinitis (AR) is a nasal mucosa chronic non inflammatory disease resulted from various inflammatory mediators. At present, the pathogenesis of AR is not clear, so the treatment is lack of specific methods. The focus of the present study is to clarify its pathogenesis and find safe and effective therapeutic regimen.Our previous study showed that zinc plays an important role in the occurrence and development of AR, and our clinical study showed that zinc adjuvant therapy can significantly improve the symptoms and signs of patients with AR. At the same time, recent studies have shown that zinc can affect the immune reaction by regulating the expression of NF-κB/MAPK pathway.Based on the above evidence, we hypothesizes that trace element zinc can interfere the immune reaction process of AR by regulating the NF- kappa B/MAPK pathway.We will establish AR mouse models for zinc deficiency, normal zinc, zinc excess and zinc supplementation, and cultivate mouse mast cell lines in vitro. We will detect the levels of inflammatory factors involved in the immune reaction and signaling pathway expression by using ELISA and Westernblot technology.We aims to elucidate the protective effect of zinc on immune reaction in the occurrence and development of AR and to reveal the mediated mechanism of zinc in NF- kappa B/MAPK pathway. On this basis, we will further confirm the therapeutic effect of zinc supplementation on AR, which will provide theoretical and experimental basis for the accurate treatment of AR.

变应性鼻炎(AR)是由多种炎性介质介导的鼻粘膜慢性非炎症性疾病。目前发病机制不清，治疗缺乏特异性方法，现研究的焦点是明确其发病机制并寻找安全有效的治疗方案。本课题组前期基础研究显示锌参与AR的发生发展过程，并且我们的临床研究显示锌辅助治疗能明显改善AR患者的症状及体征；同时近期有研究表明锌可通过调控NF-κB/MAPK通路的表达从而影响免疫反应。故本课题组提出假说：微量元素锌可通过调控NF-κB/MAPK通路干预AR的免疫反应过程。我们将建立锌缺乏、锌正常、锌过量、缺锌补锌AR小鼠模型；体外培养小鼠肥大细胞株，采用ELISA、Westernblot等技术，检测参与免疫反应的炎性因子水平及信号通路表达情况，拟阐明锌在AR的发生发展过程中对免疫反应的保护作用，并揭示锌在NF-κB/MAPK通路中的介导机制；在此基础上，进一步证实补充锌对AR的治疗效应，将为AR的精准治疗提供理论基础和实验依据。

变应性鼻炎（allergic rhinitis，AR）是一种常见的慢性过敏性呼吸道疾病。AR发病率逐年增加，已成为全球范围内公共卫生问题。本研究结果表明AR患者血清锌水平下降，细胞炎症因子IL-13、IL-33表达升高，通过补锌治疗可以改善过敏状态。在体外实验中，硫酸锌促进肥大细胞增殖，联合黄花蒿变应原共同干预小鼠P815肥大细胞，发现细胞上清液中IL-33表达降低，其受体ST2蛋白表达减弱，下游信号p38、p65蛋白表达亦减弱；当固定黄花蒿变应原浓度在0.01µg/ml不变时，硫酸锌浓度越高，其抑制此反应的程度越明显；当硫酸锌浓度固定在100µmol/L时，随着黄花蒿变应原浓度的增加，其对过敏反应的抑制作用亦减弱。由此可见，硫酸锌在一定程度上抑制了过敏反应，并且与变应原的表达程度以及锌的干预浓度有密切的关系。同时，建立了变应性鼻炎小鼠模型，发现缺锌加重AR小鼠的鼻部过敏症状，促进OVA诱导的AR小鼠体内炎症细胞浸润，从而加速疾病进展过程。补锌可以有效缓解OVA诱导的AR小鼠鼻/耳部摩擦和打喷嚏的次数，降低AR小鼠血清中总IgE和OVA特异性IgE的水平；同时，补锌抑制AR小鼠血液和鼻腔黏膜中炎症细胞因子IL-6和TNF-α的产生，并且显著抑制鼻黏膜中P38MAPK磷酸化水平。进一步实验发现P38蛋白的表达和激活在锌过量组AR小鼠体内最低，在缺锌AR小鼠中显著升高，补锌后其激活被显著抑制。为进一步探讨P38MAPK通路在缺锌AR小鼠中的作用机制，本研究中通过腹膜内注射P38MAPK通路抑制剂SB203580治疗锌缺乏AR小鼠，结果表明：阻断P38MAPK信号通道不仅可以减轻AR小鼠打喷嚏、鼻痒和抓鼻子等鼻部症状，还可以显著抑制IgE、OVA-sIgE和炎症细胞因子IL-6和TNF-α的产生。该项研究是目前所知微量元素锌与变应性鼻炎关系的首项动物体内研究，初步揭示，锌通过调控P38MAPK通路的活性对AR的鼻部免疫炎症起保护作用。因此，我们认为该研究揭示了锌补充剂在预防或治疗变应性鼻炎方面有巨大潜力。