HNE介导自噬调控慢性鼻-鼻窦炎中MUC5AC表达的作用及机制研究

Chronic rhinosinusitis(CRS) is a disease with mucus hypersecretion of nasal navity and sinus , the main ingredient of mucus is MUC5AC,which is over-expressed in CRS,however,its mechinism of regulation is unknown.It was reported that human neutrophil elastase（HNE)can induce cell autophagy,which can activate activator protein-1(AP-1) ,then resulting in overexpression of MUC5AC. Meanwhile,Our previous research demonstrated that HNE is an important factor of MUC5AC over-expression,Epidermal growth factor receptor(EGFR）signaling is very important for MUC5AC over-expression induced by HNE.In our primary experiment,the expression of autophage related protein LC3B-Ⅱwas higher than normal one. Taken together,we hypothesize that HNE can regulate MUC5AC secretion by EGFR-autophagy-AP-1. In our study,we will detect the expression of LC3B-Ⅱ、MUC5AC in CRS with more samples,then establish the primary nasal epithelium cells and high mucus rats model and detect the role and mechanism of autophagy to the MUC5AC expression induced by HNE through EGFR-autophagy-AP-1. The aim of our study is to illuminate the role and mechinism of regulation to increase MUC5AC secretion in CRS and supply the theoretical reference for immunotherapy to cure CRS patients.

慢性鼻-鼻窦炎（CRS）是黏液高分泌性疾病，表现为黏液主要成份黏蛋白MUC5AC过度表达，但调控MU5AC表达的机理还不清楚。文献报道人嗜中性粒细胞弹性蛋白酶（HNE）能诱发自噬的发生，自噬可通过激活蛋白-1（AP-1）参与MUC5AC的过度表达。我们前期研究发现HNE可通过内皮生长因子受体（EGFR）信号通路促进CRS中MUC5AC过度表达，初步实验结果显示CRS中自噬相关蛋白LC3B-Ⅱ表达升高。据此，我们假设在CRS中HNE介导EGFR-自噬-AP-1通路诱导 MUC5AC 表达升高。为此，本研究拟扩大样本检测CRS中LC3B-Ⅱ、MUC5AC等的表达情况；通过体外鼻黏膜原代细胞培养和小鼠鼻腔黏液高分泌模型，检测自噬对HNE诱导MUC5AC表达的影响及各信号分子在其中的作用。本课题的实施旨在于阐明CRS中MUC5AC表达的调控机制，为CRS的免疫治疗提供理论依据。

慢性鼻-鼻窦炎（CRS）是黏液高分泌性疾病，表现为黏液主要成份黏蛋白MUC5AC过度表达，但调控MU5AC表达的机理还不清楚。文献报道人嗜中性粒细胞弹性蛋白酶（HNE）能诱发自噬的发生，自噬可通过激活蛋白-1（AP-1）参与MUC5AC的过度表达。我们前期研究发现HNE可通过内皮生长因子受体（EGFR）信号通路促进CRS中MUC5AC过度表达，初步实验结果显示CRS中自噬相关蛋白LC3B-Ⅱ表达升高。据此，我们假设在CRS中HNE介导EGFR-自噬-AP-1通路诱导 MUC5AC 表达升高。为此，本研究扩大样本检测CRS中LC3B-Ⅱ、MUC5AC等的表达情况；通过体外鼻黏膜原代细胞培养和小鼠鼻腔黏液高分泌模型，检测自噬对HNE诱导MUC5AC表达的影响及各信号分子在其中的作用。通过实验，得出以下结果：1、对照相比，通过 qRT-PCR、IHC、ELISA发现 CRSwNP和 CRSsNP组的 HNE、LC3B、JNK、AP-1、MUC5AC显着上调（P <0.05）。2、HNE（10nM，24h）组中，MUC5AC表达上调最显著；自噬溶酶体抑制剂（Bafilomycin A1）处理组中，WB示 LC3B-II表达增加且 MUC5AC的表达下.降；透射电子显微镜观察 HNE刺激以后有自噬体存在；3、自噬基因 BECN1、ATG5、c-Jun的 siRNA慢病毒载体作用后，其下游蛋白（p-JNK、p-c-Jun、MUC5AC）表达下降（p <0.05）；JNK特异性阻断剂（SP600125）作用后，c-Jun、MUC5AC表达下降（p <0.05）。本课题的实施旨在于阐明CRS中MUC5AC表达的调控机制，为CRS的免疫治疗提供理论依据。