背景:气道上皮是气道结构的重要组成部分,是哮喘气道重塑的始发地。细胞外基质(ECM)的变化,如胶原蛋白沉积和结构紊乱,是气道重塑的典型病理特征。因此,确定来自气道上皮并能够调节ECM的关键介质可能为哮喘的靶向治疗提供有价值的见解.
方法:分析来自基因表达综合数据库的数据集,以筛选哮喘气道上皮中差异表达的基因。我们从哮喘和健康受试者收集支气管镜活检和血清样品以评估赖氨酰氧化酶样2(L0XL2)表达。进行RNA测序和各种实验以确定卵白蛋白(OVA)诱导的小鼠模型中L0XL2敲低的影响。利用L0XL2小分子干扰RNA,探讨L0XL2在支气管上皮细胞中的作用及机制。过表达质粒和AKT抑制剂。
结果:生物信息学分析和进一步实验均显示LOXL2在哮喘患者的气道上皮中高表达。在体内,L0XL2敲低显著抑制小鼠OVA诱导的ECM沉积和上皮-间质转化(EMT)。体外,在16HBE细胞上的转染实验表明,LOXL2过表达增加了N-cadherin和纤连蛋白的表达,并降低了E-cadherin的表达。相反,L0XL2沉默后,E-cadherin的表达上调。此外,L0XL2在16HBE细胞中过表达和沉默后,转化生长因子β1诱导的重塑和EMT过程可以增强和减弱。结合小鼠肺组织的RNA测序和体外实验,LOXL2参与AKT信号通路的调控。此外,AKT抑制剂的体外治疗部分缓解了与LOXL2过表达相关的后果.
结论:综合来看,结果表明,上皮L0XL2部分通过AKT信号通路在哮喘气道重塑中发挥作用,并强调了L0XL2作为哮喘气道重塑治疗靶点的潜力.
BACKGROUND: Airway epithelium is an important component of airway structure and the initiator of airway remodeling in asthma. The changes of extracellular matrix (ECM), such as collagen deposition and structural disturbance, are typical pathological features of airway remodeling. Thus, identifying key mediators that derived from airway epithelium and capable of modulating ECM may provide valuable insights for targeted therapy of asthma.
METHODS: The datasets from Gene Expression Omnibus database were analyzed to screen differentially expressed genes in airway epithelium of asthma. We collected bronchoscopic biopsies and serum samples from asthmatic and healthy subjects to assess lysyl oxidase like 2 (LOXL2) expression. RNA sequencing and various experiments were performed to determine the influences of LOXL2 knockdown in ovalbumin (OVA)-induced mouse models. The roles and mechanisms of LOXL2 in bronchial epithelial cells were explored using LOXL2 small interfering RNA, overexpression plasmid and AKT inhibitor.
RESULTS: Both bioinformatics analysis and further experiments revealed that LOXL2 is highly expressed in airway epithelium of asthmatics. In vivo, LOXL2 knockdown significantly inhibited OVA-induced ECM deposition and epithelial-mesenchymal transition (EMT) in mice. In vitro, the transfection experiments on 16HBE cells demonstrated that LOXL2 overexpression increases the expression of N-cadherin and fibronectin and reduces the expression of E-cadherin. Conversely, after silencing LOXL2, the expression of E-cadherin is up-regulated. In addition, the remodeling and EMT process that induced by transforming growth factor-β1 could be enhanced and weakened after LOXL2 overexpression and silencing in 16HBE cells. Combining the RNA sequencing of mouse lung tissues and experiments in vitro, LOXL2 was involved in the regulation of AKT signaling pathway. Moreover, the treatment with AKT inhibitor in vitro partially alleviated the consequences associated with LOXL2 overexpression.
CONCLUSIONS: Taken together, the results demonstrated that epithelial LOXL2 plays a role in asthmatic airway remodeling partly via the AKT signaling pathway and highlighted the potential of LOXL2 as a therapeutic target for airway remodeling in asthma.