Liang Shixiu, Zhou Zicong, Zhou Zili, Liang Jiayuan, Lin Weixian, Zhang Changyun, Zhou Chi, Zhao Haijin, Meng Xiaojing, Zou Fei, Yu Changhui, Cai Shaoxi
Department of Respiratory and Critical Care Medicine, Chronic Airways Diseases Laboratory, Nanfang Hospital, Southern Medical University, China.
Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China.
Int Immunopharmacol. 2022 Dec;113(Pt A):109333. doi: 10.1016/j.intimp.2022.109333. Epub 2022 Oct 25.
Epithelial barrier dysfunction is involved in the pathogenesis of asthma. Previous studies show that SUMOylation can regulate epithelial junction molecule localization. However, the role of SUMOylation in epithelial barrier dysfunction in asthma remains unclear. This study found that inhibition of SUMOylation attenuates house dust mite (HDM)-induced epithelial barrier dysfunction. The SUMOylation levels of junction molecules were determined by co-immunoprecipitation (CO-IP) and proximity ligation assay (PLA). HDM treatment significantly enhanced SUMOylation levels of β-catenin, while no effect was seen on ZO-1, Occludin, and E-cadherin SUMOylation levels. Inhibition of β-catenin SUMOylation through 2-D08 treatment or SUMOylation modification site mutant (K233A) promoted its membrane localization and repressed Wnt/β-catenin signaling. Further, we identified that CBX4, an E3 ligase, mediated SUMOylation of β-catenin. Knockdown of CBX4 promoted β-catenin membrane localization and improved epithelial barrier function. In vivo analysis showed that AAV6-shCBX4-mediated knockdown of CBX4 attenuated HDM-induced allergic airway inflammation and epithelial barrier dysfunction. The findings showed that inhibiting β-catenin SUMOylation by targeting CBX4 mitigated HDM-induced epithelial barrier dysfunction in asthma.
上皮屏障功能障碍参与哮喘的发病机制。先前的研究表明，SUMO化可调节上皮连接分子的定位。然而，SUMO化在哮喘上皮屏障功能障碍中的作用仍不清楚。本研究发现，抑制SUMO化可减轻屋尘螨（HDM）诱导的上皮屏障功能障碍。通过免疫共沉淀（CO-IP）和邻近连接分析（PLA）测定连接分子的SUMO化水平。HDM处理显著提高了β-连环蛋白的SUMO化水平，而对紧密连接蛋白1（ZO-1）、闭合蛋白（Occludin）和E-钙黏蛋白（E-cadherin）的SUMO化水平没有影响。通过2-D08处理或SUMO化修饰位点突变体（K233A）抑制β-连环蛋白的SUMO化，可促进其膜定位并抑制Wnt/β-连环蛋白信号通路。此外，我们确定E3连接酶CBX4介导β-连环蛋白的SUMO化。敲低CBX4可促进β-连环蛋白的膜定位并改善上皮屏障功能。体内分析表明，AAV6-shCBX4介导的CBX4敲低减轻了HDM诱导的过敏性气道炎症和上皮屏障功能障碍。这些发现表明，通过靶向CBX4抑制β-连环蛋白的SUMO化可减轻HDM诱导的哮喘上皮屏障功能障碍。
