我们先前的研究表明,粘附分子连环蛋白α样1(CTNNAL1)在哮喘患者和哮喘动物模型的气道上皮细胞中下调,但对CTNNAL1如何影响哮喘发病机制知之甚少。为了揭示哮喘与CTNNAL1之间的直接关系,以腺相关病毒(AAV)为载体,通过引入CTNNAL1-siRNA序列,构建了支气管肺组织中CTNNAL1缺陷小鼠模型。通过屋尘螨(HDM)刺激建立哮喘小鼠模型。在受到HDM挑战之后,有明显的气道炎症,尤其是CTNNAL1缺陷小鼠的粘液分泌过多。此外,CTNNAL1缺陷小鼠肺IL-4和IL-13水平增加,HDM暴露后杯状细胞增生和MUC5AC明显增加。Yes相关蛋白(YAP)的表达,与α-连环蛋白相互作用的蛋白质,在CTNNAL1沉默后下调,并由于其过表达而上调。此外,CTNNAL1和YAP之间的相互作用通过CO-IP得到证实。此外,抑制YAP可以减少MUC5AC的分泌,CTNNAL1缺陷型16HBE14o细胞中的IL-4和IL-13。以上结果表明,CTNNAL1通过YAP途径调节粘液高分泌。此外,ROCK2的表达在CTNNAL1沉默时增加,在YAP沉默后下降,抑制YAP可降低CTNNAL1缺陷型HBE细胞中ROCK2的表达。抑制ROCK2降低MUC5AC表达和IL-13分泌。总之,我们的研究表明,CTNNAL1在HDM诱导的哮喘中起重要作用,通过YAP-ROCK2途径介导粘液分泌。
Our previous study indicated that adhesion molecule catenin alpha-like 1(
CTNNAL1) is downregulated in airway epithelial cells of asthma patients and asthma animal model but little is known about how the CTNNAL1 affects asthma pathogenesis. To reveal the direct relationship between asthma and
CTNNAL1,
CTNNAL1-deficient mouse model in bronchopulmonary tissue was constructed by introducing CTNNAL1-siRNA sequence using adeno-associated virus (AAV) as vector. The mouse model of asthma was established by stimulation of house dust mite (HDM). After HDM-challenged, there was marked airway inflammation, especially mucus hypersecretion in the CTNNAL1-deficient mice. In addition, the CTNNAL1-deficient mice exhibited an increase of lung IL-4 and IL-13 levels, as well as a significant increase of goblet cell hyperplasia and MUC5AC after HDM exposure. The expression of Yes-associated protein (YAP), protein that interacted with α-catenin, was downregulated after CTNNAL1 silencing and was upregulated due to its overexpression. In addition, the interaction between
CTNNAL1 and YAP was confirmed by CO-IP. Besides, inhibition of YAP could decrease the secretion of MUC5AC, IL-4 and IL-13 in CTNNAL1-deficient 16HBE14o-cells. Above results indicated us that
CTNNAL1 regulated mucus hypersecretion through YAP pathway. In addition, the expression of ROCK2 increased when CTNNAL1 was silenced and decreased after YAP silencing, and inhibition of YAP decreased the expression of ROCK2 in
CTNNAL1-deficient HBE cells. Inhibition of ROCK2 decreased MUC5AC expression and IL-13 secretion. In all, our study demonstrates that CTNNAL1 plays an important role in HDM-induced asthma, mediating mucus secretion through the YAP-ROCK2 pathway.