Integrin β4 was downregulated on the airway epithelia of asthma patients

The shedding of airway epithelial cells and loss of epithelial functional homeostasis are major pathological characteristics of asthma; however, the mechanism underlying these pathologies remains obscure. Our previous work showed that there were three variation sites in 5 0 flanking region of integrin b4 in asthma patients, which was correlated with decreased expression of integrin b4 in peripheral leukocytes. Integrin b4 is an important structural adhesion molecule on airway epithelia to keep the structural adhesion of epithelial cells. In this work, we further demonstrated that integrin b4 expression was downregulated in airway epithelia of asthma patients. To probe the relationship between imbalanced expression of integrin b4 and dysfunction of the airway epithelial cells in asthma, integrin b 4w as silenced in human bronchial epithelium cells (16HBE14O) by integrin b4 small-interfering RNA lentivirus vector. Upon silencing of integrin b4, 16HBE14O cells showed reduced proliferation and wound repair. Most cells were shown to be arrested in G1 phase after integrin b4 silencing, and increased apoptosis was induced in the integrin b4-silenced cells. In summary, our results provided compelling evidence that integrin b4 was involved in the structural integrity and functional homeostasis of airway epithelial cells. It is likely that downregulation of integrin b 4o n asthma airway epithelia contributes to the structural disruption and dysfunction of airway epithelial cells.