Neutrophil-Mediating Lung Diseases and Integrin α subfamily, α4 and α9

Abstract

Neutrophil-mediating acute lung injury like aspiration pneumonia is a serious problem in the elderly. Although integrin b2 plays an important role in neutrophil-mediating lung diseases, integrin b2-independent neutrophil transmigration pathways have also been reported. Several members of the integrin a subfamily (a2b1,  a3b1, a4b1, a5b1, a6b1 and  a9b1) are known to be expressed on neutrophils, and up-regulated by activation. And these integrins  on systemic neutrophils might mediate migration into the site of pulmonary inflammation. Especially, integrin  a9b1 and integrin a4b1 have been also shown to mediate adhesion to vascular cell adhesion molecule (VCAM)-1. In this draft, author focused lung diseases  and the involvement of integrin a9 and a4. And the future direction as the therapeutic strategy against neutrophil-mediating lung injury was also discussed.