The Role Of Activin Receptor-Like Kinase 5 Inhibition In Inflammatory Lung Injury

Many signal transduction pathways are involved in the pathogenesis of inflammatory lung injury. Activin receptor-like kinase 5 (ALK5) mediates TGFs'biological fuctions through the Smads signal transduction pathway. In order to figure out the role that ALK5 played in inflammatory lung injury, the animal model of LPS induced lung injury was adopted. Results show significant inhibition of Smads activities and activation of p38 MAPK contrarily after lung injury, but application of SB431542, a special inhibitor of ALK5, only inhibits Smads activities. Augmentation of lung inflammatory reaction caused by inflammatory cytokines up-regulation and anti-inflammatory cytokines down regulation, degradation of extracellular matrix mediated by matrix metalloproteinase 9 and damage of lung cells are observed following inhibition of ALK5. It can be concluded that ALK5 and Smads pathway are involved in the pathogenesis of inflammatory, and inhibition of their activities promotes inflammatory lung injury.