Targeting periostin reduces inflammation and respiratory barrier injury in lung diseases.

Periostin (POSTN) is a matricellular protein that plays a key role in development and repair within the biological matrix of the lung. POSTN is highly expressed in several cell types in lung such as epithelial or endothelial cells, fibroblasts, smooth muscle and mast cells, contributing to mucus secretion, alveolar epithelial repair, and lung fibrosis. However, the underlying mechanism how POSTN contributes to the development of lung inflammation remains unclear. In the current study, we attempted to determine whether treatment with a monoclonal anti-POSTN antibody induces a significant inhibition of asthmatic reactions in a mouse asthma model. Mice sensitized and challenged with papain evidenced an increased periostin expression in lung and typical asthmatic reactions, as follows: an increase in the number of eosinophils in bronchoalveolar lavage fluid; a marked influx of inflammatory cells into the lung around blood vessels and airways, and Th2 cytokines including IL-4 and IL-5 and chemokines in the bronchoalveolar lavage (BAL) fluid; emphysema; the detection of thymic stromal lymphopoietin (TSLP) produced by epithelial cells. However, the administration of anti-POSTN prior to the final airway papain challenge resulted in a significant inhibition of all asthmatic reactions. We also demonstrated that anti-POSTN antibody treatment resulted in significant reductions on collagen expression and a reduction in the increased eosinophil. The treatment of animals with anti-POSTN resulted in a significant reduction in the concentrations of the chemokines (CCL-11 and CCL-17) in the airways, without any concomitant increase in the concentration of Th1 cytokines. This study identifies a novel therapeutic strategy for airway hyperresponsiveness, which uses antibodies reactive against POSTN via the inhibition of the Th2 response. It also provides theoretical evidence for the control of allergic asthma and fibrosis by targeting POSTN.