The Role of Secreted Frizzled-related Protein-1 in Allergic Asthma.

Although allergic asthma is a highly prevalent chronic inflammatory condition, the underlying pathogenesis driving T-helper cell type 2 inflammation is not well understood. Wnt/β-catenin signaling has been implicated, but the influence of individual members of the pathway is not clear. We hypothesized that SFRP-1 (secreted frizzled-related protein-1), a Wnt signaling modulator, plays an important role in the development of allergic inflammation in asthma. Using an house dust mite asthma model, mice were sensitized, and their BAL fluid was collected to evaluate airway inflammation. mice exhibited less inflammation with reduced cellular infiltration and concentration of IL-5 in bronchoalveolar lavage fluid compared with wild-type (WT) mice. Similar findings were observed in WT mice treated with SFRP-1 inhibitor, WAY316606. Alveolar macrophages from sensitized mice demonstrated reduced alternative polarization compared with WT, indicating that macrophages could mediate the alteration in inflammation seen in these mice. These findings suggest that SFRP-1 is an important potentiator of asthmatic airway inflammation.