Foxf1 enchances pulmonary inflammation and mastocytosis

The Forkhead Box f1 (Foxf1) transcriptional factor (previously known as HFH-8 or Freac-1) is expressed in endothelial and smooth muscle cells in the embryonic and adult lung. To assess effects of Foxf1 during lung injury, we used CCl4 injury model. Foxf1+/- mice developed severe airway obstruction and bronchial edema, associated with increased numbers of pulmonary mast cells and increased mast cell degranulation following injury. Pulmonary inflammation in Foxf1+/- mice was associated with diminished expression of Foxf1, increased mast cell tryptase and increased expression of CXCL12, the latter being essential for mast cell migration and chemotaxis. Foxf1 haploinsufficiency caused pulmonary mastocytosis and enhanced pulmonary inflammation following chemically-induced lung injury, indicating an important role for Foxf1 in the pathogenesis of pulmonary inflammatory responses. Keywords: Influence of genetic modification on the pulmonary inflamation Foxf1+/- mice in which the Foxf1 allele was disrupted by an in-frame insertion of a nuclear localizing beta-galactosidase (B-Gal) gene were bred for ten generations into the Black Swiss mouse genetic background. Carbon tetrachloride (CCl4; Sigma, St Louis, MO) was dissolved in mineral oil at a 1:20 ratio v/v and a single intraperitoneal (i.p.) injection of CCl4 (0.5 microliter of CCl4/ 1g of body weight) was administered to male Foxf1+/- mice or their wild type (WT) littermates as described.