Project description:Idiopathic pulmonary fibrosis (IPF) is characterized by aberrant accumulation of collagen-secreting myofibroblasts. Development of effective therapies is limited due to incomplete understanding of molecular mechanisms regulating myofibroblast expansion. FOXF1 transcription factor is expressed in resident lung fibroblasts, but its role in lung fibrosis remains unknown due to the lack of genetic mouse models. Through comprehensive analysis of human IPF genomics data, lung biopsies and transgenic mice with fibroblast-specific inactivation of FOXF1, the present study shows that FOXF1 inhibits pulmonary fibrosis. FOXF1 deletion increases myofibroblast invasion, collagen secretion, and promotes a switch from of N-cadherin (CDH2) to Cadherin-11 (CDH11), which is critical step in acquisition of pro-fibrotic phenotype. FOXF1 directly binds to Cdh2 and Cdh11 promoters and differentially regulates transcription of these genes. Re-expression of CDH2 or inhibition of CDH11 in FOXF1-deficient cells reduces myofibroblast invasion in vitro. FOXF1 inhibits pulmonary fibrosis by regulating a switch from CDH2 to CDH11 in lung myofibroblasts.
Project description:Idiopathic pulmonary fibrosis (IPF) is characterized by aberrant accumulation of collagen-secreting myofibroblasts. Development of effective therapies is limited due to incomplete understanding of molecular mechanisms regulating myofibroblast expansion. FOXF1 transcription factor is expressed in resident lung fibroblasts, but its role in lung fibrosis remains unknown due to the lack of genetic mouse models. Through comprehensive analysis of human IPF genomics data, lung biopsies, and transgenic mice with fibroblast-specific inactivation of FOXF1, we show that FOXF1 inhibits pulmonary fibrosis. FOXF1 deletion increases myofibroblast invasion and collagen secretion and promotes a switch from N-cadherin (CDH2) to Cadherin-11 (CDH11), which is a critical step in the acquisition of the pro-fibrotic phenotype. FOXF1 directly binds to Cdh2 and Cdh11 promoters and differentially regulates transcription of these genes. Re-expression of CDH2 or inhibition of CDH11 in FOXF1-deficient cells reduces myofibroblast invasion in vitro. FOXF1 inhibits pulmonary fibrosis by regulating a switch from CDH2 to CDH11 in lung myofibroblasts.
Project description:Hepatic fibrosis is the common end stage to a variety of chronic liver injuries and is characterized by an excessive deposition of extracellular matrix (ECM), which disrupts the liver architecture and impairs liver function. The fibrous lesions are produced by myofibroblasts, which differentiate from hepatic stellate cells (HSC). The myofibroblasts transcriptional networks remain poorly characterized. Previous studies have shown that the Forkhead box F1 (FOXF1) transcription factor is expressed in HSCs and stimulates their activation during acute liver injury; however, the role of FOXF1 in the progression of hepatic fibrosis is unknown. In the present study, we generated αSMACreER;Foxf1fl/fl mice to conditionally inactivate Foxf1 in myofibroblasts during carbon tetrachloride-mediated liver fibrosis. Foxf1 deletion increased collagen depositions and disrupted liver architecture. Timp2 expression was significantly increased in Foxf1-deficient mice while MMP9 activity was reduced. RNA sequencing of purified liver myofibroblasts demonstrated that FOXF1 inhibits expression of pro-fibrotic genes, Col1α2, Col5α2, and Mmp2 in fibrotic livers and binds to active repressors located in promotors and introns of these genes. Overexpression of FOXF1 inhibits Col1a2, Col5a2, and MMP2 in primary murine HSCs in vitro. Altogether, FOXF1 prevents aberrant ECM depositions during hepatic fibrosis by repressing pro-fibrotic gene transcription in myofibroblasts and HSCs.
Project description: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 -galactosidase (-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 l of CCl4/ 1g of body weight) was administered to male Foxf1+/- mice or their wild type (WT) littermates as described.
Project description: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
Project description:FOXF1 targets in embryonic day 18.5 mouse lungs were determined using FOXF1 immunoprecipitation followed by sequencing. FOXF1 binding sites in two biological replicates of pooled E18.5 wildtype mouse lungs (n=3) were to a 2% input control sample.
Project description:Analysis of genes dysregulated due to haploinsufficiency of Foxf1 in postnatal day 0.5 mouse lungs Total RNA obtained from six Foxf1+/- mouse lungs compared to six wildtype littermate mouse lungs
Project description:FOXF1, a member of the forkhead box family of transcription factors, has been previously shown to be critical for lung development, homeostasis, and injury responses. However, the role of FOXF1 in lung regeneration is unknown. Herein, we performed partial pneumonectomy, a model of lung regeneration, in mice lacking one Foxf1 allele in endothelial cells (PDGFb-iCre/Foxf1fl/+ mice). Endothelial cell proliferation was significantly reduced in regenerating lungs from mice deficient for endothelial Foxf1. Decreased endothelial proliferation was associated with delayed lung regeneration as shown by reduced respiratory volume in Foxf1-deficient lungs. FACS-sorted endothelial cells isolated from regenerating PDGFb-iCre/Foxf1fl/+ and control lungs were used for RNAseq analysis to identify FOXF1 target genes. Foxf1 deficiency altered expression of numerous genes including those regulating extracellular matrix remodeling (Timp3, Adamts9) and cell cycle progression (Cdkn1a, Cdkn2b, Cenpj, Tubb4a), which are critical for lung regeneration. Deletion of Foxf1 increased Timp3 mRNA and protein, decreasing MMP14 activity in regenerating lungs. ChIPseq analysis for FOXF1 and histone methylation marks identified DNA regulatory regions with the Cd44, Cdkn1a, and Cdkn2b genes, indicating they are direct FOXF1 targets. Thus FOXF1 stimulates lung regeneration following partial pneumonectomy via direct transcriptional regulation of genes critical for extracellular matrix remodeling and cell cycle progression.
Project description:Aberrant expression of master phenotype regulators by lung fibroblasts may play a central role in idiopathic pulmonary fibrosis (IPF). Interrogating IPF fibroblast transcriptome datasets, we identified Forkhead Box F1 (FOXF1), a DNA-binding protein required for lung development, as a candidate actor in IPF. Thus, we determined FOXF1 expression levels in fibroblasts cultured from normal or IPF lungs in vitro, and explored FOXF1 functions in these cells using transient and stable loss-of-function and gain-of-function models. FOXF1 mRNA and protein were expressed at higher levels in IPF compared with controls. In normal lung fibroblasts, FOXF1 repressed key fibroblast functions such as proliferation, survival, and expression of collagen-1 (COL1) and actin related protein 2/3 complex, subunit 2 (ARPC2). ARPC2 knockdown mimicked FOXF1 overexpression with regard to proliferation and COL1 expression. FOXF1 expression was induced by the antifibrotic mediator prostaglandin E2 (PGE2). Ex vivo, FOXF1 knockdown conferred CCL-210 lung fibroblasts the ability to implant and survive in uninjured mouse lungs. In IPF lung fibroblasts, FOXF1 regulated COL1 but not ARPC2 expression. In conclusion, FOXF1 functions and regulation were consistent with an antifibrotic role in lung fibroblasts. Higher FOXF1 levels in IPF fibroblasts may thus participate in a compensatory response to fibrogenesis. Lung fibroblasts derived from 4 different IPF patients (P313, P355, P375 and P426) were transiently transfected with pcfoxf1 or control pcDNA3.1-constructs. Total RNAs were extracted 24 h after transfection and hybridized on microarrays. One color experiment with 2 experimental conditions: pcfoxf1 and pcDNA3.1