Project description:The activated fibroblast is the putative effector cell for the progressive fibrotic phenotype idiopathic pulmonary fibrosis (IPF). Recent studies investigating global gene expression differences between normal and IPF fibroblasts indicate that changes in gene expression occur in these fibroblasts in culture. Employing a technique that minimizes cellular phenotypic alterations, we characterized the global gene expression changes in pulmonary fibroblasts by comparing both cultured and non-cultured IPF and normal cells. The results revealed dramatic difference between IPF and normal fibroblast as they progressed in culture. While there are significant differences in gene expression between IPF and normal fibroblast at P0, after 3 passages in culture, no statistically significant difference was observed. This study is a comprehensive investigation of gene expression within IPF and normal fibroblasts in culture and sheds light on the efficacy of in vitro models of pulmonary fibroblasts.
Project description:The activated fibroblast is the central effector cell for the progressive fibrotic process that characterizes idiopathic pulmonary fibrosis (IPF). An understanding of the genomic phenotype of this cell in isolation is essential to the understanding of disease pathogenesis and is integral to strategizing therapeutic trials. Employing a unique technique that minimizes cellular phenotypic alterations, we characterized the genomic phenotype of non-cultured pulmonary fibroblasts from the lungs of patients with advanced IPF. This approach revealed several novel genes and pathways previously unreported in IPF fibroblasts. Specifically, we demonstrate altered expression in proteasomal constituents, ubiquitination mediators, the Wnt pathway and several cell cycle regulators suggestive of loss of normal cell cycle controls. The pro-inflammatory cytokine CXCL12 was also up-regulated which may provide a mechanism for fibrocytes’ recruitment, while up-regulated oncogenic KIT may promote fibroblast over proliferation. Paradoxically, pro-apoptotic inducers such as death inducing ligand TRAIL (TNFSF10) and pro-apoptotic Bax were also up-regulated. This comprehensive description of altered gene expression within IPF fibroblasts sheds further light on the complex interactions that characterize IPF. Further studies including therapeutic interventions directed at these pathways hold promise for the treatment of this devastating disease.
Project description:The activated fibroblast is the central effector cell for the progressive fibrotic process that characterizes idiopathic pulmonary fibrosis (IPF). An understanding of the genomic phenotype of this cell in isolation is essential to the understanding of disease pathogenesis and is integral to strategizing therapeutic trials. Employing a unique technique that minimizes cellular phenotypic alterations, we characterized the genomic phenotype of non-cultured pulmonary fibroblasts from the lungs of patients with advanced IPF. This approach revealed several novel genes and pathways previously unreported in IPF fibroblasts. Specifically, we demonstrate altered expression in proteasomal constituents, ubiquitination mediators, the Wnt pathway and several cell cycle regulators suggestive of loss of normal cell cycle controls. The pro-inflammatory cytokine CXCL12 was also up-regulated which may provide a mechanism for fibrocytes’ recruitment, while up-regulated oncogenic KIT may promote fibroblast over proliferation. Paradoxically, pro-apoptotic inducers such as death inducing ligand TRAIL (TNFSF10) and pro-apoptotic Bax were also up-regulated. This comprehensive description of altered gene expression within IPF fibroblasts sheds further light on the complex interactions that characterize IPF. Further studies including therapeutic interventions directed at these pathways hold promise for the treatment of this devastating disease. 58 samples of total RNA isolated from 12 lungs of patients with end-stage idiopathic pulmonary fibrosis and 6 donors of normal lungs (controls) who were designated brain dead, non-diseased donors whose lungs failed criteria for transplantation and who were organ donors for research. RNA extraction followed the Qiagen RNeasy Kit using QIshredder columns for shredding of DNA contiminants. Experimental/control samples were amplified amino-allylated RNA labeled with Cy5 and Stratagene Reference RNA was amplified and amino-allylated and labeled with Cy3. Amplification was one round using Ambion MessageAmp II kit with amino-allylated UTP according to the protocol of the Duke University Institute for Genome Sciences and Policy. Amplification and amino-allylation of the Stratagene Reference RNA and Hybridization of Reference with patient samples and controls was done by the Duke Institute for Genomic Sciences and Policy.
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
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.
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.
Project description:Analysis of gene expression of lung fibroblasts seeded onto decellularized extracellular matrix (ECM). Experiment had 2x2 design where fibroblasts from idiopathic pulmonary fibrosis (IPF) or control patients were seeded onto decelluarized lung tissue from IPF or control patients allowing for determination of gene expression differences that were driven by IPF ECM and which differences were driven by the IPF fibroblast. Lung fibroblasts from 5 patients with idiopathic pulmonary fibrosis and 5 control patients were cultured on decellularized ECM from IPF or control lung. Total RNA and polyribosome RNA were isolated after the cells were cultured on the decellularized ECM for 18 hours. When possible, a control cell line and a diseased cell line were cultured (and processed) simultaneously to minimize the effect of experimental variance induced by running the experiment at different times.Samples with the same batch number (provied in the sample 'characteristics' field) were cultured and processed at the same time.
Project description:Phenotypic changes in lung fibroblasts are believed to contribute to the development of Idiopathic Pulmonary Fibrosis (IPF), a progressive and fatal lung disease. Long intergenic non-coding RNAs (lincRNAs) have been identified as novel regulators of gene expression and protein activity. In non-stimulated cells, we observed reduced proliferation and inflammation but no difference in the fibrotic response of IPF fibroblasts. These functional changes in non-stimulated cells were associated with changes in the expression of the histone marks, H3K4me1, H3K4me3 and H3K27ac indicating a possible involvement of epigenetics. Following activation with TGF-b1 and IL-1b, we demonstrated an increased fibrotic but reduced inflammatory response in IPF fibroblasts. There was no significant difference in proliferation following PDGF exposure. The lincRNAs, LINC00960 and LINC01140 were upregulated in IPF fibroblasts. Knockdown studies showed that LINC00960 and LINC01140 were positive regulators of proliferation in both control and IPF fibroblasts but had no effect upon the fibrotic response. Knockdown of LINC01140 but not LINC00960 increased the inflammatory response, which was greater in IPF compared to control fibroblasts. Overall, these studies demonstrate for the first time that lincRNAs are important regulators of proliferation and inflammation in human lung fibroblasts and that these might mediate the reduced inflammatory response observed in IPF-derived fibroblasts.