Project description:We conducted fibroblast-specific transcriptome analysis by next generation sequencing in order to investigate qualitative change and activation signatures of lung fibroblasts in bleomycin-induced pulmonary fibrosis. Lung fibroblasts were identified by using reporter mice of collagen-α2(I), in which collagen I-producing fibroblasts were labeled with EGFP. Lungs were dissociated with protease sollution, and single cell suspension were stained with lineage markers (Ter119, CD45, CD31, EpCAM). Lineage- GFP+ cells were sorted out and mRNA was collected. Using serial analysis of gene expression (SAGE) method, we identified 2,973,937 SAGE tags (1,080,798 tags from saline-treated GFP+ fibroblasts and 1,893,139 tags from bleomycin-treated GFP+ fibroblasts). We found that genes related to extracellular matrix construction were highly up-regulated in fibroblasts from belomycin-treated lungs. Moreover, an analysis of mRNA profiles revealed biological functions such as proliferation, invasion, adhesion, and migration were promoted in fibroblasts from bleomycin-treated lung, which recapitulated the role of fibroblasts in the fibrogenesis. These fibroblast-specific gene expression profiles will be important notions in future fibrosis studies. mRNA profiles of Lung fibroblasts from 3 mice at day 14 after saline or bleomycin treatment.
Project description:A hallmark of pulmonary fibrosis is aberrant activation of lung fibroblasts to become pathological fibroblasts producing excessive extracellular matrix (ECM). Here, we showed Lepr-CreERT2 lineage labels lung mesenchymal cells including the majority of alveolar fibroblasts, which signigicatly contribute to pathological fibroblasts in bleomycin induced lung fibrosis.
Project description:We have employed whole genome microarray expression profiling as a discovery platform to identify genes with the potential to distinguish Mmp19 regulation of fibroblast phenotype changes in mouse lungs. Pulmonary fibrosis was induced by bleomycin at 0.08 u in 50ul of saline. At 21st day the mice were sacrificed and mouse lung fibroblasts were isolated and cultured in FBM plus additives following Lonza's portocol. RNA was extracted with miRNA mini kit from Qiagen. Gene expression microarray was performed with Agilent. A 834-gene consensus signature was identified that distinguished between Mmp19 knockout mice from wildtype. Some gene expression in the same RNA samples were validtaed by real-time PCR. The established bleomycin induced fibrosis was used in this experiment. At day 21 the fibrosis would be the situation of stable fibrosis. We administrated 0.08u of bleomycin intratracheally into wildtype and Mmp19 knockout mice, sacrificed the mice at 21st day and isolated the lung fibroblasts and culturing. Five independent experiments were performed and 3 for gene expression experiment.
Project description:A hallmark of pulmonary fibrosis is aberrant activation of lung fibroblasts to become pathological fibroblasts producing excessive extracellular matrix (ECM). Here, we showed Lepr-Cre lineage labels multiple cells types including the majority of alveolar fibroblasts, which signigicatly contribute to pathological fibroblasts in bleomycin induced lung fibrosis.
Project description:Analysis of whole genome gene expression levels in distal lung tissue from mice with systemically bleomycin-induced pulmonary fibrosis. The hypothesis is that bleomycin promotes a specific genotype associated with development of pulmonary fibrosis and that treatment with compound EXT reduces the induction of genes related to the early progression of fibrosis.
Project description:Idiopathic pulmonary fibrosis (IPF) is a progressive, irreversible fibrotic disease of the distal lung alveoli that culminates in respiratory failure and reduced lifespan. Unlike normal lung repair in response to injury, IPF is associated with the accumulation and persistence of fibroblasts and myofibroblasts and continued production of collagen and other extracellular matrix (ECM) components. Prior in vitro studies have led to the hypothesis that the development of resistance to Fas-induced apoptosis by lung fibroblasts and myofibroblasts contibributes to their accumulation in the distal lung tissues of IPF patients. Here, we test this hypothesis in vivo in the resolving model of bleomycin-induced pulmonary fibrosis in mice. Using genetic loss-of-function approaches to inhibit Fas signaling in fibroblasts, novel flow cytometry strategies to quantify lung fibroblast subsets and transcriptional profiling of lung fibroblasts by bulk and single cell RNA-sequencing, we show that Fas is necessary for lung fibroblast apoptosis during homeostatic resolution of bleomycin-induced pulmonary fibrosis in vivo. Furthermore, we show that loss of Fas signaling leads to the persistence and continued pro-fibrotic functions of lung fibroblasts. Our studies provide novel insights into the mechanisms that contribute to fibroblast survival, persistence and continued ECM deposition in the context of IPF and how failure to undergo Fas-induced apoptosis prevents fibrosis resolution.
Project description:We conducted fibroblast-specific transcriptome analysis by next generation sequencing in order to investigate qualitative change and activation signatures of lung fibroblasts in bleomycin-induced pulmonary fibrosis. Lung fibroblasts were identified by using reporter mice of collagen-α2(I), in which collagen I-producing fibroblasts were labeled with EGFP. Lungs were dissociated with protease sollution, and single cell suspension were stained with lineage markers (Ter119, CD45, CD31, EpCAM). Lineage- GFP+ cells were sorted out and mRNA was collected. Using serial analysis of gene expression (SAGE) method, we identified 2,973,937 SAGE tags (1,080,798 tags from saline-treated GFP+ fibroblasts and 1,893,139 tags from bleomycin-treated GFP+ fibroblasts). We found that genes related to extracellular matrix construction were highly up-regulated in fibroblasts from belomycin-treated lungs. Moreover, an analysis of mRNA profiles revealed biological functions such as proliferation, invasion, adhesion, and migration were promoted in fibroblasts from bleomycin-treated lung, which recapitulated the role of fibroblasts in the fibrogenesis. These fibroblast-specific gene expression profiles will be important notions in future fibrosis studies.
Project description:Idiopathic pulmonary fibrosis is a chronic devastating disease of unknown etiology. No therapy is currently available. A growing body of evidence supports the role of TGFβ1 as the major player in the pathogenesis of the disease. This study designed novel human- and mouse-specific siRNAs and siRNA/DNA chimeras targeting both human and mouse common sequences and evaluated their inhibitory activity in pulmonary fibrosis induced by bleomycin and lung-specific transgenic expression of human TGFβ1. Selective novel sequences of siRNA and siRNA/DNA chimeras efficiently inhibited pulmonary fibrosis, indicating their applicability as tools for treating fibrotic disease in humans. Total RNA was extracted from lung tissue from mice with bleomycin (BLM)-induced lung fibrosis treated with mouse TGFβ1 siRNAs or vehicle on different days after BLM infusion.
Project description:Pulmonary fibrosis includes a variety of underlying causes of fibrosing interstitial lung diseases (ILDs). Pulmonary fibrosis is usually considered to be related to chronic inflammation of lung tissue and excessive proliferation of fibroblasts, however, the mechanism is complex and unclear.To study the underlying molecular mechanisms, we further applied high-throughput sequencing to analyze the differentially expressed genes in rat lung tissues induced by Bleomycin.