Project description:Bleomycin (BLM) induces lung injury, leading to inflammation and pulmonary fibrosis. Regulatory T cells (Tregs) maintain self-tolerance and control host immune responses. However, little is known about their involvement in the pathology of pulmonary fibrosis. Here we show that a unique Treg subset that expresses trefoil factor family 1(Tff1) emerges in the BLM-injured lung. These Tff1-expressing Tregs (Tff1-Tregs) were induced by IL-33. Moreover, although Tff1 ablation in Tregs had no impact, selective ablation of Tff1-Tregs using an intersectional genetic method promoted pro-inflammatory features of macrophages in the injured lung and exacerbated the fibrosis. Taken together, our study revealed the presence of a unique Treg subset expressing Tff1 in BLM-injured lungs and their critical role in the injured lung to ameliorate fibrosis.
Project description:Bleomycin (BLM) induces lung injury, leading to inflammation and pulmonary fibrosis. Regulatory T cells (Tregs) maintain self-tolerance and control host immune responses. However, little is known about their involvement in the pathology of pulmonary fibrosis. Here we show that a unique Treg subset that expresses trefoil factor family 1(Tff1) emerges in the BLM-injured lung. These Tff1-expressing Tregs (Tff1-Tregs) were induced by IL-33. Moreover, although Tff1 ablation in Tregs had no impact, selective ablation of Tff1-Tregs using an intersectional genetic method promoted pro-inflammatory features of macrophages in the injured lung and exacerbated the fibrosis. Taken together, our study revealed the presence of a unique Treg subset expressing Tff1 in BLM-injured lungs and their critical role in the injured lung to ameliorate fibrosis.
Project description:Pulmonary fibrosis is a disease characterized by inflammatory cell infiltration, scar formation, deposition of extracellular matrix, alveolar epithelial cell injury and hyperplasia. To determine if alterations in microRNA expression contribute to these phenotypes, microRNA expression profiling of the lungs from bleomycin treated C57Bl/6J mice, relative to that of untreated controls, was undertaken. Mice were treated at 8 weeks old with 100 Units/kg of bleomycin delivered subcutaneously with osmotic minipumps. At 42 days post treatment mice were euthanized and lung microRNA isolated. We identified 11 microRNA's to be significantly differentially expressed (FDR threshold of 0.01) in the lungs of bleomycin treated mice and confirmed these data with real time PCR measurements. These included bleomycin upregulated miR-34a, 335-5p, 207, 21, 301a, 146b, 199a-5p, and 449a and bleomycin downregulated miR-151-3p, 26a and 676. We have previously shown that 1558 genes are differentially expressed in the lungs of bleomycin treated mice. Of the 1412 targets of upregulated microRNAs, 142 were confirmed to be downregulated in the gene expression profile (GEP). Of the 583 targets of downregulated microRNAs, 53 were confirmed to be upregulated in the gene expression profile. Pathway analysis of the microRNA targets and GEP overlapping genes indicated that altered microRNA expression is associated with cellular development, cellular growth, cellular proliferation and changed tissue/cell morphology. Specific pathways include HGF signaling, Cholecystokinin/Gastrin-mediated signaling, Endothelin-1 signaling, RAR activation, Phospholipase C signaling and IGF1 signaling. We conclude that altered microRNA expression is a feature of pulmonary fibrosis which putatively influences components of the altered airway disease. Two condition study, C57Bl/6J mice treated with 100 Units/kg bleomycin and untreated controls. Biological replicated n =3 for each group. Left lung tissue.
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:Pulmonary fibrosis is a disease characterized by inflammatory cell infiltration, scar formation, deposition of extracellular matrix, alveolar epithelial cell injury and hyperplasia. To determine if alterations in microRNA expression contribute to these phenotypes, microRNA expression profiling of the lungs from bleomycin treated C57Bl/6J mice, relative to that of untreated controls, was undertaken. Mice were treated at 8 weeks old with 100 Units/kg of bleomycin delivered subcutaneously with osmotic minipumps. At 42 days post treatment mice were euthanized and lung microRNA isolated. We identified 11 microRNA's to be significantly differentially expressed (FDR threshold of 0.01) in the lungs of bleomycin treated mice and confirmed these data with real time PCR measurements. These included bleomycin upregulated miR-34a, 335-5p, 207, 21, 301a, 146b, 199a-5p, and 449a and bleomycin downregulated miR-151-3p, 26a and 676. We have previously shown that 1558 genes are differentially expressed in the lungs of bleomycin treated mice. Of the 1412 targets of upregulated microRNAs, 142 were confirmed to be downregulated in the gene expression profile (GEP). Of the 583 targets of downregulated microRNAs, 53 were confirmed to be upregulated in the gene expression profile. Pathway analysis of the microRNA targets and GEP overlapping genes indicated that altered microRNA expression is associated with cellular development, cellular growth, cellular proliferation and changed tissue/cell morphology. Specific pathways include HGF signaling, Cholecystokinin/Gastrin-mediated signaling, Endothelin-1 signaling, RAR activation, Phospholipase C signaling and IGF1 signaling. We conclude that altered microRNA expression is a feature of pulmonary fibrosis which putatively influences components of the altered airway disease.
Project description:Genomic profiling of bleomycin- and saline-treated mice across 7 timepoints (1, 2, 7, 14, 21, 28, 35 days post treatment) was carried out in C57BL6/J mice to determine the phases of response to bleomycin treatment which correspond to onset of active pulmonary fibrosis. Temporal genomic characterization of lung homogenate from male C57BL6/J mice treated intratracheally with bleomycin or saline was carried out at 7 timepoints post treatment (1, 2, 7, 14, 21, 28, 35 days). Bleomycin (2U/kg) in 50 μl was intratracheally sprayed once into mice lightly anaesthetized with isoflurane (5% in 100% O2). Control animals received 50 μl of saline. Total RNA was isolated from the mouse lung tissue of bleomycin- and saline-treated mice across the 7 time points (n=8 per group) and homogenized in QIAzol reagent. Purified total RNA was amplified and labeled using NuGen Ovation kits (NuGEN Technologies, Inc., San Carlos, CA), and RNA from samples was hybridized to Affymetrix Mouse 430 2.0 arrays. One sample (saline treated, d14) was flagged as an outlier in principal component analysis and removed from subsequent analysis.
Project description:The objective of this study was to determine if a subset of regulatory T cells (Tregs) expressing the transcription factor, Zbtb20, played a unique role in the function of the immune system. Genetic reporter mice were used to isolate Zbtb20-expressing Tregs as well as activated (CD62Llo) and naive (CD62Lhi) Tregs. The gene expression in these cells was determined with RNA-seq.