Project description:Accelerated senescence in lung epithelial cells is known to play a key role in the pathogenesis of idiopathic pulmonary fibrosis (IPF). However, the exact mechanisms underlying the IPF-related epithelial cell phenotype have yet to be elucidated. Increasing evidence supports the concept that extracellular vesicles (EVs), including exosomes and microvesicles, mediate intercellular communication that contributes to diverse aspects of physiology and pathogenesis. Here, we demonstrate that lung fibroblasts (LFs) from IPF patients accelerate epithelial cell senescence via EV-mediated transfer of LF-derived pathogenic cargo to lung epithelial cells. Mechanistically, IPF LF-derived EVs increase mitochondrial reactive oxygen species (mtROS) and associated mitochondrial damage in lung epithelial cells, leading to mtROS-mediated activation of the DNA damage response and subsequent epithelial cell senescence. We show that IPF LF-derived EVs contain elevated levels of miR-23b-3p and miR-494-3p that are responsible for suppressing SIRT3, resulting in the EV-induced phenotypic changes of lung epithelial cells. Furthermore, we observe that miR-23b-3p and miR-494-3p expression increases in lung epithelial cells from IPF patients’ lungs. Finally, the levels of miR-23b-3p and 494-3p found in IPF LF-derived EVs correlate positively with IPF disease severity. These findings reveal that the accelerated epithelial cell mitochondrial damage and senescence observed during IPF pathogenesis are caused by a novel mechanism in which SIRT3 is suppressed by miR-containing EVs derived from IPF fibroblasts.
Project description:Viruses in acute exacerbations of idiopathic pulmonary fibrosis Keywords: viral detection BAL from patients with acute exacerbations of IPF and stable IPF were hybridized to a pan-viral cDNA microarray to evaluate the presence of virus during these episodes
Project description:Idiopathic pulmonary fibrosis (IPF) is a disease related to AT2 cell. We used flow cytometry to analyze the epithelial component of donor and IPF lungs. From the live cells, we first excluded the CD31PosCD45Pos and then selected the EPCAMPos cells for further analysis using the human AT2 cell marker HTll-280 and the surface marker PD-L1. Our data indicate that, the bona fide differentiated AT2 cells (HTll-280High PD-L1Neg), were drastically reduced in the context of IPF. More interestingly, the number of HTll-280Low/Neg PD-L1High was drastically increased, suggesting that HTll-280Low PD-L1High epithelial cells could represent a pool of progenitors linked to the deficient AT2 lineage. The aim of this experiment is further characterization of AT2 and PDL1+ cells in donor and IPF.
Project description:Tissue fibrosis is a common pathological outcome of chronic disease that markedly impairs organ function leading to morbidity and mortality. In the lung, idiopathic pulmonary fibrosis (IPF) is an insidious and fatal interstitial lung disease associated with declining pulmonary function. Single cell RNA sequencing was used to map epithelial cell types of the normal human airway and alveolaor as well as IPF explant tissue.
Project description:Archived lung tissues of patients with IPF were obtained from the tissue bank of the Department of Pathology at the University of Pittsburgh. The diagnosis of IPF was confirmed by open lung biopsy. All patients fulfilled the criteria of the American Thoracic Society and European Respiratory Society for the diagnosis of IPF. Normal histology lung tissues resected from patients with lung cancer were used as controls. Keywords: parallel sample
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.