scholarly journals Telomere Dysfunction in Idiopathic Pulmonary Fibrosis

2021 ◽  
Vol 8 ◽  
Author(s):  
Kexiong Zhang ◽  
Lu Xu ◽  
Yu-Sheng Cong
Keyword(s):  
Stem Cell ◽  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Transforming Growth Factor ◽  
Immune Cell ◽  
Unknown Etiology ◽  
Lung Pathology ◽  
Telomere Dysfunction ◽  
Cell Dysfunction ◽  
Fibrotic Process

Idiopathic pulmonary fibrosis is an age-dependent progressive and fatal lung disease of unknown etiology, which is characterized by the excessive accumulation of extracellular matrix inside the interstitial layer of the lung parenchyma that leads to abnormal scar architecture and compromised lung function capacity. Recent genetic studies have attributed the pathological genes or genetic mutations associated with familial idiopathic pulmonary fibrosis (IPF) and sporadic IPF to telomere-related components, suggesting that telomere dysfunction is an important determinant of this disease. In this study, we summarized recent advances in our understanding of how telomere dysfunction drives IPF genesis. We highlighted the key role of alveolar stem cell dysfunction caused by telomere shortening or telomere uncapping, which bridged the gap between telomere abnormalities and fibrotic lung pathology. We emphasized that senescence-associated secretory phenotypes, innate immune cell infiltration, and/or inflammation downstream of lung stem cell dysfunction influenced the native microenvironment and local cell signals, including increased transforming growth factor-beta (TGF-β) signaling in the lung, to induce pro-fibrotic conditions. In addition, the failed regeneration of new alveoli due to alveolar stem cell dysfunction might expose lung cells to elevated mechanical tension, which could activate the TGF-β signaling loop to promote the fibrotic process, especially in a periphery-to-center pattern as seen in IPF patients. Understanding the telomere-related molecular and pathophysiological mechanisms of IPF would provide new insights into IPF etiology and therapeutic strategies for this fatal disease.

scholarly journals LTBP2 is secreted from lung myofibroblasts and is a potential biomarker for idiopathic pulmonary fibrosis

2018 ◽  
Vol 132 (14) ◽  
pp. 1565-1580 ◽  
Author(s):  
Yasunori Enomoto ◽  
Sayomi Matsushima ◽  
Kiyoshi Shibata ◽  
Yoichiro Aoshima ◽  
Haruna Yagi ◽  
...  
Keyword(s):  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Bootstrap Method ◽  
Transforming Growth Factor Β ◽  
Lung Fibroblasts ◽  
Potential Biomarker ◽  
Fibrotic Process ◽  
Mouse Lungs

Although differentiation of lung fibroblasts into α-smooth muscle actin (αSMA)-positive myofibroblasts is important in the progression of idiopathic pulmonary fibrosis (IPF), few biomarkers reflecting the fibrotic process have been discovered. We performed microarray analyses between FACS-sorted steady-state fibroblasts (lineage (CD45, TER-119, CD324, CD31, LYVE-1, and CD146)-negative and PDGFRα-positive cells) from untreated mouse lungs and myofibroblasts (lineage-negative, Sca-1-negative, and CD49e-positive cells) from bleomycin-treated mouse lungs. Amongst several genes up-regulated in the FACS-sorted myofibroblasts, we focussed on Ltbp2, the gene encoding latent transforming growth factor-β (TGF-β) binding protein-2 (LTBP2), because of the signal similarity to Acta2, which encodes αSMA, in the clustering analysis. The up-regulation was reproduced at the mRNA and protein levels in human lung myofibroblasts induced by TGF-β1. LTBP2 staining in IPF lungs was broadly positive in the fibrotic interstitium, mainly as an extracellular matrix (ECM) protein; however, some of the αSMA-positive myofibroblasts were also stained. Serum LTBP2 concentrations, evaluated using ELISA, in IPF patients were significantly higher than those in healthy volunteers (mean: 21.4 compared with 12.4 ng/ml) and showed a negative correlation with % predicted forced vital capacity (r = −0.369). The Cox hazard model demonstrated that serum LTBP2 could predict the prognosis of IPF patients (hazard ratio for death by respiratory events: 1.040, 95% confidence interval: 1.026–1.054), which was validated using the bootstrap method with 1000-fold replication. LTBP2 is a potential prognostic blood biomarker that may reflect the level of differentiation of lung fibroblasts into myofibroblasts in IPF.

scholarly journals GDF15 is an epithelial-derived biomarker of idiopathic pulmonary fibrosis

2019 ◽  
Vol 317 (4) ◽  
pp. L510-L521 ◽  
Author(s):  
Yingze Zhang ◽  
Mao Jiang ◽  
Mehdi Nouraie ◽  
Mark G. Roth ◽  
Tracy Tabib ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Transforming Growth Factor ◽  
Primary Source ◽  
Transforming Growth Factor Β ◽  
Alveolar Epithelial Cells ◽  
Lung Epithelial Cells ◽  
Secreted Protein ◽  
Telomere Dysfunction

Idiopathic pulmonary fibrosis (IPF) is the most common and devastating of the interstitial lung diseases. Epithelial dysfunction is thought to play a prominent role in disease pathology, and we sought to characterize secreted signals that may contribute to disease pathology. Transcriptional profiling of senescent type II alveolar epithelial cells from mice with epithelial-specific telomere dysfunction identified the transforming growth factor-β family member, growth and differentiation factor 15 ( Gdf15), as the most significantly upregulated secreted protein. Gdf15 expression is induced in response to telomere dysfunction and bleomycin challenge in mice. Gdf15 mRNA is expressed by lung epithelial cells, and protein can be detected in peripheral blood and bronchoalveolar lavage following bleomycin challenge in mice. In patients with IPF, GDF15 mRNA expression in lung tissue is significantly increased and correlates with pulmonary function. Single-cell RNA sequencing of human lungs identifies epithelial cells as the primary source of GDF15, and circulating concentrations of GDF15 are markedly elevated and correlate with disease severity and survival in multiple independent cohorts. Our findings suggest that GDF15 is an epithelial-derived secreted protein that may be a useful biomarker of epithelial stress and identifies IPF patients with poor outcomes.

scholarly journals The Role of TGF-β Signaling in Lung Cancer Associated with Idiopathic Pulmonary Fibrosis

2018 ◽  
Vol 19 (11) ◽  
pp. 3611 ◽  
Author(s):  
Akira Saito ◽  
Masafumi Horie ◽  
Patrick Micke ◽  
Takahide Nagase
Keyword(s):  
Lung Cancer ◽  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Molecular Mechanisms ◽  
Transforming Growth Factor ◽  
Current Knowledge ◽  
Field Cancerization ◽  
Unknown Etiology ◽  
Dismal Prognosis ◽  
Increased Risk

Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease of unknown etiology and dismal prognosis. IPF patients are known to have an increased risk of lung cancer and careful decision-making is required for the treatment of lung cancer associated with IPF. Transforming growth factor (TGF)-β signaling plays a central role in tissue fibrosis and tumorigenesis. TGF-β-mediated pathological changes that occur in IPF lung tissue may promote the process of field cancerization and provide the microenvironment favorable to cancer initiation and progression. This review summarizes the current knowledge related to IPF pathogenesis and explores the molecular mechanisms that underlie the occurrence of lung cancer in the background of IPF, with an emphasis on the multifaceted effects of TGF-β signaling.

MicroRNA regulatory networks in idiopathic pulmonary fibrosis

2015 ◽  
Vol 93 (2) ◽  
pp. 129-137 ◽  
Author(s):  
Kusum V. Pandit ◽  
Jadranka Milosevic
Keyword(s):  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Regulatory Networks ◽  
Transforming Growth Factor ◽  
Epithelial Mesenchymal Transition ◽  
Epigenetic Modification ◽  
Unknown Etiology ◽  
Mesenchymal Transition ◽  
Functional Studies ◽  
Important Player

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and fatal scarring lung disease of unknown etiology, characterized by changes in microRNA expression. Activation of transforming growth factor (TGF-β) is a key event in the development of IPF. Recent reports have also identified epigenetic modification as an important player in the pathogenesis of IPF. In this review, we summarize the main results of studies that address the role of microRNAs in IPF and highlight the synergistic actions of these microRNAs in regulating TGF-β, the primary fibrogenic mediator. We outline epigenetic regulation of microRNAs by methylation. Functional studies identify microRNAs that alter proliferative and migratory properties of fibroblasts, and induce phenotypic changes in epithelial cells consistent with epithelial-mesenchymal transition. Though these studies were performed in isolation, we identify multiple co-operative actions after assembling the results into a network. Construction of such networks will help identify disease-propelling hubs that can be targeted for therapeutic purposes.

scholarly journals Molecular biomarkers in idiopathic pulmonary fibrosis

2014 ◽  
Vol 307 (9) ◽  
pp. L681-L691 ◽  
Author(s):  
Brett Ley ◽  
Kevin K. Brown ◽  
Harold R. Collard
Keyword(s):  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Alveolar Epithelial Cell ◽  
Underlying Disease ◽  
Current Approach ◽  
Molecular Biomarkers ◽  
Alveolar Epithelial ◽  
Cell Dysfunction ◽  
Collaborative Efforts ◽  
Intended Use

Molecular biomarkers are highly desired in idiopathic pulmonary fibrosis (IPF), where they hold the potential to elucidate underlying disease mechanisms, accelerated drug development, and advance clinical management. Currently, there are no molecular biomarkers in widespread clinical use for IPF, and the search for potential markers remains in its infancy. Proposed core mechanisms in the pathogenesis of IPF for which candidate markers have been offered include alveolar epithelial cell dysfunction, immune dysregulation, and fibrogenesis. Useful markers reflect important pathological pathways, are practically and accurately measured, have undergone extensive validation, and are an improvement upon the current approach for their intended use. The successful development of useful molecular biomarkers is a central challenge for the future of translational research in IPF and will require collaborative efforts among those parties invested in advancing the care of patients with IPF.

scholarly journals Moving stem cell therapy to patients with idiopathic pulmonary fibrosis

Respirology ◽  
2014 ◽  
Vol 19 (7) ◽  
pp. 950-951 ◽  
Author(s):  
Marilyn K. Glassberg ◽  
Rebecca L. Toonkel
Keyword(s):  
Stem Cell ◽  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Cell Therapy ◽  
Stem Cell Therapy

scholarly journals A Rnd3/p190RhoGAP pathway regulates RhoA activity in idiopathic pulmonary fibrosis fibroblasts

2018 ◽  
Vol 29 (18) ◽  
pp. 2165-2175 ◽  
Author(s):  
Elizabeth Monaghan-Benson ◽  
Erika S. Wittchen ◽  
Claire M. Doerschuk ◽  
Keith Burridge
Keyword(s):  
Extracellular Matrix ◽  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Normal Lung ◽  
Rhoa Activity ◽  
Incurable Disease ◽  
Normal Lung Function ◽  
Growth Factor Beta

Idiopathic pulmonary fibrosis (IPF) is an incurable disease of the lung that is characterized by excessive deposition of extracellular matrix (ECM), resulting in disruption of normal lung function. The signals regulating fibrosis include both transforming growth factor beta (TGF-β) and tissue rigidity and a major signaling pathway implicated in fibrosis involves activation of the GTPase RhoA. During studies exploring how elevated RhoA activity is sustained in IPF, we discovered that not only is RhoA activated by profibrotic stimuli but also that the expression of Rnd3, a major antagonist of RhoA activity, and the activity of p190RhoGAP (p190), a Rnd3 effector, are both suppressed in IPF fibroblasts. Restoration of Rnd3 levels in IPF fibroblasts results in an increase in p190 activity, a decrease in RhoA activity and a decrease in the overall fibrotic phenotype. We also find that treatment with IPF drugs nintedanib and pirfenidone decreases the fibrotic phenotype and RhoA activity through up-regulation of Rnd3 expression and p190 activity. These data provide evidence for a pathway in IPF where fibroblasts down-regulate Rnd3 levels and p190 activity to enhance RhoA activity and drive the fibrotic phenotype.

scholarly journals Di-Tyrosine Crosslinking and NOX4 Expression as Oxidative Pathological Markers in the Lungs of Patients with Idiopathic Pulmonary Fibrosis

Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1833
Author(s):  
Sanja Blaskovic ◽  
Yves Donati ◽  
Isabelle Ruchonnet-Metrailler ◽  
Tamara Seredenina ◽  
Karl-Heinz Krause ◽  
...  
Keyword(s):  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Human Fibroblasts ◽  
Cell Types ◽  
Post Translational Modification ◽  
Pulmonary Tissue ◽  
Nadph Oxidase 4

Idiopathic pulmonary fibrosis (IPF) is a noninflammatory progressive lung disease. Oxidative damage is a hallmark of IPF, but the sources and consequences of oxidant generation in the lungs are unclear. In this study, we addressed the link between the H2O2-generating enzyme NADPH oxidase 4 (NOX4) and di-tyrosine (DT), an oxidative post-translational modification in IPF lungs. We performed immunohistochemical staining for DT and NOX4 in pulmonary tissue from patients with IPF and controls using validated antibodies. In the healthy lung, DT showed little or no staining and NOX4 was mostly present in normal vascular endothelium. On the other hand, both markers were detected in several cell types in the IPF patients, including vascular smooth muscle cells and epithelium (bronchial cells and epithelial cells type II). The link between NOX4 and DT was addressed in human fibroblasts deficient for NOX4 activity (mutation in the CYBA gene). Induction of NOX4 by Transforming growth factor beta 1 (TGFβ1) in fibroblasts led to moderate DT staining after the addition of a heme-containing peroxidase in control cells but not in the fibroblasts deficient for NOX4 activity. Our data indicate that DT is a histological marker of IPF and that NOX4 can generate a sufficient amount of H2O2 for DT formation in vitro.

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