scholarly journals MUTYH Deficiency Is Associated with Attenuated Pulmonary Fibrosis in a Bleomycin-Induced Model

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Qingmin Sun ◽  
Jingwen Chen ◽  
Lizhi Xu ◽  
Jiaqi Kang ◽  
Xin Wu ◽  
...  
Keyword(s):  
Pulmonary Fibrosis ◽  
Oxidative Dna Damage ◽  
Excision Repair ◽  
Unknown Etiology ◽  
Mitochondrial Dynamic ◽  
Pulmonary Tissue ◽  
Dynamic Regulation ◽  
Protein Levels ◽  
Age Related ◽  
Mutyh Gene

Idiopathic pulmonary fibrosis (IPF) is a progressive, irreversible lung disease of unknown etiology with limited survival. IPF incidence and prevalence increase significantly with aging, which is associated with an age-related accumulation of oxidative DNA damage. The Mutyh gene is involved in the base excision repair (BER) system, which is critical for repairing the misincorporated adenine that is opposite to the oxidized guanine base, 8-oxoguanine, and maintaining the fidelity of DNA replication. We used Mutyh knockout mice and a bleomycin-induced pulmonary fibrosis model to test the effect of MUTYH deficiency on lesion progression. Unexpectedly, a much less severe lesion of pulmonary fibrosis was observed in Mutyh-/- than in Mutyh+/+mice, which was supported by assay on protein levels of TGF-β1 and both fibrotic markers, α-SMA and Vimentin, in pulmonary tissues of the model animals. Mechanically, MUTYH deficiency prevented the genomic DNA of pulmonary tissue cells from the buildup of single-strand breaks (SSBs) of DNA and maintained the integrity of mtDNA. Furthermore, increased mitochondrial dynamic regulation and mitophagy were detected in pulmonary tissues of the bleomycin-induced Mutyh-/- model mice, which could reduce the pulmonary epithelial cell apoptosis. Our results suggested that MUTYH deficiency could even induce protective responses of pulmonary tissue under severe oxidative stress.

scholarly journals IGFBP2 protects against pulmonary fibrosis through inhibiting P21-mediated senescence

2021 ◽  
Author(s):  
Chin Chiahsuan ◽  
John Lee ◽  
Ranjith Ravichandran ◽  
Timothy Fleming ◽  
Stephen Wheatcroft ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Pulmonary Fibrosis ◽  
Lung Epithelial Cells ◽  
Mouse Lung ◽  
Type Ii ◽  
P21 Protein ◽  
Aged Mice ◽  
Protein Levels ◽  
Age Related ◽  
Lung Epithelial

AbstractAccumulation of senescent cells contributes to age related diseases including idiopathic pulmonary fibrosis (IPF). Insulin-like growth factor binding proteins (IGFBPs) are evolutionarily conserved proteins that play a vital role in many biological processes. Overall, little is known about the functions of IGFBP2 in the epigenetic regulation of cellular senescence and pulmonary fibrosis. Here, we show that Igfbp2 expression was significantly downregulated at both mRNA and protein levels in a low-dose bleomycin-induced pulmonary fibrosis model of aged mice. Using the reduced representation of bisulfite sequencing technique, we demonstrated Igfbp2 downregulation is attributed to DNA methylation of CpG islands in fibrotic lungs of aged mice. Furthermore, Igfbp2 siRNA knockdown increased both P53 and P21 protein levels in mouse lung epithelial cells exposed to hypoxia treatment. Lentiviral mediated expression of Igfb2 decreased P21 protein levels and significantly reduced beta galactosidase activity in mouse lung epithelial cells challenged with a senescent drug (atazanavir) and hypoxia treatments. Using the RT2 Profiler PCR Array, we found that P21, PAI-1, IRF-5 and IRF-7, important regulators of senescence pathway, were significantly downregulated specifically in type-II alveolar epithelial cells (AECs) of aged human-Igfbp2 transgenic mice after bleomycin challenge. Finally, transgenic expression of human-Igfbp2 in type-II AECs from aged bleomycin challenged mice significantly decreased senescent associated secretory phenotype factors and also reduced extracellular matrix markers compared to aged wild-type mice challenged with bleomycin injury. Collectively, these findings reveal that epigenetic repression of Igfbp2 promotes pulmonary fibrosis and that restoring IGFBP2 in fibrotic lungs could prove effective in IPF treatment.

scholarly journals The Response to Oxidative DNA Damage in Neurons: Mechanisms and Disease

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Laura Narciso ◽  
Eleonora Parlanti ◽  
Mauro Racaniello ◽  
Valeria Simonelli ◽  
Alessio Cardinale ◽  
...  
Keyword(s):  
Dna Damage ◽  
Genome Stability ◽  
Oxidative Dna Damage ◽  
Excision Repair ◽  
Strand Breaks ◽  
Single Strand Breaks ◽  
Age Related ◽  
Neurological Alterations ◽  
Base Excision ◽  
And Function

There is a growing body of evidence indicating that the mechanisms that control genome stability are of key importance in the development and function of the nervous system. The major threat for neurons is oxidative DNA damage, which is repaired by the base excision repair (BER) pathway. Functional mutations of enzymes that are involved in the processing of single-strand breaks (SSB) that are generated during BER have been causally associated with syndromes that present important neurological alterations and cognitive decline. In this review, the plasticity of BER during neurogenesis and the importance of an efficient BER for correct brain function will be specifically addressed paying particular attention to the brain region and neuron-selectivity in SSB repair-associated neurological syndromes and age-related neurodegenerative diseases.

scholarly journals Mitochondrial Quality Control in Age-Related Pulmonary Fibrosis

2020 ◽  
Vol 21 (2) ◽  
pp. 643 ◽  
Author(s):  
Willy Roque ◽  
Karina Cuevas-Mora ◽  
Freddy Romero
Keyword(s):  
Dna Damage ◽  
Quality Control ◽  
Growth Factors ◽  
Pulmonary Fibrosis ◽  
Mitochondrial Biogenesis ◽  
Tissue Repair ◽  
Mitochondrial Protein ◽  
Unknown Etiology ◽  
Mitochondrial Quality Control ◽  
Age Related

Idiopathic pulmonary fibrosis (IPF) is age-related interstitial lung disease of unknown etiology. About 100,000 people in the U.S have IPF, with a 3-year median life expectancy post-diagnosis. The development of an effective treatment for pulmonary fibrosis will require an improved understanding of its molecular pathogenesis and the “normal” and “pathological’ hallmarks of the aging lung. An important characteristic of the aging organism is its lowered capacity to adapt quickly to, and counteract, disturbances. While it is likely that DNA damage, chronic endoplasmic reticulum (ER) stress, and accumulation of heat shock proteins are capable of initiating tissue repair, recent studies point to a pathogenic role for mitochondrial dysfunction in the development of pulmonary fibrosis. These studies suggest that damage to the mitochondria induces fibrotic remodeling through a variety of mechanisms including the activation of apoptotic and inflammatory pathways. Mitochondrial quality control (MQC) has been demonstrated to play an important role in the maintenance of mitochondrial homeostasis. Different factors can induce MQC, including mitochondrial DNA damage, proteostasis dysfunction, and mitochondrial protein translational inhibition. MQC constitutes a complex signaling response that affects mitochondrial biogenesis, mitophagy, fusion/fission and the mitochondrial unfolded protein response (UPRmt) that, together, can produce new mitochondria, degrade the components of the oxidative complex or clearance the entire organelle. In pulmonary fibrosis, defects in mitophagy and mitochondrial biogenesis have been implicated in both cellular apoptosis and senescence during tissue repair. MQC has also been found to have a role in the regulation of other protein activity, inflammatory mediators, latent growth factors, and anti-fibrotic growth factors. In this review, we delineated the role of MQC in the pathogenesis of age-related pulmonary fibrosis.

scholarly journals Regorafenib-Attenuated, Bleomycin-Induced Pulmonary Fibrosis by Inhibiting the TGF-β1 Signaling Pathway

2021 ◽  
Vol 22 (4) ◽  
pp. 1985
Author(s):  
Xiaohe Li ◽  
Ling Ma ◽  
Kai Huang ◽  
Yuli Wei ◽  
Shida Long ◽  
...  
Keyword(s):  
Pulmonary Fibrosis ◽  
Signaling Pathway ◽  
Transforming Growth Factor ◽  
Kinase Inhibitor ◽  
In Vivo Experiments ◽  
Age Related ◽  
And Migration ◽  
Tgf Β1

Idiopathic pulmonary fibrosis (IPF) is a fatal and age-related pulmonary disease. Nintedanib is a receptor tyrosine kinase inhibitor, and one of the only two listed drugs against IPF. Regorafenib is a novel, orally active, multi-kinase inhibitor that has similar targets to nintedanib and is applied to treat colorectal cancer and gastrointestinal stromal tumors in patients. In this study, we first identified that regorafenib could alleviate bleomycin-induced pulmonary fibrosis in mice. The in vivo experiments indicated that regorafenib suppresses collagen accumulation and myofibroblast activation. Further in vitro mechanism studies showed that regorafenib inhibits the activation and migration of myofibroblasts and extracellular matrix production, mainly through suppressing the transforming growth factor (TGF)-β1/Smad and non-Smad signaling pathways. In vitro studies have also indicated that regorafenib could augment autophagy in myofibroblasts by suppressing TGF-β1/mTOR (mechanistic target of rapamycin) signaling, and could promote apoptosis in myofibroblasts. In conclusion, regorafenib attenuates bleomycin-induced pulmonary fibrosis by suppressing the TGF-β1 signaling pathway.

scholarly journals The perplexing role of RAGE in pulmonary fibrosis: causality or casualty?

2021 ◽  
Vol 15 ◽  
pp. 175346662110160
Author(s):  
Timothy N. Perkins ◽  
Tim D. Oury
Keyword(s):  
Respiratory Failure ◽  
Pulmonary Fibrosis ◽  
Disease Progression ◽  
Advanced Glycation Endproducts ◽  
Experimental Studies ◽  
Normal Lung ◽  
Unknown Etiology ◽  
Chronic Lung Diseases ◽  
Incidence And Mortality

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal lung disease in which most patients die within 3 years of diagnosis. With an unknown etiology, IPF results in progressive fibrosis of the lung parenchyma, diminishing normal lung function, which results in respiratory failure, and eventually, death. While few therapies are available to reduce disease progression, patients continue to advance toward respiratory failure, leaving lung transplantation the only viable option for survival. As incidence and mortality rates steadily increase, the need for novel therapeutics is imperative. The receptor for advanced glycation endproducts (RAGE) is most highly expressed in the lungs and plays a significant role in a number of chronic lung diseases. RAGE has long been linked to IPF; however, confounding data from both human and experimental studies have left an incomplete and perplexing story. This review examines the present understanding of the role of RAGE in human and experimental models of IPF, drawing parallels to recent advances in RAGE biology. Moreover, this review discusses the role of RAGE in lung injury response, type 2 immunity, and cellular senescence, and how such mechanisms may relate to RAGE as both a biomarker of disease progression and potential therapeutic target in IPF. The reviews of this paper are available via the supplemental material section.

Age-related changes in renal and hepatic cellular mechanisms associated with variations in rat serum thyroid hormone levels

2008 ◽  
Vol 294 (6) ◽  
pp. E1160-E1168 ◽  
Author(s):  
Elena Silvestri ◽  
Assunta Lombardi ◽  
Pieter de Lange ◽  
Luigi Schiavo ◽  
Antonia Lanni ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Total Protein ◽  
Protein Level ◽  
Monocarboxylate Transporter ◽  
Type I ◽  
Peripheral Tissues ◽  
Protein Levels ◽  
Age Related ◽  
Liver And Kidney ◽  
Age Related Changes

Aging is associated with changes in thyroid gland physiology. Age-related changes in the contribution of peripheral tissues to thyroid hormone serum levels have yet to be systematically assessed. Here, we investigated age-related alterations in the contributions of the liver and kidney to thyroid hormone homeostasis using 6-, 12-, and 24-mo-old male Wistar rats. A significant and progressive decline in plasma thyroxine occurred with age, but triiodothyronine (T3) was decreased only at 24 mo. This was associated with an unchanged protein level of the thyroid hormone transporter monocarboxylate transporter 8 (MCT8) in the kidney and with a decreased MCT8 level in the liver at 24 mo. Hepatic type I deiodinase (D1) protein level and activity declined progressively with age. Renal D1 levels were decreased at both 12 and 24 mo but D1 activity was decreased only at 24 mo. In the liver, no changes occurred in thyroid hormone receptor (TR) TRα1, whereas a progressive increase in TRβ1 occurred at both mRNA and total protein levels. In the kidney, both TRα1 and TRβ1 mRNA and total protein levels were unchanged between 6 and 12 mo but increased at 24 mo. Interestingly, nuclear TRβ1 levels were decreased in both liver and kidney at 12 and 24 mo, whereas nuclear TRα1 levels were unchanged. Collectively, our data show differential age-related changes among hepatic and renal MCT8 and D1 and TR expressions, and they suggest that renal D1 activity is maintained with age to compensate for the decrease in hepatic T3 production.

When things go wrong: Exploring possible mechanisms driving the progressive fibrosis phenotype in interstitial lung diseases

2021 ◽  
pp. 2004507
Author(s):  
Moisés Selman ◽  
Annie Pardo
Keyword(s):  
Pulmonary Fibrosis ◽  
Lung Diseases ◽  
Molecular Mechanisms ◽  
Lung Parenchyma ◽  
Interstitial Lung Diseases ◽  
Unknown Etiology ◽  
Clinical Behavior ◽  
The Past ◽  
Appropriate Treatment ◽  
Different Types

Interstitial lung diseases (ILD) comprise a large and heterogeneous group of disorders of known and unknown etiology characterised by diffuse damage of the lung parenchyma. In the past years, it has become evident that patients with different types of ILD are at risk of developing progressive pulmonary fibrosis known as pulmonary fibrosing ILD (PF-ILD). This is a phenotype behaving similar to idiopathic pulmonary fibrosis, the archetypical example of progressive fibrosis. PF-ILD is not a distinct clinical entity but describes a group of ILD with a similar clinical behavior. This phenotype may occur in diseases displaying distinct etiologies and different biopathology during their initiation and development. Importantly, these entities may have the potential for improvement or stabilisation prior to entering in the progressive fibrosing phase. The crucial questions are (1) why a subset of patients develops a progressive and irreversible fibrotic phenotype even with appropriate treatment, and (2) what the pathogenic mechanisms driving progression possibly are. We here provide a framework highlighting putative mechanisms underlying progression, including genetic susceptibility, aging, epigenetics, the structural fibrotic distortion, the aberrant composition and stiffness of the extracellular matrix, and the emergence of distinct profibrotic cell subsets. Understanding the cellular and molecular mechanisms behind PF-ILD will provide the basis for identifying risk factors and appropriate therapeutical strategies.

ID: 140: KLOTHO, AN ANTI-AGING MOLECULE, REGULATES ALVEOLAR EPITHELIAL CELL MTDNA DAMAGE AND APOPTOSIS

2016 ◽  
Vol 64 (4) ◽  
pp. 961.1-961
Author(s):  
S Kim ◽  
P Cheresh ◽  
RP Jablonski ◽  
DW Kamp ◽  
M Eren ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Dna Damage ◽  
Epithelial Cell ◽  
Pulmonary Fibrosis ◽  
Oxidative Dna Damage ◽  
Alveolar Epithelial Cell ◽  
Premature Aging ◽  
Protective Effects ◽  
Mtdna Damage ◽  
Alveolar Epithelial

RationaleConvincing evidence has emerged that impaired alveolar epithelial cell (AEC) injury and repair resulting from ‘exaggerated’ lung aging and mitochondrial dysfunction are critical determinants of the lung fibrogenic potential of toxic agents, including asbestos fibers, but the mechanisms underlying these findings is unknown. We showed that the extent of AEC mitochondrial DNA (mtDNA) damage and apoptosis are critical determinants of asbestos-induced pulmonary fibrosis (Cheresh et al AJRCMB 2014, Kim et al JBC 2014). Klotho is an age-inhibiting gene and Klotho-deficient mice demonstrate a premature aging phenotype that includes a reduced lifespan, arteriosclerosis, and lung oxidative DNA damage, and that Klotho attenuates hyperoxic-induced AEC DNA damage and apoptosis (Ravikumar et al AJP-Lung 2014). We reason that Klotho has an important role in limiting pulmonary fibrosis by protecting the AECs from oxidative stress.MethodsQuantitative PCR-based measurement of mtDNA damage was assessed following transient transfection with wild-type Klotho, Klotho siRNA or AKT siRNA in A549 and/or MLE-12 cells for 48 hrs followed by exposure to either amosite asbestos (25 µg/cm2) or H2O2 (200 µM) for 24 hrs. Apoptosis was assessed by cleaved caspase-9/3 levels and DNA fragmentation assay. Murine pulmonary fibrosis was analyzed in male 8–10 week old WT (C3H/C57B6J) mice or Klotho heterozygous knockout (Kl+/−) mice following intratracheal instillation of a single dose of 100 µg crocidolite asbestos or titanium dioxide (negative control) using histology (fibrosis score by Masson's trichrome staining) and lung collagen (Sircoll assay).ResultsCompared to control, amosite asbestos or H2O2 reduces Klotho mRNA/protein expression. Notably, silencing of Klotho promotes oxidative stress-induced AEC mtDNA damage and apoptosis whereas Klotho-enforced expression (EE) and Euk-134, a mitochondrial ROS scavenger, are protective. Interestingly, Kl+/− mice have increased asbestos-induced lung fibrosis. Also, we find that inhibition or silencing of AKT augments oxidant-induced AEC mtDNA damage and apoptosis.ConclusionsOur data demonstrate a crucial role for AEC AKT signaling in mediating the mtDNA damage protective effects of Klotho. Given the importance of AEC aging and apoptosis in pulmonary fibrosis, we reason that Klotho/AKT axis is an innovative therapeutic target for preventing common lung diseases of aging (i.e. IPF, COPD, lung cancer, etc.) for which more effective management regimens are clearly needed.FundingNIH-RO1 ES020357-01A1 (DK) and VA Merit (DK).

scholarly journals SPLUNC1 degradation by the cystic fibrosis mucosal environment drives airway surface liquid dehydration

2018 ◽  
Vol 52 (4) ◽  
pp. 1800668 ◽  
Author(s):  
Megan J. Webster ◽  
Boris Reidel ◽  
Chong D. Tan ◽  
Arunava Ghosh ◽  
Neil E. Alexis ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Airway Surface Liquid ◽  
The Novel ◽  
Pulmonary Tissue ◽  
Tissue Samples ◽  
Protein Levels ◽  
Surface Liquid ◽  
Protease Degradation ◽  
Mucosal Secretions ◽  
Cystic Fibrosis Transmembrane

The multi-organ disease cystic fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane regulator gene (CFTR) that lead to diminished transepithelial anion transport. CF lungs are characterised by airway surface liquid (ASL) dehydration, chronic infection/inflammation and neutrophilia. Dysfunctional CFTR may upregulate the epithelial Na+ channel (ENaC), further exacerbating dehydration. We previously demonstrated that short palate lung and nasal epithelial clone 1 (SPLUNC1) negatively regulates ENaC in normal airway epithelia.Here, we used pulmonary tissue samples, sputum and human bronchial epithelial cells (HBECs) to determine whether SPLUNC1 could regulate ENaC in a CF-like environment.We found reduced endogenous SPLUNC1 in CF secretions, and rapid degradation of recombinant SPLUNC1 (rSPLUNC1) by CF secretions. Normal sputum, containing SPLUNC1 and SPLUNC1-derived peptides, inhibited ENaC in both normal and CF HBECs. Conversely, CF sputum activated ENaC, and rSPLUNC1 could not reverse this phenomenon. Additionally, we observed upregulation of ENaC protein levels in human CF bronchi. Unlike SPLUNC1, the novel SPLUNC1-derived peptide SPX-101 resisted protease degradation, bound apically to HBECs, inhibited ENaC and prevented ASL dehydration following extended pre-incubation with CF sputum.Our data indicate that CF mucosal secretions drive ASL hyperabsorption and that protease-resistant peptides, e.g. SPX-101, can reverse this effect to rehydrate CF ASL.

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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