scholarly journals Human lung myofibroblast-derived inducers of alveolar epithelial apoptosis identified as angiotensin peptides

1999 ◽  
Vol 277 (6) ◽  
pp. L1158-L1164 ◽  
Author(s):  
Rongi Wang ◽  
Carlos Ramos ◽  
Iravati Joshi ◽  
Alex Zagariya ◽  
Annie Pardo ◽  
...  
Keyword(s):  
Conditioned Medium ◽  
Human Lung ◽  
Smooth Muscle Actin ◽  
Alveolar Epithelial Cells ◽  
Lung Fibroblasts ◽  
Normal Fibroblast ◽  
Ang Ii ◽  
Alveolar Epithelial ◽  
Apoptotic Activity

Earlier work from this laboratory found that fibroblasts isolated from fibrotic human lung [human interstitial pulmonary fibrosis (HIPF)] secrete a soluble inducer(s) of apoptosis in alveolar epithelial cells (AECs) in vitro [B. D. Uhal, I. Joshi, A. True, S. Mundle, A. Raza, A. Pardo, and M. Selman. Am. J. Physiol. 269 ( Lung Cell. Mol. Physiol. 13): L819–L828, 1995]. The cultured human fibroblast strains most active in producing the apoptotic activity contained high numbers of stellate cells expressing α-smooth muscle actin, a myofibroblast marker. The apoptotic activity eluted from gel-filtration columns only in fractions corresponding to proteins. Western blotting of the protein fraction identified immunoreactive angiotensinogen (ANGEN), and two-step RT-PCR revealed expression of ANGEN by HIPF fibroblasts but not by normal human lung fibroblasts. Specific ELISA detected angiotensin II (ANG II) at concentrations sixfold higher in HIPF-conditioned medium than in normal fibroblast-conditioned medium. Pretreatment of the concentrated medium with purified renin plus purified angiotensin-converting enzyme (ACE) further increased the ELISA-detectable ANG II eightfold. Apoptosis of AECs in response to HIPF-conditioned medium was completely abrogated by the ANG II receptor antagonist saralasin (50 μg/ml) or anti-ANG II antibodies. These results identify the protein inducers of AEC apoptosis produced by HIPF fibroblasts as ANGEN and its derivative ANG II. They also suggest a mechanism for AEC death adjacent to HIPF myofibroblasts [B. D. Uhal,, I. Joshi, C. Ramos, A. Pardo, and M. Selman. Am. J. Physiol. 275 ( Lung Cell. Mol. Physiol. 19): L1192–L1199, 1998].

Essential role for cathepsin D in bleomycin-induced apoptosis of alveolar epithelial cells

2004 ◽  
Vol 287 (1) ◽  
pp. L46-L51 ◽  
Author(s):  
Xiaopeng Li ◽  
Heather Rayford ◽  
Ruijie Shu ◽  
Jiaju Zhuang ◽  
Bruce D. Uhal
Keyword(s):  
Enzymatic Activity ◽  
Cathepsin D ◽  
Alveolar Epithelial Cells ◽  
Type Ii ◽  
Ang Ii ◽  
Nuclear Fragmentation ◽  
Alveolar Epithelial ◽  
Induced Apoptosis ◽  
Pepstatin A

Our earlier studies showed that bleomycin-induced apoptosis of type II alveolar epithelial cells (AECs) requires the autocrine synthesis and proteolytic processing of angiotensinogen into ANG II and that inhibitors of ANG-converting enzyme (ACEis) block bleomycin-induced apoptosis (Li X, Zhang H, Soledad-Conrad V, Zhuang J, and Uhal BD. Am J Physiol Lung Cell Mol Physiol 284: L501–L507, 2003). Given the documented role of cathepsin D (CatD) in apoptosis of other cell types, we hypothesized that CatD might be the AEC enzyme responsible for the conversion of angiotensinogen into ANG I, the substrate for ACE. Primary cultures of rat type II AECs challenged with bleomycin in vitro showed upregulation and secretion of CatD enzymatic activity and immunoreactive protein but no increases in CatD mRNA. The aspartyl protease inhibitor pepstatin A, which completely blocked CatD enzymatic activity, inhibited bleomycin-induced nuclear fragmentation by 76% and reduced bleomycin-induced caspase-3 activation by 47%. Antisense oligonucleotides against CatD mRNA reduced CatD-immunoreactive protein and inhibited bleomycin-induced nuclear fragmentation by 48%. A purified fragment of angiotensinogen (F1–14) containing the CatD and ACE cleavage sites, when applied to unchallenged AEC in vitro, yielded mature ANG II peptide and induced apoptosis. The apoptosis induced by F1–14 was inhibited 96% by pepstatin A and 77% by neutralizing antibodies specific for CatD (both P < 0.001). These data indicate a critical role for CatD in bleomycin-induced apoptosis of cultured AEC and suggest that the role(s) of CatD in AEC apoptosis include the conversion of newly synthesized angiotensinogen to ANG II.

scholarly journals Protective Effect of Remdesivir Against Pulmonary Fibrosis in Mice

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaohe Li ◽  
Rui Liu ◽  
Yunyao Cui ◽  
Jingjing Liang ◽  
Zhun Bi ◽  
...  
Keyword(s):  
Pulmonary Fibrosis ◽  
Antiviral Drug ◽  
Alveolar Epithelial Cells ◽  
Lung Damage ◽  
Lung Fibroblasts ◽  
Mesenchymal Transition ◽  
Alveolar Epithelial ◽  
Tgf Β1

Pulmonary fibrosis is a known sequela of severe or persistent lung damage. Existing clinical, imaging and autopsy studies have shown that the lungs exhibit a pathological pulmonary fibrosis phenotype after infection with coronaviruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Pulmonary fibrosis may be one of the most serious sequelae associated with coronavirus disease 2019 (COVID-19). In this study, we aimed to examine the preventative effects of the antiviral drug remdesivir on pulmonary fibrosis. We used a mouse model of bleomycin-induced pulmonary fibrosis to evaluate the effects of remdesivir on pulmonary fibrosis in vivo and further explored the potential pharmacological mechanisms of remdesivir in lung fibroblasts and alveolar epithelial cells in vitro. The preventive remdesivir treatment was started on the day of bleomycin installation, and the results showed that remdesivir significantly alleviated bleomycin-induced collagen deposition and improved pulmonary function. In vitro experiments showed that remdesivir dose-dependently suppressed TGF-β1-induced lung fibroblast activation and improved TGF-β1-induced alveolar epithelial to mesenchymal transition. Our results indicate that remdesivir can preventatively alleviate the severity of pulmonary fibrosis and provide some reference for the prevention of pulmonary fibrosis in patients with COVID-19.

M2 macrophages have unique transcriptomes but conditioned media does not promote profibrotic responses in lung fibroblasts or alveolar epithelial cells in vitro

2021 ◽  
Author(s):  
Elissa M Hult ◽  
Stephen James Gurczynski ◽  
Bethany B Moore
Keyword(s):  
Pulmonary Fibrosis ◽  
Alveolar Epithelial Cell ◽  
Conditioned Media ◽  
Alveolar Epithelial Cells ◽  
Lung Fibroblasts ◽  
M2 Macrophage ◽  
M2 Macrophages ◽  
Alveolar Epithelial ◽  
Fibroblast Migration

Macrophages are critical regulators of pulmonary fibrosis. Their plasticity, proximity, and ability to crosstalk with structural cells of the lung make them a key cell type of interest in the regulation of lung fibrosis. Macrophages can express a variety of phenotypes which have been historically represented through an "M1-like" to "M2-like" delineation. In this classification, M1-like macrophages are proinflammatory and have increased phagocytic capacity compared to alternatively activated M2-like macrophages that are profibrotic and are associated with wound healing. Extensive evidence in the field in both patients and animal models align pulmonary fibrosis with M2 macrophages. In this paper, we performed RNAseq to fully characterize M1 vs. M2-skewed bone marrow-derived macrophages (BMDMs) and investigated the profibrotic abilities of M2 BMDM conditioned media (CM) to promote fibroblast migration, proliferation, alveolar epithelial cell (AEC) apoptosis, and mRNA expression of key fibrotic genes in both fibroblasts and in AECs. Although M2 CM-treated fibroblasts had increased migration and M2 CM-treated fibroblasts and AECs had increased expression of profibrotic proteins over M1 CM-treated cells, all differences can be attributed to M2 polarization reagents IL-4 and IL-13 also present in the CM. Collectively, these data suggest that the profibrotic effects associated with M2 macrophage CM in vitro are attributable to effects of polarization cytokines rather than additional factors secreted in response to those polarizing cytokines.

Protective effect of IL-6 on alveolar epithelial cell death induced by hydrogen peroxide

2005 ◽  
Vol 288 (2) ◽  
pp. L342-L349 ◽  
Author(s):  
Hiroshi Kida ◽  
Mitsuhiro Yoshida ◽  
Shigenori Hoshino ◽  
Koji Inoue ◽  
Yukihiro Yano ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Death ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Alveolar Epithelial Cell ◽  
Alveolar Epithelial Cells ◽  
Lung Fibroblasts ◽  
Alveolar Epithelial ◽  
Epithelial Cell Death

The goal of this study was to examine whether IL-6 could directly protect lung resident cells, especially alveolar epithelial cells, from reactive oxygen species (ROS)-induced cell death. ROS induced IL-6 gene expression in organotypic lung slices of wild-type (WT) mice. ROS also induced IL-6 gene expression in mouse primary lung fibroblasts, dose dependently. The organotypic lung slices of WT were more resistant to ROS-induced DNA fragmentation than those of IL-6-deficient (IL-6−/−) mice. WT resistance against ROS was abrogated by treatment with anti-IL-6 antibody. TdT-mediated dUTP nick end labeling stain and electron microscopy revealed that DNA fragmented cells in the IL-6−/− slice included alveolar epithelial cells and endothelial cells. In vitro studies demonstrated that IL-6 reduced ROS-induced A549 alveolar epithelial cell death. Together, these data suggest that IL-6 played an antioxidant role in the lung by protecting lung resident cells, especially alveolar epithelial cells, from ROS-induced cell death.

scholarly journals A Senescence Bystander Effect in Human Lung Fibroblasts

Biomedicines ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1162
Author(s):  
David W. Waters ◽  
Michael Schuliga ◽  
Prabuddha S. Pathinayake ◽  
Lan Wei ◽  
Hui-Ying Tan ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Bystander Effect ◽  
Human Lung ◽  
Primary Cultures ◽  
A549 Cells ◽  
Lung Parenchyma ◽  
Alveolar Epithelial Cells ◽  
Lung Fibroblasts ◽  
Human Lung Fibroblasts

Idiopathic pulmonary fibrosis (IPF) is a chronic disease characterised by a dense fibrosing of the lung parenchyma. An association between IPF and cellular senescence is well established and several studies now describe a higher abundance of senescent fibroblasts and epithelial cells in the lungs of IPF patients compared with age-matched controls. The cause of this abnormal accumulation of senescent cells is unknown but evidence suggests that, once established, senescence can be transferred from senescent to non-senescent cells. In this study, we investigated whether senescent human lung fibroblasts (LFs) and alveolar epithelial cells (AECs) could induce a senescent-like phenotype in “naïve” non-senescent LFs in vitro. Primary cultures of LFs from adult control donors (Ctrl-LFs) with a low baseline of senescence were exposed to conditioned medium (CM) from: (i) Ctrl-LFs induced to become senescent using H2O2 or etoposide; (ii) LFs derived from IPF patients (IPF-LFs) with a high baseline of senescence; or (iii) senescence-induced A549 cells, an AEC line. Additionally, ratios of non-senescent Ctrl-LFs and senescence-induced Ctrl-LFs (100:0, 0:100, 50:50, 90:10, 99:1) were co-cultured and their effect on induction of senescence measured. We demonstrated that exposure of naïve non-senescent Ctrl-LFs to CM from senescence-induced Ctrl-LFs and AECs and IPF-LFs increased the markers of senescence including nuclear localisation of phosphorylated-H2A histone family member X (H2AXγ) and expression of p21, IL-6 and IL-8 in Ctrl-LFs. Additionally, co-cultures of non-senescent and senescence-induced Ctrl-LFs induced a senescent-like phenotype in the non-senescent cells. These data suggest that the phenomenon of “senescence-induced senescence” can occur in vitro in primary cultures of human LFs, and provides a possible explanation for the abnormal abundance of senescent cells in the lungs of IPF patients.

scholarly journals A Role for HAPLN1 During Phenotypic Modulation of Human Lung Fibroblasts In Vitro

2020 ◽  
Vol 68 (11) ◽  
pp. 797-811
Author(s):  
Stephen P. Evanko ◽  
Michel D. Gooden ◽  
Inkyung Kang ◽  
Christina K. Chan ◽  
Robert B. Vernon ◽  
...  
Keyword(s):  
Human Lung ◽  
Smooth Muscle Actin ◽  
Intracellular Localization ◽  
Lung Fibroblasts ◽  
Human Lung Fibroblasts ◽  
Link Protein ◽  
Interphase Cells ◽  
Tgf Β1

Hyaluronan and proteoglycan link protein 1 (HAPLN1) stabilizes interactions between two important extracellular matrix (ECM) macromolecules, versican and hyaluronan, which facilitate proliferation of fibroblasts and their conversion to myofibroblasts. However, the role of HAPLN1 in these events has not been studied. Using immunocytochemistry, cellular and ECM locations of HAPLN1 were evaluated in cultured human lung fibroblasts during proliferation and conversion to myofibroblasts. HAPLN1 localized to pericellular matrices, associating with both versican and hyaluronan in the ECM and on the cell surface. Nuclear and total HAPLN1 immunostaining increased after myofibroblast induction. Confocal microscopy showed HAPLN1 predominant in the ECM under cells while versican predominated above cells. Versican and HAPLN1 were also juxtaposed in columnar inclusions in the cytoplasm and nucleus. Nuclear HAPLN1 staining in interphase cells redistributed to the cytosol during mitosis. In the absence of TGF-β1, addition of exogenous bovine HAPLN1 (together with aggrecan G1) facilitated myofibroblast formation, as seen by significant upregulation of α-smooth muscle actin (SMA) staining, while adding full-length bovine versican had no effect. Increased compaction of hyaluronan-rich ECM suggests that HAPLN1 plus G1 addition affects hyaluronan networks and myofibroblast formation. These observations demonstrate changes in both extracellular and intracellular localization of HAPLN1 during fibroblast proliferation and myofibroblast conversion suggesting a possible role in fibrotic remodeling:

scholarly journals Macrophage-derived exosomes attenuate fibrosis in airway epithelial cells through delivery of antifibrotic miR-142-3p

Thorax ◽  
2020 ◽  
Vol 75 (10) ◽  
pp. 870-881 ◽  
Author(s):  
Julien Guiot ◽  
Maureen Cambier ◽  
Amandine Boeckx ◽  
Monique Henket ◽  
Olivier Nivelles ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Pulmonary Fibrosis ◽  
Transforming Growth Factor ◽  
Airway Epithelial Cells ◽  
Alveolar Epithelial Cells ◽  
Lung Fibroblasts ◽  
Target Cells ◽  
Alveolar Epithelial ◽  
The Impact

IntroductionIdiopathic pulmonary fibrosis (IPF) is a progressive fibrosing interstitial lung disease of unknown aetiology and cure. Recent studies have reported a dysregulation of exosomal microRNAs (miRs) in the IPF context. However, the impact of IPF-related exosomal miRs on the progression of pulmonary fibrosis is unknown.MethodsTwo independent cohorts were enrolled at the ambulatory care polyclinic of Liège University. Exosomes from sputum were obtained from 19 patients with IPF and 23 healthy subjects (HSs) (cohort 1), and the ones from plasma derived from 14 patients with IPF and 14 HSs (cohort 2). Exosomal miR expression was performed by quantitative reverse transcription–PCR. The functional role of exosomal miRs was assessed in vitro by transfecting miR mimics in human alveolar epithelial cells and lung fibroblasts.ResultsExosomal miR analysis showed that miR-142-3p was significantly upregulated in sputum and plasma of patients with IPF (8.06-fold, p<0.0001; 1.64 fold, p=0.008, respectively). Correlation analysis revealed a positive association between exosomal miR-142-3p and the percentage of macrophages from sputum of patients with IPF (r=0.576, p=0.012), suggesting macrophage origin of exosomal miR-142-3p upregulation. The overexpression of miR-142-3p in alveolar epithelial cells and lung fibroblasts was able to reduce the expression of transforming growth factor β receptor 1 (TGFβ-R1) and profibrotic genes. Furthermore, exosomes isolated from macrophages present antifibrotic properties due in part to the repression of TGFβ-R1 by miR-142-3p transfer in target cells.DiscussionOur results suggest that macrophage-derived exosomes may fight against pulmonary fibrosis progression via the delivery of antifibrotic miR-142–3 p to alveolar epithelial cells and lung fibroblasts.

In vitro effects of aldehydes present in tobacco smoke on gene expression in human lung alveolar epithelial cells

2013 ◽  
Vol 27 (3) ◽  
pp. 1072-1081 ◽  
Author(s):  
Nuan P. Cheah ◽  
Jeroen L.A. Pennings ◽  
Jolanda P. Vermeulen ◽  
Frederik J. van Schooten ◽  
Antoon Opperhuizen
Keyword(s):  
Gene Expression ◽  
Epithelial Cells ◽  
Tobacco Smoke ◽  
Human Lung ◽  
Alveolar Epithelial Cells ◽  
Alveolar Epithelial ◽  
In Vitro Effects

scholarly journals Fenofibrate inhibits TGF‐β‐induced myofibroblast differentiation and activation in human lung fibroblasts in vitro

FEBS Open Bio ◽  
2021 ◽  
Author(s):  
Ryota Kikuchi ◽  
Yuki Maeda ◽  
Takao Tsuji ◽  
Kazuhiro Yamaguchi ◽  
Shinji Abe ◽  
...  
Keyword(s):  
Human Lung ◽  
Lung Fibroblasts ◽  
Myofibroblast Differentiation ◽  
Human Lung Fibroblasts

scholarly journals Regulation of Cellular Senescence Is Independent from Profibrotic Fibroblast-Deposited ECM

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1628
Author(s):  
Kaj E. C. Blokland ◽  
Habibie Habibie ◽  
Theo Borghuis ◽  
Greta J. Teitsma ◽  
Michael Schuliga ◽  
...  
Keyword(s):  
Growth Factor ◽  
Cellular Senescence ◽  
Transforming Growth Factor ◽  
Cell Function ◽  
Smooth Muscle Actin ◽  
Transforming Growth Factor Β1 ◽  
Tissue Growth ◽  
Alveolar Epithelial Cells ◽  
Lung Fibroblasts ◽  
Alpha Smooth Muscle Actin

Idiopathic pulmonary fibrosis (IPF) is a devastating lung disease with poor survival. Age is a major risk factor, and both alveolar epithelial cells and lung fibroblasts in this disease exhibit features of cellular senescence, a hallmark of ageing. Accumulation of fibrotic extracellular matrix (ECM) is a core feature of IPF and is likely to affect cell function. We hypothesize that aberrant ECM deposition augments fibroblast senescence, creating a perpetuating cycle favouring disease progression. In this study, primary lung fibroblasts were cultured on control and IPF-derived ECM from fibroblasts pretreated with or without profibrotic and prosenescent stimuli, and markers of senescence, fibrosis-associated gene expression and secretion of cytokines were measured. Untreated ECM derived from control or IPF fibroblasts had no effect on the main marker of senescence p16Ink4a and p21Waf1/Cip1. However, the expression of alpha smooth muscle actin (ACTA2) and proteoglycan decorin (DCN) increased in response to IPF-derived ECM. Production of the proinflammatory cytokines C-X-C Motif Chemokine Ligand 8 (CXCL8) by lung fibroblasts was upregulated in response to senescent and profibrotic-derived ECM. Finally, the profibrotic cytokines transforming growth factor β1 (TGF-β1) and connective tissue growth factor (CTGF) were upregulated in response to both senescent- and profibrotic-derived ECM. In summary, ECM deposited by IPF fibroblasts does not induce cellular senescence, while there is upregulation of proinflammatory and profibrotic cytokines and differentiation into a myofibroblast phenotype in response to senescent- and profibrotic-derived ECM, which may contribute to progression of fibrosis in IPF.

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