Antifibrotic properties of caveolin-1 scaffolding domain in vitro and in vivo

2008 ◽  
Vol 294 (5) ◽  
pp. L843-L861 ◽  
Author(s):  
Elena Tourkina ◽  
Mathieu Richard ◽  
Pal Gööz ◽  
Michael Bonner ◽  
Jaspreet Pannu ◽  
...  
Keyword(s):  
Lung Fibrosis ◽  
Smooth Muscle Actin ◽  
Lung Fibroblasts ◽  
Normal Lung ◽  
Signaling Molecule ◽  
Caveolin 1 ◽  
Tenascin C ◽  
Ecm Proteins

Lung fibrosis involves the overexpression of ECM proteins, primarily collagen, by α-smooth muscle actin (ASMA)-positive cells. Caveolin-1 is a master regulator of collagen expression by cultured lung fibroblasts and of lung fibrosis in vivo. A peptide equivalent to the caveolin-1 scaffolding domain (CSD peptide) inhibits collagen and tenascin-C expression by normal lung fibroblasts (NLF) and fibroblasts from the fibrotic lungs of scleroderma patients (SLF). CSD peptide inhibits ASMA expression in SLF but not NLF. Similar inhibition of collagen, tenascin-C, and ASMA expression was also observed when caveolin-1 expression was upregulated using adenovirus. These observations suggest that the low caveolin-1 levels in SLF cause their overexpression of collagen, tenascin-C, and ASMA. In mechanistic studies, MEK, ERK, JNK, and Akt were hyperactivated in SLF, and CSD peptide inhibited their activation and altered their subcellular localization. These studies and experiments using kinase inhibitors suggest many differences between NLF and SLF in signaling cascades. To validate these data, we determined that the alterations in signaling molecule activation observed in SLF also occur in fibrotic lung tissue from scleroderma patients and in mice with bleomycin-induced lung fibrosis. Finally, we demonstrated that systemic administration of CSD peptide to bleomycin-treated mice blocks epithelial cell apoptosis, inflammatory cell infiltration, and changes in tissue morphology as well as signaling molecule activation and collagen, tenascin-C, and ASMA expression associated with lung fibrosis. CSD peptide may be a prototype for novel treatments for human lung fibrosis that act, in part, by inhibiting the expression of ASMA and ECM proteins.

scholarly journals Loss of Fas-signaling in pro-fibrotic fibroblasts impairs homeostatic fibrosis resolution and promotes persistent pulmonary fibrosis

2020 ◽  
Author(s):  
Elizabeth F. Redente ◽  
Sangeeta Chakraborty ◽  
Satria Sajuthi ◽  
Bart P. Black ◽  
Benjamin L. Edelman ◽  
...  
Keyword(s):  
Pulmonary Fibrosis ◽  
Lung Fibroblast ◽  
Lung Fibroblasts ◽  
Normal Lung ◽  
Loss Of Function ◽  
Fas Signaling ◽  
Distal Lung ◽  
Induced Apoptosis

ABSTRACTIdiopathic pulmonary fibrosis (IPF) is a progressive, irreversible fibrotic disease of the distal lung alveoli that culminates in respiratory failure and reduced lifespan. Unlike normal lung repair in response to injury, IPF is associated with the accumulation and persistence of fibroblasts and myofibroblasts and continued production of collagen and other extracellular matrix (ECM) components. Prior in vitro studies have led to the hypothesis that the development of resistance to Fas-induced apoptosis by lung fibroblasts and myofibroblasts contibributes to their accumulation in the distal lung tissues of IPF patients. Here, we test this hypothesis in vivo in the resolving model of bleomycin-induced pulmonary fibrosis in mice. Using genetic loss-of-function approaches to inhibit Fas signaling in fibroblasts, novel flow cytometry strategies to quantify lung fibroblast subsets and transcriptional profiling of lung fibroblasts by bulk and single cell RNA-sequencing, we show that Fas is necessary for lung fibroblast apoptosis during homeostatic resolution of bleomycin-induced pulmonary fibrosis in vivo. Furthermore, we show that loss of Fas signaling leads to the persistence and continued pro-fibrotic functions of lung fibroblasts. Our studies provide novel insights into the mechanisms that contribute to fibroblast survival, persistence and continued ECM deposition in the context of IPF and how failure to undergo Fas-induced apoptosis prevents fibrosis resolution.

scholarly journals Alcohol induces TGFβ1 via downregulation of miR-1946a in murine lung fibroblast

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Xian Fan ◽  
Stephen T. Mills ◽  
Mevelyn J. Kaalla ◽  
Viranuj Sueblinvong
Keyword(s):  
Protein Expression ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Direct Interaction ◽  
Lung Fibroblasts ◽  
Murine Lung ◽  
Gene And Protein Expression

Abstract Exaggerated transforming growth factor-beta 1 (TGFβ1) expression worsens fibroproliferation following bleomycin-induced lung injury in alcohol-fed mice. MicroRNA (miR)-1946a is predicted to bind to the TGFβ1 3′ untranslated region (UTR), thereby inhibiting its transcription. We hypothesize that alcohol suppresses miR-1946a and induces TGFβ1. Primary murine lung fibroblasts (PLFs) were cultured ± alcohol, miR-1946a mimic or inhibitor, and TGFβ1 signaling inhibitors. miR-1946a was analyzed after alcohol treatment in vitro and in vivo. TGFβ1 expression and TGFβ1 3′UTR-luciferase activity was quantified. We showed that alcohol suppressed miR-1946a in the alcohol-fed mouse lungs and PLFs. MiR-1946a inhibitor increased TGFβ1 expression in the fibroblast. MiR-1946a mimic treatment suppressed TGFβ1 gene expression and TGFβ1 3′UTR activity. Overexpression of miR1946a inhibited alcohol-induced TGFβ1 gene and protein expression as well as alcohol-induced TGFβ1 and α-smooth muscle actin (SMA) protein expression in PLFs. In conclusion, miR-1946a modulates TGFβ1 expression through direct interaction with TGFβ1 3′UTR. These findings identify a novel mechanism by which alcohol induces TGFβ1 in the lung.

Profibrogenic phenotype in caveolin-1 deficiency via differential regulation of STAT-1/3 proteins

2014 ◽  
Vol 92 (5) ◽  
pp. 370-378 ◽  
Author(s):  
Stefan W. Ryter ◽  
Augustine M.K. Choi ◽  
Hong Pyo Kim
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Tyrosine Phosphatase ◽  
Transforming Growth Factor Β ◽  
Lung Fibroblasts ◽  
Caveolin 1 ◽  
Expression Of Genes ◽  
Liver And Kidney

Fibrosis underlies the pathogenesis of several human diseases, which can lead to severe injury of vital organs. We previously demonstrated that caveolin-1 expression is reduced in experimental fibrosis and that caveolin-1 exerts antiproliferative and antifibrotic effects in lung fibrosis models. The signal transducers and activators of transcription (STAT) proteins, STAT1 and STAT3, can be activated simultaneously. STAT1 can inhibit cell growth and promote apoptosis while STAT3 inhibits apoptosis. Here, we show that caveolin-1-deficient (cav-1−/−) lung fibroblasts display dramatically upregulated STAT3 activation in response to platelet-derived growth factor-BB and transforming growth factor-β stimuli, whereas STAT1 activation is undetectable. Downregulation of protein tyrosine phosphatase-1B played a role in the preferential activation of STAT3 in cav-1−/− fibroblasts. Genetic deletion of STAT3 by siRNA modulated the expression of genes involved in cell proliferation and fibrogenesis. Basal expression of α-smooth muscle actin was prominent in cav-1−/− liver and kidney, consistent with deposition of collagen in these organs. Collectively, we demonstrate that the antiproliferative and antifibrogenic properties of caveolin-1 in vitro are mediated by the balance between STAT1 and STAT3 activation. Deregulated STAT signaling associated with caveolin-1 deficiency may be relevant to proliferative disorders such as tissue fibrosis.

scholarly journals Tenascin-C deficiency attenuates TGF-β-mediated fibrosis following murine lung injury

2010 ◽  
Vol 299 (6) ◽  
pp. L785-L793 ◽  
Author(s):  
William A. Carey ◽  
Glen D. Taylor ◽  
Willow B. Dean ◽  
James D. Bristow
Keyword(s):  
Lung Injury ◽  
Nuclear Translocation ◽  
Interstitial Fibrosis ◽  
Smooth Muscle Actin ◽  
Transcript Abundance ◽  
Lung Fibroblasts ◽  
Wild Type ◽  
Tenascin C ◽  
Smad 3

Tenascin-C (TNC) is an extracellular matrix glycoprotein of unknown function that is highly expressed in adult lung parenchyma following acute lung injury (ALI). Here we report that mice lacking TNC are protected from interstitial fibrosis in the bleomycin model of ALI. Three weeks after exposure to bleomycin, TNC-null mice had accumulated 85% less lung collagen than wild-type mice. The lung interstitium of TNC-null mice also appeared to contain fewer myofibroblasts and fewer cells with intranuclear Smad-2/3 staining, suggesting impaired TGF-β activation or signaling. In vitro, TNC-null lung fibroblasts exposed to constitutively active TGF-β expressed less α-smooth muscle actin and deposited less collagen I into the matrix than wild-type cells. Impaired TGF-β responsiveness was correlated with dramatically reduced Smad-3 protein levels and diminished nuclear translocation of Smad-2 and Smad-3 in TGF-β-exposed TNC-null cells. Reduced Smad-3 in TNC-null cells reflects both decreased transcript abundance and enhanced ubiquitin-proteasome-mediated protein degradation. Together, these studies suggest that TNC is essential for maximal TGF-β action after ALI. The clearance of TNC that normally follows ALI may restrain TGF-β action during lung healing, whereas prolonged or exaggerated TNC expression may facilitate TGF-β action and fibrosis after ALI.

FGF-18 is upregulated in the postnatal rat lung and enhances elastogenesis in myofibroblasts

2005 ◽  
Vol 288 (1) ◽  
pp. L43-L51 ◽  
Author(s):  
Bernadette Chailley-Heu ◽  
Olivier Boucherat ◽  
Anne-Marie Barlier-Mur ◽  
Jacques R. Bourbon
Keyword(s):  
Lung Development ◽  
Lysyl Oxidase ◽  
Smooth Muscle Actin ◽  
Fold Increase ◽  
Fetal Lung ◽  
Lung Fibroblasts ◽  
Rat Lung ◽  
Fetal Fibroblasts

The fibroblast growth factors (FGFs) are key players in fetal lung development, but little is known about their status in postnatal lung. Here, we investigated the expression pattern of FGF-18 transcripts through the perinatal period and evidenced a sevenfold increase after birth that paralleled changes in elastin expression. In vitro, recombinant human (rh)FGF-18 had a mitogenic activity on day 21 fetal rat lung fibroblasts and stimulated its own expression in the latter, whereas FGF-2 inhibited it. At 50 or 100 ng/ml, rhFGF-18 increased the expression of α-smooth muscle actin (α-SMA; 2.5-fold), a characteristic marker of myofibroblasts, of tropoelastin (6.5-fold), of lysyl oxidase (2-fold), and of fibulins 1 and 5 (8- and 2.2-fold) in confluent fibroblasts isolated from fetal day 21 lung; similar results were obtained with fibroblasts from day 3 postnatal lungs. Elastin protein expression was also slightly increased in fetal fibroblasts. Lung analysis on day 4 in rat pups that had received rhFGF-18 (3 μg) on days 0 and 1 showed a 1.7-fold increase of tropoelastin transcripts, whereas α-SMA transcripts were unchanged. In contrast, rhFGF-2 markedly decreased expression of elastin in vitro and in vivo and of fibulin 5 in vitro. In addition, vitamin A, which is known to enhance alveolar development, elevated FGF-18 and elastin expressions in day 2 lungs, thus advancing the biological increase. We postulate that FGF-18 is involved in postnatal lung development through stimulating myofibroblast proliferation and differentiation.

scholarly journals Let-7d microRNA affects mesenchymal phenotypic properties of lung fibroblasts

2014 ◽  
Vol 306 (6) ◽  
pp. L534-L542 ◽  
Author(s):  
Luai Huleihel ◽  
Ahmi Ben-Yehudah ◽  
Jadranka Milosevic ◽  
Guoying Yu ◽  
Kusum Pandit ◽  
...  
Keyword(s):  
Epithelial To Mesenchymal Transition ◽  
Smooth Muscle Actin ◽  
High Mobility ◽  
Lung Fibroblasts ◽  
Phenotypic Properties ◽  
Mesenchymal Transition ◽  
Junction Protein ◽  
Primary Fibroblasts

MicroRNAs are small noncoding RNAs that inhibit protein expression. We have previously shown that the inhibition of the microRNA let-7d in epithelial cells caused changes consistent with epithelial-to-mesenchymal transition (EMT) both in vitro and in vivo. The aim of this study was to determine whether the introduction of let-7d into fibroblasts alters their mesenchymal properties. Transfection of primary fibroblasts with let-7d caused a decrease in expression of the mesenchymal markers α-smooth muscle actin, N-cadherin, fibroblast-specific protein-1, and fibronectin, as well as an increase in the epithelial markers tight junction protein-1 and keratin 19. Phenotypic changes were also present, including a delay in wound healing, reduced motility, and proliferation of fibroblasts following transfection. In addition, we examined the effects of transfection on fibroblast responsiveness to TGF-β, an important factor in many fibrotic processes such as lung fibrosis and found that let-7d transfection significantly attenuated high-mobility group-A2 protein induction by TGF-β. Our results indicate that administration of the epithelial microRNA let-7d can significantly alter the phenotype of primary fibroblasts.

scholarly journals Tetrandrine modulates SQSTM1-mediated selective autophagy and protects pulmonary fibrosis

2021 ◽  
Author(s):  
Yuanyuan Liu ◽  
Wenshan Zhong ◽  
Jinming Zhang ◽  
Weimou Chen ◽  
Ye Lu ◽  
...  
Keyword(s):  
Pulmonary Fibrosis ◽  
Lung Fibrosis ◽  
Smooth Muscle Actin ◽  
Lung Fibroblasts ◽  
Therapeutic Effects ◽  
The Novel ◽  
Induced Expression ◽  
Tgf Β1

Background and Purpose Idiopathic pulmonary fibrosis is a progressive fatal disease characterized by interstitial remodeling, with high lethality and a lack of effective medical therapies. Tetrandrine has been proposed to present anti-fibrotic effects, but the efficacy and mechanisms of tetrandrine against lung fibrosis has not been systematically evaluated. We sought to study the potential therapeutic effects and mechanisms of tetrandrine in lung fibrosis. Experimental Approach The anti-fibrotic effects of tetrandrine were evaluated in bleomycin-induced mouse models and TGF-β1-stimulated murine lung fibroblasts. We performed Chromatin Immunoprecipitation (ChIP), Immunoprecipitation (IP) and mRFP-GFP-MAP1LC3B adenovirus construct to investigate the novel mechanisms of tetrandrine-induced autophagy. Key Results Tetrandrine decreased TGF-β1-induced expression of α-smooth muscle actin, fibronectin, vimentin and type 1 collagen and proliferation in fibroblasts. Tetrandrine restored TGF-β1-induced impaired autophagy, accompanied by the up-regulation and enhanced interaction of SQSTM1 and MAP1LC3-Ⅱ. ChIP studies revealed that NRF2 bound to SQSTM1 promoter in tetrandrine-induced autophagy. Furthermore, TGF-β1-induced phosphorylated mTOR was inhibited by tetrandrine, with reduced activation levels of Rheb. In vivo tetrandrine suppressed the bleomycin-induced expression of fibrotic markers and improved pulmonary function. Conclusion and Implications Our data suggest that tetrandrine might be recognized as a novel autophagy inducer, thus attenuating lung fibrosis. Tetrandrine should be investigated as a novel therapeutic strategy for IPF.

scholarly journals Macrocybin, a mushroom natural triglyceride, reduces tumor growth in vitro and in vivo through caveolin-mediated interference with the actin cytoskeleton

2020 ◽  
Author(s):  
Marcos Vilariño ◽  
Josune García-Sanmartín ◽  
Laura Ochoa-Callejero ◽  
Alberto López-Rodríguez ◽  
Jaime Blanco-Urgoiti ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Actin Cytoskeleton ◽  
Tumor Cells ◽  
Cell Lines ◽  
Active Compound ◽  
Biologically Active ◽  
Normal Lung ◽  
Caveolin 1

AbstractMushrooms have been used for millennia as cancer remedies. Our goal was to screen several species from the rain forest of Costa Rica looking for new antitumor molecules. Mushroom extracts were screened using two human cell lines: A549 (lung adenocarcinoma) and NL20 (immortalized normal lung epithelium). Extracts able to kill tumor cells while preserving nontumor cells were considered “anticancer”. The mushroom with better properties was Macrocybe titans. Positive extracts were fractionated further and tested for biological activity on the cell lines. The chemical structure of the active compound was partially elucidated through nuclear magnetic resonance, mass spectrometry, and other ancillary techniques. Chemical analysis showed that the active molecule was a triglyceride containing oleic acid, palmitic acid, and a more complex fatty acid with 2 double bonds. Synthesis of all possible triglycerides and biological testing identified the natural compound, which was named Macrocybin. A xenograft study showed that Macrocybin significantly reduces A549 tumor growth. In addition, Macrocybin treatment resulted in the upregulation of Caveolin-1 expression and the disassembly of the actin cytoskeleton in tumor cells (but not in normal cells). In conclusion, we have shown that Macrocybin constitutes a new biologically active compound that may be taken into consideration for cancer treatment.

scholarly journals Cancer Cells Can Exhibit a Sparing FLASH Effect at Low Doses Under Normoxic In Vitro-Conditions

2021 ◽  
Vol 11 ◽  
Author(s):  
Gabriel Adrian ◽  
Elise Konradsson ◽  
Sarah Beyer ◽  
Anders Wittrup ◽  
Karl T. Butterworth ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Lines ◽  
Lung Fibroblasts ◽  
Normal Lung ◽  
Tumor Control ◽  
High Dose ◽  
Low Doses ◽  
Early Passage

BackgroundIrradiation with ultra-high dose rate (FLASH) has been shown to spare normal tissue without hampering tumor control in several in vivo studies. Few cell lines have been investigated in vitro, and previous results are inconsistent. Assuming that oxygen depletion accounts for the FLASH sparing effect, no sparing should appear for cells irradiated with low doses in normoxia.MethodsSeven cancer cell lines (MDA-MB-231, MCF7, WiDr, LU-HNSCC4, HeLa [early passage and subclone]) and normal lung fibroblasts (MRC-5) were irradiated with doses ranging from 0 to 12 Gy using FLASH (≥800 Gy/s) or conventional dose rates (CONV, 14 Gy/min), with a 10 MeV electron beam from a clinical linear accelerator. Surviving fraction (SF) was determined with clonogenic assays. Three cell lines were further studied for radiation-induced DNA-damage foci using a 53BP1-marker and for cell cycle synchronization after irradiation.ResultsA tendency of increased survival following FLASH compared with CONV was suggested for all cell lines, with significant differences for 4/7 cell lines. The magnitude of the FLASH-sparing expressed as a dose-modifying factor at SF=0.1 was around 1.1 for 6/7 cell lines and around 1.3 for the HeLasubclone. Similar cell cycle distributions and 53BP1-foci numbers were found comparing FLASH to CONV.ConclusionWe have found a FLASH effect appearing at low doses under normoxic conditions for several cell lines in vitro. The magnitude of the FLASH effect differed between the cell lines, suggesting inherited biological susceptibilities for FLASH irradiation.

Sign in / Sign up

Export Citation Format

Share Document