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 Targeting Lysyl oxidase-like 2 in Idiopathic Pulmonary Fibrosis

2019 ◽  
Author(s):  
Milena S. Espindola ◽  
David M Habiel ◽  
Ana Lucia Coelho ◽  
Amanda Mikels-Vigdal ◽  
Cory M. Hogaboam
Keyword(s):  
Pulmonary Fibrosis ◽  
Mouse Model ◽  
Lysyl Oxidase ◽  
Lung Fibroblasts ◽  
Normal Lung ◽  
Dependent Manner ◽  
Humanized Mouse ◽  
Humanized Mouse Model

AbstractThe composition of extracellular matrix (ECM) is altered during pathologic scarring in damaged organs including the lung. One major change in the ECM involves the cross-linking of collagen, which promotes fibroblast to myofibroblast differentiation.ObjectiveWe examined the role of lysyl oxidase (LOX)-like 2 in lung fibroblasts cultured from normal or IPF lung samples and in a humanized mouse model of IPF using a monoclonal antibody (Simtuzumab).Research Design and MethodsPrimary lung fibroblasts from normal donor lungs and IPF lung explants were examined for expression of LOXL2. Targeting LOXL2 with Simtuzumab on normal and IPF fibroblasts was examined both in vitro and in vivo for synthetic, functional, and profibrotic properties.ResultsLOXL2 was increased at transcript and protein level in IPF compared with normal lung samples. In a dose-dependent manner, Simtuzumab enhanced differentiation of fibroblasts into myofibroblasts. Inhibition of LOXL2 also enhanced fibroblast invasion and accelerated the outgrowth of fibroblasts from dissociated human lung cell preparations. Finally, preventative or delayed delivery of Simtuzumab enhanced lung fibrosis in a humanized mouse model of pulmonary fibrosis.ConclusionConsistent with its failure in a Phase 2 clinical trial, Simtuzumab exhibited no therapeutic efficacy in translational in vitro and in vivo assays.

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.

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 Saracatinib, a Selective Src Kinase Inhibitor, Blocks Fibrotic Responses in In Vitro, In Vivo and Ex Vivo Models of Pulmonary Fibrosis

2022 ◽  
Author(s):  
Farida Ahangari ◽  
Christine Becker ◽  
Daniel G Foster ◽  
Maurizio Chioccioli ◽  
Meghan Nelson ◽  
...  
Keyword(s):  
Pulmonary Fibrosis ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Kinase Inhibitor ◽  
Recombinant Adenovirus ◽  
Ex Vivo ◽  
Src Kinase ◽  
Lung Fibroblasts

Idiopathic Pulmonary Fibrosis (IPF) is a chronic, progressive, and often fatal disorder. Two FDA approved anti-fibrotic drugs, nintedanib and pirfenidone, slow the rate of decline in lung function, but responses are variable and side effects are common. Using an in-silico data-driven approach, we identified a robust connection between the transcriptomic perturbations in IPF disease and those induced by saracatinib, a selective Src kinase inhibitor, originally developed for oncological indications. Based on these observations, we hypothesized that saracatinib would be effective at attenuating pulmonary fibrosis. We investigated the anti-fibrotic efficacy of saracatinib relative to nintedanib and pirfenidone in three preclinical models: (i) in vitro in normal human lung fibroblasts (NHLFs); (ii) in vivo in bleomycin and recombinant adenovirus transforming growth factor-beta (Ad-TGF-β) murine models of pulmonary fibrosis; and (iii) ex vivo in precision cut lung slices from these mouse models. In each model, the effectiveness of saracatinib in blocking fibrogenic responses was equal or superior to nintedanib and pirfenidone.

scholarly journals SLC25A21 Suppresses Cell Growth in Bladder Cancer Via The Reactive Oxygen Species-Mediated Mitochondrion-Dependent Apoptosis Pathway

2021 ◽  
Author(s):  
Yong Wang ◽  
Jiawen Gao ◽  
Shasha Hu ◽  
Weiting Zeng ◽  
Hongjun Yang ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Treatment Strategies ◽  
Migration And Invasion ◽  
Loss Of Function ◽  
Apoptosis Pathway ◽  
Normal Tissues ◽  
Induced Apoptosis ◽  
New Diagnosis

Abstract Background: Bladder cancer (BCa) is a commonly diagnosed malignancy worldwide that has poor survival depending on its intrinsic biologic aggressiveness and a peculiar radio- and chemoresistance features. Gaining a better understanding of tumorigenesis and developing new diagnosis and treatment strategies for BCa is important for improving BCa clinical outcome. SLC25 family member 21 (SLC25A21), a carrier transporting C5-C7 oxodicarboxylates, has been reported to contribute to oxoadipate acidemia. However, the potential role of SLC25A21 in cancer remains absolutely unknown. Methods: The expression levels of SLC25A21 in BCa and normal tissues were examined by real-time PCR and immunohistochemistry. Gain-of- and loss-of-function experiments were performed to detect the biological functions of SLC25A21 in vitro and in vivo by CCK-8 assay, plate colony formation assay, cell migration, invasion assay and experimental animal models. The subcellular distribution of substrate mediated by SLC25A21, mitochondrial membrane potential and ROS production were assessed to explore the potential mechanism of SLC25A21 in BCa.Results: We found that the expression of SLC25A21 was downregulated in BCa tissues compared to normal tissues. A significant positive correlation between decreased SLC25A21 expression and poor prognosis was observed in BCa patients. Overexpression of SLC25A21 significantly inhibited cell proliferation, migration and invasion and induced apoptosis in vitro. Moreover, the enhanced SLC25A21 expression significantly suppressed tumor growth in a xenograft mouse model. Furthermore, we revealed that SLC25A21 suppressed BCa growth by inducing the efflux of mitochondrial α-KG to the cytosol, decreasing to against oxidative stress, and activating the ROS-mediated mitochondrion-dependent apoptosis pathway. Conclusions: Our findings provide the first link between SLC25A21 expression and BCa and demonstrate that SLC25A21 acts as a crucial suppressor in BCa progression, which may help to provide new targets for BCa intervention.

ID: 112: ROLE OF PHOSPHOLIPASE D IN IDIOPATHIC PULMONARY FIBROSIS

2016 ◽  
Vol 64 (4) ◽  
pp. 964.1-964
Author(s):  
V Suryadevara ◽  
T Royston ◽  
E Berdyshev ◽  
L Huang ◽  
V Natarajan ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Phospholipase D ◽  
Human Lung ◽  
Lung Fibroblasts ◽  
Human Lung Fibroblasts

Idiopathic pulmonary fibrosis (IPF) is a deadly interstitial disease that leads to scarring and fibrosis of the lung tissue. In pulmonary fibrosis, there is injury and denudation of the alveolar epithelium, which further leads to activation of fibroblasts which differentiate into myofibroblasts. This includes several mechanisms including epithelial to mesenchymal transition (EMT). In this study, we investigated the role of phospholipase D (PLD) in IPF and also its underlying mechanism like EMT and fibroblast proliferation and differentiation. An in vivo murine model of bleomycin-induced pulmonary fibrosis (PF) and in vitro models of murine alveolar type-II epithelial cells (MLE-12) and human lung fibroblasts were used. C57BL/6 and genetically engineered PLD2−/− mice were intratracheally challenged with bleomycin (1.5 U/kg animal) for 14 days and markers of inflammation, EMT and fibrosis were determined. MLE-12 cells were treated with specific PLD1 or PLD2 inhibitors prior to bleomycin (10 mU/ml) challenge, and the role of PLD in EMT and apoptosis of alveolar epithelial cells was studied. Human lung fibroblasts were serum-starved (3h), pretreated with PLD1 or PLD2 inhibitors, and the effect of TGF-β (5 ng/ml) on differentiation of lung fibroblast to myofibroblast was determined. Intra-tracheal instillation of bleomycin in the mice for 14 days leads to the progression of fibrosis in the lung. The lung tissues of the bleomycin treated mice were found to have increased PLD2 protein expression, myofibroblast markers like α-SMA, fibronectin, mesenchymal markers like vimentin, inflammatory cytokines and collagen. Genetic deletion of PLD2 in mice attenuated bleomycin-induced lung inflammation and pulmonary fibrosis. In vitro, MLE-12 cells pretreated with either PLD1 or PLD2 inhibitor did not show a profound reduction either in apoptosis or the expression of transcription factors such as SNAIL, and other markers of EMT. However, MLE-12 cells pretreated with both PLD1 (250 nM) and PLD2 (500 nM) inhibitors were resistant to bleomycin-induced apoptosis, and exhibited reduced expression of SNAIL and mesenchymal markers. On the contrary, human lung fibroblasts pretreated with PLD1 and PLD2 inhibitors showed increased fibroblast to myofibroblast differentiation mediated by TGF-β. The present study suggests a role for PLD2 in bleomycin-induced PF. In vitro, inhibition of both PLD1 and PLD2 was necessary to attenuate bleomycin-induced EMT in epithelial cells and TGF-β mediated differentiation of fibroblasts to myofibroblasts. The in vivo and in vitro results identify the mechanism by which PLD regualtes PF and suggest PLD as a potential therapeutic target in pulmonary fibrosis. This work was supported by National Institutes of Health grant P01 HL98050 to VN.

scholarly journals TNF Is Necessary for Castration-Induced Prostate Regression, Whereas TRAIL and FasL Are Dispensable

2011 ◽  
Vol 25 (4) ◽  
pp. 611-620 ◽  
Author(s):  
Jennifer S. Davis ◽  
Kent L. Nastiuk ◽  
John J. Krolewski
Keyword(s):  
Mrna Levels ◽  
Wild Type ◽  
Mouse Prostate ◽  
Epithelial Cell Apoptosis ◽  
Androgen Withdrawal ◽  
Fas Signaling ◽  
Induced Apoptosis ◽  
Physiologic Role

TNF, a proinflammatory and immune-regulatory cytokine, is a potent apoptotic stimulus in vitro. However, there have been few examples of a physiologic role for TNF-induced apoptosis in vivo. Here, we describe a novel role for TNF in prostate epithelial cell apoptosis after androgen withdrawal. Employing high-resolution serial magnetic resonance imaging to measure mouse prostate volume changes over time, we demonstrate that the extent of castration-induced prostate regression is significantly reduced in mice null for either the Tnf or Tnfr1 genes but not mice deficient for TNF-related apoptosis-inducing ligand or Fas signaling. Wild-type mice receiving soluble TNF (sTNF) receptor 2 (to bind TNF and block signaling) before castration exhibit an identical reduction of prostate regression. Together, these data indicate that uniquely among known extrinsic death signals, TNF is required for castration-induced prostate regression. Additionally, membrane-bound TNF protein and stromal cell specific TNF mRNA levels increase in rat prostate after castration. This is consistent with a paracrine role for TNF in prostate regression. When injected into the peritoneum of Tnf−/− mice at the time of castration, sTNF restores normal levels of prostate regression. However, wild-type mice receiving sTNF in the absence of castration do not exhibit prostate regression, indicating that TNF alone is not sufficient but acts in the context of additional castration-induced signals. These findings support a physiologic role for TNF in prostate regression after androgen withdrawal. Understanding this role may lead to novel therapies for prostate cancer.

scholarly journals Disruption of Src function potentiates Chk1-inhibitor–induced apoptosis in human multiple myeloma cells in vitro and in vivo

Blood ◽  
2011 ◽  
Vol 117 (6) ◽  
pp. 1947-1957 ◽  
Author(s):  
Yun Dai ◽  
Shuang Chen ◽  
Rena Shah ◽  
Xin-Yan Pei ◽  
Li Wang ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Xenograft Model ◽  
Mitogen Activated Protein Kinase ◽  
Loss Of Function ◽  
Compensatory Response ◽  
Human Multiple Myeloma ◽  
Chk1 Inhibitor ◽  
Induced Apoptosis

Abstract Ras/MEK/ERK pathway activation represents an important compensatory response of human multiple myeloma (MM) cells to checkpoint kinase 1 (Chk1) inhibitors. To investigate the functional roles of Src in this event and potential therapeutic significance, interactions between Src and Chk1 inhibitors (eg, UCN-01 or Chk1i) were examined in vitro and in vivo. The dual Src/Abl inhibitors BMS354825 and SKI-606 blocked Chk1-inhibitor–induced extracellular signal-regulated kinase 1/2 (ERK1/2) activation, markedly increasing apoptosis in association with BimEL up-regulation, p34cdc2 activation, and DNA damage in MM cell lines and primary CD138+ MM samples. Loss-of-function Src mutants (K297R, K296R/Y528F) or shRNA knock-down of Src prevented the ERK1/2 activation induced by Chk1 inhibitors and increased apoptosis. Conversely, constitutively active Ras or mitogen-activated protein kinase/ERK kinase 1 (MEK1) significantly diminished the ability of Src inhibitors to potentiate Chk1-inhibitor lethality. Moreover, Src/Chk1-inhibitor cotreatment attenuated MM-cell production of vascular endothelial growth factor and other angiogenic factors (eg, ANG [angiogenin], TIMP1/2 [tissue inhibitor of metalloproteinases 1/2], and RANTES [regulated on activation normal T-cell expressed and secreted]), and inhibited in vitro angiogenesis. Finally, coadministration of BMS354825 and UCN-01 suppressed human MM tumor growth in a murine xenograft model, increased apoptosis, and diminished angiogenesis. These findings suggest that Src kinase is required for Chk1-inhibitor–mediated Ras → ERK1/2 signaling activation, and that disruption of this event sharply potentiates the anti-MM activity of Chk1 inhi-bitors in vitro and in vivo.

scholarly journals Glucocorticoid signalling drives reduced versican levels in the fetal mouse lung

2020 ◽  
Vol 64 (3) ◽  
pp. 155-164
Author(s):  
Kelly L Short ◽  
A Daniel Bird ◽  
Bennet K L Seow ◽  
Judy Ng ◽  
Annie R A McDougall ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Fetal Lung ◽  
Lung Fibroblasts ◽  
Normal Lung ◽  
Mouse Lung ◽  
Mrna Levels ◽  
Lung Maturation ◽  
Fetal Mouse ◽  
Distal Lung

Glucocorticoid (GC) signaling via the glucocorticoid receptor (GR) is essential for lung maturation in mammals. Previous studies using global or conditional mouse model knockouts of the GR gene have established that GR-mediated signaling in the interstitial mesenchyme of the fetal lung is critical for normal lung development. Screens for downstream GC-targets in conditional mesenchymal GR deficient mouse lung (GRmesKO) identified Versican (Vcan), an important extracellular matrix component and cell proliferation regulator, as a potential GR-regulated target. We show that, of the five major VCAN isoforms, the VCAN-V1 isoform containing the GAGβ domain is the predominant VCAN isoform in the fetal mouse lung distal mesenchyme at both E16.5 and E18.5, whereas the GAGα-specific VCAN-V2 isoform was only localized to the smooth muscle surrounding proximal airways. Both Vcan-V1 mRNA and protein levels were strongly overexpressed in the GRmesKO lung at E18.5. Finally, we investigated the GC regulation of the ECM protease ADAMTS 12 and showed that Adamts 12 mRNA levels were markedly reduced at E18.5 in GRmesKO fetal mouse lung and were strongly induced by both cortisol and betamethasone in cultures of primary rat fetal lung fibroblasts. ADAMTS12 protein immunoreactivity was also strongly increased in the distal lung at E18.5, after dexamethasone treatment in utero. In summary, glucocorticoid signaling via GR represses GAGβ domain-containing VCAN isoforms in distal lung mesenchyme in vivo by repressing Vcan gene expression and, in part, by inducing the ECM protease ADAMTS12, thereby contributing to the control of ECM remodelling and lung cell proliferation prior to birth.

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