Loss of cells expressing fibroblast activation protein has variable effects in models of TGF-β and chronic bleomycin-induced fibrosis

Fibroblast activation protein (FAP), a cell surface serine protease, is upregulated on a subset of activated fibroblasts (often distinct from α-smooth muscle actin-expressing myofibroblasts) associated with matrix remodeling, including fibroblasts in idiopathic pulmonary fibrosis (Acharya PS, Zukas A, Chandan V, Katzenstein AL, Puré E. Hum Pathol 37: 352–360, 2006.). As FAP+fibroblasts could be pivotal in either breakdown and/or production of collagen and other matrix components, the goal of this study was to define the role of FAP+cells in pulmonary fibrosis in two established, but different, mouse models of chronic lung fibrosis: repetitive doses of intratracheal bleomycin and a single dose of an adenoviral vector encoding constitutively active TGF-β1 (Ad-TGFβ). To determine their role in fibrotic remodeling, FAP-expressing cells were depleted by injection of T cells expressing a chimeric antigen receptor specific for murine FAP in mice with established fibrosis. The contribution of FAP to the function of FAP-expressing cells was assessed in FAP knockout mice. Using histological analyses, quantification of soluble collagen content, and flow cytometry, we found that loss of FAP+cells exacerbated fibrosis in the bleomycin model, a phenotype largely recapitulated by the genetic deletion of FAP, indicating that FAP plays a role in this model. In contrast, depletion of FAP+cells or genetic deletion of FAP had little effect in the Ad-TGFβ model highlighting the potential for distinct mechanisms driving fibrosis depending on the initiating insult. The role of FAP in human lung fibrosis will need to be well understood to guide the use of FAP-targeted therapeutics that are being developed.

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Role of Alpha-Smooth Muscle Actin and Fibroblast Activation Protein Alpha in Ovarian Neoplasms

Gynecologic and Obstetric Investigation ◽

10.1159/000488088 ◽

2018 ◽

Vol 83 (4) ◽

pp. 381-387 ◽

Cited By ~ 1

Author(s):

Ana Carolinne da Silva ◽

Millena Prata Jammal ◽

Renata Margarida Etchebehere ◽

Eddie Fernando Candido Murta ◽

Rosekeila Simões Nomelini

Keyword(s):

Smooth Muscle ◽

Ovarian Neoplasms ◽

Smooth Muscle Actin ◽

Fibroblast Activation Protein ◽

Muscle Actin ◽

Alpha Smooth Muscle Actin ◽

Fibroblast Activation ◽

Fibroblast Activation Protein Alpha

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An Essential Role For Fibroblast Activation Protein (FAP) In Matrix Remodeling In Pulmonary Fibrosis

10.1164/ajrccm-conference.2011.183.1_meetingabstracts.a6430 ◽

2011 ◽

Author(s):

Ming-Hui Fan ◽

Melpo Christofidou-Solomidou ◽

David Speicher ◽

Ellen Pure'

Keyword(s):

Pulmonary Fibrosis ◽

Essential Role ◽

Fibroblast Activation Protein ◽

Matrix Remodeling ◽

Fibroblast Activation

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LncRNA SNHG16 promotes pulmonary fibrosis by targeting miR-455-3p to regulate the Notch2 pathway

Respiratory Research ◽

10.1186/s12931-021-01632-z ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Panpan Liu ◽

Lei Zhao ◽

Yuxia Gu ◽

Meilan Zhang ◽

Hongchang Gao ◽

...

Keyword(s):

Pulmonary Fibrosis ◽

Lung Fibrosis ◽

Transforming Growth Factor ◽

Transforming Growth Factor Β ◽

Interstitial Lung Diseases ◽

Luciferase Reporter ◽

Qrt Pcr ◽

Rna Immunoprecipitation ◽

And Migration

Abstract Background Idiopathic pulmonary fibrosis (IPF) is the most common interstitial lung diseases with a poor prognosis. Long non-coding RNAs (lncRNAs) have been reported to be involved in IPF in several studies. However, the role of lncRNA SNHG16 in IPF is largely unknown. Methods Firstly, experimental pulmonary fibrosis model was established by using bleomycin (BML). Histology and Western blotting assays were used to determine the different stages of fibrosis and expression of several fibrosis biomarkers. The expression of SNHG16 was detected by quantitative real-time polymerase chain reaction (qRT‐PCR). EdU staining and wound-healing assay were utilized to analyze proliferation and migration of lung fibroblast cells. Molecular mechanism of SNHG16 was explored by bioinformatics, dual-luciferase reporter assay, RNA immunoprecipitation assay (RIP), and qRT-PCR. Results The expression of SNHG16 was significantly up-regulated in bleomycin-(BLM) induced lung fibrosis and transforming growth factor-β (TGF-β)-induced fibroblast. Knockdown of SNHG16 could attenuate fibrogenesis. Mechanistically, SNHG16 was able to bind and regulate the expression of miR-455-3p. Moreover, SNHG16 also regulated the expression of Notch2 by targeting miR-455-3p. Finally, SNHG16 could promote fibrogenesis by regulating the expression of Notch2. Conclusion Taken together, our study demonstrated that SNHG16 promoted pulmonary fibrosis by targeting miR-455-3p to regulate the Notch2 pathway. These findings might provide a novel insight into pathologic process of lung fibrosis and may provide prevention strategies in the future.

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Fibroblast Activation Protein ± (FAP) Is Differentially Expressed In Fibroblast Cultures From Normal Human And Idiopathic Pulmonary Fibrosis Lungs

10.1164/ajrccm-conference.2010.181.1_meetingabstracts.a3513 ◽

2010 ◽

Author(s):

Nathalie Rosales Díaz Escobar ◽

Yair Romero López ◽

Luis G. Vazquez de Lara

Keyword(s):

Idiopathic Pulmonary Fibrosis ◽

Pulmonary Fibrosis ◽

Fibroblast Activation Protein ◽

Differentially Expressed ◽

Fibroblast Activation ◽

Fibroblast Cultures ◽

Normal Human

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Anti-fibrosis effect for Hirsutella sinensis mycelium based on inhibition of mTOR p70S6K phosphorylation

Innate Immunity ◽

10.1177/1753425917726361 ◽

2017 ◽

Vol 23 (7) ◽

pp. 615-624 ◽

Cited By ~ 5

Author(s):

Huimin Yue ◽

Yarong Zhao ◽

Haining Wang ◽

Feiya Ma ◽

Fei Liu ◽

...

Keyword(s):

Pulmonary Fibrosis ◽

Lung Fibrosis ◽

Molecular Mechanisms ◽

Histopathological Examination ◽

Smooth Muscle Actin ◽

A549 Cells ◽

Mtor Pathway ◽

Cordyceps Sinensis ◽

Tgf Β1

Hirsutella sinensis, cultured in vitro, is an attractive substitute for Cordyceps sinensis as health supplement. The aim of this study was to demonstrate whether H. sinensis mycelium (HSM) attenuates murine pulmonary fibrosis induced by bleomycin and to explore the underlying molecular mechanisms. Using lung fibrosis modle induced by intratracheal instillation of bleomycin (BLM; 4 mg/kg), we observed that the administration of HSM reduced HYP, TGF-β1 and the production of several pro-fibrosis cytokines (α-smooth muscle actin, fibronectin and vimentin) in fibrotic mice lung sections. Histopathological examination of lung tissues also demonstrated that HSM improved BLM-induced pathological damage. Concurrently, HSM supplementation markedly reduced the chemotaxis of alveolar macrophages and potently suppressed the expression of inflammatory cytokines. Also, HSM influenced Th1/Th2 and Th17/Treg imbalance and blocked the phosphorylation of mTOR pathway in vivo. Alveolar epithelial A549 cells acquired a mesenchymal phenotype and an increased expression of myofibroblast markers of differentiation (vimentin and fibronectin) after treatment with TGF-β1. HSM suppressed these markers and blocked the phosphorylation of mTOR pathway in vitro. The results provide evidence supporting the use of HSM in the intervention of pulmonary fibrosis and suggest that HSM is a potential therapeutic agent for lung fibrosis.

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Beclin 1, LC3, and p62 expression in paraquat-induced pulmonary fibrosis

Human & Experimental Toxicology ◽

10.1177/0960327119842633 ◽

2019 ◽

Vol 38 (7) ◽

pp. 794-802 ◽

Cited By ~ 4

Author(s):

G Xu ◽

X Wang ◽

H Yu ◽

C Wang ◽

Y Liu ◽

...

Keyword(s):

Pulmonary Fibrosis ◽

Light Chain ◽

Lung Fibrosis ◽

Beclin 1 ◽

Related Protein ◽

Protein Expressions ◽

Hematoxylin And Eosin ◽

Hematoxylin And Eosin Staining ◽

Related Proteins

Paraquat (PQ) is a highly toxic herbicide to humans. Pulmonary fibrosis is one of the most typical features of PQ poisoning, which develops from several days to weeks after ingestion. However, the mechanism of fibrosis is still unclear. In this study, we aimed to determine expressions of autophagy-related markers Beclin 1, microtubule-associated protein light chain 3 (LC3), and p62 in PQ-poisoned lungs and to explore the role of autophagy in pulmonary fibrosis induced by PQ. We detected markers of lung fibrosis and expressions of autophagy-related protein in the specimens from eight fatal cases of PQ poisoning by hematoxylin and eosin staining, Masson’s trichrome staining, and immunohistochemistry. Based on the staining results of lung fibrosis, these cases were divided into two groups, fibrosis and non-fibrosis groups. The correlation between autophagy protein expressions and pulmonary fibrosis was examined. The results demonstrated that the autophagy-related proteins were significantly expressed in fibrosis group compared with the non-fibrosis group. There was a significantly positive correlation between these protein expressions and severity of lung fibrosis. In conclusion, autophagy dysfunction may be involved in lung fibrogenesis caused by PQ poisoning. This may be a promising clue for understanding the molecular mechanism underlying PQ-induced lung fibrosis and provide evidence for treating fibrosis by regulating the level of autophagy.

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HDAC8 inhibition ameliorates pulmonary fibrosis

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00551.2017 ◽

2019 ◽

Vol 316 (1) ◽

pp. L175-L186 ◽

Cited By ~ 9

Author(s):

Shigeki Saito ◽

Yan Zhuang ◽

Takayoshi Suzuki ◽

Yosuke Ota ◽

Marjorie E. Bateman ◽

...

Keyword(s):

Smooth Muscle ◽

Pulmonary Fibrosis ◽

Transforming Growth Factor ◽

Therapeutic Potential ◽

Smooth Muscle Actin ◽

Lung Fibroblasts ◽

Peroxisome Proliferator ◽

Collagen Gels ◽

Cell Contractility

Idiopathic pulmonary fibrosis (IPF) is a fibroproliferative lung disease, and fibroblast-myofibroblast differentiation (FMD) is thought to be a key event in the pathogenesis of IPF. Histone deacetylase-8 (HDAC8) has been shown to associate with α-smooth muscle actin (α-SMA; a marker of FMD) and regulates cell contractility in vascular smooth muscle cells. However, the role of HDAC8 in FMD or pulmonary fibrosis has never been reported. This study investigated the role of HDAC8 in pulmonary fibrosis with a focus on FMD. We observed that HDAC8 expression was increased in IPF lung tissue as well as transforming growth factor (TGF)β1-treated normal human lung fibroblasts (NHLFs). Immunoprecipitation experiments revealed that HDAC8 was associated with α-SMA in TGFβ1-treated NHLFs. HDAC8 inhibition with NCC170 (HDAC8-selective inhibitor) repressed TGFβ1-induced fibroblast contraction and α-SMA protein expression in NHLFs cultured in collagen gels. HDAC8 inhibition with HDAC8 siRNA also repressed TGFβ1-induced expression of profibrotic molecules such as fibronectin and increased expression of antifibrotic molecules such as peroxisome proliferator-activated receptor-γ (PPARγ). Chromatin immunoprecipitation quantitative PCR using an antibody against H3K27ac (histone H3 acetylated at lysine 27; a known HDAC8 substrate and a marker for active enhancers) suggested that HDAC8 inhibition with NCC170 ameliorated TGFβ1-induced loss of H3K27ac at the PPARγ gene enhancer. Furthermore, NCC170 treatment significantly decreased fibrosis measured by Ashcroft score as well as expression of type 1 collagen and fibronectin in bleomycin-treated mouse lungs. These data suggest that HDAC8 contributes to pulmonary fibrosis and that there is a therapeutic potential for HDAC8 inhibitors to treat IPF as well as other fibrotic lung diseases.

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TBK1 regulates YAP/TAZ and fibrogenic fibroblast activation

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00324.2019 ◽

2020 ◽

Vol 318 (5) ◽

pp. L852-L863 ◽

Cited By ~ 1

Author(s):

Aja Aravamudhan ◽

Andrew J. Haak ◽

Kyoung Moo Choi ◽

Jeffrey A. Meridew ◽

Nunzia Caporarello ◽

...

Keyword(s):

Pulmonary Fibrosis ◽

Large Scale ◽

Smooth Muscle Actin ◽

Lung Fibroblasts ◽

Cell Contact ◽

Actin Stress Fiber ◽

Fibroblast Activation ◽

Protein Levels ◽

Major Cell Type ◽

Interfering Rna

Idiopathic pulmonary fibrosis (IPF) results in scarring of the lungs by excessive extracellular matrix (ECM) production. Resident fibroblasts are the major cell type involved in ECM deposition. The biochemical pathways that facilitate pathological fibroblast activation leading to aberrant ECM deposition are not fully understood. Tank binding protein kinase-1 (TBK1) is a kinase that regulates multiple signaling pathways and was recently identified as a candidate regulator of fibroblast activation in a large-scale small-interfering RNA (siRNA) screen. To determine the effect of TBK1 on fibroblast activation, TBK1 was inhibited pharmacologically (MRT-68601) and genetically (siRNA) in normal and IPF human lung fibroblasts. Reducing the activity or expression of TBK1 led to reduction in α-smooth muscle actin stress fiber levels by 40–60% and deposition of ECM components collagen I and fibronectin by 50% in TGF-β-stimulated normal and IPF fibroblasts. YAP and TAZ are homologous mechanoregulatory profibrotic transcription cofactors known to regulate fibroblast activation. TBK1 knockdown or inhibition decreased the total and nuclear protein levels of YAP/TAZ. Additionally, low cell-cell contact and increased ECM substrate stiffness augmented the phosphorylation and activation of TBK1, consistent with cues that regulate YAP/TAZ. The action of TBK1 toward YAP/TAZ activation was independent of LATS1/2 and canonical downstream TBK1 signaling mediator IRF3 but dependent on proteasomal machinery of the cell. This study identifies TBK1 as a fibrogenic activator of human pulmonary fibroblasts, suggesting TBK1 may be a novel therapeutic target in pulmonary fibrosis.

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Prostaglandin E2 protects murine lungs from bleomycin-induced pulmonary fibrosis and lung dysfunction

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00176.2011 ◽

2011 ◽

Vol 301 (5) ◽

pp. L645-L655 ◽

Cited By ~ 49

Author(s):

Ryan T. Dackor ◽

Jennifer Cheng ◽

James W. Voltz ◽

Jeffrey W. Card ◽

Catherine D. Ferguson ◽

...

Keyword(s):

Pulmonary Fibrosis ◽

Therapeutic Effect ◽

Lung Fibrosis ◽

Prostaglandin E ◽

Therapeutic Effects ◽

Inflammatory Factor ◽

Cellular Infiltration ◽

Static Compliance ◽

Lung Dysfunction

Prostaglandin E2 (PGE2) is a lipid mediator that is produced via the metabolism of arachidonic acid by cyclooxygenase enzymes. In the lung, PGE2 acts as an anti-inflammatory factor and plays an important role in tissue repair processes. Although several studies have examined the role of PGE2 in the pathogenesis of pulmonary fibrosis in rodents, results have generally been conflicting, and few studies have examined the therapeutic effects of PGE2 on the accompanying lung dysfunction. In this study, an established model of pulmonary fibrosis was used in which 10–12-wk-old male C57BL/6 mice were administered a single dose (1.0 mg/kg) of bleomycin via oropharyngeal aspiration. To test the role of prostaglandins in this model, mice were dosed, via surgically implanted minipumps, with either vehicle, PGE2 (1.32 μg/h), or the prostacyclin analog iloprost (0.33 μg/h) beginning 7 days before or 14 days after bleomycin administration. Endpoints assessed at 7 days after bleomycin administration included proinflammatory cytokine levels and measurement of cellular infiltration into the lung. Endpoints assessed at 21 days after bleomycin administration included lung function assessment via invasive (FlexiVent) analysis, cellular infiltration, lung collagen content, and semiquantitative histological analysis of the degree of lung fibrosis (Ashcroft method). Seven days after bleomycin administration, lymphocyte numbers and chemokine C-C motif ligand 2 expression were significantly lower in PGE2- and iloprost-treated animals compared with vehicle-treated controls ( P < 0.05). When administered 7 days before bleomycin challenge, PGE2 also protected against the decline in lung static compliance, lung fibrosis, and collagen production that is associated with 3 wk of bleomycin exposure. However, PGE2 had no therapeutic effect on these parameters when administered 14 days after bleomycin challenge. In summary, PGE2 prevented the decline in lung static compliance and protected against lung fibrosis when it was administered before bleomycin challenge but had no therapeutic effect when administered after bleomycin challenge.

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