scholarly journals TBK1 regulates YAP/TAZ and fibrogenic fibroblast activation

2020 ◽  
Vol 318 (5) ◽  
pp. L852-L863 ◽  
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.

scholarly journals Sirtuin 7 is decreased in pulmonary fibrosis and regulates the fibrotic phenotype of lung fibroblasts

2017 ◽  
Vol 312 (6) ◽  
pp. L945-L958 ◽  
Author(s):  
Anne E. Wyman ◽  
Zahid Noor ◽  
Rita Fishelevich ◽  
Virginia Lockatell ◽  
Nirav G. Shah ◽  
...  
Keyword(s):  
Pulmonary Fibrosis ◽  
Smooth Muscle Actin ◽  
Accelerated Aging ◽  
Lung Fibroblasts ◽  
Mrna Levels ◽  
Muscle Actin ◽  
Limited Data ◽  
Severe Condition ◽  
Protein Levels ◽  
Induced Changes

Pulmonary fibrosis is a severe condition with no cure and limited therapeutic options. A better understanding of its pathophysiology is needed. Recent studies have suggested that pulmonary fibrosis may be driven by accelerated aging-related mechanisms. Sirtuins (SIRTs), particularly SIRT1, SIRT3, and SIRT6, are well-known mediators of aging; however, limited data exist on the contribution of sirtuins to lung fibrosis. We assessed the mRNA and protein levels of all seven known sirtuins in primary lung fibroblasts from patients with idiopathic pulmonary fibrosis (IPF) and systemic sclerosis-associated interstitial lung disease (SSc-ILD) in comparison with lung fibroblasts from healthy controls. These unbiased tests revealed a tendency for all sirtuins to be expressed at lower levels in fibroblasts from patients compared with controls, but the greatest decrease was observed with SIRT7. Similarly, SIRT7 was decreased in lung tissues of bleomycin-challenged mice. Inhibition of SIRT7 with siRNA in cultured lung fibroblasts resulted in an increase in collagen and α-smooth muscle actin (α-SMA). Reciprocally, overexpression of SIRT7 resulted in lower basal and TGF-β-induced levels of COL1A1, COL1A2, COL3A1, and α-SMA mRNAs, as well as collagen and α-SMA proteins. Induced changes in SIRT7 had no effect on endogenous TGF-β mRNA levels or latent TGF-β activation, but overexpression of SIRT7 reduced the levels of Smad3 mRNA and protein. In conclusion, the decline in SIRT7 in lung fibroblasts has a profibrotic effect, which is mediated by changes in Smad3 levels.

scholarly journals RXFP1 expression is regulated by miR-144-3p in Fibroblasts from Patients with Idiopathic Pulmonary Fibrosis

2017 ◽  
Author(s):  
Harinath Bahudhanapati ◽  
Jiangning Tan ◽  
Justin A Dutta ◽  
Stephen B Strock ◽  
Yingze Zhang ◽  
...  
Keyword(s):  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Smooth Muscle Actin ◽  
Negative Regulator ◽  
Lung Fibroblasts ◽  
Luciferase Reporter ◽  
Alpha Smooth Muscle Actin ◽  
Protein Levels ◽  
Donor Lung ◽  
Luciferase Reporter Vector

ABSTRACTRelaxin has been considered as a potential therapy for patients with pulmonary fibrosis. We have previously shown, however, that a potential limitation of relaxin-based therapy for Idiopathic Pulmonary Fibrosis (IPF) is the loss of expression of the relaxin receptor Relaxin/Insulin Like Receptor 1 (RXFP1) expression in fibroblasts. The molecular mechanism for RXFP1 down-regulation in IPF patients remains unclear. To determine whether microRNAs play a role in RXFP1 gene expression, we employed a bioinformatics approach to identify microRNAs (miRs) that are predicted to target RXFP1. By in silico analysis, we identified a putative target site in the RXFP1 mRNA for the miR-144 family. We found that miR-144-3p was upregulated in IPF fibroblasts compared to donor lung fibroblast controls. Forced miR-144-3p mimic expression reduced RXFP1 mRNA and protein levels and increased expression of the myofibroblast marker alpha-smooth muscle actin (α-SMA) in donor lung fibroblasts. IPF lung fibroblasts transfected with a miR-144-3p inhibitor increased RXFP1 expression and reduced α-SMA expression. A lentiviral luciferase reporter vector carrying the WT 3’UTR of RXFP1 was repressed more in lung fibroblasts whereas vector carrying a mutated miR-144-3p binding site exhibited less sensitivity to endogenous miR-144-3p expression, suggesting that RXFP1 is a direct target of miR-144-3p. Thus, miR-144-3p is highly expressed in IPF fibroblasts and acts as a negative regulator of RXFP1 protein expression.

scholarly journals CXXC5 Attenuates Pulmonary Fibrosis in a Bleomycin-Induced Mouse Model and MLFs by Suppression of the CD40/CD40L Pathway

2020 ◽  
Vol 2020 ◽  
pp. 1-15 ◽  
Author(s):  
Wei Cheng ◽  
Fangfang Wang ◽  
Airan Feng ◽  
Xiaodan Li ◽  
Wencheng Yu
Keyword(s):  
Pulmonary Fibrosis ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Feedback Regulation ◽  
Collagen Type I ◽  
Mouse Lung ◽  
Type I ◽  
Negative Feedback Regulation ◽  
Protein Levels ◽  
Proliferation And Apoptosis

Objective. To investigate the role of CXXC5 and the CD40/CD40L pathway in lung fibrosis. Methods. (1) We constructed mouse models of bleomycin-induced pulmonary fibrosis and transfected them with a CXXC5 overexpression vector to evaluate the severity of pulmonary fibrosis. (2) Mouse lung fibroblast (MLF) models stably overexpressed or knockout of CXXC5 vector were constructed. After transforming growth factor-β1 (TGF-β1) stimulation, we examined the proliferation and apoptosis of the MLF model and evaluated the expression of mesenchymal markers and the CXXC5/CD40/CD40L pathway. Results. (1) Compared with other groups, the overexpressed CXXC5 group had less alveolar structure destruction, thinner alveolar septum, and lower Ashcroft score. (2) In bleomycin-induced mice, the expression of CD40 and CD40L increased at both transcriptional and protein levels, and the same changes were observed in α-smooth muscle actin (α-SMA) and collagen type I (Colla I). After upregulation of CXXC5, the increase in CD40, CD40L, α-SMA, and Colla I was attenuated. (3) Stimulated with TGF-β1, MLF proliferation was activated, apoptosis was suppressed, and the expression of CD40, CD40L, α-SMA, and Colla I was increased at both transcriptional and protein levels. After upregulation of CXXC5, these changes were attenuated. Conclusion. CXXC5 inhibits pulmonary fibrosis and transformation to myofibroblasts by negative feedback regulation of the CD40/CD40L pathway.

scholarly journals HDAC8 inhibition ameliorates pulmonary fibrosis

2019 ◽  
Vol 316 (1) ◽  
pp. L175-L186 ◽  
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.

scholarly journals LTBP2 is secreted from lung myofibroblasts and is a potential biomarker for idiopathic pulmonary fibrosis

2018 ◽  
Vol 132 (14) ◽  
pp. 1565-1580 ◽  
Author(s):  
Yasunori Enomoto ◽  
Sayomi Matsushima ◽  
Kiyoshi Shibata ◽  
Yoichiro Aoshima ◽  
Haruna Yagi ◽  
...  
Keyword(s):  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Bootstrap Method ◽  
Transforming Growth Factor Β ◽  
Lung Fibroblasts ◽  
Potential Biomarker ◽  
Fibrotic Process ◽  
Mouse Lungs

Although differentiation of lung fibroblasts into α-smooth muscle actin (αSMA)-positive myofibroblasts is important in the progression of idiopathic pulmonary fibrosis (IPF), few biomarkers reflecting the fibrotic process have been discovered. We performed microarray analyses between FACS-sorted steady-state fibroblasts (lineage (CD45, TER-119, CD324, CD31, LYVE-1, and CD146)-negative and PDGFRα-positive cells) from untreated mouse lungs and myofibroblasts (lineage-negative, Sca-1-negative, and CD49e-positive cells) from bleomycin-treated mouse lungs. Amongst several genes up-regulated in the FACS-sorted myofibroblasts, we focussed on Ltbp2, the gene encoding latent transforming growth factor-β (TGF-β) binding protein-2 (LTBP2), because of the signal similarity to Acta2, which encodes αSMA, in the clustering analysis. The up-regulation was reproduced at the mRNA and protein levels in human lung myofibroblasts induced by TGF-β1. LTBP2 staining in IPF lungs was broadly positive in the fibrotic interstitium, mainly as an extracellular matrix (ECM) protein; however, some of the αSMA-positive myofibroblasts were also stained. Serum LTBP2 concentrations, evaluated using ELISA, in IPF patients were significantly higher than those in healthy volunteers (mean: 21.4 compared with 12.4 ng/ml) and showed a negative correlation with % predicted forced vital capacity (r = −0.369). The Cox hazard model demonstrated that serum LTBP2 could predict the prognosis of IPF patients (hazard ratio for death by respiratory events: 1.040, 95% confidence interval: 1.026–1.054), which was validated using the bootstrap method with 1000-fold replication. LTBP2 is a potential prognostic blood biomarker that may reflect the level of differentiation of lung fibroblasts into myofibroblasts in IPF.

scholarly journals ERK1/2 Signaling Pathway Activated by EGF Promotes Proliferation, Transdifferentiation, and Migration of Cultured Primary Newborn Rat Lung Fibroblasts

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Yu Hu ◽  
JianHua Fu ◽  
XueYan Liu ◽  
XinDong Xue
Keyword(s):  
Western Blotting ◽  
Cell Cycle Progression ◽  
Cellular Proliferation ◽  
Smooth Muscle Actin ◽  
S Phase ◽  
Cell Counting ◽  
Lung Fibroblasts ◽  
Newborn Rats ◽  
Protein Levels ◽  
And Migration

Background. Bronchopulmonary dysplasia (BPD) is a common and serious complication in premature infants. Lung fibroblasts (LFs) are present in the extracellular matrix and participate in pulmonary development in response to BPD. The aim of this study was to investigate the effect of extracellular signal-regulated kinase (ERK) on LFs cultured from newborn rats. Material and Methods. Primary LFs were isolated and treated with epidermal growth factor (EGF, 20 ng/mL) in the presence or absence of an ERK inhibitor, PD98059 (10 μmol/L). Phosphorylated ERK1/2 (p-ERK1/2) protein levels were determined using immunocytochemistry, western blotting, and real-time reverse transcription quantitative (RT–q)PCR. LF proliferation was examined by flow cytometry and a cell counting kit-8 assay. LF transdifferentiation was examined by protein and mRNA expression of α-smooth muscle actin (α-SMA) by immunocytochemistry, western blotting, and RT–qPCR. LF migration was examined by the transwell method. Results. Phosphorylated ERK1/2, which was activated by EGF, promoted LF proliferation by accelerating cell-cycle progression from the G1 to S phase. After treatment with PD98059, the expression of p-ERK1/2 in LFs, cellular proliferation, and the percentage of cells in S phase were significantly decreased. Phosphorylated ERK1/2 also promoted the differentiation of LFs into myofibroblasts through increased α-SMA synthesis and migration. Conclusion. The activation of ERK promotes proliferation, transdifferentiation, and migration of lung fibroblasts from newborn rats.

Inhibition of miR-182-5p attenuates pulmonary fibrosis via TGF-β/Smad pathway

2019 ◽  
Vol 39 (5) ◽  
pp. 683-695 ◽  
Author(s):  
Y Chen ◽  
Q Zhang ◽  
Y Zhou ◽  
Z Yang ◽  
M Tan
Keyword(s):  
Pulmonary Fibrosis ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Lung Fibroblasts ◽  
In Vitro Assays ◽  
Luciferase Reporter ◽  
High Morbidity ◽  
Human Embryonic Lung ◽  
Promising Therapeutic Approach ◽  
Tgf Β1

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive lung disease with high morbidity and mortality. miR-182-5p is overexpressed in several fibrosis-related diseases but its effect in pulmonary fibrosis has not been reported yet. To investigate the function of miR-182-5p in pulmonary fibrosis, we established bleomycin (BLM)-induced fibrotic mice model and transforming growth factor-β1 (TGF-β1)-treated human embryonic lung fibroblasts model. In this study, miR-182-5p was highly expressed in pulmonary tissues of BLM-induced fibrotic mice. The content of hydroxyproline and TGF-β1 was decreased by downregulating the expression of miR-182-5p, indicating that fibrosis was alleviated in mice treated with Lentivirus-anti-miR-182-5p.Quantification of fibrosis-related proteins demonstrated that downregulation of miR-182-5p inhibited the expression of profibrotic proteins (fibronectin, α-smooth muscle actin, p-Smad2/p-Smad3) as well as enhanced the level of Smad7. In vitro assays validated that miR-182-5p was induced by TGF-β1 with the function of promoting fibrosis. In dual-luciferase reporter assay, Smad7 was demonstrated to be negatively regulated by miR-182-5p. Moreover, the effect of knocking down miR-182-5p on inhibiting fibrosis was achieved by upregulating the expression of Smad7. Therefore, miR-182-5p can be regarded as a biomarker of IPF and its inhibition may be a promising therapeutic approach in treating IPF.

scholarly journals A Missing Piece of the Puzzle in Pulmonary Fibrosis: Anoikis Resistance Promotes Fibroblast Activation

2021 ◽  
Author(s):  
Juan Yin ◽  
Jing Wang ◽  
Xinxin Zhang ◽  
Yan Liao ◽  
Wei Luo ◽  
...  
Keyword(s):  
Pulmonary Fibrosis ◽  
Cell Types ◽  
Pathological Process ◽  
Specific Pattern ◽  
Alveolar Epithelial Cells ◽  
Lung Fibroblasts ◽  
Anoikis Resistance ◽  
Fibroblast Activation ◽  
Alveolar Epithelial ◽  
Novel Therapeutic Strategies

Abstract Background Pulmonary fibrosis initiates a pneumonic cascade that leads to the dysfunction of fibroblasts characterized by excess proliferation. Anoikis is a physiological process that ensures tissue development and homeostasis. Whether disruption of anoikis is involved in pulmonary fibrosis remains unclear. Results Here, we investigated the mechanism by which silica induces fibroblast activation via anoikis resistance in the subsequent fibrosis. Anoikis of lung fibroblasts, alveolar epithelial cells and endothelial cells during the process of fibrosis was detected by CCK-8, western blot, cell count and flow cytometry (FCM) assays. While the three cell types showed similar increases in cell proliferation, the expression of NTRK2, a marker of anoikis resistance, was upregulated specifically in fibroblasts, indicating the unique proliferative mechanism of fibroblasts in pulmonary fibrosis, which may be related to anoikis resistance. Furthermore, the CRISPR/Cas9 system was used to investigate the molecular mechanism of anoikis resistance; the SiO2-induced inflammatory response activated the MAPK/PI3K signaling pathway in lung fibroblasts and then induced the protein expression of ZC3H4, which specifically mediated anoikis resistance, followed by pulmonary fibrosis. Conclusion The current study revealed a specific pattern of fibroblast proliferation, and targeting anoikis resistance may inhibit the pathological process of pulmonary fibrosis. This result provides a new approach for treating pulmonary fibrosis and new insights for the potential application of ZC3H4 in the development of novel therapeutic strategies for mitigating pulmonary fibrosis.

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 Metformin Attenuates Silica-Induced Pulmonary Fibrosis by Activating Autophagy via the AMPK-mTOR Signaling Pathway

2021 ◽  
Vol 12 ◽  
Author(s):  
Shu-xian Li ◽  
Chao Li ◽  
Xin-ru Pang ◽  
Juan Zhang ◽  
Gong-chang Yu ◽  
...  
Keyword(s):  
Pulmonary Fibrosis ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Mammalian Target Of Rapamycin ◽  
Specific Treatment ◽  
Transforming Growth Factor Β1 ◽  
Silica Particles ◽  
Protein Levels

Long-term exposure to crystalline silica particles leads to silicosis characterized by persistent inflammation and progressive fibrosis in the lung. So far, there is no specific treatment to cure the disease other than supportive care. In this study, we examined the effects of metformin, a prescribed drug for type || diabetes on silicosis and explored the possible mechanisms in an established rat silicosis model in vivo, and an in vitro co-cultured model containing human macrophages cells (THP-1) and human bronchial epithelial cells (HBEC). Our results showed that metformin significantly alleviated the inflammation and fibrosis of lung tissues of rats exposed to silica particles. Metformin significantly reduced silica particle-induced inflammatory cytokines including transforming growth factor-β1 (TGF-β1), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in rat lung tissue and HBEC culture supernatant. The protein levels of Vimentin and α-smooth muscle actin (α-SMA) were significantly decreased by metfomin while expression level of E-cadherin (E-Cad) increased. Besides, metformin increased the expression levels of phosphorylated adenosine 5′-monophosphate (AMP)-activated protein kinase (p-AMPK), microtubule-associated protein (MAP) light chain 3B (LC3B) and Beclin1 proteins, and reduced levels of phosphorylated mammalian target of rapamycin (p-mTOR) and p62 proteins in vivo and in vitro. These results suggest that metformin could inhibit silica-induced pulmonary fibrosis by activating autophagy through the AMPK-mTOR pathway.

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