scholarly journals Self DNA perpetuates IPF lung fibroblast senescence in a cGAS-dependent manner

2020 ◽  
Vol 134 (7) ◽  
pp. 889-905 ◽  
Author(s):  
Michael Schuliga ◽  
Jane Read ◽  
Kaj E.C. Blokland ◽  
David W. Waters ◽  
Janette Burgess ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Idiopathic Pulmonary Fibrosis ◽  
The Elderly ◽  
Lung Fibroblast ◽  
Lung Fibroblasts ◽  
Dependent Manner ◽  
Mitochondrial Stress ◽  
Therapeutic Implications ◽  
Age Related ◽  
P16 Expression

Abstract Senescence and mitochondrial stress are mutually reinforcing age-related processes that contribute to idiopathic pulmonary fibrosis (IPF); a lethal disease that manifests primarily in the elderly. Whilst evidence is accumulating that GMP-AMP synthase (cGAS) is crucial in perpetuating senescence by binding damaged DNA released into the cytosol, its role in IPF is not known. The present study examines the contributions of cGAS and self DNA to the senescence of lung fibroblasts from IPF patients (IPF-LFs) and age-matched controls (Ctrl-LFs). cGAS immunoreactivity was observed in regions of fibrosis associated with fibroblasts in lung tissue of IPF patients. Pharmacological inhibition of cGAS or its knockdown by silencing RNA (siRNA) diminished the escalation of IPF-LF senescence in culture over 7 days as measured by decreased p21 and p16 expression, histone 2AXγ phosphorylation and/or IL-6 production (P < 0.05, n = 5–8). The targeting of cGAS also attenuated etoposide-induced senescence in Ctrl-LFs (P < 0.05, n = 5–8). Levels of mitochondrial DNA (mDNA) detected by qPCR in the cytosol and medium of IPF-LFs or senescence-induced Ctrl-LFs were higher than Ctrl-LFs at baseline (P < 0.05, n = 5–7). The addition of DNAse I (100 U/ml) deaccelerated IPF-LF senescence (P < 0.05, n = 5), whereas ectopic mDNA or the induction of endogenous mDNA release augmented Ctrl-LF senescence in a cGAS-dependent manner (P < 0.05, n = 5). In conclusion, we provide evidence that cGAS reinforces lung fibroblast senescence involving damaged self DNA. The targeting of cGAS to supress senescent-like responses may have potential important therapeutic implications in the treatment of IPF.

scholarly journals Pink1/Parkin link inflammation, mitochondrial stress, and neurodegeneration

2018 ◽  
Vol 217 (10) ◽  
pp. 3327-3329 ◽  
Author(s):  
Laura E. Newman ◽  
Gerald S. Shadel
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Mitochondrial Dna ◽  
Neurodegenerative Diseases ◽  
Mitochondrial Stress ◽  
Mitochondrial Dna Mutations ◽  
Dna Mutations ◽  
Age Related ◽  
Sting Pathway

What causes inflammation in age-related neurodegenerative diseases remains a mystery. Sliter et al. (2018. Nature. https://doi.org/10.1038/s41586-018-0448-9) show that, when damaged mitochondria cannot be removed by mitophagy, stress from exercise or mitochondrial DNA mutations activates the proinflammatory cGAS–STING pathway that may contribute to Parkinson’s disease.

scholarly journals Ascorbic acid improves brachial artery vasodilation during progressive handgrip exercise in the elderly through a nitric oxide-mediated mechanism

2016 ◽  
Vol 310 (6) ◽  
pp. H765-H774 ◽  
Author(s):  
Joel D. Trinity ◽  
D. Walter Wray ◽  
Melissa A. H. Witman ◽  
Gwenael Layec ◽  
Zachary Barrett-O'Keefe ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Ascorbic Acid ◽  
Free Radical ◽  
Brachial Artery ◽  
Vascular Function ◽  
The Elderly ◽  
Voluntary Contraction ◽  
Dependent Manner ◽  
Handgrip Exercise ◽  
Age Related

The proposed mechanistic link between the age-related attenuation in vascular function and free radicals is an attractive hypothesis; however, direct evidence of free radical attenuation and a concomitant improvement in vascular function in the elderly is lacking. Therefore, this study sought to test the hypothesis that ascorbic acid (AA), administered intra-arterially during progressive handgrip exercise, improves brachial artery (BA) vasodilation in a nitric oxide (NO)-dependent manner, by mitigating free radical production. BA vasodilation (Doppler ultrasound) and free radical outflow [electron paramagnetic resonance (EPR) spectroscopy] were measured in seven healthy older adults (69 ± 2 yr) during handgrip exercise at 3, 6, 9, and 12 kg (∼13–52% of maximal voluntary contraction) during the control condition and nitric oxide synthase (NOS) inhibition via NG-monomethyl-l-arginine (l-NMMA), AA, and coinfusion of l-NMMA + AA. Baseline BA diameter was not altered by any of the treatments, while l-NMMA and l-NMMA + AA diminished baseline BA blood flow and shear rate. AA improved BA dilation compared with control at 9 kg (control: 6.5 ± 2.2%, AA: 10.9 ± 2.5%, P = 0.01) and 12 kg (control: 9.5 ± 2.7%, AA: 15.9 ± 3.7%, P < 0.01). NOS inhibition blunted BA vasodilation compared with control and when combined with AA eliminated the AA-induced improvement in BA vasodilation. Free radical outflow increased with exercise intensity but, interestingly, was not attenuated by AA. Collectively, these results indicate that AA improves BA vasodilation in the elderly during handgrip exercise through an NO-dependent mechanism; however, this improvement appears not to be the direct consequence of attenuated free radical outflow from the forearm.

scholarly journals Galactose-modified duocarmycin prodrugs as senolytics

2019 ◽  
Author(s):  
Ana Guerrero ◽  
Romain Guiho ◽  
Nicolás Herranz ◽  
Anthony Uren ◽  
Dominic J. Withers ◽  
...  
Keyword(s):  
Whole Body ◽  
Dependent Manner ◽  
Doxorubicin Treatment ◽  
Therapeutic Implications ◽  
Age Related ◽  
Wide Range ◽  
Selective Elimination ◽  
Elevated Activity ◽  
Stable Growth ◽  
Adamantinomatous Craniopharyngioma

SUMMARYSenescence is a stable growth arrest that impairs the replication of damaged, old or preneoplastic cells, therefore contributing to tissue homeostasis. Senescent cells accumulate during ageing and are associated with diseases, such as cancer, fibrosis and many age-related pathologies. Recent evidence suggests that the selective elimination of senescent cells can be effective on the treatment of many of these senescence-associated diseases. A universal characteristic of senescent cells is that they display elevated activity of the lysosomal β-galactosidase this has been exploited as a marker for senescence (senescence-associated β-galactosidase activity). Consequently, we hypothesised that galactose-modified cytotoxic prodrugs will be preferentially processed by senescent cells, resulting in their selective killing. Here, we show that different galactose-modified duocarmycin (GMD) derivatives preferentially kill senescent cells. GMD prodrugs induce selective apoptosis of senescent cells in a lysosomal β-galactosidase (GLB1)-dependent manner. GMD prodrugs can eliminate a broad range of senescent cells in culture, and treatment with a GMD prodrug enhances the elimination of bystander senescent cells that accumulate upon whole body irradiation or doxorubicin treatment of mice. Moreover, taking advantage of a mouse model of human adamantinomatous craniopharyngioma (ACP), we show that treatment with a GMD pro-drug result selectively reduced the number of β-catenin-positive preneoplastic senescent cells, what could have therapeutic implications. In summary, the above results show that galactose-modified duocarmycin prodrugs behave as senolytics, suggesting that they could be used to treat a wide range of senescence-related pathologies.

Glucocorticoid-induced contractility and F-actin content of human lung fibroblasts in three-dimensional culture

2000 ◽  
Vol 278 (1) ◽  
pp. L13-L18 ◽  
Author(s):  
Hiroyuki Miki ◽  
Tadashi Mio ◽  
Sonoko Nagai ◽  
Yuma Hoshino ◽  
Takeo Tsutsumi ◽  
...  
Keyword(s):  
Wound Healing ◽  
Human Lung ◽  
Healing Process ◽  
Lung Fibroblast ◽  
Lung Fibroblasts ◽  
Wound Healing Process ◽  
Architectural Distortion ◽  
Type I ◽  
Dependent Manner ◽  
Human Lung Fibroblast

Fibroblast contractility plays a useful role in the wound healing process but contributes to architectural distortion in the lungs. Glucocorticoids (GCs) have been reported to reduce dermal fibroblast contractility, which may result in delaying wound healing, but the effects on lung fibroblasts are unknown. In this study, we examined how human lung fibroblast contractility is altered in the presence of GCs. Lung fibroblast cell lines ( n = 5) were established from normal parts of surgically resected lung tissue. The effects of GCs on contractility were investigated with a type I collagen gel contraction assay. Filamentous actin (F-actin) content was detected by confocal microscopy and measured with a fluorescent phalloidin binding assay. GCs augmented fibroblast contraction in a concentration-dependent manner, with an approximate EC50 of 1.8 × 10−8 M, whereas other steroid derivatives had no effects. GC contractility needed de novo protein synthesis. The GC-induced increase in contractility was found to be consistent with an increase in F-actin content. In conclusion, lung fibroblast contractility was enhanced with GCs through an upregulation of lung fibroblast F-actin.

scholarly journals Differential regulation of metalloproteinase production, proliferation and chemotaxis of human lung fibroblasts by PDGF, Interleukin-1β and TNF-α

2000 ◽  
Vol 9 (3-4) ◽  
pp. 155-160 ◽  
Author(s):  
Masahiro Sasaki ◽  
Masayuki Kashima ◽  
Takefumi Ito ◽  
Akiko Watanabe ◽  
Noriko Izumiyama ◽  
...  
Keyword(s):  
Matrix Metalloproteinase ◽  
Human Lung ◽  
Lung Fibroblast ◽  
Differential Sensitivity ◽  
Lung Fibroblasts ◽  
Type I ◽  
Dependent Manner ◽  
Human Lung Fibroblast ◽  
Human Lung Fibroblasts ◽  
Tnf Α

Fibroblast migration, proliferation, extracellular matrix protein synthesis and degradation,all of which play important roles in inflammation, are them selves induced by various growth factors and cytokines. Less is known about the interaction of these substances on lung fibroblast function in pulmonary fibrosis.The goal of this study was to investigate the effects of PDGF alone and in combination with IL–1β and TNF–α on the production of human lung fibroblast matrix metalloproteinases, proliferation, and the chemotactic response. The assay for MMPs activity against FITC labeled type I and IV collagen was based on the specificity of the enzyme cleavage of collagen. Caseinolytis and gelatinolytic activities of secreted proteinases were analyzed by zymography. Fibronectin in conditioned media was measured using human lung fibronectin enzyme immunoassay. Cell proliferation was measured by 3H-Thymidine incorporation assay. Cell culture supernatants were tested for PGE2 content by ELISA. Chemotactic activity was measured using the modified Boyden chamber.Matrix metalloproteinase assay indicated that IL–1β, TNF–α and PDGF induced intestitial collagenase (MMP-1) production. MMP assay also indicated that IL–1β and TNF–α had inhibitory effects on MMP-2,9(gelatinaseA,B) production. Casein zymography confirmed that IL–1β stimulated stromlysin (matrix metalloproteinase 3; MMP–3) and gelatin zymography demonstrated that TNF–α induced MMP–9 production in human lung fibroblast, whereas PDGF alone did not. PDGF in combination with IL–1β and TNF–α induced MMP–3 and MMP–9 activity, as demonstrated by zymography. PDGF stimulated lung fibroblast proliferation in a concentration-dependent manner, whereas IL–1β and TNF–α alone had no effect. In contrast, the proliferation of human lung fibroblasts by PDGF was inhibited in the presence of IL–1β and TNF–α, and this inhibition was not a consequence of any elevation of PGE2. PDGF stimulated fibroblast chemotaxis in a concentrationdependent manner, and this stimulation was augmented by combining PDGF with IL–1β and TNF–α.These findings suggested that PDGF differentially regulated MMPs production in combination with cytokines, and further that MMP assay and zymography had differential sensitivity for detecting MMPs. The presence of cytokines with PDGF appears to modulate the proliferation and chemotaxis of human lung fibroblasts.

scholarly journals IL-25 contributes to lung fibrosis by directly acting on alveolar epithelial cells and fibroblasts

2019 ◽  
Vol 244 (9) ◽  
pp. 770-780 ◽  
Author(s):  
Xuefeng Xu ◽  
Sa Luo ◽  
Biyun Li ◽  
Huaping Dai ◽  
Jinglan Zhang
Keyword(s):  
Epithelial Cells ◽  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Lung Fibrosis ◽  
Lung Fibroblast ◽  
Alveolar Epithelial Cells ◽  
Lung Fibroblasts ◽  
Rt Pcr ◽  
Alveolar Epithelial

Interleukin (IL)-25 is shown to potentiate type-2 immunity and contribute to chronic airway inflammation and remodeling in allergic airway diseases. However, the role of IL-25 in idiopathic pulmonary fibrosis (IPF), dominated by nonatopic type-2 immunity, still remains largely unclear. Herein, we detected the expression levels of IL-25 and IL-17BR (IL-25’s receptor) by using lung tissue samples gained from IPF patients and normal subjects. Also, by directly intranasal (IN) instillation of IL-25 to mice, we examined the potential roles and mechanisms of IL-25 in the development of lung fibrosis. Furthermore, we tested whether IL-25 can directly activate human lung fibroblast by in vitro cell culture. Immunohistochemical, Western blot, and real-time reverse transcription-polymerase chain reaction (RT-PCR) showed that the mRNA and protein levels of IL-25 and IL-17BR are significantly higher in IPF patients when compared with normal controls. Intranasal instillation of IL-25 to mice markedly induces the expressions of alveolar IL-5 and IL-13. Furthermore, immunohistochemical analysis showed that the main components of the extracellular matrix including collagen I, collagen III and fibronectin are notably induced by IL-25 instillation in lung parenchyma (especially in alveolar epithelial cells [AECs]). Also, IL-25 potentiates the expression of connective tissue growth factor (CTGF) in AECs and the recruitment of lung fibroblast. By using Cell Counting Kit-8 and EDU incorporation assay, we found that IL-25 markedly enhances the proliferation of lung fibroblast. Finally, IL-25 potentiates fibroblast to produce several fibrogenic genes including collagen I/III, fibronectin, CTGF, α smooth muscle (α-SMA) and tissue inhibitor of metalloproteinase (TIMP)-1 as determined by RT-PCR assay. Collectively, we concluded that IL-25 is increased in IPF lungs and contributes to lung fibrosis by directly mediating AECs/fibroblast activation. Impact statement Our work focused on alveolar epithelial cells (AECs)-derived type-2 cytokine (interleukin [IL]-25) in the pathogenesis of idiopathic pulmonary fibrosis (IPF). We showed that IL-25 and IL-17BR (IL-25’s receptor) is upregulated in lung tissues (especially in AECs and lung fibroblasts) of IPF patients and contributes to lung fibrosis by directly activating lung fibroblasts and modulating epithelial–mesenchymal transition (EMT) of AECs. We suggest that IL-25 may be one of the master switches hidden in the milieu of abnormal epithelial–mesenchymal crosstalk. Treatment targeting IL-25 may be the potential and novel method for IPF patients.

Effects of neuropeptides on human lung fibroblast proliferation and chemotaxis

1995 ◽  
Vol 268 (2) ◽  
pp. L278-L283 ◽  
Author(s):  
N. K. Harrison ◽  
K. E. Dawes ◽  
O. J. Kwon ◽  
P. J. Barnes ◽  
G. J. Laurent ◽  
...  
Keyword(s):  
Human Lung ◽  
Colorimetric Assay ◽  
Mesenchymal Cells ◽  
Lung Fibroblast ◽  
Lung Fibroblasts ◽  
Boyden Chamber ◽  
Neurokinin A ◽  
Dependent Manner ◽  
Fibroblast Proliferation ◽  
Human Lung Fibroblast

An increase in subepithelial mesenchymal cells and associated connective tissue is a feature of bronchial asthma. We determined whether neuropeptides could modulate fibroblast activity, particularly with respect to proliferation and chemotaxis. Human lung fibroblasts were cultured with neurokinin A (NKA), substance P (SP), vasoactive intestinal peptide (VIP), and calcitonin-gene-related peptide (CGRP). After 48 h, fibroblast proliferation was measured by a colorimetric assay based on the uptake and subsequent release of methylene blue. The chemotactic response to neuropeptides was determined with the use of a modified Boyden chamber. Both NKA and SP (10(-7)-10(-4) M) stimulated human lung fibroblast proliferation in HFL1 and IMR-90 fibroblasts. VIP and CGRP had no effect on fibroblast proliferation. NKA alone stimulated fibroblast chemotaxis maximally at 10(-10) M. Neutral endopeptidase (NEP) activity of 0.52 and 5.2 pmol/10(6) cells was assayed in IMR-90 and Hs68 fibroblasts, respectively. Phosphoramidon (5 x 10(-6)-10(-5) M), an NEP inhibitor, enhanced fibroblast proliferation in a dose-dependent manner. Thus neuropeptides have the potential to cause activation of mesenchymal cells, and neuropeptide release may contribute to the structural abnormalities observed in asthmatic airways.

scholarly journals PGE2Desensitizesβ-Agonist Effect on Human Lung Fibroblast-Mediated Collagen Gel Contraction through Upregulating PDE4

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Qiuhong Fang ◽  
Yingmin Ma ◽  
Jing Wang ◽  
Joel Michalski ◽  
Stephen I. Rennard ◽  
...  
Keyword(s):  
Human Lung ◽  
Collagen Gel ◽  
Inhibitory Effect ◽  
Lung Fibroblast ◽  
Lung Fibroblasts ◽  
Pde4 Inhibitor ◽  
Dependent Manner ◽  
Human Lung Fibroblast ◽  
Collagen Gel Contraction ◽  
Long Acting

In the current study, we investigated the effect of a long-actingβ-agonist (salmeterol) and a phosphodiesterase 4 (PDE4) inhibitor (cilomilast) on human lung fibroblast-mediated collagen gel contraction. Higher concentrations of salmeterol (10−7and 10−6 M) inhibited fibroblast-mediated collagen gel contraction. No effect was observed with cilomilast alone (up to 10−5 M). In the presence of 10−8 M salmeterol, however, cilomilast could significantly inhibit fibroblast-mediated collagen gel contraction in a concentration-dependent manner (10−7~10−5 M). Blockade of endogenous PGE2by indomethacin further potentiated the inhibitory effect of salmeterol on fibroblast-mediated collagen gel contraction, but it did not affect cilomilast's effect. Pretreatment with PGE2abolished the inhibitory effect of salmeterol, but it potentiated the inhibitory effect of cilomilast on fibroblast-mediated collagen gel contraction. Finally, indomethacin slightly inhibited PDE4C expression, while PGE2stimulated the expression of PDE4A and -4C in human lung fibroblasts. These findings suggest that long-actingβ-agonist and PDE4 inhibitor have a synergistic effect in regulating fibroblast tissue repair functions and that PGE2can modulate the effect ofβ-agonist and PDE4 inhibitor at least in part through the mechanism of regulating PDE4 expression.

Coagulation Factor-XII induces interleukin-6 by primary lung fibroblasts: A role in idiopathic pulmonary fibrosis?

2021 ◽  
Author(s):  
Jade Jaffar ◽  
Laura McMillan ◽  
Nick Wilson ◽  
Con Panousis ◽  
Charles Hardy ◽  
...  
Keyword(s):  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Lung Tissue ◽  
Plasma Levels ◽  
Lung Fibroblasts ◽  
Factor Xii ◽  
Dependent Manner ◽  
Healthy Donors ◽  
Mechanistic Investigation ◽  
The Impact

Background The mechanisms driving idiopathic pulmonary fibrosis (IPF) remain undefined, however it is postulated that coagulation imbalances may play a role. The impact of blood-derived clotting factors, including factor XII (FXII) has not been investigated in the context of IPF. Methods Plasma levels of FXII were measured by ELISA in patients with IPF and age-matched healthy donors. Expression of FXII in human lung tissue was quantified using multiplex immunohistochemistry and western blotting. Mechanistic investigation of FXII activity was assessed in vitro on primary lung fibroblasts using qPCR and specific receptor/FXII inhibition. The functional outcome of FXII on fibroblast migration was examined by high-content image analysis. Findings Compared to 35 healthy donors, plasma levels of FXII were not higher in IPF (n=27, p>0·05). Tissue FXII was elevated in IPF (n=11) and increased numbers of FXII+ cells were found in IPF (n=8) lung tissue compared to non-diseased controls (n=6, p<0·0001). Activated FXII induced IL6 mRNA and IL-6 protein in fibroblasts that was blocked by anti-FXII antibody, CSL312. FXII-induced IL-6 production via PAR-1 and NF-kB. FXII induced migration of fibroblasts in a concentration-dependent manner. Interpretation FXII is normally confined to the circulation but leaks from damaged vessels into the lung interstitium in IPF where it 1) induces IL-6 production and 2) enhances migration of resident fibroblasts, critical events that drive chronic inflammation and therefore, contribute to fibrotic disease progression. Targeting FXII-induced fibroblastic processes in IPF may ameliorate pulmonary fibrosis. Funding National Health and Medical Research Council CRE in Lung Fibrosis and CSL Ltd.

scholarly journals Identification of Paired-related Homeobox Protein 1 as a key mesenchymal transcription factor in Idiopathic Pulmonary Fibrosis

2021 ◽  
Author(s):  
E. Marchal-Duval ◽  
M. Homps-Legrand ◽  
A. Froidure ◽  
M. Jaillet ◽  
M. Ghanem ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Ex Vivo ◽  
Lung Fibroblasts ◽  
Matrix Remodeling ◽  
Dependent Manner ◽  
Homeobox Protein

ABSTRACTMatrix remodeling is a salient feature of idiopathic pulmonary fibrosis (IPF). Targeting cells driving matrix remodeling could be a promising avenue for IPF treatment. Analysis of transcriptomic database identified the mesenchymal transcription factor PRRX1 as upregulated in IPF.PRRX1, strongly expressed by lung fibroblasts, was regulated by a TGF-β/PGE2 balance in vitro in control and IPF fibroblasts, while IPF fibroblast-derived matrix increased PRRX1 expression in a PDGFR dependent manner in control ones.PRRX1 inhibition decreased fibroblast proliferation by downregulating the expression of S phase cyclins. PRRX1 inhibition also impacted TGF-β driven myofibroblastic differentiation by inhibiting SMAD2/3 phosphorylation through phosphatase PPM1A upregulation and TGFBR2 downregulation, leading to TGF-β response global decrease.Finally, targeted inhibition of Prrx1 attenuated fibrotic remodeling in vivo with intra-tracheal antisense oligonucleotides in bleomycin mouse model of lung fibrosis and ex vivo using precision-cut lung slices.Our results identified PRRX1 as a mesenchymal transcription factor driving lung fibrogenesis.Brief SummaryInhibition of a single fibroblast-associated transcription factor, namely paired-related homeobox protein 1, is sufficient to dampen lung fibrogenesis.

Sign in / Sign up

Export Citation Format

Share Document