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Cell Reports. Medicine Mar 2023Accumulation of senescent cells contributes to age-related diseases including idiopathic pulmonary fibrosis (IPF). Insulin-like growth factor binding proteins (IGFBPs)...
Accumulation of senescent cells contributes to age-related diseases including idiopathic pulmonary fibrosis (IPF). Insulin-like growth factor binding proteins (IGFBPs) regulate many biological processes; however, the functional contributions of IGFBP2 in lung fibrosis remain largely unclear. Here, we report that intranasal delivery of recombinant IGFBP2 protects aged mice from weight loss and demonstrated antifibrotic effects after bleomycin lung injury. Notably, aged human-Igfbp2 transgenic mice reveal reduced senescence and senescent-associated secretory phenotype factors in alveolar epithelial type 2 (AEC2) cells and they ameliorated bleomycin-induced lung fibrosis. Finally, we demonstrate that IGFBP2 expression is significantly suppressed in AEC2 cells isolated from fibrotic lung regions of patients with IPF and/or pulmonary hypertension compared with patients with hypersensitivity pneumonitis and/or chronic obstructive pulmonary disease. Altogether, our study provides insights into how IGFBP2 regulates AEC2-cell-specific senescence and that restoring IGFBP2 levels in fibrotic lungs can prove effective for patients with IPF.
Topics: Aged; Animals; Humans; Mice; Alveolar Epithelial Cells; Bleomycin; Cellular Senescence; Idiopathic Pulmonary Fibrosis; Mice, Transgenic
PubMed: 36787736
DOI: 10.1016/j.xcrm.2023.100945 -
The European Respiratory Journal Dec 2022Accumulation of myofibroblasts is critical to fibrogenesis in idiopathic pulmonary fibrosis (IPF). Senescence and insufficient mitophagy in fibroblasts contribute to...
BACKGROUND
Accumulation of myofibroblasts is critical to fibrogenesis in idiopathic pulmonary fibrosis (IPF). Senescence and insufficient mitophagy in fibroblasts contribute to their differentiation into myofibroblasts, thereby promoting the development of lung fibrosis. Bone morphogenetic protein 4 (BMP4), a multifunctional growth factor, is essential for the early stage of lung development; however, the role of BMP4 in modulating lung fibrosis remains unknown.
METHODS
The aim of this study was to evaluate the role of BMP4 in lung fibrosis using BMP4-haplodeleted mice, BMP4-overexpressed mice, primary lung fibroblasts and lung samples from patients with IPF.
RESULTS
BMP4 expression was downregulated in IPF lungs and fibroblasts compared to control individuals, negatively correlated with fibrotic genes, and BMP4 decreased with transforming growth factor (TGF)-β1 stimulation in lung fibroblasts in a time- and dose-dependent manner. In mice challenged with bleomycin, BMP4 haploinsufficiency perpetuated activation of lung myofibroblasts and caused accelerated lung function decline, severe fibrosis and mortality. BMP4 overexpression using adeno-associated virus 9 vectors showed preventative and therapeutic efficacy against lung fibrosis. , BMP4 attenuated TGF-β1-induced fibroblast-to-myofibroblast differentiation and extracellular matrix (ECM) production by reducing impaired mitophagy and cellular senescence in lung fibroblasts. Pink1 silencing by short-hairpin RNA transfection abolished the ability of BMP4 to reverse the TGF-β1-induced myofibroblast differentiation and ECM production, indicating dependence on Pink1-mediated mitophagy. Moreover, the inhibitory effect of BMP4 on fibroblast activation and differentiation was accompanied with an activation of Smad1/5/9 signalling and suppression of TGF-β1-mediated Smad2/3 signalling and .
CONCLUSION
Strategies for enhancing BMP4 signalling may represent an effective treatment for pulmonary fibrosis.
Topics: Animals; Mice; Bleomycin; Bone Morphogenetic Protein 4; Cellular Senescence; Fibroblasts; Idiopathic Pulmonary Fibrosis; Lung; Mice, Inbred C57BL; Mitophagy; Myofibroblasts; Protein Kinases; Transforming Growth Factor beta1
PubMed: 35777761
DOI: 10.1183/13993003.02307-2021 -
Nature Communications Nov 2022Pulmonary fibrosis is a chronic interstitial lung disease that causes irreversible and progressive lung scarring and respiratory failure. Activation of fibroblasts plays...
Pulmonary fibrosis is a chronic interstitial lung disease that causes irreversible and progressive lung scarring and respiratory failure. Activation of fibroblasts plays a central role in the progression of pulmonary fibrosis. Here we show that platelet endothelial aggregation receptor 1 (PEAR1) in fibroblasts may serve as a target for pulmonary fibrosis therapy. Pear1 deficiency in aged mice spontaneously causes alveolar collagens accumulation. Mesenchyme-specific Pear1 deficiency aggravates bleomycin-induced pulmonary fibrosis, confirming that PEAR1 potentially modulates pulmonary fibrosis progression via regulation of mesenchymal cell function. Moreover, single cell and bulk tissue RNA-seq analysis of pulmonary fibroblast reveals the expansion of Activated-fibroblast cluster and enrichment of marker genes in extracellular matrix development in Pear1 fibrotic lungs. We further show that PEAR1 associates with Protein Phosphatase 1 to suppress fibrotic factors-induced intracellular signalling and fibroblast activation. Intratracheal aerosolization of monoclonal antibodies activating PEAR1 greatly ameliorates pulmonary fibrosis in both WT and Pear1-humanized mice, significantly improving their survival rate.
Topics: Mice; Animals; Pulmonary Fibrosis; Mice, Inbred C57BL; Fibroblasts; Extracellular Matrix; Bleomycin
PubMed: 36402779
DOI: 10.1038/s41467-022-34870-w -
Nature Communications Feb 2023Interstitial lung diseases such as idiopathic pulmonary fibrosis (IPF) are caused by persistent micro-injuries to alveolar epithelial tissues accompanied by aberrant...
Interstitial lung diseases such as idiopathic pulmonary fibrosis (IPF) are caused by persistent micro-injuries to alveolar epithelial tissues accompanied by aberrant repair processes. IPF is currently treated with pirfenidone and nintedanib, compounds which slow the rate of disease progression but fail to target underlying pathophysiological mechanisms. The DNA repair protein 8-oxoguanine DNA glycosylase-1 (OGG1) has significant roles in the modulation of inflammation and metabolic syndromes. Currently, no pharmaceutical solutions targeting OGG1 have been utilized in the treatment of IPF. In this study we show Ogg1-targeting siRNA mitigates bleomycin-induced pulmonary fibrosis in male mice, highlighting OGG1 as a tractable target in lung fibrosis. The small molecule OGG1 inhibitor, TH5487, decreases myofibroblast transition and associated pro-fibrotic gene expressions in fibroblast cells. In addition, TH5487 decreases levels of pro-inflammatory mediators, inflammatory cell infiltration, and lung remodeling in a murine model of bleomycin-induced pulmonary fibrosis conducted in male C57BL6/J mice. OGG1 and SMAD7 interact to induce fibroblast proliferation and differentiation and display roles in fibrotic murine and IPF patient lung tissue. Taken together, these data suggest that TH5487 is a potentially clinically relevant treatment for IPF but further study in human trials is required.
Topics: Male; Mice; Humans; Animals; Lung; Idiopathic Pulmonary Fibrosis; Fibrosis; Pneumonia; Bleomycin; DNA Glycosylases
PubMed: 36746968
DOI: 10.1038/s41467-023-36314-5 -
International Journal of Molecular... Feb 2023Fibrosis and structural remodeling of the lung tissue can significantly impair lung function, often with fatal consequences. The etiology of pulmonary fibrosis (PF) is... (Review)
Review
Fibrosis and structural remodeling of the lung tissue can significantly impair lung function, often with fatal consequences. The etiology of pulmonary fibrosis (PF) is diverse and includes different triggers such as allergens, chemicals, radiation, and environmental particles. However, the cause of idiopathic PF (IPF), one of the most common forms of PF, remains unknown. Experimental models have been developed to study the mechanisms of PF, and the murine bleomycin (BLM) model has received the most attention. Epithelial injury, inflammation, epithelial-mesenchymal transition (EMT), myofibroblast activation, and repeated tissue injury are important initiators of fibrosis. In this review, we examined the common mechanisms of lung wound-healing responses after BLM-induced lung injury as well as the pathogenesis of the most common PF. A three-stage model of wound repair involving injury, inflammation, and repair is outlined. Dysregulation of one or more of these three phases has been reported in many cases of PF. We reviewed the literature investigating PF pathogenesis, and the role of cytokines, chemokines, growth factors, and matrix feeding in an animal model of BLM-induced PF.
Topics: Mice; Animals; Bleomycin; Lung; Fibrosis; Inflammation; Idiopathic Pulmonary Fibrosis; Lung Injury; Epithelial-Mesenchymal Transition; Disease Models, Animal
PubMed: 36834561
DOI: 10.3390/ijms24043149 -
Cell Death & Disease May 2022Idiopathic pulmonary fibrosis (IPF) was considered as a telomere-mediated disease. TERT and TERC correlated with telomere length. Although telomerase gene mutations were...
Idiopathic pulmonary fibrosis (IPF) was considered as a telomere-mediated disease. TERT and TERC correlated with telomere length. Although telomerase gene mutations were associated with IPF, majority patients did not carry mutations. The mechanism by which telomerase expression was regulated in IPF are still unclear. In this study, we aimed to delineate the mechanisms that how TERT protein expression were regulated in alveolar epithelial cells (AECs) in pulmonary fibrosis. Here, we found that P16, P21 and fibrosis markers (αSMA and Collagen-I) were prominently increased in lung tissues of IPF patients and bleomycin-induced mouse models, while the expression of KLF4 and TERT were decreased in AECs. In vivo experiments, AAV-6 vectors mediated KLF4 over-expression with specific SP-C promoter was constructed. Over-expression of KLF4 in AECs could protect TERT expression and suppress the development of pulmonary fibrosis in bleomycin-induced mouse models. In the mechanism exploration of TERT regulation, KLF4 and TERT were both down-regulated in bleomycin-induced senescent MLE-12 and BEAS-2B cells. Compared with control group, small-interfering RNA targeting KLF4 significantly reduced the TERT expression and telomerase activity, while overexpression of KLF4 can increased the expression of TERT and telomerase activity in senescent AECs. Furthermore, ChIP showed that KLF4 protein could bind to the TERT promoter region in MLE-12 cells, suggesting that KLF4 could implicate in pathogenesis of lung fibrosis through regulating TERT transcription in AECs. Taken together, this study identified that KLF4 might be a promising potential target for further understanding the mechanism and developing novel strategy for the treatment of lung fibrosis in IPF.
Topics: Alveolar Epithelial Cells; Animals; Bleomycin; Disease Models, Animal; Epithelial Cells; Humans; Idiopathic Pulmonary Fibrosis; Lung; Mice; Telomerase
PubMed: 35508454
DOI: 10.1038/s41419-022-04886-7 -
American Journal of Respiratory and... Dec 2022Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and often fatal disorder. Two U.S. Food and Drug Administration-approved antifibrotic drugs, nintedanib...
Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and often fatal disorder. Two U.S. Food and Drug Administration-approved antifibrotic drugs, nintedanib and pirfenidone, slow the rate of decline in lung function, but responses are variable and side effects are common. Using an 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 antifibrotic efficacy of saracatinib relative to nintedanib and pirfenidone in three preclinical models: ) in normal human lung fibroblasts; ) in bleomycin and recombinant Ad-TGF-β (adenovirus transforming growth factor-β) murine models of pulmonary fibrosis; and ) in mice and human precision-cut lung slices from these two murine models as well as patients with IPF and healthy donors. In each model, the effectiveness of saracatinib in blocking fibrogenic responses was equal or superior to nintedanib and pirfenidone. Transcriptomic analyses of TGF-β-stimulated normal human lung fibroblasts identified specific gene sets associated with fibrosis, including epithelial-mesenchymal transition, TGF-β, and WNT signaling that was uniquely altered by saracatinib. Transcriptomic analysis of whole-lung extracts from the two animal models of pulmonary fibrosis revealed that saracatinib reverted many fibrogenic pathways, including epithelial-mesenchymal transition, immune responses, and extracellular matrix organization. Amelioration of fibrosis and inflammatory cascades in human precision-cut lung slices confirmed the potential therapeutic efficacy of saracatinib in human lung fibrosis. These studies identify novel Src-dependent fibrogenic pathways and support the study of the therapeutic effectiveness of saracatinib in IPF treatment.
Topics: Animals; Humans; Mice; Bleomycin; Fibroblasts; Fibrosis; Idiopathic Pulmonary Fibrosis; Lung; Protein Kinase Inhibitors; src-Family Kinases; Transforming Growth Factor beta
PubMed: 35998281
DOI: 10.1164/rccm.202010-3832OC -
The Journal of Clinical Investigation Jan 2021Fibrosis is a macrophage-driven process of uncontrolled extracellular matrix accumulation. Neuronal guidance proteins such as netrin-1 promote inflammatory scarring. We...
Fibrosis is a macrophage-driven process of uncontrolled extracellular matrix accumulation. Neuronal guidance proteins such as netrin-1 promote inflammatory scarring. We found that macrophage-derived netrin-1 stimulates fibrosis through its neuronal guidance functions. In mice, fibrosis due to inhaled bleomycin engendered netrin-1-expressing macrophages and fibroblasts, remodeled adrenergic nerves, and augmented noradrenaline. Cell-specific knockout mice showed that collagen accumulation, fibrotic histology, and nerve-associated endpoints required netrin-1 of macrophage but not fibroblast origin. Adrenergic denervation; haploinsufficiency of netrin-1's receptor, deleted in colorectal carcinoma; and therapeutic α1 adrenoreceptor antagonism improved collagen content and histology. An idiopathic pulmonary fibrosis (IPF) lung microarray data set showed increased netrin-1 expression. IPF lung tissues were enriched for netrin-1+ macrophages and noradrenaline. A longitudinal IPF cohort showed improved survival in patients prescribed α1 adrenoreceptor blockade. This work showed that macrophages stimulate lung fibrosis via netrin-1-driven adrenergic processes and introduced α1 blockers as a potentially new fibrotic therapy.
Topics: Animals; Bleomycin; Female; Lung; Macrophages; Male; Mice; Mice, Transgenic; Netrin-1; Norepinephrine; Pulmonary Fibrosis
PubMed: 33393489
DOI: 10.1172/JCI136542 -
The Journal of Clinical Investigation May 2019Idiopathic Pulmonary Fibrosis (IPF) is a deadly disease with limited therapies. Tissue fibrosis is associated with Type 2 immune response, although the causal...
Idiopathic Pulmonary Fibrosis (IPF) is a deadly disease with limited therapies. Tissue fibrosis is associated with Type 2 immune response, although the causal contribution of immune cells is not defined. The AP-1 transcription factor Fra-2 is upregulated in IPF lung sections and Fra-2 transgenic mice (Fra-2tg) exhibit spontaneous lung fibrosis. Here we show that Bleomycin-induced lung fibrosis is attenuated upon myeloid-inactivation of Fra-2 and aggravated in Fra-2tg bone marrow chimeras. Type VI collagen (ColVI), a Fra-2 transcriptional target, is up-regulated in three lung fibrosis models, and macrophages promote myofibroblast activation in vitro in a ColVI- and Fra-2-dependent manner. Fra-2 or ColVI inactivation does not affect macrophage recruitment and alternative activation, suggesting that Fra-2/ColVI specifically controls the paracrine pro-fibrotic activity of macrophages. Importantly, ColVI knock-out mice (KO) and ColVI-KO bone marrow chimeras are protected from Bleomycin-induced lung fibrosis. Therapeutic administration of a Fra-2/AP-1 inhibitor reduces ColVI expression and ameliorates fibrosis in Fra-2tg mice and in the Bleomycin model. Finally, Fra-2 and ColVI positively correlate in IPF patient samples and co-localize in lung macrophages. Therefore, the Fra-2/ColVI pro-fibrotic axis is a promising biomarker and therapeutic target for lung fibrosis, and possibly other fibrotic diseases.
Topics: Allografts; Animals; Bleomycin; Bone Marrow; Bone Marrow Transplantation; Collagen Type VI; Fos-Related Antigen-2; Humans; Idiopathic Pulmonary Fibrosis; Macrophages; Mice; Mice, Knockout; Myofibroblasts; Transplantation Chimera
PubMed: 31135379
DOI: 10.1172/JCI125366 -
The European Respiratory Journal Jun 2020Idiopathic pulmonary fibrosis (IPF) is a complex disease of unknown aetiology, which makes drug development challenging. Single administration of bleomycin directly to... (Review)
Review
Idiopathic pulmonary fibrosis (IPF) is a complex disease of unknown aetiology, which makes drug development challenging. Single administration of bleomycin directly to the lungs of mice is a widely used experimental model for studying pulmonary fibrogenesis and evaluating the effect of therapeutic antifibrotic strategies. The model works by inducing an early inflammatory phase, which transitions into fibrosis after 5-7 days. This initial inflammation makes therapeutic timing crucial. To accurately assess antifibrotic efficacy, the intervention should inhibit fibrosis without impacting early inflammation.Studies published between 2008 and 2019 using the bleomycin model to investigate pulmonary fibrosis were retrieved from PubMed, and study characteristics were analysed. Intervention-based studies were classified as either preventative (starting <7 days after bleomycin installation) or therapeutic (>7 days). In addition, studies were cross-referenced with current major clinical trials to assess the availability of preclinical rationale.A total of 976 publications were evaluated. 726 investigated potential therapies, of which 443 (61.0%) were solely preventative, 166 (22.9%) were solely therapeutic and 105 (14.5%) were both. Of the 443 preventative studies, only 70 (15.8%) characterised inflammation during the model's early inflammatory phase. In the reported 145 IPF clinical trials investigating 93 compounds/combinations, only 25 (26.9%) interventions had any preclinical data on bleomycin available on PubMed.Since 2008, we observed a shift (from <5% to 37.4%) in the number of studies evaluating drugs in the therapeutic setting in the bleomycin model. While this shift is encouraging, further characterisation of early inflammation and appropriate preclinical therapeutic testing are still needed. This will facilitate fruitful drug development in IPF, and more therapeutic strategies for patients with this devastating disease.
Topics: Animals; Bleomycin; Disease Models, Animal; Fibrosis; Humans; Idiopathic Pulmonary Fibrosis; Lung; Mice
PubMed: 32165401
DOI: 10.1183/13993003.01105-2019