Transcription factor ets-2 plays an important role in the pathogenesis of pulmonary fibrosis

Phosphoproteomic profiling of early rheumatoid arthritis synovium reveals active signalling pathways and differentiates inflammatory pathotypes

BACKGROUND

Kinases are intracellular signalling mediators and key to sustaining the inflammatory process in rheumatoid arthritis (RA). Oral inhibitors of Janus Kinase family (JAKs) are widely used in RA, while inhibitors of other kinase families e.g. phosphoinositide 3-kinase (PI3K) are under development. Most current biomarker platforms quantify mRNA/protein levels, but give no direct information on whether proteins are active/inactive. Phosphoproteome analysis has the potential to measure specific enzyme activation status at tissue level.

METHODS

We validated the feasibility of phosphoproteome and total proteome analysis on 8 pre-treatment synovial biopsies from treatment-naive RA patients using label-free mass spectrometry, to identify active cell signalling pathways in synovial tissue which might explain failure to respond to RA therapeutics.

RESULTS

Differential expression analysis and functional enrichment revealed clear separation of phosphoproteome and proteome profiles between lymphoid and myeloid RA pathotypes. Abundance of specific phosphosites was associated with the degree of inflammatory state. The lymphoid pathotype was enriched with lymphoproliferative signalling phosphosites, including Mammalian Target Of Rapamycin (MTOR) signalling, whereas the myeloid pathotype was associated with Mitogen-Activated Protein Kinase (MAPK) and CDK mediated signalling. This analysis also highlighted novel kinases not previously linked to RA, such as Protein Kinase, DNA-Activated, Catalytic Subunit (PRKDC) in the myeloid pathotype. Several phosphosites correlated with clinical features, such as Disease-Activity-Score (DAS)-28, suggesting that phosphosite analysis has potential for identifying novel biomarkers at tissue-level of disease severity and prognosis.

CONCLUSIONS

Specific phosphoproteome/proteome signatures delineate RA pathotypes and may have clinical utility for stratifying patients for personalised medicine in RA.

Gene expression profiles in mesenchymal stromal cells from bone marrow, adipose tissue and lung tissue of COPD patients and controls

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is characterized by irreversible lung tissue damage. Novel regenerative strategies are urgently awaited. Cultured mesenchymal stem/stromal cells (MSCs) have shown promising results in experimental models of COPD, but differences between sources may impact on their potential use in therapeutic strategies in patients.

AIM

To assess the transcriptome of lung-derived MSCs (LMSCs), bone marrow-derived MSCs (BM-MSC) and adipose-derived MSCs (AD-MSCs) from COPD patients and non-COPD controls.

METHODS

We studied differences in gene expression profiles between the MSC-subtypes, as well as between COPD and control using RNA sequencing (RNA-seq).

RESULTS

We show that besides heterogeneity between donors, MSCs from different sources have strongly divergent gene signatures. The growth factors FGF10 and HGF were predominantly expressed in LMSCs. MSCs from all sources displayed altered expression profiles in COPD, with most pronounced significantly up- and downregulated genes in MSCs from adipose tissue. Pathway analysis revealed that the most differentially expressed genes in COPD-derived AD-MSCs are involved in extracellular matrix (ECM) binding and expression. In LMSCs, the gene that differed most strongly between COPD and control was CSGALNACT1, an ECM modulating gene.

CONCLUSION

Autologous MSCs from COPD patients display abnormalities with respect to their transcriptome, which were surprisingly most profound in MSCs from extrapulmonary sources. LMSCs may be optimally equipped for lung tissue repair because of the expression of specific growth factor genes.

microRNA-145-5p attenuates acute lung injury via targeting ETS2

The protective effect of microRNA (miR)-145-5p in acute lung injury (ALI) has been discovered previously. Thus, in this study, we attempted to further investigate the mechanism of miR-145-5p in ALI through the downstream E26 transformation-specific proto-oncogene 2 (ETS2)/transforming growth factor β1 (TGF-β1)/Smad pathway. A lipopolysaccharide (LPS)-induced ALI rat model was established. The expression of miR-145-5p in ALI rat lung tissues was up-regulated. Afterward, pathological damage in the lung tissue, the wet/dry (W/D) ratio, apoptosis, and serum inflammatory factor contents were observed. miR-145-5p, ETS2, TGF-β1, Smad2/3, and phosphorylated Smad2/3 levels were measured in rats. miR-145-5p expression was down-regulated, ETS2 expression was up-regulated, and the TGF-β1/Smad pathway was activated in LPS-exposed rats. Overexpression of miR-145-5p inactivated the TGF-β1/Smad pathway and attenuated ALI, as reflected by relieved pathological damage, a decreased W/D ratio, reduced apoptosis, and suppressed inflammatory response. In contrast, loss of miR-145-5p or elevated ETS2 levels worsened ALI and activated the TGF-β1/Smad pathway. Moreover, elevation of ETS2 diminished miR-145-5p-mediated protection against ALI. Evidently, miR-145-5p negatively regulates ETS2 expression and inactivates the TGF-β1/Smad pathway to ameliorate ALI in rats.

A novel tissue specific alternative splicing variant mitigates phenotypes in Ets2 frame-shift mutant models

E26 avian leukemia oncogene 2, 3′ domain (Ets2) has been implicated in various biological processes. An Ets2 mutant model (Ets2^db1/db1), which lacks the DNA-binding domain, was previously reported to exhibit embryonic lethality caused by a trophoblast abnormality. This phenotype could be rescued by tetraploid complementation, resulting in pups with wavy hair and curly whiskers. Here, we generated new Ets2 mutant models with a frame-shift mutation in exon 8 using the CRISPR/Cas9 method. Homozygous mutants could not be obtained by natural mating as embryonic development stopped before E8.5, as previously reported. When we rescued them by tetraploid complementation, these mice did not exhibit wavy hair or curly whisker phenotypes. Our newly generated mice exhibited exon 8 skipping, which led to in-frame mutant mRNA expression in the skin and thymus but not in E7.5 Ets2^em1/em1 embryos. This exon 8-skipped Ets2 mRNA was translated into protein, suggesting that this Ets2 mutant protein complemented the Ets2 function in the skin. Our data implies that novel splicing variants incidentally generated after genome editing may complicate the phenotypic analysis but may also give insight into the new mechanisms related to biological gene functions.

Particulate matters increase epithelial-mesenchymal transition and lung fibrosis through the ETS-1/NF-κB-dependent pathway in lung epithelial cells

Background

Particulate matters (PMs) in ambient air pollution are closely related to the incidence of respiratory diseases and decreased lung function. Our previous report demonstrated that PMs-induced oxidative stress increased the expression of proinflammatory intracellular adhesion molecule-1 (ICAM-1) through the IL-6/AKT/STAT3/NF-κB pathway in A549 cells. However, the role of O-PMs in epithelial-mesenchymal transition (EMT) development and pulmonary fibrosis and the related mechanisms have not been determined. The aim of this study was to investigate the effects of O-PMs on the pathogenesis of EMT and pulmonary fibrosis as well as the expression of ETS-1 and NF-κB p65, in vitro and in vivo.

Results

O-PMs treatment induced EMT development, fibronectin expression, and cell migration. O-PMs affected the expression of the EMT-related transcription factors NF-κB p65 and ETS-1. Interference with NF-κB p65 significantly decreased O-PMs-induced fibronectin expression. In addition, O-PMs affected the expression of fibronectin, E-cadherin, and vimentin through modulating ETS-1 expression. ATN-161, an antagonist of integrin α5β1, decreased the expression of fibronectin and ETS-1 and EMT development. EMT development and the expression of fibronectin and ETS-1 were increased in the lung tissue of mice after exposure to PMs for 7 and 14 days. There was a significant correlation between fibronectin and ETS-1 expression in human pulmonary fibrosis tissue.

Conclusion

O-PMs can induce EMT and fibronectin expression through the activation of transcription factors ETS-1 and NF-κB in A549 cells. PMs can induce EMT development and the expression of fibronectin and ETS-1 in mouse lung tissues. These findings suggest that the ETS-1 pathway could be a novel and alternative mechanism for EMT development and pulmonary fibrosis.

Ets-2 deletion in myeloid cells attenuates IL-1α-mediated inflammatory disease caused by a Ptpn6 point mutation

The SHP-1 protein encoded by the Ptpn6 gene has been extensively studied in hematopoietic cells in the context of inflammation. A point mutation in this gene (Ptpn6^spin) causes spontaneous inflammation in mice, which has a striking similarity to neutrophilic dermatoses in humans. Recent findings highlighted the role of signaling adapters and kinases in promoting inflammation in Ptpn6^spin mice; however, the underlying transcriptional regulation is poorly understood. Here, we report that SYK is important for driving neutrophil infiltration and initiating wound healing responses in Ptpn6^spin mice. Moreover, we found that deletion of the transcription factor Ets2 in myeloid cells ameliorates cutaneous inflammatory disease in Ptpn6^spin mice through transcriptional regulation of its target inflammatory genes. Furthermore, Ets-2 drives IL-1α-mediated inflammatory signaling in neutrophils of Ptpn6^spin mice. Overall, in addition to its well-known role in driving inflammation in cancer, Ets-2 plays a major role in regulating IL-1α-driven Ptpn6^spin-mediated neutrophilic dermatoses. Model for the role of ETS-2 in neutrophilic inflammation in Ptpn6^spin mice. Mutation of the Ptpn6 gene results in SYK phosphorylation which then sequentially activates MAPK signaling pathways and activation of ETS-2. This leads to activation of ETS-2 target genes that contribute to neutrophil migration and inflammation. When Ets2 is deleted in Ptpn6^spin mice, the expression of these target genes is reduced, leading to the reduced pathology in neutrophilic dermatoses.

ETS2 promotes epithelial-to-mesenchymal transition in renal fibrosis by targeting JUNB transcription

Epithelial-to-mesenchymal transition (EMT) plays an important role in the progression of renal tubulointerstitial fibrosis, a common mechanism leading to end-stage renal failure. V-ets erythroblastosis virus E26 oncogene homolog 2 (ETS2), a transcription factor, exhibits diverse roles in pathogenesis; however, its role in renal fibrosis is not yet fully understood. In this study, we detected the expression of ETS2 in an animal model of renal fibrosis and evaluated the potential role of ETS2 in tubular EMT induced by TGF-β1. We found that ETS2 and profibrogenic factors, alpha-smooth muscle actin (α-SMA) and fibronectin (FN), were significantly increased in the unilateral ureteral obstruction (UUO)-induced renal fibrosis model in mice. In vitro, TGF-β1 induced a high expression of ETS2 dependent on Smad3 and ERK signaling pathway in human proximal tubular epithelial cells (HK2). Knockdown of ETS2 abrogated TGF-β1-mediated expression of profibrogenic factors vimentin, α-SMA, collagen I, and FN in HK2 cells. Mechanistically, ETS2 promoted JUNB expression in HK2 cells after TGF-β1 stimulation. Furthermore, luciferase and Chromatin Immunoprecipitation (ChIP) assays revealed that the binding of ETS2 to three EBS motifs on the promoter of JUNB triggered its transcription. Notably, silencing JUNB reversed the ETS2-induced upregulation of the profibrogenic factors in HK2 cells after TGF-β1 stimulation. These findings suggest that ETS2 mediates TGF-β1-induced EMT in renal tubular cells through JUNB, a novel pathway for preventing renal fibrosis.

Kcnq1ot1/miR-381-3p/ETS2 Axis Regulates Inflammation in Mouse Models of Acute Respiratory Distress Syndrome

Inflammatory mediators play a key role in the pathogenesis of acute respiratory distress syndrome (ARDS). In this study, we aimed to explore the involvement of the Kcnq1 opposite strand/antisense transcript 1 (Kcnq1ot1)/miR-381-3p/E26 transformation-specific proto-oncogene 2 (ETS2) axis in inflammation of lipopolysaccharide (LPS)-induced ARDS. Microarray analysis revealed ETS2 as an upregulated gene in ARDS. Then, a LPS-induced ARDS mouse model was constructed, with a series of gain- or loss-of-function experiments conducted to evaluate the lung function and neutrophil extracellular trap (NET) formation in lung tissue and determine the neutrophil number, myeloperoxidase (MPO) activity, and inflammatory factor levels in bronchoalveolar lavage fluid (BALF). As the results revealed, downregulated expression of ETS2 resulted in improved lung function, decreased NETs, MPO activity, and levels of interleukin (IL)-6 and tumor necrosis factor alpha (TNF-α), as well as increased IL-10 level. Then, the assays of dual-luciferase reporter, RNA-binding protein immunoprecipitation (RIP), and RNA pull-down were performed to validate that Kcnq1ot1 promoted ETS2 expression by competitively binding to miR-381-3p. Meanwhile, it was also found that Kcnq1ot1 silencing reversed the promotive effect of EST2 on ARDS. Our results provide evidence that Kcnq1ot1 silencing may reduce the inflammatory response in LPS-induced ARDS via inhibition of miR-381-30-dependent ETS2, thereby presenting new molecular understanding for the development of ARDS.

Identification of novel target genes in human lung tissue involved in chronic obstructive pulmonary disease

Introduction

As part of a study aimed at illuminating at least some of the complex molecular events taking place in COPD, we screened tissues by means of transcriptome analyses.

Materials and methods

Tissues were subjected to transcriptome analysis. Candidate genes were identified and validated by immunohistochemistry. Primary human lung cells were subjected to stimulation with cigarette smoke extract for further validation by real time PCR.

Results

Six candidate genes were selected for further investigations: Aquaporin 3 (AQP3), extracellular matrix protein 1 (ECM1), four and a half LIM domain 1 (FHL1), milk fat globule epidermal growth factor 8 (MFGE8, lactadherin), phosphodiesterase 4D-interacting protein (PDE4DIP), and creatine transporter SLC6A8. All six proteins were allocated to distinct cell types by immunohistochemistry. Upon stimulation with cigarette smoke extract, human type II pneumocytes showed a dose-dependent down-regulation of MFGE8, while ECM1 and FHL1 also tended to be down-regulated. Although present, none of the candidates was regulated by cigarette smoke extract in primary human macrophages.

Discussion

MFGE8 turned out to be an interesting new candidate gene in COPD deserving further studies.

An Elf2-like transcription factor acts as repressor of the mouse ecto-5'-nucleotidase gene expression in hepatic myofibroblasts

Hepatic fibrosis represents a pathological wound healing and tissue repair process triggered in response to chronic liver injury. A heterogeneous population of activated non-parenchymal liver cells, known as liver myofibroblasts, functions as the effector cells in hepatic fibrosis. Upon activation, liver myofibroblasts become fibrogenic, acquiring contractile properties and increasing collagen production capacity, while developing enhanced sensitivity to endogenous molecules and factors released in the local microenvironment. Hepatic extracellular adenosine is a bioactive small molecule, increasingly recognized as an important regulator of liver myofibroblast functions, and an important mediator in the pathogenesis of liver fibrosis overall. Remarkably, ecto-5'-nucleotidase/Nt5e/Cd73 enzyme, which accounts for the dominant adenosine-generating activity in the extracellular medium, is expressed by activated liver myofibroblasts. However, the molecular signals regulating Nt5e gene expression in liver myofibroblasts remain poorly understood. Here, we show that activated mouse liver myofibroblasts express Nt5e gene products and characterize the putative Nt5e minimal promoter in the mouse species. We describe the existence of an enhancer sequence upstream of the mouse Nt5e minimal promoter and establish that the mouse Nt5e minimal promoter transcriptional activity is negatively regulated by an Elf2-like Ets-related transcription factor in activated mouse liver myofibroblasts.

MicroRNA-101 attenuates pulmonary fibrosis by inhibiting fibroblast proliferation and activation

Aberrant proliferation and activation of lung fibroblasts contribute to the initiation and progression of idiopathic pulmonary fibrosis (IPF). However, the mechanisms responsible for the proliferation and activation of fibroblasts are not fully understood. The objective of this study was to investigate the role of miR-101 in the proliferation and activation of lung fibroblasts. miR-101 expression was determined in lung tissues from patients with IPF and mice with bleomycin-induced pulmonary fibrosis. The regulation of miR-101 and cellular signaling was investigated in pulmonary fibroblasts in vitro The role of miR-101 in pulmonary fibrosis in vivo was studied using adenovirus-mediated gene transfer in mice. The expression of miR-101 was down-regulated in fibrotic lungs from patients with IPF and bleomycin-treated mice. The down-regulation of miR-101 occurred via the E26 transformation-specific (ETS) transcription factor. miR-101 suppressed the WNT5a-induced proliferation of lung fibroblasts by inhibiting NFATc2 signaling via targeting Frizzled receptor 4/6 and the TGF-β-induced activation of lung fibroblasts by inhibition of SMAD2/3 signaling via targeting the TGF-β receptor 1. Adenovirus-mediated miR-101 gene transfer in the mouse lung attenuated bleomycin-induced lung fibrosis and improved lung function. Our data suggest that miR-101 is an anti-fibrotic microRNA and a potential therapeutic target for pulmonary fibrosis.

Erythroblast transformation-specific 2 correlates with vascular smooth muscle cell apoptosis in rat heterotopic heart transplantation model

BACKGROUND

Cardiac allograft vasculopathy (CAV) decreases the long-term survival of heart transplantation recipients. Vascular smooth muscle cell (VSMC) apoptosis is an important pathological feature of CAV. Erythroblast transformation-specific 2 (Ets-2), as a transcription factor, participates in cell apoptosis and plays an important role in organ transplantation.

METHODS

Hearts from Wistar-Furth (WF:RT1u) rats were heterotopically transplanted into Lewis (Lew:RT1(l)) rats without immunosuppression. Additional syngeneic heterotopic cardiac transplantations were performed in Lewis rats. HE staining was used to identify CAV. Ets-2 expression was examined by western blot. Ets-2 tissue location was examined by immunohistochemical assay and double immunostaining. Cleaved caspase 3 expression was detected by western blot. Co-localization of Ets-2 and cleaved caspase 3 was detected by double immunostaining. Ets-2, p53, cleaved caspase 3 and Bcl-xl expression in rat VSMC line A7R5 was examined after Ets-2 siRNA transfection. TUNEL assay was applied to detect A7R5 apoptosis with or without ETS-2 siRNA transfection. Immunoprecipitation was performed to explore the interaction between Ets-2 and p53.

RESULTS

Ets-2 expression decreased in the allograft group but had no obvious change in the isograft group. Meanwhile, the phenomenon of CAV was observed in the allograft group and there is neointima formation in the isograft group which is not obvious compared with allograft group. Additionally, Ets-2 expression was opposite to VSMC apoptosis in the allograft group. In vitro, Ets-2 siRNA transfection in A7R5cells resulted in enhanced cell apoptosis. Finally, Ets-2 interacted with p53.

CONCLUSIONS

Ets-2 might inhibit VSMC apoptosis via p53 pathway. The results further elucidate the molecular mechanism of VSMC apoptosis after heart transplantation during CAV and provide theoretical basis for seeking new specific drug targets for CAV prevention and treatment.

The mitochondrial cardiolipin remodeling enzyme lysocardiolipin acyltransferase is a novel target in pulmonary fibrosis

RATIONALE

Lysocardiolipin acyltransferase (LYCAT), a cardiolipin-remodeling enzyme regulating the 18:2 linoleic acid pattern of mammalian mitochondrial cardiolipin, is necessary for maintaining normal mitochondrial function and vascular development. We hypothesized that modulation of LYCAT expression in lung epithelium regulates development of pulmonary fibrosis.

OBJECTIVES

To define a role for LYCAT in human and murine models of pulmonary fibrosis.

METHODS

We analyzed the correlation of LYCAT expression in peripheral blood mononuclear cells (PBMCs) with the outcomes of pulmonary functions and overall survival, and used the murine models to establish the role of LYCAT in fibrogenesis. We studied the LYCAT action on cardiolipin remodeling, mitochondrial reactive oxygen species generation, and apoptosis of alveolar epithelial cells under bleomycin challenge.

MEASUREMENTS AND MAIN RESULTS

LYCAT expression was significantly altered in PBMCs and lung tissues from patients with idiopathic pulmonary fibrosis (IPF), which was confirmed in two preclinical murine models of IPF, bleomycin- and radiation-induced pulmonary fibrosis. LYCAT mRNA expression in PBMCs directly and significantly correlated with carbon monoxide diffusion capacity, pulmonary function outcomes, and overall survival. In both bleomycin- and radiation-induced pulmonary fibrosis murine models, hLYCAT overexpression reduced several indices of lung fibrosis, whereas down-regulation of native LYCAT expression by siRNA accentuated fibrogenesis. In vitro studies demonstrated that LYCAT modulated bleomycin-induced cardiolipin remodeling, mitochondrial membrane potential, reactive oxygen species generation, and apoptosis of alveolar epithelial cells, potential mechanisms of LYCAT-mediated lung protection.

CONCLUSIONS

This study is the first to identify modulation of LYCAT expression in fibrotic lungs and offers a novel therapeutic approach for ameliorating lung inflammation and pulmonary fibrosis.

Fli1 represses transcription of the human α2(I) collagen gene by recruitment of the HDAC1/p300 complex

Fli1, a member of the Ets transcription factor family, is a key repressor of the human α2(I) collagen (COL1A2) gene. Although our previous studies have delineated that TGF-β induces displacement of Fli1 from the COL1A2 promoter through sequential post-translational modifications, the detailed mechanism by which Fli1 functions as a potent transcriptional repressor of the COL1A2 gene has not been fully investigated. To address this issue, we carried out a series of experiments especially focusing on protein-protein interaction and epigenetic transcriptional regulation. The combination of tandem affinity purification and mass spectrometry identified HDAC1 as a Fli1 interacting protein. Under quiescent conditions, HDAC1 induced deacetylation of Fli1 resulting in an increase of Fli1 DNA binding ability and p300 enhanced this process by promoting the formation of a Fli1-HDAC1-p300 complex. TGF-β-induced phosphorylation of Fli1 at threonine 312 led to disassembly of this protein complex. In quiescent dermal fibroblasts Fli1, HDAC1, and p300 occupied the −404 to −237 region, including the Fli1 binding site, of the COL1A2 promoter. TGF-β induced Fli1 and HDAC1 dissociation from the COL1A2 promoter, while promoting Ets1 and p300 recruitment. Furthermore, acetylation levels of histone H3 around the Fli1 binding site in the COL1A2 promoter inversely correlated with the DNA occupancy of Fli1 and HDAC1, while positively correlating with that of Ets1 and p300. In the functional studies, HDAC1 overexpression magnified the inhibitory effect of Fli1 on the COL1A2 promoter. Moreover, pharmacological blockade of HDAC1 by entinostat enhanced collagen production in dermal fibroblasts. Collectively, these results indicate that under quiescent conditions Fli1 recruits HDAC1/p300 to the COL1A2 promoter and suppresses the expression of the COL1A2 gene by chromatin remodeling through histone deacetylation. TGF-β-dependent phosphorylation of Fli1 at threonine 312 is a critical step regulating the remodeling of the Fli1 transcription repressor complex, leading to transcriptional activation of the COL1A2 gene.

Epigenetic regulation of miR-17~92 contributes to the pathogenesis of pulmonary fibrosis

RATIONALE

Idiopathic pulmonary fibrosis (IPF) is a disease of progressive lung fibrosis with a high mortality rate. In organ repair and remodeling, epigenetic events are important. MicroRNAs (miRNAs) regulate gene expression post-transcriptionally and can target epigenetic molecules important in DNA methylation. The miR-17~92 miRNA cluster is critical for lung development and lung epithelial cell homeostasis and is predicted to target fibrotic genes and DNA methyltransferase (DNMT)-1 expression.

OBJECTIVES

We investigated the miR-17~92 cluster expression and its role in regulating DNA methylation events in IPF lung tissue.

METHODS

Expression and DNA methylation patterns of miR-17~92 were determined in human IPF lung tissue and fibroblasts and fibrotic mouse lung tissue. The relationship between the miR-17~92 cluster and DNMT-1 expression was examined in vitro. Using a murine model of pulmonary fibrosis, we examined the therapeutic potential of the demethylating agent, 5'-aza-2'-deoxycytidine.

MEASUREMENTS AND MAIN RESULTS

Compared with control samples, miR-17~92 expression was reduced in lung biopsies and lung fibroblasts from patients with IPF, whereas DNMT-1 expression and methylation of the miR-17~92 promoter was increased. Several miRNAs from the miR-17~92 cluster targeted DNMT-1 expression resulting in a negative feedback loop. Similarly, miR-17~92 expression was reduced in the lungs of bleomycin-treated mice. Treatment with 5'-aza-2'-deoxycytidine in a murine bleomycin-induced pulmonary fibrosis model reduced fibrotic gene and DNMT-1 expression, enhanced miR-17~92 cluster expression, and attenuated pulmonary fibrosis.

CONCLUSIONS

This study provides insight into the pathobiology of IPF and identifies a novel epigenetic feedback loop between miR-17~92 and DNMT-1 in lung fibrosis.

Eureka! Ets a target for fibrosis!

The oncogenic Ets family of transcription factors is now recognized to play a key role in fibroblasts as it controls the expression of a variety of pro-fibrotic genes, including the induction of CCN2 by transforming growth factor β. A recent report (Baran et al., Am J Respir Cell Mol Biol. 2011 May 11) shows that mice containing a version of ets2 that is incapable of being phosphorylated are resistant to bleomycin-induced lung fibrosis. This latter paper is the subject of this commentary.