scholarly journals TGFβ1 Controls PPARγExpression, Transcriptional Potential, and Activity, in Part, through Smad3 Signaling in Murine Lung Fibroblasts

PPAR Research ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Allan Ramirez ◽  
Erin N. Ballard ◽  
Jesse Roman
Keyword(s):  
Transforming Growth Factor ◽  
Gene Promoter ◽  
Negative Regulator ◽  
Lung Fibroblasts ◽  
Luciferase Reporter ◽  
Peroxisome Proliferator ◽  
Reporter Expression ◽  
Peroxisome Proliferator Activated Receptor ◽  
3T3 Fibroblasts ◽  
Nih 3T3

Transforming growth factorβ1 (TGFβ1) promotes fibrosis by, among other mechanisms, activating quiescent fibroblasts into myofibroblasts and increasing the expression of extracellular matrices. Recent work suggests that peroxisome proliferator-activated receptorγ(PPARγ) is a negative regulator of TGFβ1-induced fibrotic events. We, however, hypothesized that antifibrotic pathways mediated by PPARγare influenced by TGFβ1, causing an imbalance towards fibrogenesis. Consistent with this, primary murine primary lung fibroblasts responded to TGFβ1 with a sustained downregulation of PPARγtranscripts. This effect was dampened in lung fibroblasts deficient in Smad3, a transcription factor that mediates many of the effects of TGFβ1. Paradoxically, TGFβ1 stimulated the activation of the PPARγgene promoter and induced the phosphorylation of PPARγin primary lung fibroblasts. The ability of TGFβ1 to modulate the transcriptional activity of PPARγwas then tested in NIH/3T3 fibroblasts containing a PPARγ-responsive luciferase reporter. In these cells, stimulation of TGFβ1 signals with a constitutively active TGFβ1 receptor transgene blunted PPARγ-dependent reporter expression induced by troglitazone, a PPARγactivator. Overexpression of PPARγprevented TGFβ1 repression of troglitazone-induced PPARγ-dependent gene transcription, whereas coexpression of PPARγand Smad3 transgenes recapitulated the TGFβ1 effects. We conclude that modulation of PPARγis controlled by TGFβ1, in part through Smad3 signals, involving regulation of PPARγexpression and transcriptional potential.

Disruption of transforming growth factor-β signaling by curcumin induces gene expression of peroxisome proliferator-activated receptor-γ in rat hepatic stellate cells

2007 ◽  
Vol 292 (1) ◽  
pp. G113-G123 ◽  
Author(s):  
Shizhong Zheng ◽  
Anping Chen
Keyword(s):  
Gene Expression ◽  
Hepatic Stellate Cells ◽  
Molecular Mechanisms ◽  
Transforming Growth Factor ◽  
Gene Promoter ◽  
Stellate Cells ◽  
Transforming Growth Factor Β ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Ppar Γ

Activation of hepatic stellate cells (HSC), the major effectors of hepatic fibrogenesis, is coupled with sequential alterations in gene expression, including an increase in receptors for transforming growth factor-β (TGF-β) and a dramatic reduction in the peroxisome proliferator-activated receptor-γ (PPAR-γ). The relationship between them remains obscure. We previously demonstrated that curcumin induced gene expression of PPAR-γ in activated HSC, leading to reducing cell proliferation, inducing apoptosis and suppressing expression of extracellular matrix genes. The underlying molecular mechanisms are largely unknown. We recently observed that stimulation of PPAR-γ activation suppressed gene expression of TGF-β receptors in activated HSC, leading to the interruption of TGF-β signaling. This observation supported our assumption of an antagonistic relationship between PPAR-γ activation and TGF-β signaling in HSC. In this study, we further hypothesize that TGF-β signaling might negatively regulate gene expression of PPAR-γ in activated HSC. The present report demonstrates that exogenous TGF-β1 inhibits gene expression of PPAR-γ in activated HSC, which is eliminated by the pretreatment with curcumin likely by interrupting TGF-β signaling. Transfection assays further indicate that blocking TGF-β signaling by dominant negative type II TGF-β receptor increases the promoter activity of PPAR-γ gene. Promoter deletion assays, site-directed mutageneses, and gel shift assays localize two Smad binding elements (SBEs) in the PPAR-γ gene promoter, acting as curcumin response elements and negatively regulating the promoter activity in passaged HSC. The Smad3/4 protein complex specifically binds to the SBEs. Overexpression of Smad4 dose dependently eliminates the inhibitory effects of curcumin on the PPAR-γ gene promoter and TGF-β signaling. Taken together, these results demonstrate that the interruption of TGF-β signaling by curcumin induces gene expression of PPAR-γ in activated HSC in vitro. Our studies provide novel insights into the molecular mechanisms of curcumin in the induction of PPAR-γ gene expression and in the inhibition of HSC activation.

scholarly journals Induction of peroxisome proliferator-activated receptor gamma during the conversion of 3T3 fibroblasts into adipocytes is mediated by C/EBPbeta, C/EBPdelta, and glucocorticoids.

1996 ◽  
Vol 16 (8) ◽  
pp. 4128-4136 ◽  
Author(s):  
Z Wu ◽  
N L Bucher ◽  
S R Farmer
Keyword(s):  
Gene Expression ◽  
Expression System ◽  
Ectopic Expression ◽  
Response To Treatment ◽  
Peroxisome Proliferator ◽  
Differentiation Process ◽  
Peroxisome Proliferator Activated Receptor ◽  
Initial Exposure ◽  
3T3 Fibroblasts ◽  
Nih 3T3

The differentiation of 3T3 preadipocytes into adipocytes is accompanied by a transient induction of C/EBPbeta and C/EBPdelta expression in response to treatment of the cells with methylisobutylxanthine (MIX) and dexamethasone (DEX), respectively. In this report, we demonstrate that peroxisome proliferator-activated receptor gamma (PPARgamma) expression in 3T3-L1 preadipocytes is induced by MIX and DEX, suggesting that C/EBPbeta and C/EBPdelta may be involved in this process. Using a tetracycline-responsive expression system, we have recently shown that the conditional ectopic expression of C/EBPbeta in NIH 3T3 fibroblasts (beta2 cells) in the presence of DEX activates the synthesis of peroxisome PPARgamma mRNA. Subsequent exposure of these cells to PPAR activators stimulates their conversion into adipocytes; however, neither the expression of C/EBPbeta nor exposure to DEX alone is capable of inducing PPARgamma expression in the beta2 cell line. We find that unlike the case for 3T3 preadipocytes, C/EBPdelta is not induced by DEX in these 3T3 fibroblasts and therefore is not relaying the effect of this glucocorticoid to the PPARgamma gene. To define the role of glucocorticoids in regulating PPARgamma expression and the possible involvement of C/EBPdelta, we have established an additional set of NIH 3T3 cell lines expressing either C/EBPdelta alone (delta23 cells) or C/EBPdelta and C/EBPbeta together (beta/delta39 cells), using the tetracycline-responsive system. Culture of these cells in tetracycline-deficient medium containing DEX, MIX, insulin, and fetal bovine serum shows that the beta/delta39 cells express PPARgamma and aP2 mRNAs at levels that are almost equivalent to those observed in fully differentiated 3T3-L1 adipocytes. These levels are approximately threefold higher than their levels of expression in the beta2 cells. Despite the fact that these beta/delta39 cells produce abundant amounts of C/EBPbeta and C/EBPdelta (in the absence of tetracycline), they still require glucocorticoids to attain maximum expression of PPARgamma mRNA. Furthermore, the induction of PPARgamma mRNA by exposure of these cells to DEX occurs in the absence of ongoing protein synthesis. The delta23 cells, on the other hand, are not capable of activating PPARgamma gene expression when exposed to the same adipogenic inducers. Finally, attenuation of ectopic C/EBPbeta production at various stages during the differentiation process results in a concomitant inhibition of PPARgamma and the adipogenic program. These data strongly suggest that the induction of PPARgamma gene expression in multipotential mesenchymal stem cells (NIH 3T3 fibroblasts) is dependent on elevated levels of C/EBPbeta throughout the differentiation process, as well as an initial exposure to glucocorticoids. C/EBPdelta may function by synergizing with C/EBPbeta to enhance the level of PPARgamma expression.

Abstract 14298: The Normal Balance Between Antifibrotic Bmp-7 and Profibrotic Tgf-β Signaling is Lost on the Pressure Overload-induced LV Remodeling and Can Be Modified Favorably. A Translational Study

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Francisco Nistal ◽  
David Merino ◽  
Ana V Villar ◽  
Raquel Garcia-Lopez ◽  
Mónica Tramullas ◽  
...  
Keyword(s):  
Transcriptional Activation ◽  
Structural Damage ◽  
Transforming Growth Factor ◽  
Linear Regression Analysis ◽  
Pressure Overload ◽  
Luciferase Reporter ◽  
Reverse Remodeling ◽  
3T3 Fibroblasts ◽  
Lv Remodeling ◽  
Nih 3T3

Introduction: Cytokynes of the Transforming Growth Factor-β(TGF-β) superfamily are involved in tissue fibrosis: TGF-β promotes fibrosis, whereas Bone Morphogenetic Protein-7 (BMP-7) is antifibrotic. Hypothesis: (i) LV remodeling in the pressure overload condition associates disequilibrium in the cellular signals mediated by these cytokynes; and (ii) BMP-7 exerts beneficial effects on LV remodeling and on reverse remodeling. Methods: We studied patients with aortic stenosis (AS; n=45) and surgical controls (n=30), and mice subjected to transverse aortic constriction (TAC; n=24). LV morphology and function were assessed by echocardiography; LV samples were analyzed by qPCR, immunoblotting and histology. Results: Pressure overload diminished the expression of BMP-7 and its effectors pSmad1/5/8 and increased the ratio TGF-β/BMP-7 in the LV from AS-patients and TAC-mice. BMP-7 expression correlated inversely with collagens, fibronectin and β-myosin heavy chain, with the degree of hypertrophy, and with the severity of diastolic dysfunction, and directly with systolic function. Multiple linear regression analysis disclosed BMP-7 and TGF-β as predictors, negative and positive, respectively, of hypertrophy. BMP-7 prevented the hypertrophic program elicited by TGF-β in cultured cardiomyocytes, and the transcriptional activation of Col1A1 promoter-luciferase reporter in NIH-3T3 fibroblasts. In TAC-mice, BMP-7 gain-of-function attenuated the development of structural damage and dysfunction, halted ongoing remodeling and facilitated reverse remodeling. BMP-7 loss-of-function exerted opposite effects. Luciferase reporter assays in NIH-3T3 fibroblasts suggested that BMP-7 promoted the transcription of the inhibitory Smad7, who in turn has a repressing effect on TGFβ signaling. Accordingly, in AS-patients and TAC-mice, the LV expressions of Smad7 and BMP-7 correlated directly. Conclusion: The disequilibrium between BMP-7 and TGF-β signals plays a relevant role in the pressure overload-induced myocardial remodeling in TAC-mice and AS-patients. We suggest that BMP-7 antagonizes the hypertrophic and profibrogenic effects of TGF-β through a mechanism involving Smad7. Funding: PI12/00999; RD12/0042/0018; RD12/0042/0012.

scholarly journals Critical Role for Ebf1 and Ebf2 in the Adipogenic Transcriptional Cascade

2006 ◽  
Vol 27 (2) ◽  
pp. 743-757 ◽  
Author(s):  
Maria A. Jimenez ◽  
Peter Åkerblad ◽  
Mikael Sigvardsson ◽  
Evan D. Rosen
Keyword(s):  
Neuronal Development ◽  
B Lymphocyte ◽  
Critical Role ◽  
Peroxisome Proliferator ◽  
Hairpin Rna ◽  
Peroxisome Proliferator Activated Receptor ◽  
Cellular Models ◽  
Helix Loop Helix ◽  
3T3 Fibroblasts ◽  
Nih 3T3

ABSTRACT The Ebf (O/E) family of helix-loop-helix transcription factors plays a significant role in B lymphocyte and neuronal development. The three primary members of this family, Ebf1, 2, and 3, are all expressed in adipocytes, and Ebf1 promotes adipogenesis when overexpressed in NIH 3T3 fibroblasts. Here we report that these three proteins have adipogenic potential in multiple cellular models and that peroxisome proliferator-activated receptor γ (PPARγ) is required for this effect, at least in part due to direct activation of the PPARγ1 promoter by Ebf1. Ebf1 also directly binds to and activates the C/EBPα promoter, which exerts positive feedback on C/EBPδ expression. Despite this, C/EBPα is dispensable for the adipogenic action of Ebf proteins. Ebf1 itself is induced by C/EBPβ and δ, which bind and activate its promoter. Reduction of Ebf1 and Ebf2 proteins by specific short hairpin RNA blocks differentiation of 3T3-L1 cells, suggesting a critical role for these factors and the absence of functional redundancy between members of this family. Altogether, these data place Ebf1 within the known transcriptional cascade of adipogenesis and suggest critical roles for Ebf1 and Ebf2.

scholarly journals Transforming growth factor (TGF)-β1-induced miR-133a inhibits myofibroblast differentiation and pulmonary fibrosis

2019 ◽  
Vol 10 (9) ◽  
Author(s):  
Peng Wei ◽  
Yan Xie ◽  
Peter W. Abel ◽  
Yapei Huang ◽  
Qin Ma ◽  
...  
Keyword(s):  
Growth Factor ◽  
Pulmonary Fibrosis ◽  
Transforming Growth Factor ◽  
Tissue Growth ◽  
Negative Regulator ◽  
Lung Fibroblasts ◽  
Luciferase Reporter ◽  
Myofibroblast Differentiation ◽  
Dependent Manner ◽  
Tgf Β1

Abstract Transforming growth factor (TGF)-β1, a main profibrogenic cytokine in the progression of idiopathic pulmonary fibrosis (IPF), induces differentiation of pulmonary fibroblasts to myofibroblasts that produce high levels of collagen, leading to concomitantly loss of lung elasticity and function. Recent studies implicate the importance of microRNAs (miRNAs) in IPF but their regulation and individual pathological roles remain largely unknown. We used both RNA sequencing and quantitative RT-PCR strategies to systematically study TGF-β1-induced alternations of miRNAs in human lung fibroblasts (HFL). Our data show that miR-133a was significantly upregulated by TGF-β1 in a time- and concentration-dependent manner. Surprisingly, miR-133a inhibits TGF-β1-induced myofibroblast differentiation whereas miR-133a inhibitor enhances TGF-β1-induced myofibroblast differentiation. Interestingly, quantitative proteomics analysis indicates that miR-133a attenuates myofibroblast differentiation via targeting multiple components of TGF-β1 profibrogenic pathways. Western blot analysis confirmed that miR-133a down-regulates TGF-β1-induced expression of classic myofibroblast differentiation markers such as ɑ-smooth muscle actin (ɑ-SMA), connective tissue growth factor (CTGF) and collagens. miRNA Target Searcher analysis and luciferase reporter assays indicate that TGF-β receptor 1, CTGF and collagen type 1-alpha1 (Col1a1) are direct targets of miR-133a. More importantly, miR-133a gene transferred into lung tissues ameliorated bleomycin-induced pulmonary fibrosis in mice. Together, our study identified TGF-β1-induced miR-133a as an anti-fibrotic factor. It functions as a feed-back negative regulator of TGF-β1 profibrogenic pathways. Thus, manipulations of miR-133a expression may provide a new therapeutic strategy to halt and perhaps even partially reverse the progression of IPF.

scholarly journals Human lung fibroblasts produce proresolving peroxisome proliferator-activated receptor-γ ligands in a cyclooxygenase-2-dependent manner

2016 ◽  
Vol 311 (5) ◽  
pp. L855-L867 ◽  
Author(s):  
Shannon H. Lacy ◽  
Collynn F. Woeller ◽  
Thomas H. Thatcher ◽  
Krishna Rao Maddipati ◽  
Kenneth V. Honn ◽  
...  
Keyword(s):  
Human Lung ◽  
Cyclooxygenase 2 ◽  
Lung Fibroblasts ◽  
Luciferase Reporter ◽  
Chronic Obstructive ◽  
Peroxisome Proliferator ◽  
Dependent Manner ◽  
Peroxisome Proliferator Activated Receptor ◽  
Human Lung Fibroblasts ◽  
Cox 2

Human lung fibroblasts (HLFs) act as innate immune sentinel cells that amplify the inflammatory response to injurious stimuli. Here, we use targeted lipidomics to explore the hypothesis that HLFs also play an active role in the resolution of inflammation. We detected cyclooxygenase-2 (COX-2)-dependent production of both proinflammatory and proresolving prostaglandins (PGs) in conditioned culture medium from HLFs treated with a proinflammatory stimulus, IL-1β. Among the proresolving PGs in the HLF lipidome were several known ligands for peroxisome proliferator-activated receptor-γ (PPARγ), a transcription factor whose activation in the lung yields potent anti-inflammatory, antifibrotic, and proresolving effects. Next, we used a cell-based luciferase reporter to confirm the ability of HLF supernatants to activate PPARγ, demonstrating, for the first time, that primary HLFs activated with proinflammatory IL-1β or cigarette smoke extract produce functional PPARγ ligands; this phenomenon is temporally regulated, COX-2- and lipocalin-type PGD synthase-dependent, and enhanced by arachidonic acid supplementation. Finally, we used luciferase reporter assays to show that several of the PGs in the lipidome of activated HLFs independently activate PPARγ and/or inhibit NFκB. These results indicate that HLFs, as immune sentinels, regulate both proinflammatory and proresolving responses to injurious stimuli. This novel endogenous resolution pathway represents a new therapeutic target for globally important inflammatory diseases such as chronic obstructive pulmonary disease.

Ca2+/calmodulin-based signalling in the regulation of the muscle fibre phenotype and its therapeutic potential via modulation of utrophin A and myostatin expression

2007 ◽  
Vol 32 (5) ◽  
pp. 921-929 ◽  
Author(s):  
Robin N. Michel ◽  
Eva R. Chin ◽  
Joe V. Chakkalakal ◽  
Joe K. Eibl ◽  
Bernard J. Jasmin
Keyword(s):  
Protein Kinase ◽  
Transforming Growth Factor ◽  
Therapeutic Potential ◽  
Negative Regulator ◽  
Mitogen Activated Protein Kinase ◽  
Peroxisome Proliferator ◽  
Force Output ◽  
Activated T Cells ◽  
Peroxisome Proliferator Activated Receptor ◽  
Hypertrophic Growth

Ca2+ signalling plays an important role in excitation–contraction coupling and the resultant force output of skeletal muscle. It is also known to play a crucial role in modulating both short- and long-term muscle cellular phenotypic adaptations associated with these events. Ca2+ signalling via the Ca2+/calmodulin (CaM)-dependent phosphatase calcineurin (CnA) and via Ca2+/CaM-dependent kinases, such as CaMKI and CaMKII, is known to regulate hypertrophic growth in response to overload, to direct slow versus fast fibre gene expression, and to contribute to mitochondrial biogenesis. The CnA- and CaMK-dependent regulation of the downstream transcription factors nuclear factor of activated T cells (NFAT) and myocyte-specific enhancer factor 2 are known to activate muscle-specific genes associated with a slower, more oxidative fibre phenotype. We have also recently shown the expression of utrophin A, a cytoskeletal protein that accumulates at the neuromuscular junction and plays a role in maturation of the postsynaptic apparatus, to be regulated by CnA–NFAT and Ca2+/CaM signalling. This regulation is fibre-type specific and potentiated by interactions with the transcriptional regulators and coactivators GA binding protein (also known as nuclear respiratory factor 2) and peroxisome proliferator-activated receptor-gamma coactivator 1 alpha. Another downstream target of CnA signalling may be myostatin, a transforming growth factor-β family member that is a negative regulator of muscle growth. While the list of the downstream targets of CnA/NFAT- and Ca2+/CaM-dependent signalling is emerging, the precise interaction of these pathways with the Ca2+-independent pathways p38 mitogen-activated protein kinase, extracellular signal-regulated kinases 1 and 2, phosphoinositide-3 kinase, and protein kinase B (Akt/PKB) must also be considered when deciphering fibre responses and plasticity to altered contractile load.

scholarly journals The Nutraceutical N-Palmitoylethanolamide (PEA) Reveals Widespread Molecular Effects Unmasking New Therapeutic Targets in Murine Varicocele

Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 734
Author(s):  
Pietro Antonuccio ◽  
Herbert Ryan Marini ◽  
Antonio Micali ◽  
Carmelo Romeo ◽  
Roberta Granese ◽  
...  
Keyword(s):  
Transforming Growth Factor ◽  
Therapeutic Targets ◽  
Sham Operation ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Pyrin Domain ◽  
Age Related ◽  
Extracellular Signal ◽  
Morphometric Assessment

Varicocele is an age-related disease with no current medical treatments positively impacting infertility. Toll-like receptor 4 (TLR4) expression is present in normal testis with an involvement in the immunological reactions. The role of peroxisome proliferator-activated receptor-α (PPAR-α), a nuclear receptor, in fertility is still unclear. N-Palmitoylethanolamide (PEA), an emerging nutraceutical compound present in plants and animal foods, is an endogenous PPAR-α agonist with well-demonstrated anti-inflammatory and analgesics characteristics. In this model of mice varicocele, PPAR-α and TLR4 receptors’ roles were investigated through the administration of ultra-micronized PEA (PEA-um). Male wild-type (WT), PPAR-α knockout (KO), and TLR4 KO mice were used. A group underwent sham operation and administration of vehicle or PEA-um (10 mg/kg i.p.) for 21 days. Another group (WT, PPAR-α KO, and TLR4 KO) underwent surgical varicocele and was treated with vehicle or PEA-um (10 mg/kg i.p.) for 21 days. At the end of treatments, all animals were euthanized. Both operated and contralateral testes were processed for histological and morphometric assessment, for PPAR-α, TLR4, occludin, and claudin-11 immunohistochemistry and for PPAR-α, TLR4, transforming growth factor-beta3 (TGF-β3), phospho-extracellular signal-Regulated-Kinase (p-ERK) 1/2, and nucleotide-binding oligomerization domain-like receptor (NLR) family pyrin domain-containing 3 (NLRP3) Western blot analysis. Collectively, our data showed that administration of PEA-um revealed a key role of PPAR-α and TLR4 in varicocele pathophysiology, unmasking new nutraceutical therapeutic targets for future varicocele research and supporting surgical management of male infertility.

The peroxisome proliferator-activated receptor-γ is a negative regulator of macrophage activation

Nature ◽  
10.1038/34178 ◽  
1998 ◽  
Vol 391 (6662) ◽  
pp. 79-82 ◽  
Author(s):  
Mercedes Ricote ◽  
Andrew C. Li ◽  
Timothy M. Willson ◽  
Carolyn J. Kelly ◽  
Christopher K. Glass
Keyword(s):  
Macrophage Activation ◽  
Negative Regulator ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor
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