Abstract 12519: Regulation of Cardiac Fibroblast Phenotype by Scleraxis

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Rushita Bagchi ◽  
Patricia Roche ◽  
Ronen Schweitzer ◽  
Michael P Czubryt
Keyword(s):  
Extracellular Matrix ◽  
Cardiac Fibroblasts ◽  
Gene Promoter ◽  
Cardiac Fibroblast ◽  
Fiber Formation ◽  
Luciferase Reporter ◽  
Collagen Gels ◽  
Contractile Phenotype ◽  
Extracellular Matrix Components ◽  
E Boxes

Cardiac fibroblasts constitute the primary extracellular matrix synthesis machinery in the myocardium. Activation of fibroblasts into a hyper-synthetic and contractile phenotype potentiates fibrosis, impairs cardiac function and contributes to heart failure. Our laboratory previously reported that the transcription factor scleraxis regulates human cardiac collagen Iα2 expression and has shown its up-regulation in the post-infarct scar. Here we demonstrate a novel regulatory role for scleraxis in governing cardiac fibroblast function and phenoconversion. Cell contractility assays using collagen gels demonstrated the abrogation of pro-fibrotic TGF-β-mediated contractility of myofibroblasts in response to scleraxis knockdown. The de novo expression of α-smooth muscle actin (αSMA) and its incorporation into stress fibers is a key feature of myofibroblasts - key causative cells of fibrosis. Scleraxis over-expression in isolated primary cardiac fibroblasts induced αSMA gene expression and stress fiber formation, and rescued the αSMA loss observed in cardiac fibroblasts from scleraxis null mice. Luciferase reporter assays demonstrated a significant transactivation of the αSMA gene promoter by scleraxis. Mutation analysis revealed that scleraxis interacts with two E-boxes within the αSMA promoter, a finding confirmed by chromatin immunoprecipitation of scleraxis in primary cardiac fibroblasts. An increase in scleraxis binding to the αSMA promoter was observed in cardiac myofibroblasts compared to fibroblasts, and also in response to TGF-β, further supporting a direct role of scleraxis in regulation of myofibroblast αSMA expression and its contractile phenotype. Gel shift assays also confirmed the direct interaction of scleraxis with E-boxes within the αSMA gene promoter. Our data indicates that scleraxis plays a required role in cardiac fibroblast phenotype and contractile function. Taken in context with our finding that scleraxis regulates expression of multiple extracellular matrix components, including fibrillar collagens, our data reveals that scleraxis exerts broad and potent pro-fibrotic effects on cardiac fibroblast form and function, and may thus represent a novel target for fibrosis therapy.

Abstract 372: The Smad3 Pathway Critically Regulates Myofibroblast Proliferation And Synthetic Activity In Healing Myocardial Infarcts

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Marcin Dobaczewski ◽  
Marcin Bujak ◽  
Carlos Gonzalez ◽  
Na Li ◽  
Xiao-Fan Wang ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Extracellular Matrix ◽  
Proliferative Activity ◽  
Essential Role ◽  
Cardiac Fibroblasts ◽  
Cardiac Fibroblast ◽  
Synthetic Activity ◽  
Dependent Manner ◽  
Tenascin C ◽  
Infarcted Heart

We have recently demonstrated that the Transforming Growth Factor (TGF)-β/Smad3 pathway is activated in healing infarcts and plays an essential role in the pathogenesis of cardiac remodeling. Smad3 −/− mice were protected from the development of ventricular dilation following infarction and exhibited markedly reduced fibrosis of the peri-infarct area and the remodeling non-infarcted heart. Accordingly, we hypothesized that Smad3 signaling plays an essential role in regulating cardiac fibroblast function and gene expression in myocardial infarction. Surprisingly, Smad3 −/− infarcts exhibited increased peak infiltration with myofibroblasts, associated with evidence of enhanced proliferative activity. Smad3 −/− mice had a higher density of Ki-67-positive proliferating myofibroblasts in the infarcted myocardium in comparison with wildtype (WT) animals (Smad3−/− 917±291 cells/mm 2 vs. WT 614±115 cells/mm 2 , p<0.05). In vitro experiments suggested that TGF-β inhibits murine cardiac fibroblast proliferation in a concentration-dependent manner and that the antiproliferative effects of TGF-β are abrogated in Smad3 −/− fibroblasts. On the other hand Smad3 signaling was essential for extracellular matrix protein synthesis by cardiac fibroblasts. TGF-β-mediated induction of procollagen type III and of the matricellular protein tenascin-C in cardiac fibroblasts was dependent on Smad3. In addition, TGF-β-induced Tissue Inhibitor of Metalloproteinases (TIMP)-1 and -2 upregulation was also abrogated in Smad3 −/− fibroblasts, suggesting that Smad3 signaling regulates matrix metabolism. In vivo, Smad3 −/− infarcts exhibited attenuated tenascin-C and collagen deposition in the infarct and in the remodeling non-infarcted heart. Our findings suggest that the Smad3 pathway critically regulates fibroblast function in healing myocardial infarction. In Smad3 −/− mice, the healing infarct contains abundant myofibroblasts that exhibit enhanced proliferative activity, but have markedly decreased ability to synthesize extracellular matrix proteins and to produce TIMPs. In the absence of Smad3, attenuated matrix deposition in the remodeling non-infarcted heart results in decreased dilation and ameliorated diastolic dysfunction. This research has received full or partial funding support from the American Heart Association, AHA South Central Affiliate (Arkansas, New Mexico, Oklahoma & Texas).

scholarly journals Glioblastoma invasion factor ODZ1 is induced by microenvironmental signals through activation of a Stat3-dependent transcriptional pathway

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Veronica Vidal ◽  
Olga Gutierrez ◽  
Ana Talamillo ◽  
Carlos Velasquez ◽  
Jose L. Fernandez-Luna
Keyword(s):  
Extracellular Matrix ◽  
Matrix Protein ◽  
Transmembrane Protein ◽  
Gene Promoter ◽  
Dominant Negative ◽  
Surrounding Tissue ◽  
Extracellular Matrix Protein ◽  
Luciferase Reporter ◽  
Dominant Negative Variant ◽  
Transcriptional Pathway

AbstractWe have previously shown that the transmembrane protein ODZ1 serves for glioblastoma (GBM) cells to invade the surrounding tissue through activation of RhoA/ROCK pathway. However, the transcriptional machinery used by GBM cells to regulate the expression of ODZ1 is unknown. Here we show that interaction with tumor microenvironment elements, mainly activated monocytes through IL-6 secretion, and the extracellular matrix protein fibronectin, induces the Stat3 transcriptional pathway and upregulates ODZ1 which results in GBM cell migration. This signaling route is abrogated by blocking the IL-6 receptor, inhibiting Jak kinases or knocking down Stat3. Furthermore, we have identified a Stat3 responsive element in the ODZ1 gene promoter, about 1 kb from the transcription start site. Luciferase-reporter assays confirmed that the promoter responds to the presence of monocytic cells and this activation is greatly reduced when the Stat3 site is mutated or following treatment with a neutralizing anti-IL-6 receptor antibody or transfecting GBM cells with a dominant negative variant of Stat3. Overall, we show that monocyte-secreted IL-6 and the extracellular matrix protein fibronectin activate the axis Stat3-ODZ1 and promote migration of GBM cells. This is the first described transcriptional mechanism used by tumor cells to promote the expression of the invasion factor ODZ1.

Cardiac Fibroblast Diversity

2020 ◽  
Vol 82 (1) ◽  
pp. 63-78 ◽  
Author(s):  
Michelle D. Tallquist
Keyword(s):  
Extracellular Matrix ◽  
Single Cell ◽  
Future Development ◽  
Cardiac Fibrosis ◽  
Cardiac Fibroblasts ◽  
Pathological Condition ◽  
Cardiac Fibroblast ◽  
Lineage Tracing ◽  
Single Cell Sequencing ◽  
Disease States

Cardiac fibrosis is a pathological condition that occurs after injury and during aging. Currently, there are limited means to effectively reduce or reverse fibrosis. Key to identifying methods for curbing excess deposition of extracellular matrix is a better understanding of the cardiac fibroblast, the cell responsible for collagen production. In recent years, the diversity and functions of these enigmatic cells have been gradually revealed. In this review, I outline current approaches for identifying and classifying cardiac fibroblasts. An emphasis is placed on new insights into the heterogeneity of these cells as determined by lineage tracing and single-cell sequencing in development, adult, and disease states. These recent advances in our understanding of the fibroblast provide a platform for future development of novel therapeutics to combat cardiac fibrosis.

scholarly journals Expression of extracellular matrix components is regulated by substratum.

1990 ◽  
Vol 110 (4) ◽  
pp. 1405-1415 ◽  
Author(s):  
C H Streuli ◽  
M J Bissell
Keyword(s):  
Extracellular Matrix ◽  
Epithelial Cells ◽  
Basement Membrane ◽  
Type I Collagen ◽  
Basement Membranes ◽  
Type I ◽  
Collagen Gels ◽  
Extracellular Matrix Components ◽  
Matrix Components ◽  
Cells Cultured

Reconstituted basement membranes and extracellular matrices have been demonstrated to affect, positively and dramatically, the production of milk proteins in cultured mammary epithelial cells. Here we show that both the expression and the deposition of extracellular matrix components themselves are regulated by substratum. The steady-state levels of the laminin, type IV collagen, and fibronectin mRNAs in mammary epithelial cells cultured on plastic dishes and on type I collagen gels have been examined, as has the ability of these cells to synthesize, secrete, and deposit laminin and other, extracellular matrix proteins. We demonstrate de novo synthesis of a basement membrane by cells cultured on type I collagen gels which have been floated into the medium. Expression of the mRNA and proteins of basement membranes, however, are quite low in these cultures. In contrast, the levels of laminin, type IV collagen, and fibronectin mRNAs are highest in cells cultured on plastic surfaces, where no basement membrane is deposited. It is suggested that the interaction between epithelial cells and both basement membrane and stromally derived matrices exerts a negative influence on the expression of mRNA for extracellular matrix components. In addition, we show that the capacity for lactational differentiation correlates with conditions that favor the deposition of a continuous basement membrane, and argue that the interaction between specialized epithelial cells and stroma enables them to create their own microenvironment for accurate signal transduction and phenotypic function.

scholarly journals Normal versus Pathological Cardiac Fibroblast-Derived Extracellular Matrix Differentially Modulates Cardiosphere-Derived Cell Paracrine Properties and Commitment

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Francesca Pagano ◽  
Francesco Angelini ◽  
Clotilde Castaldo ◽  
Vittorio Picchio ◽  
Elisa Messina ◽  
...  
Keyword(s):  
Gene Expression ◽  
Extracellular Matrix ◽  
Immunofluorescence Microscopy ◽  
Cardiac Fibroblasts ◽  
Cardiac Fibroblast ◽  
Cardiac Cells ◽  
Cardiac Progenitor Cells ◽  
Therapeutic Success ◽  
Differentiation Potential ◽  
Heart Failure Progression

Human resident cardiac progenitor cells (CPCs) isolated as cardiosphere-derived cells (CDCs) are under clinical evaluation as a therapeutic product for cardiac regenerative medicine. Unfortunately, limited engraftment and differentiation potential of transplanted cells significantly hamper therapeutic success. Moreover, maladaptive remodelling of the extracellular matrix (ECM) during heart failure progression provides impaired biological and mechanical signals to cardiac cells, including CPCs. In this study, we aimed at investigating the differential effect on the phenotype of human CDCs of cardiac fibroblast-derived ECM substrates from healthy or diseased hearts, named, respectively, normal or pathological cardiogel (CG-N/P). After 7 days of culture, results show increased levels of cardiogenic gene expression (NKX2.5, CX43) on both decellularized cardiogels compared to control, while the proportion and staining patterns of GATA4, OCT4, NKX2.5, ACTA1, VIM, and CD90-positive CPCs were not affected, as assessed by immunofluorescence microscopy and flow cytometry analyses. Nonetheless, CDCs cultured on CG-N secreted significantly higher levels of osteopontin, FGF6, FGF7, NT-3, IGFBP4, and TIMP-2 compared to those cultured on CG-P, suggesting overall a reduced trophic and antiremodelling paracrine profile of CDCs when in contact with ECM from pathological cardiac fibroblasts. These results provide novel insights into the bidirectional interplay between cardiac ECM and CPCs, potentially affecting CPC biology and regenerative potential.

scholarly journals Cardiac Fibroblasts and the Extracellular Matrix in Regenerative and Nonregenerative Hearts

2019 ◽  
Vol 6 (3) ◽  
pp. 29 ◽  
Author(s):  
Luis Hortells ◽  
Anne Katrine Z. Johansen ◽  
Katherine E. Yutzey
Keyword(s):  
Extracellular Matrix ◽  
Collagen Fiber ◽  
Cellular Proliferation ◽  
Cardiac Fibroblasts ◽  
Postnatal Period ◽  
Cardiac Fibroblast ◽  
Scar Formation ◽  
Cardiac Cells ◽  
Fiber Organization

During the postnatal period in mammals, the heart undergoes significant remodeling and cardiac cells progressively lose their embryonic characteristics. At the same time, notable changes in the extracellular matrix (ECM) composition occur with a reduction in the components considered facilitators of cellular proliferation, including fibronectin and periostin, and an increase in collagen fiber organization. Not much is known about the postnatal cardiac fibroblast which is responsible for producing the majority of the ECM, but during the days after birth, mammalian hearts can regenerate after injury with only a transient scar formation. This phenomenon has also been described in adult urodeles and teleosts, but relatively little is known about their cardiac fibroblasts or ECM composition. Here, we review the pre-existing knowledge about cardiac fibroblasts and the ECM during the postnatal period in mammals as well as in regenerative environments.

scholarly journals Identification of Human CD4+ Sub-population of Resident Cardiac Fibroblasts Linked to Inflammation-Mediated Cardiac Fibrosis

2021 ◽  
Author(s):  
Jamila H Siamwala ◽  
Francesco Pagano ◽  
Patrycja M Dubielecka ◽  
Alexander Zhao ◽  
Sonja Chen ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
T Cell ◽  
Right Ventricle ◽  
Cardiac Fibrosis ◽  
Cardiac Fibroblasts ◽  
Interleukin 1 ◽  
Cardiac Fibroblast ◽  
Mass Cytometry ◽  
Phenotype Switching ◽  
Cardiac Myofibroblasts

Background: Infiltration with inflammatory CD4+ T-cells and the accumulation of heterogeneous cardiac myofibroblasts are hallmarks of cardiac fibrosis and remodeling. The origin, identity, states, and functions of the resident cells involved in the transition from adaptive to maladaptive fibrotic remodeling, as well as the pathways of inflammatory regulation are unclear. Methods: We performed mass cytometry profiling of resident human ventricular cardiac fibroblasts (hVCF) and determined the identity of cells contained in fibrotic right ventricle autopsy tissues from individuals diagnosed with pulmonary hypertension and tissue from SUGEN/hypoxia rats exhibiting cardiac fibrosis. We further characterized the resident cardiac fibroblast sub-population morphologically, structurally and functionally using transcriptome and secretome analysis of the secreted cytokines, chemokines, proteins, metabolites using milliplex panels, proteomics and metabolomics pipelines. Results: Single-cell mass cytometry identified remarkable plasticity of resident human cardiac fibroblasts. We provide evidence of a sub-population of resident cardiac myofibroblasts expressing high levels of CD4+, a helper T-cell surface marker in addition to mesenchymal markers, αSMA and Vimentin in all the human donors. These cardiac cells co-expressing lymphoid CD4+and αSMA+ were localized to the fibrotic regions of the human right ventricular tissue and were a common feature in the interstitial and perivascular lesions of SUGEN/Hypoxia (SuHx) rats. CD3+CD4+ T-cell numbers were higher in the right ventricle compared with the left ventricle of SuHx, as determined by flow cytometry. In vitro, T-cell homing receptors CD44, Interleukin-1 receptor (IL-1R), and CCR2 were upregulated in cardiac fibroblasts in response to IL-1β. Exposure of cardiac fibroblasts to IL-1β led to upregulation of genes regulating extracellular matrix, collagen deposition and inflammation-related genes, and induced secretion of cytokines, chemokines, and metabolites involved in innate and adaptive humoral immune responses. Cell clustering, elevated phosphorylation of MAPK p38 and inflammatory NF-κB p65 and cell phenotype switching upon IL-1β stimulation reverted with the administration of an IL-1R antagonist. Conclusions: Our data expand concepts of heterogeneity of resident cardiac fibroblasts and plasticity in response to pro-inflammatory cytokines by the demonstration of a unique subpopulation of cardiac fibroblasts exhibiting attributes of both mesenchymal and lymphoid cells. Exposure of cardiac fibroblasts to the pro-inflammatory cytokine, IL-1β, induces a robust phenotypic response linked to extracellular matrix deposition and up-regulates an immune-associated phenotype linked to expression of immune markers and secretion of immunomodulatory cytokines and chemokines. We also propose that resident cardiac fibroblast transdifferentiation and phenotype switching maybe the key process involved in adaptive to maladaptive remodeling leading to fibrosis and failure. Non-standard abbreviations: CD4; Cluster of differentiation, αSMA; alpha smooth muscle actin, IL-1R; Interleukin-1-receptor, CCR2; C-X-C Motif Chemokine Receptor 2

scholarly journals Response of basal epithelial cell surface and Cytoskeleton to solubilized extracellular matrix molecules.

1981 ◽  
Vol 91 (1) ◽  
pp. 45-54 ◽  
Author(s):  
S P Sugrue ◽  
E D Hay
Keyword(s):  
Extracellular Matrix ◽  
Cell Surface ◽  
Basal Cell ◽  
Actin Filaments ◽  
Cell Cortex ◽  
Collagen Gels ◽  
Basal Surface ◽  
Extracellular Matrix Components ◽  
Cytoplasmic Processes

Corneal epithelium removed from underlying extracellular matrix (ECM) extends numerous cytoplasmic processes (blebs) from the formerly smooth basal surface. If blebbing epithelia are grown on collagen gels or lens capsules in vitro, the basal surface flattens and takes on the smooth contour typical of epithelium in contact with basal lamina in situ. This study examines the effect of soluble extracellular matrix components on the basal surface. Corneal epithelia from 9- to 11-d-old chick embryos were isolated with trypsin-collagenase or ethylenediamine tetraacetic acid, then placed on Millipore filters (Millipore Corp., Bedford, Mass.), and cultured at the medium-air interface. Media were prepared with no serum, with 10% of calf serum, or with serum from which plasma fibronectin was removed. Epithelia grown on filters in this medium continue to bleb for the duration of the experiments (12-14 h). If soluble collagen, laminin, or fibronectin is added to the medium, however, blebs are withdrawn and by 2-6 h the basal surface is flat. Epithelia grown on filters in the presence of albumin, IgG, or glycosaminoglycans continue to bleb. Epithelia cultured on solid substrata, such as glass, also continue to bleb if ECM is absent from the medium. The basal cell cortex in situ contains a compact cortical mat of filaments that decorate with S-1 myosin subfragments; some, if not all, of these filaments point away from the plasmalemma. The actin filaments disperse into the cytoplasmic processes during blebbing and now many appear to point toward the plasmalemma. In isolated epithelia that flatten in response to soluble collagens, laminin, and fibronectin, the actin filaments reform the basal cortical mat typical or epithelial in situ. Thus, extracellular macromolecules influence and organize not only the basal cell surface but also the actin-rich basal cell cortex of epithelial cells.

scholarly journals Cardiac Fibroblast to Myofibroblast Phenotype Conversion—An Unexploited Therapeutic Target

2019 ◽  
Vol 6 (3) ◽  
pp. 28 ◽  
Author(s):  
Czubryt
Keyword(s):  
Extracellular Matrix ◽  
Cardiac Fibrosis ◽  
Therapeutic Potential ◽  
Contractile Activity ◽  
Cardiac Fibroblasts ◽  
Critical Event ◽  
Organ Function ◽  
Myofibroblast Phenotype ◽  
Extracellular Matrix Components ◽  
Contraction And Relaxation

Fibrosis occurs when the synthesis of extracellular matrix outpaces its degradation, and over time can negatively impact tissue and organ function. In the case of cardiac fibrosis, contraction and relaxation of the heart can be impaired to the point of precipitating heart failure, while at the same time fibrosis can result in arrhythmias due to altered electrical properties of the myocardium. The critical event in the evolution of cardiac fibrosis is the phenotype conversion of cardiac fibroblasts to their overly-active counterparts, myofibroblasts: cells demarked by their expression of novel markers such as periostin, by their gain of contractile activity, and by their pronounced and prolonged increase in the production of extracellular matrix components such as collagens. The phenotype change is dramatic, and can be triggered by many stimuli, including mechanical force, inflammatory cytokines, and growth factors. This review will explore fibroblast to myofibroblast transition mechanisms and will consider the therapeutic potential of targeting this process as a means to arrest or even reverse cardiac fibrosis.

Sign in / Sign up

Export Citation Format

Share Document