scholarly journals Activated Cardiac Fibroblasts Control Contraction of Human Fibrotic Cardiac Microtissues by a β-Adrenoreceptor-Dependent Mechanism

Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1270 ◽  
Author(s):  
Przemysław Błyszczuk ◽  
Christian Zuppinger ◽  
Ana Costa ◽  
Daria Nurzynska ◽  
Franca Di Meglio ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Cardiac Fibrosis ◽  
Transforming Growth Factor ◽  
Cardiac Fibroblasts ◽  
Experimental Models ◽  
Cardiac Contraction ◽  
Dependent Manner ◽  
Direct Stimulation ◽  
Beating Rate ◽  
Tgf Β1

Cardiac fibrosis represents a serious clinical problem. Development of novel treatment strategies is currently restricted by the lack of the relevant experimental models in a human genetic context. In this study, we fabricated self-aggregating, scaffold-free, 3D cardiac microtissues using human inducible pluripotent stem cell (iPSC)-derived cardiomyocytes and human cardiac fibroblasts. Fibrotic condition was obtained by treatment of cardiac microtissues with profibrotic cytokine transforming growth factor β1 (TGF-β1), preactivation of foetal cardiac fibroblasts with TGF-β1, or by the use of cardiac fibroblasts obtained from heart failure patients. In our model, TGF-β1 effectively induced profibrotic changes in cardiac fibroblasts and in cardiac microtissues. Fibrotic phenotype of cardiac microtissues was inhibited by treatment with TGF-β-receptor type 1 inhibitor SD208 in a dose-dependent manner. We observed that fibrotic cardiac microtissues substantially increased the spontaneous beating rate by shortening the relaxation phase and showed a lower contraction amplitude. Instead, no changes in action potential profile were detected. Furthermore, we demonstrated that contraction of human cardiac microtissues could be modulated by direct electrical stimulation or treatment with the β-adrenergic receptor agonist isoproterenol. However, in the absence of exogenous agonists, the β-adrenoreceptor blocker nadolol decreased beating rate of fibrotic cardiac microtissues by prolonging relaxation time. Thus, our data suggest that in fibrosis, activated cardiac fibroblasts could promote cardiac contraction rate by a direct stimulation of β-adrenoreceptor signalling. In conclusion, a model of fibrotic cardiac microtissues can be used as a high-throughput model for drug testing and to study cellular and molecular mechanisms of cardiac fibrosis.

scholarly journals The AP-1 Transcription Factor Fosl-2 Regulates Autophagy in Cardiac Fibroblasts during Myocardial Fibrogenesis

2021 ◽  
Vol 22 (4) ◽  
pp. 1861
Author(s):  
Jemima Seidenberg ◽  
Mara Stellato ◽  
Amela Hukara ◽  
Burkhard Ludewig ◽  
Karin Klingel ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Molecular Mechanisms ◽  
Cardiac Fibrosis ◽  
Type I Collagen ◽  
Transforming Growth Factor ◽  
Cardiac Fibroblasts ◽  
Smooth Muscle Actin ◽  
Beclin 1 ◽  
Type I ◽  
Alpha Smooth Muscle Actin

Background: Pathological activation of cardiac fibroblasts is a key step in development and progression of cardiac fibrosis and heart failure. This process has been associated with enhanced autophagocytosis, but molecular mechanisms remain largely unknown. Methods and Results: Immunohistochemical analysis of endomyocardial biopsies showed increased activation of autophagy in fibrotic hearts of patients with inflammatory cardiomyopathy. In vitro experiments using mouse and human cardiac fibroblasts confirmed that blockade of autophagy with Bafilomycin A1 inhibited fibroblast-to-myofibroblast transition induced by transforming growth factor (TGF)-β. Next, we observed that cardiac fibroblasts obtained from mice overexpressing transcription factor Fos-related antigen 2 (Fosl-2tg) expressed elevated protein levels of autophagy markers: the lipid modified form of microtubule-associated protein 1A/1B-light chain 3B (LC3BII), Beclin-1 and autophagy related 5 (Atg5). In complementary experiments, silencing of Fosl-2 with antisense GapmeR oligonucleotides suppressed production of type I collagen, myofibroblast marker alpha smooth muscle actin and autophagy marker Beclin-1 in cardiac fibroblasts. On the other hand, silencing of either LC3B or Beclin-1 reduced Fosl-2 levels in TGF-β-activated, but not in unstimulated cells. Using a cardiac hypertrophy model induced by continuous infusion of angiotensin II with osmotic minipumps, we confirmed that mice lacking either Fosl-2 (Ccl19CreFosl2flox/flox) or Atg5 (Ccl19CreAtg5flox/flox) in stromal cells were protected from cardiac fibrosis. Conclusion: Our findings demonstrate that Fosl-2 regulates autophagocytosis and the TGF-β-Fosl-2-autophagy axis controls differentiation of cardiac fibroblasts. These data provide a new insight for the development of pharmaceutical targets in cardiac fibrosis.

Abstract 292: TRPA1 Promoting Myofibroblast Differentiation Mediate Pressure Overload-Induced Cardiac Fibrosis

Circulation ◽  
2018 ◽  
Vol 138 (Suppl_2) ◽  
Author(s):  
Shuang Li ◽  
Dong Han ◽  
Dachun Yang
Keyword(s):  
Knockout Mice ◽  
Molecular Mechanisms ◽  
Cardiac Fibrosis ◽  
Transient Receptor Potential ◽  
Transforming Growth Factor ◽  
Ventricular Remodeling ◽  
Cardiac Fibroblasts ◽  
Gene Transfection ◽  
Pressure Overload

Background: Hypertensive ventricular remodeling is a common cause of heart failure. Activation and accumulation of cardiac fibroblasts is the key contributors to this progression. Our previous studies indicate that transient receptor potential ankyrin 1 (TRPA1), a Ca 2+ channel necessary and sufficient, play a prominent role in ventricular remodeling. However, the molecular mechanisms regulating remain poorly understood. Methods: We used TRPA1 agonists cinnamaldehyde (CA) pretreatment and TRPA1 knockout mice to understand the role of TRPA1 in ventricular remodeling of hypertensive heart. We also examine the mechanisms through gene transfection and in vitro experiments. Results: TRPA1 overexpression fully activated myofibroblast transformation, while fibroblasts lacking TRPA1 were refractory to transforming growth factor β (TGF-β) -induced transdifferentiation. TRPA1 knockout mice showed hypertensive ventricular remodeling reversal following pressure overload. We found that the TGF-β induced TRPA1 expression through calcineurin-NFAT-Dyrk1A signaling pathway via the TRPA1 promoter. Once induced, TRPA1 activates the Ca 2+ -responsive protein phosphatase calcineurin, which itself induced myofibroblast transdifferentiation. Moreover, inhibition of calcineurin prevented TRPA1-dependent transdifferentiation. Conclusion: Our study provides the first evidence that TRPA1 regulation in cardiac fibroblasts transformation in response to hypertensive stimulation. The results suggesting a comprehensive pathway for myofibroblast formation in conjunction with TGF-β, Calcineurin, NFAT and Dyrk1A. Furthermore, these data indicate that negative modulation of cardiac fibroblast TRPA1 may represent a therapeutic strategy against hypertensive cardiac remodeling.

scholarly journals A Review of the Molecular Mechanisms Underlying Cardiac Fibrosis and Atrial Fibrillation

2021 ◽  
Vol 10 (19) ◽  
pp. 4430
Author(s):  
Grażyna Sygitowicz ◽  
Agata Maciejak-Jastrzębska ◽  
Dariusz Sitkiewicz
Keyword(s):  
Atrial Fibrillation ◽  
Molecular Mechanisms ◽  
Cardiac Fibrosis ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β1 ◽  
Signalling Pathways ◽  
Ang Ii ◽  
Atrial Fibrosis ◽  
Genes Encoding ◽  
Tgf Β1

The cellular and molecular mechanism involved in the pathogenesis of atrial fibrosis are highly complex. We have reviewed the literature that covers the effectors, signal transduction and physiopathogenesis concerning extracellular matrix (ECM) dysregulation and atrial fibrosis in atrial fibrillation (AF). At the molecular level: angiotensin II, transforming growth factor-β1, inflammation, and oxidative stress are particularly important for ECM dysregulation and atrial fibrotic remodelling in AF. We conclude that the Ang-II-MAPK and TGF-β1-Smad signalling pathways play a major, central role in regulating atrial fibrotic remodelling in AF. The above signalling pathways induce the expression of genes encoding profibrotic molecules (MMP, CTGF, TGF-β1). An important mechanism is also the generation of reactive oxygen species. This pathway induced by the interaction of Ang II with the AT2R receptor and the activation of NADPH oxidase. Additionally, the interplay between cardiac MMPs and their endogenous tissue inhibitors of MMPs, is thought to be critical in atrial ECM metabolism and fibrosis. We also review recent evidence about the role of changes in the miRNAs expression in AF pathophysiology and their potential as therapeutic targets. Furthermore, keeping the balance between miRNA molecules exerting anti-/profibrotic effects is of key importance for the control of atrial fibrosis in AF.

Pirfenidone exhibits cardioprotective effects by regulating myocardial fibrosis and vascular permeability in pressure-overloaded hearts

2015 ◽  
Vol 309 (3) ◽  
pp. H512-H522 ◽  
Author(s):  
Kiyoshi Yamagami ◽  
Toru Oka ◽  
Qi Wang ◽  
Takamaru Ishizu ◽  
Jong-Kook Lee ◽  
...  
Keyword(s):  
Heart Failure ◽  
Endothelial Cells ◽  
Vascular Permeability ◽  
Molecular Mechanisms ◽  
Cardiac Fibrosis ◽  
Transforming Growth Factor ◽  
Cardiac Fibroblasts ◽  
Chronic Phase ◽  
Vehicle Group

Although cardiac fibrosis causes heart failure, its molecular mechanisms remain elusive. In this study, we investigated the mechanisms of cardiac fibrosis and examined the effects of the antifibrotic drug pirfenidone (PFD) on chronic heart failure. To understand the responsible mechanisms, we generated an in vivo pressure-overloaded heart failure model via transverse aortic constriction (TAC) and examined the effects of PFD on chronic-phase cardiac fibrosis and function. In the vehicle group, contractile dysfunction and left ventricle fibrosis progressed further from 4 to 8 wk after TAC but were prevented by PFD treatment beginning 4 wk after TAC. We isolated cardiac fibroblasts and vascular endothelial cells from the left ventricles of adult male mice and investigated the cell-type-specific effects of PFD. Transforming growth factor-β induced upregulated collagen 1 expression via p38 phosphorylation and downregulated claudin 5 (Cldn5) expression in cardiac fibroblasts and endothelial cells, respectively; both processes were inhibited by PFD. Moreover, PFD inhibited changes in the collagen 1 and Cldn5 expression levels, resulting in reduced fibrosis and serum albumin leakage into the interstitial space during the chronic phase in TAC hearts. In conclusion, PFD inhibited cardiac fibrosis by suppressing both collagen expression and the increased vascular permeability induced by pressure overload.

scholarly journals P300/CBP-Associated Factor Activates Cardiac Fibroblasts by SMAD2 Acetylation

2021 ◽  
Vol 22 (18) ◽  
pp. 9944
Author(s):  
Yongwoon Lim ◽  
Anna Jeong ◽  
Duk-Hwa Kwon ◽  
Yeong-Un Lee ◽  
Young-Kook Kim ◽  
...  
Keyword(s):  
Cardiac Fibrosis ◽  
Transforming Growth Factor ◽  
Cardiac Fibroblasts ◽  
Heart Diseases ◽  
High Dose ◽  
Mouse Heart ◽  
Associated Factor ◽  
Tgf Β1

Various heart diseases cause cardiac remodeling, which in turn leads to ineffective contraction. Although it is an adaptive response to injury, cardiac fibrosis contributes to this remodeling, for which the reactivation of quiescent myofibroblasts is a key feature. In the present study, we investigated the role of the p300/CBP-associated factor (PCAF), a histone acetyltransferase, in the activation of cardiac fibroblasts. An intraperitoneal (i.p.) injection of a high dose (160 mg/kg) of isoproterenol (ISP) induced cardiac fibrosis and reduced the amount of the PCAF in cardiac fibroblasts in the mouse heart. However, the PCAF activity was significantly increased in cardiac fibroblasts, but not in cardiomyocytes, obtained from ISP-administered mice. An in vitro study using human cardiac fibroblast cells recapitulated the in vivo results; an treatment with transforming growth factor-β1 (TGF-β1) reduced the PCAF, whereas it activated the PCAF in the fibroblasts. PCAF siRNA attenuated the TGF-β1-induced increase in and translocation of fibrosis marker proteins. PCAF siRNA blocked TGF-β1-mediated gel contraction and cell migration. The PCAF directly interacted with and acetylated mothers against decapentaplegic homolog 2 (SMAD2). PCAF siRNA prevented TGF-β1-induced phosphorylation and the nuclear localization of SMAD2. These results suggest that the increase in PCAF activity during cardiac fibrosis may participate in SMAD2 acetylation and thereby in its activation.

scholarly journals Role for high-glucose-induced protein O-GlcNAcylation in stimulating cardiac fibroblast collagen synthesis

2014 ◽  
Vol 306 (9) ◽  
pp. C794-C804 ◽  
Author(s):  
Hugo Aguilar ◽  
Eduardo Fricovsky ◽  
Sang Ihm ◽  
Magdalena Schimke ◽  
Lisandro Maya-Ramos ◽  
...  
Keyword(s):  
High Glucose ◽  
Collagen Synthesis ◽  
Cardiac Fibrosis ◽  
Transforming Growth Factor ◽  
Cardiac Fibroblasts ◽  
Transforming Growth Factor Β1 ◽  
Protein Levels ◽  
Normal Glucose ◽  
Arginase Ii ◽  
Tgf Β1

Excess enzyme-mediated protein O-GlcNAcylation is known to occur with diabetes mellitus. A characteristic of diabetic cardiomyopathy is the development of myocardial fibrosis. The role that enhanced protein O-GlcNAcylation plays in modulating the phenotype of cardiac fibroblasts (CF) is unknown. To address this issue, rat CF were cultured in normal glucose (NG; 5 mM glucose) or high-glucose (HG; 25 mM) media for 48 h. Results demonstrate that CF cultured in HG have higher levels (∼50%) of overall protein O-GlcNAcylation vs. NG cells. Key regulators of collagen synthesis such as transforming-growth factor-β1 (TGF-β1), SMADs 2/3, and SMAD 7 protein levels, including those of arginase I and II, were altered, leading to increases in collagen levels. The nuclear transcription factor Sp1 and arginase II evidence excess O-GlcNAcylation in HG cells. Expression in CF of an adenovirus coding for the enzyme N-acetylglucosaminidase, which removes O-GlcNAc moieties from proteins, decreased Sp1 and arginase II O-GlcNAcylation and restored HG-induced perturbations in CF back to NG levels. These findings may have important pathophysiological implications for the development of diabetes-induced cardiac fibrosis.

scholarly journals Cardiac fibrosis

2020 ◽  
Author(s):  
Nikolaos G Frangogiannis
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Molecular Mechanisms ◽  
Cardiac Fibrosis ◽  
Transforming Growth Factor ◽  
Cardiac Fibroblasts ◽  
Matrix Proteins ◽  
Matrix Assembly ◽  
Myocardial Diseases ◽  
Signalling Cascades

Abstract Myocardial fibrosis, the expansion of the cardiac interstitium through deposition of extracellular matrix proteins, is a common pathophysiologic companion of many different myocardial conditions. Fibrosis may reflect activation of reparative or maladaptive processes. Activated fibroblasts and myofibroblasts are the central cellular effectors in cardiac fibrosis, serving as the main source of matrix proteins. Immune cells, vascular cells and cardiomyocytes may also acquire a fibrogenic phenotype under conditions of stress, activating fibroblast populations. Fibrogenic growth factors (such as transforming growth factor-β and platelet-derived growth factors), cytokines [including tumour necrosis factor-α, interleukin (IL)-1, IL-6, IL-10, and IL-4], and neurohumoral pathways trigger fibrogenic signalling cascades through binding to surface receptors, and activation of downstream signalling cascades. In addition, matricellular macromolecules are deposited in the remodelling myocardium and regulate matrix assembly, while modulating signal transduction cascades and protease or growth factor activity. Cardiac fibroblasts can also sense mechanical stress through mechanosensitive receptors, ion channels and integrins, activating intracellular fibrogenic cascades that contribute to fibrosis in response to pressure overload. Although subpopulations of fibroblast-like cells may exert important protective actions in both reparative and interstitial/perivascular fibrosis, ultimately fibrotic changes perturb systolic and diastolic function, and may play an important role in the pathogenesis of arrhythmias. This review article discusses the molecular mechanisms involved in the pathogenesis of cardiac fibrosis in various myocardial diseases, including myocardial infarction, heart failure with reduced or preserved ejection fraction, genetic cardiomyopathies, and diabetic heart disease. Development of fibrosis-targeting therapies for patients with myocardial diseases will require not only understanding of the functional pluralism of cardiac fibroblasts and dissection of the molecular basis for fibrotic remodelling, but also appreciation of the pathophysiologic heterogeneity of fibrosis-associated myocardial disease.

Hexarelin suppresses cardiac fibroblast proliferation and collagen synthesis in rat

2007 ◽  
Vol 293 (5) ◽  
pp. H2952-H2958 ◽  
Author(s):  
Xiangbin Xu ◽  
Jinjiang Pang ◽  
Hongchao Yin ◽  
Meixiu Li ◽  
Wei Hao ◽  
...  
Keyword(s):  
Dna Synthesis ◽  
Collagen Synthesis ◽  
Molecular Mechanisms ◽  
Transforming Growth Factor ◽  
Cardiac Fibroblasts ◽  
Cardiac Fibroblast ◽  
Ang Ii ◽  
Fibroblast Proliferation ◽  
Growth Hormone Secretagogue ◽  
Tgf Β1

Abnormal growth of cardiac fibroblasts is critically involved in the pathophysiology of cardiac hypertrophy/remodeling. Hexarelin is a synthetic growth hormone secretagogue (GHS), which possesses a variety of cardiovascular protective activities mediated via the GHS receptor (GHSR), including improving cardiac dysfunction and remodeling. The cellular and molecular mechanisms underlying the effect of GHS on cardiac fibrosis are, however, not clear. In this report, cultured cardiac fibroblasts from 8-day-old rats were stimulated with ANG II or FCS to induce proliferation. The fibroblast proliferation and DNA and collagen synthesis were evaluated utilizing 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, 3H-thymidine incorporation, and 3H-proline incorporation. The level of mRNA of transforming growth factor (TGF)-β was evaluated by RT-PCR, and the active TGF-β1 release from cardiac fibroblasts was evaluated by ELISA. The level of cellular cAMP was measured by radioimmunoassay. In addition, the effects of 3,7-dimethyl-l-propargylxanthine (DMPX; a specific adenosine receptor A2R antagonist) and 8-cyclopentyl-1,3-dipropylxanthine (DPCPX; a specific A1R antagonist) were tested. It was found that incubation with 10−7 mol/l hexarelin for 24 h 1) inhibited the ANG II-induced proliferation and collagen synthesis and the 5% FCS- and TGF-β-induced increase of DNA synthesis in cardiac fibroblast and 2) reduced ANG II-induced upregulation of TGF-β mRNA expression and active TGF-β1 release from fibroblasts. Hexarelin increased the cellular level of cAMP in cardiac fibroblasts. DMPX (10−8 mol/l) but not DPCPX abolished the effect of hexarelin on cardiac fibroblast DNA synthesis. It is concluded that hexarelin inhibits DNA and collagen synthesis and proliferation of cardiac fibroblasts through activation of both GHSR and A2R and diminishment of ANG II-induced increase in TGF-β expression and release.

scholarly journals P2Y1 Receptor Agonist Attenuates Cardiac Fibroblasts Activation Triggered by TGF-β1

2021 ◽  
Vol 12 ◽  
Author(s):  
Geer Tian ◽  
Junteng Zhou ◽  
Yue Quan ◽  
Qihang Kong ◽  
Wenchao Wu ◽  
...  
Keyword(s):  
Growth Factor ◽  
P38 Mapk ◽  
Cardiac Fibrosis ◽  
Transforming Growth Factor ◽  
Purinergic Signaling ◽  
Cardiac Fibroblasts ◽  
Smooth Muscle Actin ◽  
Tissue Growth ◽  
Erk Signaling ◽  
Tgf Β1

Cardiac fibroblasts (CFs) activation is a hallmark feature of cardiac fibrosis caused by cardiac remodeling. The purinergic signaling molecules have been proven to participate in the activation of CFs. In this study, we explored the expression pattern of P2Y receptor family in the cardiac fibrosis mice model induced by the transverse aortic constriction (TAC) operation and in the activation of CFs triggered by transforming growth factor β1 (TGF-β1) stimulation. We then investigated the role of P2Y1receptor (P2Y1R) in activated CFs. The results showed that among P2Y family members, only P2Y1R was downregulated in the heart tissues of TAC mice. Consistent with our in vivo results, the level of P2Y1R was decreased in the activated CFs, when CFs were treated with TGF-β1. Silencing P2Y1R expression with siP2Y1R accelerated the effects of TGF-β1 on CFs activation. Moreover, the P2Y1R selective antagonist BPTU increased the levels of mRNA and protein of profibrogenic markers, such as connective tissue growth factor (CTGF), periostin (POSTN). periostin (POSTN), and α-smooth muscle actin(α-SMA). Further, MRS2365, the agonist of P2Y1R, ameliorated the activation of CFs and activated the p38 MAPK and ERK signaling pathways. In conclusion , our findings revealed that upregulating of P2Y1R may attenuate the abnormal activation of CFs via the p38 MAPK and ERK signaling pathway.

Abstract 367: Lysyl Oxidase Expression by Cardiac Fibroblasts is Regulated by Integrin-mediated Signaling

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Albert Gao ◽  
Lauren D Black
Keyword(s):  
Gene Expression ◽  
Cardiac Fibrosis ◽  
Lysyl Oxidase ◽  
Cardiac Fibroblasts ◽  
Therapeutic Strategies ◽  
Expression Of Genes ◽  
Adverse Remodeling ◽  
Novel Therapeutic Strategies ◽  
Free Media ◽  
Tgf Β1

Cardiac fibrosis following myocardial infarction (MI) leads to reduced cardiac function, and contributes to heart failure and mortality. Recent studies shown the extent of adverse remodeling may be mitigated by therapeutic strategies which regulate cardiac fibroblast mediated-remodeling. Since cross-linking by lysyl oxidase (LOX) increases following MI and alters the mechanical properties of the infarct, it is critical to characterize how its expression is regulated by CFs post-MI. While LOX expression is attributable to TGF-β1 signaling, we hypothesize that changes in the stiffness and composition of the ECM can also alter LOX expression via integrin-mediated signaling. To investigate this, we isolated CFs from healthy left ventricle (LV) and infarcted cardiac fibroblasts (ICFs) from 1 week post-MI LV and cultured them on tissue culture plastic (TCP) and collagen I-coated plates (COL) in serum-free media for 48 hours to assess the expression of genes associated with LOX signaling, fibrosis, and myofibroblast activation. Our results show an upregulation of LOX gene expression in both CFs and ICFs when cultured on COL and this is further emphasized with the presence of TGF-β1 (Fig. 1A). Gene expression of col1α1, integrin β1 subunit and αSMA (Fig. 1B-D) also exhibit similar upregulation. Ongoing studies will investigate how altered substrate stiffness and composition affect gene expression of LOX and other genes associated with fibrosis. By understanding the effect of the physical microenvironment on the expression of fibrotic genes including LOX, we aim to develop novel therapeutic strategies to attenuate cardiac fibrosis and thus improve cardiac recovery following MI.

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