scholarly journals Up-Regulating Relaxin Expression by G-Quadruplex Interactive Ligand to Achieve Antifibrotic Action

Endocrinology ◽  
2012 ◽  
Vol 153 (8) ◽  
pp. 3692-3700 ◽  
Author(s):  
Hui-Ping Gu ◽  
Sen Lin ◽  
Ming Xu ◽  
Hai-Yi Yu ◽  
Xiao-Jun Du ◽  
...  
Keyword(s):  
Rna Polymerase Ii ◽  
Cardiac Fibrosis ◽  
Cardiac Fibroblasts ◽  
Heart Diseases ◽  
Gene Promoter ◽  
Binding Motif ◽  
Endogenous Expression ◽  
G Quadruplex

Myocardial fibrosis is a key pathological change in a variety of heart diseases contributing to the development of heart failure, arrhythmias, and sudden death. Recent studies have shown that relaxin prevents and reverses cardiac fibrosis. Endogenous expression of relaxin was elevated in the setting of heart disease; the extent of such up-regulation, however, is insufficient to exert compensatory actions, and the mechanism regulating relaxin expression is poorly defined. In the rat relaxin-1 (RLN1, Chr1) gene promoter region we found presence of repeated guanine (G)-rich sequences, which allowed formation and stabilization of G-quadruplexes with the addition of a G-quadruplex interactive ligand berberine. The G-rich sequences and the G-quadruplexes were localized adjacent to the binding motif of signal transducer and activator of transcription (STAT)3, which negatively regulates relaxin expression. Thus, we hypothesized that the formation and stabilization of G-quadruplexes by berberine could influence relaxin expression. We found that berberine-induced formation of G-quadruplexes did increase relaxin gene expression measured at mRNA and protein levels. Formation of G-quadruplexes significantly reduced STAT3 binding to the promoter of relaxin gene. This was associated with consequent increase in the binding of RNA polymerase II and STAT5a to relaxin gene promoter. In cardiac fibroblasts and rats treated with angiotensin II, berberine was found to suppress fibroblast activation, collagen synthesis, and extent of cardiac fibrosis through up-regulating relaxin. The antifibrotic action of berberine in vitro and in vivo was similar to that by exogenous relaxin. Our findings document a novel therapeutic strategy for fibrosis through up-regulating expression of endogenous relaxin.

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.

Abstract 331: Mir-433 Controls Cardiac Fibrosis

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Lichan Tao ◽  
Xiaoting Wu ◽  
Ping Chen ◽  
Shanshan Li ◽  
Xiaomin Zhang ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Cardiac Fibrosis ◽  
Cardiac Fibroblasts ◽  
Heart Diseases ◽  
Mice Model ◽  
Ki 67 ◽  
End Stage ◽  
Common Manifestation

Background: Cardiac fibrosis, a result of multiple injurious insults in heart, is a final common manifestation of chronic heart diseases and can lead to end-stage cardiac failure. MicroRNAs (miRNAs, miRs) participate in many essential biological processes and their dysfunction has been implicated in a variety of cardiovascular diseases including fibrosis. miR-433 has recently been implicated in renal fibrosis, however, its role in cardiac fibrosis is unclear. Methods and results: miR-433 was increased in heart samples from dilated cardiomyopathy patients as determined by qRT-PCRs. In addition, miR-433 was also consistently upregulated in mice model of cardiac fibrosis after myocardial infarction or heart failure. Additionally, miR-433 was found to be enriched in fibroblasts compared to cardiomyocytes. In neonatal cardiac fibroblasts, forced expression of miR-433 promoted cell proliferation as indicated by EdU and Ki-67 staining. Moreover, miR-433 overexpression promoted the transdifferentiation of fibroblasts into myofibroblasts as determined by qRT-PCR and western blot for α-SMA and collagen whether in the presence of TGF-β or not, indicating that miR-433 is sufficient to induce fibrosis. In addition, knockdown of miR-433 inhibited proliferation and the transdifferentiation into myofibroblasts, indicating that miR-433 is required for cardiac fibrosis. Interestingly, miR-433 did not affect the migration of cardiac fibroblast. Importantly, miR-433 antagomir could partially attenuate cardiac fibrosis induced by myocardial infarction in mice. Conclusion: both in vitro and in vivo. Inhibition of miR-433 represents a novel therapeutic strategy for cardiac fibrosis.

Abstract 410: Rhein Administration Prevents Cardiac Fibrosis by Interfering with the TGF-β Pathway

2017 ◽  
Vol 121 (suppl_1) ◽  
Author(s):  
David Barbosa ◽  
Melanie Wehmöller ◽  
Maximilian R Spinner ◽  
Ulrich Rüther ◽  
Margriet Ouwens
Keyword(s):  
Cardiac Fibrosis ◽  
Heart Function ◽  
Cardiac Fibroblasts ◽  
Heart Diseases ◽  
Collagen Gel ◽  
Pressure Overload ◽  
Protein Levels ◽  
Adverse Remodeling

Fibrosis, which occurs in various heart diseases like acute myocardial ischemia and pressure overload, is triggered by the differentiation of fibroblasts into myofibroblasts. Dysregulation of this reparative mechanism results in excessive collagen accumulation leading to cardiac stiffness and impaired heart function. The aim of this study was to determine whether the rhubarb anthraquinone Rhein, a drug already used as treatment for chondroarthritis, prevents the transdifferentiation of cardiac fibroblasts. We observed that Rhein pre-treatment ameliorates the cardiac function and reduces adverse remodeling after acute myocardial infarction in mice, in vivo . In primary human cardiac fibroblasts, Rhein incubation dose-dependently inhibited the TGF-β-mediated upregulation of α-SMA, the master marker for myofibrolasts, and prevented the contraction of fibroblast-populated collagen gel lattices upon TGF-β stimulation. Further, Rhein reduced TGFβ-R1 expression in primary human cardiac fibroblast, resulting in decreased SMAD2 phosphorylation and blunting of the fibrogenic response. Furthermore, Rhein stabilized protein levels of SMAD7, a key inhibitor of TGF-β signaling. Collectively, these data show for the first time that Rhein administration prevents cardiac fibrosis in vivo and in vitro by blunting the TGF-β signaling pathway, and identify Rhein as potential therapeutic treatment to prevent excessive fibrosis and adverse remodeling in cardiac pathologies.

Abstract 277: Microrna-33 Promotes Cardiac Fibrosis by Maintaining Cellular Lipid Homeostasis

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Masataka Nishiga ◽  
Takahiro Horie ◽  
Yasuhide Kuwabara ◽  
Osamu Baba ◽  
Tetsushi Nakao ◽  
...  
Keyword(s):  
Cardiac Fibrosis ◽  
Cardiac Fibroblasts ◽  
Pressure Overload ◽  
Cholesterol Content ◽  
Atp Binding Cassette Transporter ◽  
Primary Fibroblasts ◽  
Proliferation In Vitro ◽  
Altered Lipid

Background: A highly conserved microRNA, miR-33 is considered as a potential therapeutic target for atherosclerosis, because recent reports, including ours, indicated miR-33 has atherogenic effects by reducing HDL-C. However, the functions of miR-33 in heart failure remain to be elucidated. Methods and results: To clarify the functions of miR-33 involved in cardiac hypertrophy and fibrosis in vivo, we investigated the responses to pressure overload by transverse aortic constriction (TAC) in miR-33 deficient (KO) mice. When subjected to TAC, miR-33 expression level was significantly up-regulated in wild-type (WT) left ventricles, whereas miR-33 KO hearts displayed no less hypertrophic responses than WT hearts. However, interestingly, histological and gene expression analyses showed ameliorated cardiac fibrosis in miR-33 KO hearts compared to WT hearts. Furthermore, we generated cardiac fibroblast specific miR-33 deficient mice, which also showed ameliorated cardiac fibrosis when they were subjected to TAC. We also found that cardiac fibroblasts were mainly responsible for miR-33 expression in the heart, because its expression was about 4-folds higher in isolated primary cardiac fibroblasts than cardiomyocytes. Deficiency of miR-33 impaired cell proliferation in primary fibroblasts, which was considered due to altered lipid raft cholesterol content by up-regulated ATP-binding cassette transporter A1/G1. Conclusion: Deficiency of miR-33 impaired fibroblast proliferation in vitro, and ameliorated cardiac fibrosis induced by pressure overload in vivo.

Abstract P153: Role of Nonreceptor Tyrosine Kinases in Cardiac Fibrosis in a Mouse Model of Pressure Overload Hypertrophy

2011 ◽  
Vol 109 (suppl_1) ◽  
Author(s):  
Sundaravadivel Balasubramanian ◽  
Harinath Kasiganesan ◽  
Lakeya Quinones ◽  
Yuhua Zhang ◽  
Amy Bradshaw ◽  
...  
Keyword(s):  
Tyrosine Kinases ◽  
Cardiac Fibrosis ◽  
Cardiac Fibroblasts ◽  
Heart Diseases ◽  
Pressure Overload ◽  
In Vivo Studies ◽  
Survival Pathways ◽  
And Function ◽  
Nonreceptor Tyrosine Kinases

During prolonged hypertrophic insult to the myocardium, while the function of cardiomyocytes needs to be protected, the hyperactivation of cardiac fibroblasts has to be curbed to prevent fibrosis. Previously, we showed that integrin-mediated non-receptor tyrosine kinase (NRTK) activation is required for normal functioning of both cardiac fibroblasts and cardiomyocytes. We hypothesized that inhibition of NRTKs in cardiac fibroblasts without affecting cardiomyocytes would be beneficial to the stressed myocardium. Our initial studies using kinase inactive forms of Src, Pyk2 and FAK expressed adenovirally in isolated primary cardiac fibroblasts showed that the pro-fibrotic signaling events as studied by fibronectin and collagen deposition are downregulated. Our in vivo studies in mouse transverse aortic constriction (TAC) model suggest that dasatinib, a multikinase NRTK inhibitor administration via a peritoneally implanted mini-osmotic pump is able to preserve ventricular geometry and function and reduce the accumulation of fibrotic extracellular matrix (ECM) proteins upon 4 wk pressure overload. Data obtained from cell culture experiments with kinase inactive NRTKs and dasatinib suggest that NRTK inhibition is able to reduce the proliferation, migration and mitogenic signaling in cardiac fibroblasts without affecting the cell survival pathways in cardiomyocytes. These data indicate that NRTKs play a significant pro-fibrotic role in cardiac fibroblasts and curbing the activity of NRTKs could be a potential therapeutic approach to treat fibrosis in hypertrophic heart diseases.

Novel role for cardiac myocyte-derived β-2 microglobulin in mediating cardiac fibrosis

2018 ◽  
Vol 132 (19) ◽  
pp. 2117-2120
Author(s):  
Michael J. Boyer ◽  
Satoru Eguchi
Keyword(s):  
Cardiac Fibrosis ◽  
Cardiac Myocyte ◽  
Cardiac Fibroblasts ◽  
Significant Risk ◽  
Growth Factor Receptor ◽  
Pressure Overload ◽  
Significant Risk Factor ◽  
Cardiac Complications

Hypertension is a significant risk factor for the development of cardiovascular ailments, including ischemic heart disease and diastolic dysfunction. In a recent issue of Clinical Science, Li et al. [Clin. Sci. (2018) 132, 1855–1874] report that β-2 microglobulin (β2M) is a novel secreted soluble factor released by cardiac myocytes during pressure overload that promotes profibrotic gene expression in cardiac fibroblasts both in vitro and in vivo. Their study further identifies elevated β2M levels as a possible biomarker for hypertensive patients with cardiac complications. The authors propose a mechanism that mechanically stretched cardiomyocytes release soluble β2M which, through paracrine communication with cardiac fibroblasts, transactivates epidermal growth factor receptor (EGFR) to initiate acute signal transduction and up-regulate profibrotic genes, thereby promoting fibrosis. Here, we will discuss the background, significance of the study, alternative mechanisms, and future directions.

scholarly journals Downregulation of S100A4 Alleviates Cardiac Fibrosis via Wnt/β -Catenin Pathway in Mice

2018 ◽  
Vol 46 (6) ◽  
pp. 2551-2560 ◽  
Author(s):  
LiJun Qian ◽  
Jian Hong ◽  
YanMei Zhang ◽  
MengLin Zhu ◽  
XinChun Wang ◽  
...  
Keyword(s):  
Calcium Binding ◽  
Cardiac Fibrosis ◽  
Cardiac Fibroblasts ◽  
Group A ◽  
Ischemic Diseases ◽  
Fibrotic Diseases ◽  
Signaling Activation

Background/Aims: Cardiac fibrosis is a pathological change leading to cardiac remodeling during the progression of myocardial ischemic diseases, and its therapeutic strategy remains to be explored. S100A4, a calcium-binding protein, participates in fibrotic diseases with an unclear mechanism. This study aimed to investigate the role of S100A4 in cardiac fibrosis. Methods: Cardiac fibroblasts from neonatal C57BL/6 mouse hearts were isolated and cultured. Myocardial infarction was induced by ligating the left anterior descending coronary artery (LAD). The ligation was not performed in the sham group. A volume of 5×105pfu/g adenovirus or 5 µM/g ICG-001 was intramyocardially injected into five parts bordering the infarction zone or normal region. We used Western blotting, quantitative RT-PCR, immunofluorescence, immunohistochemistry and Masson’s trichrome staining to explore the function of S100A4. Results: We found significant increases of S100A4 level and cardiac fibrosis markers, and β-catenin signaling activation in vitro and in vivo. In addition, knockdown of S100A4 significantly reduced cardiac fibrosis and β-catenin levels. Moreover, the expression of S100A4 decreased after ICG-001 inhibited β-catenin signal pathway. Conclusion: Downregulation of S100A4 alleviates cardiac fibrosis via Wnt/β -catenin pathway in mice. S100A4 may be a therapeutic target of cardiac fibrosis.

scholarly journals Th1 effector T cells selectively orchestrate cardiac fibrosis in nonischemic heart failure

2017 ◽  
Vol 214 (11) ◽  
pp. 3311-3329 ◽  
Author(s):  
Tania Nevers ◽  
Ane M. Salvador ◽  
Francisco Velazquez ◽  
Njabulo Ngwenyama ◽  
Francisco J. Carrillo-Salinas ◽  
...  
Keyword(s):  
Heart Failure ◽  
T Cells ◽  
Cardiac Fibrosis ◽  
Cardiac Fibroblasts ◽  
Th1 Cells ◽  
Dependent Manner ◽  
Effector Cells ◽  
Ifn Γ

Despite emerging data indicating a role for T cells in profibrotic cardiac repair and healing after ischemia, little is known about whether T cells directly impact cardiac fibroblasts (CFBs) to promote cardiac fibrosis (CF) in nonischemic heart failure (HF). Recently, we reported increased T cell infiltration in the fibrotic myocardium of nonischemic HF patients, as well as the protection from CF and HF in TCR-α−/− mice. Here, we report that T cells activated in such a context are mainly IFN-γ+, adhere to CFB, and induce their transition into myofibroblasts. Th1 effector cells selectively drive CF both in vitro and in vivo, whereas adoptive transfer of Th1 cells, opposite to activated IFN-γ−/− Th cells, partially reconstituted CF and HF in TCR-α−/− recipient mice. Mechanistically, Th1 cells use integrin α4 to adhere to and induce TGF-β in CFB in an IFN-γ–dependent manner. Our findings identify a previously unrecognized role for Th1 cells as integrators of perivascular CF and cardiac dysfunction in nonischemic HF.

scholarly journals Na/K-ATPase signaling regulates collagen synthesis through microRNA-29b-3p in cardiac fibroblasts

2016 ◽  
Vol 48 (3) ◽  
pp. 220-229 ◽  
Author(s):  
Christopher A. Drummond ◽  
Michael C. Hill ◽  
Huilin Shi ◽  
Xiaoming Fan ◽  
Jeffrey X. Xie ◽  
...  
Keyword(s):  
Collagen Synthesis ◽  
Cardiac Fibrosis ◽  
Cardiac Tissue ◽  
Cardiac Fibroblasts ◽  
Primary Cultures ◽  
In Vivo Models ◽  
Adult Rat ◽  
Uremic Cardiomyopathy

Chronic kidney disease (CKD) is accompanied by cardiac fibrosis, hypertrophy, and dysfunction, which are commonly referred to as uremic cardiomyopathy. Our previous studies found that Na/K-ATPase ligands or 5/6th partial nephrectomy (PNx) induces cardiac fibrosis in rats and mice. The current study used in vitro and in vivo models to explore novel roles for microRNA in this mechanism of cardiac fibrosis formation. To accomplish this, we performed microRNA profiling with RT-qPCR based arrays on cardiac tissue from rats subjected to marinobufagenin (MBG) infusion or PNx. The analysis showed that a series of fibrosis-related microRNAs were dysregulated. Among the dysregulated microRNAs, microRNA (miR)-29b-3p, which directly targets mRNA of collagen, was consistently reduced in both PNx and MBG-infused animals. In vitro experiments demonstrated that treatment of primary cultures of adult rat cardiac fibroblasts with Na/K-ATPase ligands induced significant increases in the fibrosis marker, collagen protein, and mRNA expression compared with controls, whereas miR-29b-3p expression decreased >50%. Transfection of miR-29b-3p mimics into cardiac fibroblasts inhibited cardiotonic steroids-induced collagen synthesis. Moreover, a specific Na/K-ATPase signaling antagonist, pNaKtide, prevented ouabain-induced increases in collagen synthesis and decreases in miR-29b-3p expression in these cells. In conclusion, these data are the first to indicate that signaling through Na/K-ATPase regulates miRNAs and specifically, miR-29b-3p expression both in vivo and in vitro. Additionally, these data indicate that miR-29b-3p expression plays an important role in the formation of cardiac fibrosis in CKD.

scholarly journals Intermittent hypoxia mediated by TSP1 dependent on STAT3 induces cardiac fibroblast activation and cardiac fibrosis

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Qiankun Bao ◽  
Bangying Zhang ◽  
Ya Suo ◽  
Chen Liu ◽  
Qian Yang ◽  
...  
Keyword(s):  
Intermittent Hypoxia ◽  
Cardiac Fibrosis ◽  
Synergistic Effects ◽  
Cardiac Fibroblasts ◽  
Cardiac Fibroblast ◽  
Ang Ii ◽  
Fibroblast Activation ◽  
Obstructive Sleep

Intermittent hypoxia (IH) is the predominant pathophysiological disturbance in obstructive sleep apnea (OSA), known to be independently associated with cardiovascular diseases. However, the effect of IH on cardiac fibrosis and molecular events involved in this process are unclear. Here, we tested IH in angiotensin II (Ang II)-induced cardiac fibrosis and signaling linked to fibroblast activation. IH triggered cardiac fibrosis and aggravated Ang II-induced cardiac dysfunction in mice. Plasma thrombospondin-1 (TSP1) content was upregulated in both IH-exposed mice and OSA patients. Moreover, both in vivo and in vitro results showed IH-induced cardiac fibroblast activation and increased TSP1 expression in cardiac fibroblasts. Mechanistically, phosphorylation of STAT3 at Tyr705 mediated the IH-induced TSP1 expression and fibroblast activation. Finally, STAT3 inhibitor S3I-201 or AAV9 carrying a periostin promoter driving the expression of shRNA targeting Stat3 significantly attenuated the synergistic effects of IH and Ang II on cardiac fibrosis in mice. This work suggests a potential therapeutic strategy for OSA-related fibrotic heart disease.

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