Faculty Opinions recommendation of MicroRNA-mediated in vitro and in vivo direct reprogramming of cardiac fibroblasts to cardiomyocytes.

AbstractMyocardial fibrosis and ventricular remodeling were the key pathology factors causing undesirable consequence after myocardial infarction. However, an efficient therapeutic method remains unclear, partly due to difficulty in continuously preventing neurohormonal overactivation and potential disadvantages of cell therapy for clinical practice. In this study, a rhACE2-electrospun fibrous patch with sustained releasing of rhACE2 to shape an induction transformation niche in situ was introduced, through micro-sol electrospinning technologies. A durable releasing pattern of rhACE2 encapsulated in hyaluronic acid (HA)—poly(L-lactic acid) (PLLA) core-shell structure was observed. By multiple in vitro studies, the rhACE2 patch demonstrated effectiveness in reducing cardiomyocytes apoptosis under hypoxia stress and inhibiting cardiac fibroblasts proliferation, which gave evidence for its in vivo efficacy. For striking mice myocardial infarction experiments, a successful prevention of adverse ventricular remodeling has been demonstrated, reflecting by improved ejection fraction, normal ventricle structure and less fibrosis. The rhACE2 patch niche showed clear superiority in long term function and structure preservation after ischemia compared with intramyocardial injection. Thus, the micro-sol electrospun rhACE2 fibrous patch niche was proved to be efficient, cost-effective and easy-to-use in preventing ventricular adverse remodeling.

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

Endocrinology ◽

10.1210/en.2012-1114 ◽

2012 ◽

Vol 153 (8) ◽

pp. 3692-3700 ◽

Cited By ~ 28

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.

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

Circulation Research ◽

10.1161/res.119.suppl_1.277 ◽

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.

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Myocyte-Derived Hsp90 Modulates Collagen Upregulation via Biphasic Activation of STAT-3 in Fibroblasts during Cardiac Hypertrophy

Molecular and Cellular Biology ◽

10.1128/mcb.00611-16 ◽

2016 ◽

Vol 37 (6) ◽

Cited By ~ 29

Author(s):

Ritwik Datta ◽

Trisha Bansal ◽

Santanu Rana ◽

Kaberi Datta ◽

Ratul Datta Chaudhuri ◽

...

Keyword(s):

Cardiac Hypertrophy ◽

Collagen Synthesis ◽

Cardiac Fibroblasts ◽

Heat Shock Protein 90 ◽

Signaling Mechanism ◽

Content Type ◽

Collagen Expression ◽

Significant Difference

ABSTRACT Signal transducer and activator of transcription 3 (STAT-3)-mediated signaling in relation to upregulated collagen expression in fibroblasts during cardiac hypertrophy is well defined. Our recent findings have identified heat shock protein 90 (Hsp90) to be a critical modulator of fibrotic signaling in cardiac fibroblasts in this disease milieu. The present study was therefore intended to analyze the role of Hsp90 in the STAT-3-mediated collagen upregulation process. Our data revealed a significant difference between in vivo and in vitro results, pointing to a possible involvement of myocyte-fibroblast cross talk in this process. Cardiomyocyte-targeted knockdown of Hsp90 in rats (Rattus norvegicus) in which the renal artery was ligated showed downregulated collagen synthesis. Furthermore, the results obtained with cardiac fibroblasts conditioned with Hsp90-inhibited hypertrophied myocyte supernatant pointed toward cardiomyocytes' role in the regulation of collagen expression in fibroblasts during hypertrophy. Our study also revealed a novel signaling mechanism where myocyte-derived Hsp90 orchestrates not only p65-mediated interleukin-6 (IL-6) synthesis but also its release in exosomal vesicles. Such myocyte-derived exosomes and myocyte-secreted IL-6 are responsible in unison for the biphasic activation of STAT-3 signaling in cardiac fibroblasts that culminates in excess collagen synthesis, leading to severely compromised cardiac function during cardiac hypertrophy.

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Abstract 34: Acetylation of GATA 4 Enhanced Direct Cardiac Reprogramming of Induced Cardiomyocytes

Circulation Research ◽

10.1161/res.121.suppl_1.34 ◽

2017 ◽

Vol 121 (suppl_1) ◽

Author(s):

Vivek P Singh ◽

Megumi Mathison ◽

Jaya P Pinnamaneni ◽

Deepthi Sanagasetti ◽

Narasimhaswamy S Belaguli ◽

...

Keyword(s):

Ventricular Function ◽

Troponin T ◽

Novel Mutation ◽

Cardiac Regeneration ◽

Negative Control ◽

Direct Reprogramming ◽

Wild Type ◽

Reprogramming Efficiency

Objective: Direct reprogramming of fibroblasts into induced cardiomyocytes (iCMs) by forced expression of cardiomyogenic factors, GMT (GATA4, Mef2c and Tbx5), has recently been demonstrated, suggesting a promising statregy for cardiac regeneration. However, the efficiency of direct reprogramming is usually relatively low and requires extensive epigenetic redesigning, although the underlying mechanism are largely unknown. Methods: In a recent study, we created a novel mutation in rat GATA 4 by replacing lysine residue with glutamine at position 299 i.e. (K299Q), to mimic constitutive acetylation and examined whether constitutive acetylation of GATA4, when compared with wild type GATA4, further enhance GMT-mediated direct reprogramming efficiency of induced cardiomyocytes in vitro and accordingly ventricular function after myocardial infarction in rat, in vivo . Results: We found that acetylated GATA 4 (K299Q), in the presence of Mef2c and Tbx5 upregulated cardiac-specific markers, suppressed fibroblast genes, in rat cardiac fibroblasts (RCFs) more efficiently when compared with Mef2c, Tbx5 plus wild type GATA4. FACS analyses revealed that G(K299Q) MT induced significantly more cardiomyocyte marker cardiac troponin T (cTnT) expression compared with GMT alone. Mechanistic studies demonstrated that the K299Q substitution, resulting in enriched p300 occupancy at the GATA 4 promoter, induced acetylation of Histine 3, decreased HDAC expression. In addition, substitution augmented the increase in an acetylated form of GATA-4 and its DNA binding and transcriptional activity, compared with wildtype GATA 4. In agreement with upregulated cTNT gene expression in vitro , echocardiographic analysis demonstrate that the acetylated G(K299Q) MT vectors have improved effect in enhancing ventricular function than GMT vectors from postinfarct baselines as compared to negative control [G(K299Q) MT, 15.6% ± 2.7%; G(WT)MT, 12.8% ± 1.7%; GFP, -2.3% ± 1.1%]. Conclusions: Collectivily, these data indicate that acetylated GATA4 (K299Q) significantly increases reprogramming efficiency of induced cardiomyocytes (iCMs), in vitro and in vivo, and provide new insight into the molecular mechanism underlying cardiac regeneration.

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

Clinical Science ◽

10.1042/cs20180681 ◽

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.

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

Cellular Physiology and Biochemistry ◽

10.1159/000489683 ◽

2018 ◽

Vol 46 (6) ◽

pp. 2551-2560 ◽

Cited By ~ 12

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.

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Cardiac fibroblasts: friend or foe?

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00023.2006 ◽

2006 ◽

Vol 291 (3) ◽

pp. H1015-H1026 ◽

Cited By ~ 270

Author(s):

Troy A. Baudino ◽

Wayne Carver ◽

Wayne Giles ◽

Thomas K. Borg

Keyword(s):

Cardiac Function ◽

Cardiac Fibroblasts ◽

Cell Types ◽

Dynamic Interaction ◽

Normal Function ◽

Complex Signals ◽

Stage Of Development ◽

Electrical Stimuli

Cardiac function is determined by the dynamic interaction of various cell types and the extracellular matrix that composes the heart. This interaction varies with the stage of development and the degree and duration of mechanical, chemical, and electrical signals between the various cell types and the ECM. Understanding how these complex signals interact at the molecular, cellular, and organ levels is critical to understanding the function of the heart under a variety of physiological and pathophysiological conditions. Quantitative approaches, both in vivo and in vitro, are essential to understand the dynamic interaction of mechanical, chemical, and electrical stimuli that govern cardiac function. The fibroblast can thus be a friend in normal function or a foe in pathophysiological conditions.

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Manipulating Senescence of Cardiac Fibroblasts In Vivo and In Vitro to Investigate Arrhythmogenic Effect of Senescence

The FASEB Journal ◽

10.1096/fasebj.2020.34.s1.03861 ◽

2020 ◽

Vol 34 (S1) ◽

pp. 1-1

Author(s):

Elif Sengun ◽

Brett Baggett ◽

Kevin Murphy ◽

Yichun Lu ◽

Tae-Yun Kim ◽

...

Keyword(s):

Cardiac Fibroblasts ◽

Arrhythmogenic Effect

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