scholarly journals Cardiac regeneration by direct reprogramming in this decade and beyond

2021 ◽  
Vol 41 (1) ◽  
Author(s):  
Hiroyuki Yamakawa ◽  
Masaki Ieda
Keyword(s):  
Growth Factor ◽  
Molecular Mechanisms ◽  
Cardiac Fibroblasts ◽  
Therapeutic Option ◽  
Cardiac Regeneration ◽  
Notch Signaling Pathway ◽  
Culture Conditions ◽  
Potential Candidate ◽  
Direct Reprogramming ◽  
Reprogramming Efficiency

AbstractJapan faces an increasing incidence of heart disease, owing to a shift towards a westernized lifestyle and an aging demographic. In cases where conventional interventions are not appropriate, regenerative medicine offers a promising therapeutic option. However, the use of stem cells has limitations, and therefore, “direct cardiac reprogramming” is emerging as an alternative treatment. Myocardial regeneration transdifferentiates cardiac fibroblasts into cardiomyocytes in situ.Three cardiogenic transcription factors: Gata4, Mef2c, and Tbx5 (GMT) can induce direct reprogramming of fibroblasts into induced cardiomyocytes (iCMs), in mice. However, in humans, additional factors, such as Mesp1 and Myocd, are required. Inflammation and immune responses hinder the reprogramming process in mice, and epigenetic modifiers such as TET1 are involved in direct cardiac reprogramming in humans. The three main approaches to improving reprogramming efficiency are (1) improving direct cardiac reprogramming factors, (2) improving cell culture conditions, and (3) regulating epigenetic factors. miR-133 is a potential candidate for the first approach. For the second approach, inhibitors of TGF-β and Wnt signals, Akt1 overexpression, Notch signaling pathway inhibitors, such as DAPT ((S)-tert-butyl 2-((S)-2-(2-(3,5-difluorophenyl) acetamido) propanamido)-2-phenylacetate), fibroblast growth factor (FGF)-2, FGF-10, and vascular endothelial growth factor (VEGF: FFV) can influence reprogramming. Reducing the expression of Bmi1, which regulates the mono-ubiquitination of histone H2A, alters histone modification, and subsequently the reprogramming efficiency, in the third approach. In addition, diclofenac, a non-steroidal anti-inflammatory drug, and high level of Mef2c overexpression could improve direct cardiac reprogramming.Direct cardiac reprogramming needs improvement if it is to be used in humans, and the molecular mechanisms involved remain largely elusive. Further advances in cardiac reprogramming research are needed to bring us closer to cardiac regenerative therapy.

Abstract 126: High Efficiency Reprogramming of Fibroblasts Into Cardiomyocytes Requires Suppression of Pro-fibrotic Signaling

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Kunhua Song ◽  
Yuanbiao Zhao ◽  
Pilar Londono ◽  
Emily Sharpe ◽  
Joshua R Clair ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
High Efficiency ◽  
Transforming Growth Factor ◽  
Cardiac Fibroblasts ◽  
Rho Kinase ◽  
Transforming Growth Factor Β ◽  
Direct Reprogramming ◽  
Cardiac Gene Expression ◽  
Cardiac Gene ◽  
Kinetics Of

The mammalian heart is composed of ~30% cardiomyocytes which have limited capacity to regenerate and ~70% non-cardiomyocytes including endothelial cells and cardiac fibroblasts. Direct reprogramming of fibroblasts into cardiomyocytes by forced expression of cardiomyogenic transcription factors, GMT (GATA4, Mef2C, Tbx5) or GHMT (GATA4, Hand2, Mef2C, Tbx5), has recently been demonstrated, suggesting a novel therapeutic strategy for cardiac repair. Despite extensive efforts, the efficiency of direct reprogramming of embryonic or adult fibroblasts into cardiomyocytes has yet to exceed 20%, or 0.1% respectively, leading many in the field to question the clinical translatability of this method. Here, we demonstrate that pro-fibrotic signaling events governed by transforming growth factor-β (TGF-β) and Rho kinase (ROCK) are concomitantly activated in GHMT-expressing fibroblasts, leading to potent suppression of cardiac reprogramming ( Figure 1 ). Remarkably, pharmacological inhibition of TGF-β, or ROCK leads to conversion of ≥ 60% of fibroblasts into highly functional cardiomyocytes, displaying global cardiac gene expression, spontaneous contractility, action potentials and calcium transients. Furthermore, inhibition of TGF-β, or ROCK dramatically enhances the kinetics of cardiac reprogramming, with spontaneously contracting cardiomyocytes emerging in less than two weeks, as opposed to 4 weeks with GHMT alone. These findings provide new insights into the molecular mechanisms underlying cardiac conversion of fibroblasts, and should enhance efforts to generate cardiomyocytes for clinical applications.

VEGF-C mediates cyclic pressure-induced endothelial cell proliferation

2002 ◽  
Vol 11 (3) ◽  
pp. 245-251 ◽  
Author(s):  
Hainsworth Y. Shin ◽  
Michael L. Smith ◽  
Karen J. Toy ◽  
P. Mickey Williams ◽  
Rena Bizios ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Growth Factor ◽  
Gene Transcription ◽  
Molecular Mechanisms ◽  
Transforming Growth Factor ◽  
Umbilical Vein ◽  
Culture Conditions ◽  
Endothelial Cell Proliferation ◽  
Cyclic Pressure ◽  
Cell Functions

Mechanical forces modulate endothelial cell functions through several mechanisms including regulation of gene transcription. In the present study, gene transcription by human umbilical vein endothelial cells (HUVEC) either maintained under control pressure (that is, standard cell culture conditions equivalent to 0.15 mmHg sustained hydrostatic pressure) or exposed to 60/20 mmHg sinusoidal pressures at 1 Hz were compared using Affymetrix GeneChip microarrays to identify cellular/molecular mechanisms associated with endothelial cell responses to cyclic pressure. Cyclic pressure selectively affected transcription of 14 genes that included a set of mechanosensitive proteins involved in hemostasis (tissue plasminogen activator), cell adhesion (integrin-α2), and cell signaling (Rho B, cytosolic phospholipase A2), as well as a unique subset of cyclic pressure-sensitive genes such as vascular endothelial growth factor (VEGF)-C and transforming growth factor (TGF)-β2. The present study also provided first evidence that VEGF-C, the most highly induced gene under 60/20 mmHg, mediated HUVEC proliferation in response to this cyclic pressure. Cyclic pressure is, therefore, a mechanical force that modulates endothelial cell functions (such as proliferation) by activating a specific transcriptional program.

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

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.

scholarly journals The Interactions of Nintedanib and Oral Anticoagulants—Molecular Mechanisms and Clinical Implications

2020 ◽  
Vol 22 (1) ◽  
pp. 282
Author(s):  
Grzegorz Grześk ◽  
Anita Woźniak-Wiśniewska ◽  
Jan Błażejewski ◽  
Bartosz Górny ◽  
Łukasz Wołowiec ◽  
...  
Keyword(s):  
Growth Factor ◽  
Molecular Mechanisms ◽  
Kinase Inhibitor ◽  
Therapeutic Option ◽  
Oral Anticoagulants ◽  
Concomitant Administration ◽  
Bleeding Risk ◽  
Interstitial Lung Diseases ◽  
Bleeding Complications ◽  
Endothelial Growth Factor

Nintedanib is a synthetic orally active tyrosine kinase inhibitor, whose main action is to inhibit the receptors of the platelet-derived growth factor, fibroblast growth factor and vascular endothelial growth factor families. The drug also affects other kinases, including Src, Flt-3, LCK, LYN. Nintedanib is used in the treatment of idiopathic pulmonary fibrosis, chronic fibrosing interstitial lung diseases and lung cancer. The mechanism of action suggests that nintedanib should be considered one of the potential agents for inhibiting and revising the fibrosis process related to COVID-19 infections. Due to the known induction of coagulation pathways during COVID-19 infections, possible interaction between nintedanib and anticoagulant seems to be an extremely important issue. In theory, nintedanib could increase the bleeding risk, thrombosis and lead to thrombocytopenia. The data from clinical trials on the concomitant use of nintedanib and antithrombotic agents is very limited as this patient group was within the standard exclusion criteria. Nintedanib is an important therapeutic option, despite its interaction with anticoagulants. If anticoagulant therapy is necessary, the more effective and safer option is the concomitant administration of DOACs and nintedanib, especially when drug-monitored therapy will be used in patients at high risk of bleeding complications.

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.

Mini Review: Recent Advances in the Cell-Based Therapies for Cardiac Regeneration

2020 ◽  
Vol 15 (8) ◽  
pp. 649-660 ◽  
Author(s):  
Lan Luo ◽  
Tao-Sheng Li
Keyword(s):  
Cardiac Fibroblasts ◽  
Cardiac Regeneration ◽  
Cell Types ◽  
Cardiac Stem Cells ◽  
Direct Reprogramming ◽  
Promising Candidate ◽  
Surgical Interventions ◽  
Skeletal Myoblasts ◽  
Novel Approach ◽  
Induced Pluripotent

Cardiovascular diseases (CVDs) are the leading cause of morbidity and mortality globally, and traditional pharmaceutical and surgical interventions delay the progression of CVDs. Recently, stem cell therapy has emerged as a promising candidate for treating and preventing heart failure. Increasing efforts have been devoted towards the exploration and identification of potential cell types to repair the injured heart, such as skeletal myoblasts, embryonic, induced pluripotent, bone marrowderived, mesenchymal, and resident cardiac stem cells. In addition, direct reprogramming of cardiac fibroblasts into cardiomyocytes represents a novel approach to cardiac regeneration. Herein, we summarize the recent progress in the use of various cell types for cardiac regeneration and discuss major challenges and future perspectives of cell-based therapies for CVDs.

Abstract 350: The Developmental Origin Of Cardiac Fibroblasts Influences the Efficiency of Direct Reprogramming to Cardiomyocytes

2017 ◽  
Vol 121 (suppl_1) ◽  
Author(s):  
Sara Ranjbarvaziri ◽  
Reza Ardehali
Keyword(s):  
Neural Crest ◽  
Cardiac Fibroblasts ◽  
Cardiac Regeneration ◽  
Light Sheet ◽  
Direct Conversion ◽  
Direct Reprogramming ◽  
Epigenetic Memory ◽  
A Minor ◽  
Cardiac Transcription Factors ◽  
Regenerative Therapies

Direct conversion of fibroblasts to cardiomyocytes (CM) is advancing the field of cardiac regeneration. Despite advantages of direct reprogramming, the presence of residual epigenetic memory of the original cells may hinder clinical transition. Thus, choosing a starting cell with similar ontogeny to the desired reprogrammed cell may overcome some of the limitations. Expression of key cardiogenic genes shared between cardiac fibroblasts (CFb) and CM in addition to the abundance of these cells, suggest that CFb may be the optimal autologous cell source for therapeutic manipulation in treating heart disease. We hypothesized that progenitors, transiently expressing Mesp1 generate a sub-population of CFb which are more prone to direct reprogramming and adopt a cardiomyocyte gene profile due to their maintained epigenetic memory. We generated a Mesp1CremTmG mouse to label all cells expressing Mesp1 and their progeny and we observed that the majority of the cells in the heart including CFb are derived from Mesp1 cells. We showed that ~80% of resident CFb are derived from Mesp1 while a minor non-Mesp1 subset also exists. We compared the reprogramming efficiency of CFb of Mesp1 origin to CFb of other origin to induced CM (iCM) by overexpression of specific cardiac transcription factors. Results from immunostaining and gene analysis showed higher expression of cardiac muscle markers in CM induced from Mesp1 CFb. To further delineate potential differences between two subsets, we performed RNAseq and our results showed that the non Mesp1 CFb were enriched in neural crest related genes. We generated Pax3CremTmG mice to lineage trace neural crest-derived cells. Our results confirmed a minor contribution of Pax3 cells to CFb. We developed a modified CLARITY technique to transform the heart into an optically-transparent organ for light-sheet fluorescence imaging. We observed that Pax3 CFb were mainly located in the wall of aorta while Mesp1 CFb were distributed throughout the heart. Additionally, we are studying whether each CFb subset has the tendency to generate a specific subtype of iCM (ventricular, atrial, and nodal CM). These results can identify distinct sub-populations of CFb, which can generate functional cardiomyocytes for cardiac-regenerative therapies.

scholarly journals Circular RNA mmu_circ_0005019 inhibits fibrosis of cardiac fibroblasts and reverses electrical remodeling of cardiomyocytes

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Na Wu ◽  
Chengying Li ◽  
Bin Xu ◽  
Ying Xiang ◽  
Xiaoyue Jia ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Cardiac Fibroblasts ◽  
Circular Rna ◽  
Protective Role ◽  
Luciferase Reporter ◽  
Loss Of Function ◽  
Candidate Target ◽  
Paired Control ◽  
Reporter Assays ◽  
And Migration

Abstract Background Circular RNA (circRNA) have been reported to play important roles in cardiovascular diseases including myocardial infarction and heart failure. However, the role of circRNA in atrial fibrillation (AF) has rarely been investigated. We recently found a circRNA hsa_circ_0099734 was significantly differentially expressed in the AF patients atrial tissues compared to paired control. We aim to investigate the functional role and molecular mechanisms of mmu_circ_0005019 which is the homologous circRNA in mice of hsa_circ_0099734 in AF. Methods In order to investigate the effect of mmu_circ_0005019 on the proliferation, migration, differentiation into myofibroblasts and expression of collagen of cardiac fibroblasts, and the effect of mmu_circ_0005019 on the apoptosis and expression of Ito, INA and SK3 of cardiomyocytes, gain- and loss-of-function of cell models were established in mice cardiac fibroblasts and HL-1 atrial myocytes. Dual-luciferase reporter assays and RIP were performed to verify the binding effects between mmu_circ_0005019 and its target microRNA (miRNA). Results In cardiac fibroblasts, mmu_circ_0005019 showed inhibitory effects on cell proliferation and migration. In cardiomyocytes, overexpression of mmu_circ_0005019 promoted Kcnd1, Scn5a and Kcnn3 expression. Knockdown of mmu_circ_0005019 inhibited the expression of Kcnd1, Kcnd3, Scn5a and Kcnn3. Mechanistically, mmu_circ_0005019 exerted biological functions by acting as a miR-499-5p sponge to regulate the expression of its target gene Kcnn3. Conclusions Our findings highlight mmu_circ_0005019 played a protective role in AF development and might serve as an attractive candidate target for AF treatment.

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.

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