scholarly journals SKI activates the Hippo pathway via LIMD1 to inhibit cardiac fibroblast activation

2021 ◽  
Vol 116 (1) ◽  
Author(s):  
Natalie M. Landry ◽  
Sunil G. Rattan ◽  
Krista L. Filomeno ◽  
Thomas W. Meier ◽  
Simon C. Meier ◽  
...  
Keyword(s):  
Cardiac Fibroblasts ◽  
Cardiac Fibroblast ◽  
Negative Regulator ◽  
Expression Vectors ◽  
Cell Phenotype ◽  
Hippo Signaling ◽  
Fibroblast Activation ◽  
Elastic Substrates ◽  
Human Cardiac Fibroblasts

AbstractWe have previously shown that overexpression of SKI, an endogenous TGF-β1 repressor, deactivates the pro-fibrotic myofibroblast phenotype in the heart. We now show that SKI also functions independently of SMAD/TGF-β signaling, by activating the Hippo tumor-suppressor pathway and inhibiting the Transcriptional co-Activator with PDZ-binding motif (TAZ or WWTR1). The mechanism(s) by which SKI targets TAZ to inhibit cardiac fibroblast activation and fibrogenesis remain undefined. A rat model of post-myocardial infarction was used to examine the expression of TAZ during acute fibrogenesis and chronic heart failure. Results were then corroborated with primary rat cardiac fibroblast cell culture performed both on plastic and on inert elastic substrates, along with the use of siRNA and adenoviral expression vectors for active forms of SKI, YAP, and TAZ. Gene expression was examined by qPCR and luciferase assays, while protein expression was examined by immunoblotting and fluorescence microscopy. Cell phenotype was further assessed by functional assays. Finally, to elucidate SKI’s effects on Hippo signaling, the SKI and TAZ interactomes were captured in human cardiac fibroblasts using BioID2 and mass spectrometry. Potential interactors were investigated in vitro to reveal novel mechanisms of action for SKI. In vitro assays on elastic substrates revealed the ability of TAZ to overcome environmental stimuli and induce the activation of hypersynthetic cardiac myofibroblasts. Further cell-based assays demonstrated that SKI causes specific proteasomal degradation of TAZ, but not YAP, and shifts actin cytoskeleton dynamics to inhibit myofibroblast activation. These findings were supported by identifying the bi-phasic expression of TAZ in vivo during post-MI remodeling and fibrosis. BioID2-based interactomics in human cardiac fibroblasts suggest that SKI interacts with actin-modifying proteins and with LIM Domain-containing protein 1 (LIMD1), a negative regulator of Hippo signaling. Furthermore, we found that LATS2 interacts with TAZ, whereas LATS1 does not, and that LATS2 knockdown prevented TAZ downregulation with SKI overexpression. Our findings indicate that SKI’s capacity to regulate cardiac fibroblast activation is mediated, in part, by Hippo signaling. We postulate that the interaction between SKI and TAZ in cardiac fibroblasts is arbitrated by LIMD1, an important intermediary in focal adhesion-associated signaling pathways. This study contributes to the understanding of the unique physiology of cardiac fibroblasts, and of the relationship between SKI expression and cell phenotype.

scholarly journals Soluble St2 Induces Cardiac Fibroblast Activation and Collagen Synthesis via Neuropilin-1

Cells ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1667 ◽  
Author(s):  
Lara Matilla ◽  
Vanessa Arrieta ◽  
Eva Jover ◽  
Amaia Garcia-Peña ◽  
Ernesto Martinez-Martinez ◽  
...  
Keyword(s):  
Collagen Synthesis ◽  
Cardiac Fibrosis ◽  
Transforming Growth Factor ◽  
Cardiac Fibroblasts ◽  
Interleukin 1 ◽  
Cardiac Fibroblast ◽  
Pathogenic Role ◽  
Fibroblast Activation ◽  
Neuropilin 1 ◽  
Human Cardiac Fibroblasts

Circulating levels of soluble interleukin 1 receptor-like 1 (sST2) are increased in heart failure and associated with poor outcome, likely because of the activation of inflammation and fibrosis. We investigated the pathogenic role of sST2 as an inductor of cardiac fibroblasts activation and collagen synthesis. The effects of sST2 on human cardiac fibroblasts was assessed using proteomics and immunodetection approaches to evidence the upregulation of neuropilin-1 (NRP-1), a regulator of the profibrotic transforming growth factor (TGF)-β1. In parallel, sST2 increased fibroblast activation, collagen and fibrosis mediators. Pharmacological inhibition of nuclear factor-kappa B (NF-κB) restored NRP-1 levels and blocked profibrotic effects induced by sST2. In NRP-1 knockdown cells, sST2 failed to induce fibroblast activation and collagen synthesis. Exogenous NRP-1 enhanced cardiac fibroblast activation and collagen synthesis via NF-κB. In a pressure overload rat model, sST2 was elevated in association with cardiac fibrosis and was positively correlated with NRP-1 expression. Our study shows that sST2 induces human cardiac fibroblasts activation, as well as the synthesis of collagen and profibrotic molecules. These effects are mediated by NRP-1. The blockade of NF-κB restored NRP-1 expression, improving the profibrotic status induced by sST2. These results show a new pathogenic role for sST2 and its mediator, NRP-1, as cardiac fibroblast activators contributing to cardiac fibrosis.

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.

scholarly journals Inhibition of Mitofusin-2 Promotes Cardiac Fibroblast Activation via the PERK/ATF4 Pathway and Reactive Oxygen Species

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Yanguo Xin ◽  
Wenchao Wu ◽  
Jing Qu ◽  
Xiaojiao Wang ◽  
Song Lei ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Mitochondrial Dynamics ◽  
Cardiac Fibroblasts ◽  
Reactive Oxygen ◽  
Cardiac Fibroblast ◽  
Oxygen Species ◽  
Mitofusin 2 ◽  
Fibroblast Activation

Mitofusin-2 (Mfn2) is a key outer mitochondrial membrane protein, which maintains normal mitochondrial dynamics and function. However, its role in cardiac fibroblast activation remains poorly understood. In the present study, a rat model of transverse aortic constriction (TAC) was established to observe the cardiac fibroblast activation in vivo. TGF-β1 treatment for 24 hours was used to induce cardiac fibroblast activation in vitro. As a result, the expression of Mfn2 decreased in the hypertrophic heart tissues and cardiac fibroblasts treated with TGF-β1. siMfn2 and adenovirus were applied to mediate Mfn2 gene silencing and overexpression in cardiac fibroblasts to elucidate the relationship between Mfn2 and cardiac fibroblast activation, as well as the possible underlying mechanisms. Knockdown of Mfn2 further promoted TGF-β1-induced cardiac fibroblast activation, while forced expression of Mfn2 attenuated this pathological reaction. The PERK/ATF4 pathway, one of the branches of endoplasmic reticulum (ER) stress, was identified to be involved in this process. Knockdown and overexpression of Mfn2 lead to aggravation or alleviation of the PERK/ATF4 pathway. Blocking this pathway by silencing ATF4 with siATF4 attenuated the pathological process. During the activation of cardiac fibroblasts, knockdown of Mfn2 also increased the production of reactive oxygen species (ROS), while ROS scavenger N-acetyl-l-cysteine (NAC) could attenuate the effect caused by knockdown of Mfn2. Our data suggested that inhibition of Mfn2 could promote cardiac fibroblast activation by activating the PERK/ATF4 signaling pathway and increasing the generation of ROS.

scholarly journals Recent Advances in Single-Cell Profiling and Multispecific Therapeutics: Paving the Way for a New Era of Precision Medicine Targeting Cardiac Fibroblasts

2021 ◽  
Vol 23 (7) ◽  
Author(s):  
Sally Yu Shi ◽  
Xin Luo ◽  
Tracy M. Yamawaki ◽  
Chi-Ming Li ◽  
Brandon Ason ◽  
...  
Keyword(s):  
Heart Failure ◽  
Precision Medicine ◽  
Single Cell ◽  
Cardiac Fibroblasts ◽  
Rapid Development ◽  
Cardiac Fibroblast ◽  
New Era ◽  
Fibroblast Activation ◽  
Cell Gene Expression ◽  
The Way

Abstract Purpose of Review Cardiac fibroblast activation contributes to fibrosis, maladaptive remodeling and heart failure progression. This review summarizes the latest findings on cardiac fibroblast activation dynamics derived from single-cell transcriptomic analyses and discusses how this information may aid the development of new multispecific medicines. Recent Findings Advances in single-cell gene expression technologies have led to the discovery of distinct fibroblast subsets, some of which are more prevalent in diseased tissue and exhibit temporal changes in response to injury. In parallel to the rapid development of single-cell platforms, the advent of multispecific therapeutics is beginning to transform the biopharmaceutical landscape, paving the way for the selective targeting of diseased fibroblast subpopulations. Summary Insights gained from single-cell technologies reveal critical cardiac fibroblast subsets that play a pathogenic role in the progression of heart failure. Combined with the development of multispecific therapeutic agents that have enabled access to previously “undruggable” targets, we are entering a new era of precision medicine.

scholarly journals The Functional Role of Zinc Finger E Box-Binding Homeobox 2 (Zeb2) in Promoting Cardiac Fibroblast Activation

2018 ◽  
Vol 19 (10) ◽  
pp. 3207 ◽  
Author(s):  
Fahmida Jahan ◽  
Natalie Landry ◽  
Sunil Rattan ◽  
Ian Dixon ◽  
Jeffrey Wigle
Keyword(s):  
Smooth Muscle ◽  
Zinc Finger ◽  
Cardiac Fibrosis ◽  
Smooth Muscle Actin ◽  
Critical Role ◽  
Cardiac Fibroblast ◽  
In Vivo Studies ◽  
Fibroblast Activation ◽  
E Box

Following cardiac injury, fibroblasts are activated and are termed as myofibroblasts, and these cells are key players in extracellular matrix (ECM) remodeling and fibrosis, itself a primary contributor to heart failure. Nutraceuticals have been shown to blunt cardiac fibrosis in both in-vitro and in-vivo studies. However, nutraceuticals have had conflicting results in clinical trials, and there are no effective therapies currently available to specifically target cardiac fibrosis. We have previously shown that expression of the zinc finger E box-binding homeobox 2 (Zeb2) transcription factor increases as fibroblasts are activated. We now show that Zeb2 plays a critical role in fibroblast activation. Zeb2 overexpression in primary rat cardiac fibroblasts is associated with significantly increased expression of embryonic smooth muscle myosin heavy chain (SMemb), ED-A fibronectin and α-smooth muscle actin (α-SMA). We found that Zeb2 was highly expressed in activated myofibroblast nuclei but not in the nuclei of inactive fibroblasts. Moreover, ectopic Zeb2 expression in myofibroblasts resulted in a significantly less migratory phenotype with elevated contractility, which are characteristics of mature myofibroblasts. Knockdown of Zeb2 with siRNA in primary myofibroblasts did not alter the expression of myofibroblast markers, which may indicate that Zeb2 is functionally redundant with other profibrotic transcription factors. These findings add to our understanding of the contribution of Zeb2 to the mechanisms controlling cardiac fibroblast activation.

Abstract 363: In Situ Cardiac Cellular Reprogramming Using Adenoviral Vectors: Implication for Clinical Myocardial Regeneration

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Megumi Mathison ◽  
Vivek P Singh ◽  
Maria J Chiuchiolo ◽  
Deepthi Sanagasetti ◽  
Yun Mao ◽  
...  
Keyword(s):  
Cardiac Fibroblasts ◽  
Lentiviral Vectors ◽  
Adenoviral Vectors ◽  
Cellular Reprogramming ◽  
Expression Vectors ◽  
Coronary Artery Ligation ◽  
Sprague Dawley ◽  
Artery Ligation ◽  
Lentivirus Vectors

Objective: The reprogramming of cardiac fibroblasts into induced cardiomyocytes (iCMs) improves ventricular function in myocardial infarction models. Only integrating chronic expression vectors have thus far been used to administer reprogramming genes, potentially limiting clinical applicability. We hypothesized that reprogramming could be achieved using non-integrating, acute expression adenoviral vectors. Methods: Adenoviral (Ad) and lentiviral vectors encoding Gata4 (G), Mef2c (M) and Tbx5 (T) were validated in vitro . Sprague Dawley rats then underwent coronary artery ligation and Ad-mediated administration of vascular endothelial growth factor to provide infarct prevascularization. Three weeks later, Ad or lentivirus encoding G, M, or T or an equivalent dose of a null vector was administered. Outcomes were analyzed by serial echocardiography, and by terminal MRI and histology. Results: Ad and lentivirus vectors provided equivalent in vitro GMT expression by Western blotting and AdGMT induced expression of the cardiomyocyte marker cTnT in approximately 7% of cardiac fibroblasts, compared to 4% of cells infected with LentiGMT. Sections of infarcted myocardium from rats that had been treated with AdGMT or LentiGMT demonstrated higher density of cells expressing the cardiomyocyte marker MHY7 compared to AdNull treated animals (p<0.05). Echocardiography demonstrated that AdGMT significantly increased ejection fraction compared to AdNull (AdGMT: 21% ± 3%, LentiGMT: 14% ± 5%, AdNull: -0.4% ± 2%; p<0.05). Conclusions: Adenoviral vectors are at least as effective as lentiviral vectors in inducing cardiac fibroblast transdifferentiation into iCMs and improving cardiac function in post-infarct rat hearts. The utility of short-term expression Ad vectors represents an important potential tool in inducing cardiac cellular reprogramming clinically.

In vitro differentiation of human cardiac fibroblasts into myofibroblasts: characterization using electrical impedance

2021 ◽  
Author(s):  
Amelie Degache ◽  
Florence Poulletier de Gannes ◽  
André Garenne ◽  
Rémy Renom ◽  
Yann Percherancier ◽  
...  
Keyword(s):  
Electrical Impedance ◽  
Cardiac Fibroblasts ◽  
In Vitro Differentiation ◽  
Human Cardiac Fibroblasts

scholarly journals Human Cardiac Organoids for Modeling Genetic Cardiomyopathy

Cells ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1733 ◽  
Author(s):  
Michele Filippo Buono ◽  
Lisa von Boehmer ◽  
Jaan Strang ◽  
Simon P. Hoerstrup ◽  
Maximilian Y. Emmert ◽  
...  
Keyword(s):  
Cardiac Fibroblasts ◽  
Induced Pluripotent Stem Cell ◽  
Patient Specific ◽  
Promising Tool ◽  
Vitro Model ◽  
Human Cardiac Fibroblasts ◽  
Induced Pluripotent ◽  
First Time ◽  
Design And Testing

Genetic cardiomyopathies are characterized by changes in the function and structure of the myocardium. The development of a novel in vitro model could help to better emulate healthy and diseased human heart conditions and may improve the understanding of disease mechanisms. In this study, for the first time, we demonstrated the generation of cardiac organoids using a triculture approach of human induced pluripotent stem-cell-derived cardiomyocytes (hiPS-CMs)—from healthy subjects and cardiomyopathy patients—human cardiac microvascular endothelial cells (HCMECs) and human cardiac fibroblasts (HCFs). We assessed the organoids’ suitability as a 3D cellular model for the representation of phenotypical features of healthy and cardiomyopathic hearts. We observed clear differences in structure and beating behavior between the organoid groups, depending on the type of hiPS-CMs (healthy versus cardiomyopathic) used. Organoids may thus prove a promising tool for the design and testing of patient-specific treatments as well as provide a platform for safer and more efficacious drug development.

scholarly journals (Letter to the Editor) Response to: protective role of peroxiredoxin-4 in heart failure

2020 ◽  
Vol 134 (1) ◽  
pp. 73-74
Author(s):  
Natalia López-Andrés
Keyword(s):  
Heart Failure ◽  
Dilated Cardiomyopathy ◽  
Cardiac Fibroblasts ◽  
Direct Consequence ◽  
Protective Role ◽  
Mitochondrial Proteins ◽  
Galectin 3 ◽  
Human Cardiac Fibroblasts

Abstract We thank Ahmed et al. for their letter regarding our study ‘Galectin-3 down-regulates antioxidant peroxiredoxin-4 in human cardiac fibroblasts’ [1]. As emphasized by Ahmed et al., Prx-4 levels decrease [2] whereas MFN-2, OPA-1 and PGC-1α levels increase [3] in dilated cardiomyopathy (DCM). Moreover, Gal-3 expression is also increased in DCM [4]. In our study, we showed in vitro that Gal-3 decreased Prx-4 without modifying MFN-2 or PGC-1α levels in human cardiac fibroblasts. Although cardiac Prx-4 decrease could be a direct consequence of Gal-3 effects on cardiac fibroblasts, we cannot exclude the possibility that other factors increase MFN-2, OPA-1 and PGC-1α levels in both cardiac fibroblasts or cardiomyocytes in the context of DCM. Further studies are needed to clarify the association between Prx-4 decrease and the increase in other mitochondrial proteins in DCM.

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