scholarly journals In vitro models of human cardiac fibrotic tissue on ‘bioartificial’ scaffolds

Author(s):  
Alice Zoso ◽  
Irene Carmagnola ◽  
Gerardina Ruocco ◽  
Mattia Spedicati ◽  
Valeria Chiono

Cardiac infarction is a global burden worldwide that leads to fibrotic and not contractile myocardial tissue. In this work, in vitro models of infarcted tissue were developed as tools to test novel therapies for cardiac regeneration in the future. Human cardiac fibroblasts were cultured on scaffolds, with different compositions and architectures, as to mimic structural and chemical features of infarcted cardiac tissue. Early findings from in vitro cell tests were reported, showing an enhancement of cell attachment and proliferation in the case of “bioartificial” scaffolds, i.e. scaffolds based on a synthetic and a bioactive polymer.

Author(s):  
Zhe Li ◽  
Tuan T. Nguyen ◽  
Alan Valaperti

AbstractHeart inflammation is one of the major causes of heart damage that leads to dilated cardiomyopathy and often progresses to end-stage heart failure. In the present study, we aimed to assess whether human cardiac cells could release immune mediators upon stimulation of Toll-like receptors (TLRs) and Retinoic acid-inducible gene (RIG)-I-like receptors (RLRs).Commercially available human cardiac fibroblasts and an immortalized human cardiomyocyte cell line were stimulated in vitro with TLR2, TLR3, and TLR4 agonists. In addition, cytosolic RLRs were activated in cardiac cells after transfection of polyinosinic-polycytidylic acid (PolyIC). Upon stimulation of TLR3, TLR4, MDA5, and RIG-I, but not upon stimulation of TLR2, human cardiac fibroblasts produced high amounts of the pro-inflammatory cytokines IL-6 and IL-8. On the contrary, the immortalized human cardiomyocyte cell line was unresponsive to the tested TLRs agonists. Upon RLRs stimulation, cardiac fibroblasts, and to a lesser extent the cardiomyocyte cell line, induced anti-viral IFN-β expression.These data demonstrate that human cardiac fibroblasts and an immortalized human cardiomyocyte cell line differently respond to various TLRs and RLRs ligands. In particular, human cardiac fibroblasts were able to induce pro-inflammatory and anti-viral cytokines on their own. These aspects will contribute to better understand the immunological function of the different cell populations that make up the cardiac tissue.


2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Yi-Li Min ◽  
Svetlana Bezprozvannaya ◽  
Drazen Šošic ◽  
Young-Jae Nam ◽  
Hesham Sadek ◽  
...  

Cardiomyocyte renewal occurs very slowly in adult mammals, and little is known of the genetic basis of cardiac regeneration. Twist is a highly conserved bHLH transcription factor responsible for Drosophila mesoderm formation during embryogenesis. Recent studies have shown that Twist protein is essential for muscle regeneration in adult Drosophila, but the potential role of Twist in the mammalian heart has not been explored. There are two Twist genes in vertebrates, Twist-1 and -2. We show that Twist-1 and -2 are expressed in epicardium and interstitial cells but not in differentiated cardiomyocytes in mice. To understand the potential function of Twist-dependent lineages in the adult heart, we generated inducible Twist2CreERT2; ROSA26-tdTomato reporter mice. By treating these mice with tamoxifen at 8 weeks of age, we observed progressive labeling of various cell types, such as epithelial cells, cardiac fibroblasts, and cardiomyocytes in the heart. We isolated Tomato-positive nonmyocytes from these mice and found that these cells can differentiate into cardiomyocytes and other cell types in vitro. Furthermore, cardiac-specific deletion of both Twist1 and Twist2 resulted in an age-dependent lethal cardiomyopathy. These findings reveal an essential contribution of Twist to long-term maintenance of cardiac function and support the concept of slow, lifelong renewal of cardiomyocytes from a Twist-dependent cell lineage in the adult heart.


Author(s):  
Amelie Degache ◽  
Florence Poulletier de Gannes ◽  
André Garenne ◽  
Rémy Renom ◽  
Yann Percherancier ◽  
...  

2011 ◽  
Vol 301 (3) ◽  
pp. H841-H847 ◽  
Author(s):  
Brett S. Harris ◽  
Yuhua Zhang ◽  
Lauren Card ◽  
Lee B. Rivera ◽  
Rolf A. Brekken ◽  
...  

Cardiac tissue from mice that do not express secreted protein acidic and rich in cysteine (SPARC) have reduced amounts of insoluble collagen content at baseline and in response to pressure overload hypertrophy compared with wild-type (WT) mice. However, the cellular mechanism by which SPARC affects myocardial collagen is not clearly defined. Although expression of SPARC by cardiac myocytes has been detected in vitro, immunohistochemistry of hearts demonstrated SPARC staining primarily associated with interstitial fibroblastic cells. Primary cardiac fibroblasts isolated from SPARC-null and WT mice were assayed for collagen I synthesis by [3H]proline incorporation into procollagen and by immunoblot analysis of procollagen processing. Bacterial collagenase was used to discern intracellular from extracellular forms of collagen I. Increased amounts of collagen I were found associated with SPARC-null versus WT cells, and the proportion of total collagen I detected on SPARC-null fibroblasts without propeptides [collagen-α1(I)] was higher than in WT cells. In addition, the amount of total collagen sensitive to collagenase digestion (extracellular) was greater in SPARC-null cells than in WT cells, indicating an increase in cell surface-associated collagen in the absence of SPARC. Furthermore, higher levels of collagen type V, a fibrillar collagen implicated in collagen fibril initiation, were found in SPARC-null fibroblasts. The absence of SPARC did not result in significant differences in proliferation or in decreased production of procollagen I by cardiac fibroblasts. We conclude that SPARC regulates collagen in the heart by modulating procollagen processing and interactions with fibroblast cell surfaces. These results are consistent with decreased levels of interstitial collagen in the hearts of SPARC-null mice being due primarily to inefficient collagen deposition into the extracellular matrix rather than to differences in collagen production.


Cells ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1733 ◽  
Author(s):  
Michele Filippo Buono ◽  
Lisa von Boehmer ◽  
Jaan Strang ◽  
Simon P. Hoerstrup ◽  
Maximilian Y. Emmert ◽  
...  

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.


2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Tashalee R. Brown ◽  
Trine Krogh-Madsen ◽  
David J. Christini

The adult heart is composed of a dense network of cardiomyocytes surrounded by nonmyocytes, the most abundant of which are cardiac fibroblasts. Several cardiac diseases, such as myocardial infarction or dilated cardiomyopathy, are associated with an increased density of fibroblasts, that is, fibrosis. Fibroblasts play a significant role in the development of electrical and mechanical dysfunction of the heart; however the underlying mechanisms are only partially understood. One widely studied mechanism suggests that fibroblasts produce excess extracellular matrix, resulting in collagenous septa. These collagenous septa slow propagation, cause zig-zag conduction paths, and decouple cardiomyocytes resulting in a substrate for arrhythmia. Another emerging mechanism suggests that fibroblasts promote arrhythmogenesis through direct electrical interactions with cardiomyocytes via gap junctions. Due to the challenges of investigating fibroblast-myocyte coupling in native cardiac tissue, computational modeling andin vitroexperiments have facilitated the investigation into the mechanisms underlying fibroblast-mediated changes in cardiomyocyte action potential morphology, conduction velocity, spontaneous excitability, and vulnerability to reentry. In this paper, we summarize the major findings of the existing computational studies investigating the implications of fibroblast-myocyte interactions in the normal and diseased heart. We then present investigations from our group into the potential role of voltage-dependent gap junctions in fibroblast-myocyte interactions.


2020 ◽  
Vol 134 (1) ◽  
pp. 73-74
Author(s):  
Natalia López-Andrés

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.


Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 451 ◽  
Author(s):  
Priyadharshni Muniyandi ◽  
Vivekanandan Palaninathan ◽  
Srivani Veeranarayanan ◽  
Tomofumi Ukai ◽  
Toru Maekawa ◽  
...  

Cardiac tissue engineering (CTE) aims to generate potential scaffolds to mimic extracellular matrix (ECM) for recreating the injured myocardium. Highly porous scaffolds with properties that aid cell adhesion, migration and proliferation are critical in CTE. In this study, electrospun porous poly (l-lactic acid) (PLLA) porous scaffolds were fabricated and modified with different ECM derived proteins such as collagen, gelatin, fibronectin and poly-L-lysine. Subsequently, adult human cardiac fibroblasts (AHCF) were cultured on the protein modified and unmodified fibers to study the cell behavior and guidance. Further, the cytotoxicity and reactive oxygen species (ROS) assessments of the respective fibers were performed to determine their biocompatibility. Excellent cell adhesion and proliferation of the cardiac fibroblasts was observed on the PLLA porous fibers regardless of the surface modifications. The metabolic rate of cells was on par with the conventional cell culture ware while the proliferation rate surpassed the latter by nearly two-folds. Proteome profiling revealed that apart from being an anchorage platform for cells, the surface topography has modulated significant expression of the cellular proteome with many crucial proteins responsible for cardiac fibroblast growth and proliferation.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Yue Guo ◽  
Xingfeng Xu ◽  
Lingling Wu ◽  
Xiaodong Zhuang ◽  
Xinxue Liao

Introduction: The activation of NF-κB is the dominant process that correlates with the pathogenesis of diabetic cardiomyopathy (DCM). Recently, accumulating evidence shows that long noncoding RNAs (lncRNAs) play crucial roles in sustaining the NF-κB pathway. However, the underlying mechanisms remain unclear. In this study, we identified the upregulated expressed lncRNA NBR2 in adipocyte-derived exosomes (AdEXO) and investigated its regulatory role in diabetic myocardial fibrosis. Hypothesis: We hypothesized that AdEXO-NBR2 promotes diabetic myocardial fibrosis through regulating the IκBα/NF-κB pathway. Methods: We examined the effect of exosomes from diabetic (db/db) mice-derived adipocytes on ANG-II-induced cardiac fibrosis and function in non-diabetic (C57BL/6J mice). In the invitro study, HG (33mmol/L)-stimulated AdEXO were cultured with adult human cardiac fibroblasts (aHCFs). Differentially expressed lncRNAs in AdEXO were screened using lncRNA sequencing. Results: Intramyocardial injection of diabetic AdEXO in the non-diabetic heart significantly exacerbated myocardial fibrosis, as evidenced by poorer cardiac function and enhancer collagen deposition. Whereas administration of a exosomes biogenesis inhibitor mitigated cardiac fibrosis in diabetic mice. We found lncRNA-NBR2 is a common molecule significantly increased in diabetic AdEXO and HG-stimulated non-diabetic AdEXO. After four weeks of ANG II infusion, EXO-db/dbWT-injected mice displayed fibrosis in the heart. However, interestingly, mice receiving NBR2-deficient db/db-EXO showed a decrease in cardiac fibrosis. Similarly, AdEXO-NBR2 promoted aHCFs proliferation and transformation capabilities in vitro. Mechanistically, NBR2 was loaded to AdEXO by directly interacting with heterogeneous nuclear ribonucleoprotein K (hnRNPK). Subsequently, AdEXO-NBR2 was internalized by aHCFs and epigenetically downregulated IκBα expression by recruitment of hnRNPK/SETDB1 and increasing the H3K9 trimethylation level in the IκBα promoter, ultimately activating the NF-κB pathway. Conclusions: Our findings highlight a novel epigenetic mechanism of AdEXO lncRNA-mediated diabetic cardiac fibrosis and identify NBR2 as a therapeutic target of DCM.


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