251 results found
Kit-Anan W, Mazo M, Wang BX, et al., 2020, Multiplexing physical stimulation on single human induced pluripotent stem cell-derived cardiomyocytes for phenotype modulation, Biofabrication, ISSN: 1758-5082
Traditional in vitro bioengineering approaches whereby only individual biophysical cues are manipulated at any one time are highly inefficient, falling short when recapitulating the complexity of the cardiac environment. Multiple biophysical cues are present in the native myocardial niche and are essential during development, as well as in maintenance of adult cardiomyocyte (CM) phenotype in both health and disease. This study establishes a novel biofabrication workflow to study and manipulate hiPSC-CMs and to understand how these cells respond to a multiplexed biophysical environment, namely microscopic topography (3D shape resembling that of adult CM) and substrate stiffness, at a single cell level. Silicon masters were fabricated and developed to generate pillars of the desired 3D shapes, which would be used to mould the designed microwell arrays into a hydrogel. Polyacrylamide was modified with the incorporation of acrylic acid to provide a carboxylic group conjugation site for adhesion motifs, without comprising its capacity to modulate the stiffness. In this manner, individual parameters can be finely tuned independently within the hydrogel: the dimension of 3D shaped microwell and its stiffness. The design allows the platform to isolate single hiPSC-CMs to study solely biophysical cues in an absence of cell-cell physical interaction. Under physiologic-like physical conditions (3D shape resembling that of adult CM and 9.83 kPa substrate stiffness), isolated single hiPSC-CMs exhibit increased Cx-43 density, cell Peer reviewed version of the manuscript published in final form at Biofabrication (2020). membrane stiffness and calcium transient amplitude; co-expression of the subpopulation-related MYL2- MYL7 proteins; while displaying higher anisotropism in comparison to pathologic-like conditions (flat surface and 112 kPa substrate stiffness). This demonstrates that supplying a physiological or pathological microenvironment to an isolated single hiPSC-CM in absen
Zwi Dantsis L, Winter CW, Kauscher U, et al., 2020, Highly purified extracellular vesicles from human cardiomyocytes demonstrate preferential uptake by human endothelial cells, Nanoscale, Vol: 12, Pages: 19844-19854, ISSN: 2040-3364
Extracellular vesicles (EVs) represent a promising cell-free alternative for treatment of cardiovascular diseases. Nevertheless, the lack of standardised and reproducible isolation methods capable of recovering pure, intact EVs presents a significant obstacle. Additionally, there is significant interest in investigating the interactions of EVs with different cardiac cell types. Here we established a robust technique for the production and isolation of EVs harvested from an enriched (>97% purity) population of human induced pluripotent stem cell (iPSC)-derived cardiomyocytes (CMs) with size exclusion chromatography. Utilizing an advanced fluorescence labelling strategy, we then investigated the interplay of the CM-EVs with the three major cellular components of the myocardium (fibroblasts, cardiomyocytes and endothelial cells) and identified that cardiac endothelial cells show preferential uptake of these EVs. Overall, our findings provide a great opportunity to overcome the translational hurdles associated with the isolation of intact, non-aggregated human iPSC-CM EVs at high purity. Furthermore, understanding in detail the interaction of the secreted EVs with their surrounding cells in the heart may open promising new avenues in the field of EV engineering for targeted delivery in cardiac regeneration.
Lyon A, Babalis D, Morley-Smith AC, et al., 2020, Investigation of the safety and feasibility of AAV1/SERCA2a gene transfer in patients with chronic heart failure supported with a left ventricular assist device – the SERCA-LVAD TRIAL, Gene Therapy, ISSN: 0969-7128
The SERCA-LVAD trial was a phase 2a trial assessing the safety and feasibility of delivering an adeno-associated vector 1 carrying the cardiac isoform of the sarcoplasmic reticulum calcium ATPase (AAV1/SERCA2a) to adult chronic heart failure patients implanted with a left ventricular assist device. Enrolled subjects were randomised to receive a single intracoronary infusion of 1x1013 DNase-resistant AAV1/SERCA2a particles or a placebo solution in a double-blinded design, stratified by presence of neutralising antibodies to AAV. Elective endomyocardial biopsy was performed at 6 months unless the subject had undergone cardiac transplantation, with myocardial samples assessed for the presence of exogenous viral DNA from the treatment vector. Safety assessments including ELISPOT were serially performed. Although designed as a 24 subject trial, recruitment was stopped after five subjects had been randomised and received infusion due to the neutral result from the CUPID 2 trial. Here we describe the results from the 5 patients, which confirmed that viral DNA was delivered to the failing human heart in 2 patients receiving gene therapy with vector detectable at follow up endomyocardial biopsy or cardiac transplantation. Absolute levels of detectable transgene DNA were low, and no functional benefit was observed. There were no safety concerns in this small cohort. This trial identified some of the challenges of performing gene therapy trials in this LVAD patient cohort, which may help guide future trial design.
Fuchs M, Kreutzer FP, Kapsner LA, et al., 2020, Integrative Bioinformatic Analyses of Global Transcriptome Data Decipher Novel Molecular Insights into Cardiac Anti-Fibrotic Therapies, INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES, Vol: 21
Pitoulis F, Watson S, Perbellini F, et al., 2020, Myocardial slices come to age: An intermediate complexity in vitro cardiac model for translational research, Cardiovascular Research, Vol: 116, Pages: 1275-1287, ISSN: 0008-6363
Although past decades have witnessed significant reductions in mortality of heart failure together with advances in our understanding of its cellular, mo-lecular, and whole-heart features, a lot of basic cardiac research still fails to translate into clinical practice.In this review we examine myocardial slices, a novel modelin the translational arena. Myocardial slices are living ultra-thin sections of heart tissue. Slices maintain the myocardium’s native function (contractility, electrophysiology) and structure (multicellularity, extracellular matrix), and can be prepared from animal and human tissue. Thediscussion9beginswith the history and current advances in the model, the different in-terlaboratory methods of preparation and their potentialimpact on results. We then contextualise slices’ advantages and limitations by comparing itwith other cardiac models. Recently, sophisticated methods have enabled slices to be cultured chronically in vitro whilepreserving thefunctional and structural phenotype. This is more timely now than ever where chronic physiologically relevant in vitro platforms for assessment of therapeutic strategies are urgently needed. We interrogate the technological developments that have per-mitted this, their limitations, and future directions. Finally, we look into the general obstacles faced by the translational field, and how implementation of research systems utilising slices could help in resolving these.
King O, Cruz-Moreira D, Kermani F, et al., 2020, NON-MYOCYTE INFLUENCE ON EXCITATION-CONTRACTION COUPLING IN INDUCED PLURIPOTENT STEM CELL DERIVED MYOCARDIUM, Publisher: SPRINGER, Pages: 272-272, ISSN: 0920-3206
Pitoulis FG, Hasan W, Papadaki M, et al., 2020, Intact myocardial preparations reveal intrinsic transmural heterogeneity in cardiac mechanics, Journal of Molecular and Cellular Cardiology, Vol: 141, Pages: 11-16, ISSN: 0022-2828
Determining transmural mechanical properties in the heart provides a foundation to understand physiological and pathophysiological cardiac mechanics. Although work on mechanical characterisation has begun in isolated cells and permeabilised samples, the mechanical profile of living individual cardiac layers has not been examined. Myocardial slices are 300 μm-thin sections of heart tissue with preserved cellular stoichiometry, extracellular matrix, and structural architecture. This allows for cardiac mechanics assays in the context of an intact in vitro organotypic preparation. In slices obtained from the subendocardium, midmyocardium and subepicardium of rats, a distinct pattern in transmural contractility is found that is different from that observed in other models. Slices from the epicardium and midmyocardium had a higher active tension and passive tension than the endocardium upon stretch. Differences in total myocyte area coverage, and aspect ratio between layers underlined the functional readouts, while no differences were found in total sarcomeric protein and phosphoprotein between layers. Such intrinsic heterogeneity may orchestrate the normal pumping of the heart in the presence of transmural strain and sarcomere length gradients in the in vivo heart.
Bardi I, Dries E, Nunez-Toldra R, et al., 2020, The use of living myocardial slices as a novel disease model to study cardiac arrhythmogenicity in vitro, 23rd World Congress of the International-Society-for-Heart-Research (ISHR), Publisher: ELSEVIER SCI LTD, Pages: 49-50, ISSN: 0022-2828
Pitoulis FG, Terracciano CM, 2020, Heart Plasticity in Response to Pressure- and Volume-Overload: A Review of Findings in Compensated and Decompensated Phenotypes, FRONTIERS IN PHYSIOLOGY, Vol: 11, ISSN: 1664-042X
Poulet C, Sanchez-Alonso J, Swiatlowska P, et al., 2020, Junctophilin-2 tethers T-tubules and recruits functional L-type calcium channels to lipid rafts in adult cardiomyocytes, Cardiovascular Research, ISSN: 0008-6363
Aim: In cardiomyocytes, transverse tubules (T-tubules) associate with the sarcoplasmic reticulum (SR), forming junctional membrane complexes (JMCs) where L-type calcium channels (LTCCs) are juxtaposed to Ryanodine receptors (RyR). Junctophilin-2 (JPH2) supports the assembly of JMCs by tethering T-tubules to the SR membrane. T-tubule remodeling in cardiac diseases is associated with down-regulation of JPH2 expression suggesting that JPH2 plays a crucial role in T-tubule stability. Furthermore, increasing evidence indicate that JPH2 might additionally act as a modulator of calcium signaling by directly regulating RyR and LTCCs. This study aimed at determining whether JPH2 overexpression restores normal T-tubule structure and LTCC function in cultured cardiomyocytes.Methods and results: Rat ventricular myocytes kept in culture for 4 days showed extensive T-tubule remodeling with impaired JPH2 localization and relocation of the scaffolding protein Caveolin3 (Cav3) from the T-tubules to the outer membrane. Overexpression of JPH2 restored T-tubule structure and Cav3 relocation. Depletion of membrane cholesterol by chronic treatment with Methyl-β-cyclodextrin (MβCD) countered the stabilizing effect of JPH2 overexpression on T-tubules and Cav3. Super-resolution scanning patch-clamp showed that JPH2 overexpression greatly increased the number of functional LTCCs at the plasma membrane. Treatment with MβCD reduced LTCC open probability and activity. Proximity ligation assays showed that MβCD did not affect JPH2 interaction with RyR and the pore-forming LTCC subunit Cav1.2, but strongly impaired JPH2 association with Cav3 and the accessory LTCC subunit Cavβ2. Conclusions: JPH2 promotes T-tubule structural stability and recruits functional LTCCs to the membrane, most likely by directly binding to the channel. Cholesterol is involved in the binding of JPH2 to T-tubules as well as in the modulation of LTCC activity. We propose a model where cholesterol an
Zwi Dantsis L, Wang B, Marijon C, et al., 2020, Remote magnetic nanoparticle manipulation enables the dynamic patterning of cardiac tissues, Advanced Materials, Vol: 32, Pages: 1-6, ISSN: 0935-9648
The ability to manipulate cellular organization within soft materials has important potential in biomedicine and regenerative medicine; however, it often requires complex fabrication procedures. Here, we develop a simple, cost-effective, and one-step approach that enables the control of cell orientation within 3-dimensional (3D) collagen hydrogels to dynamically create various tailored microstructures of cardiac tissues. This isachieved by incorporating iron-oxide nanoparticles into human cardiomyocytes (CMs) and applying a short-term external magnetic field to orient the cells along the applied field to impart different shapes without any mechanical supports. The patterned constructs areviable and functional, canbe detected by T2*-weighted MRI and induceno alteration to normal cardiac function after grafting onto rat hearts. This strategy paves the way to creating customized, macroscale, 3D tissue constructs with various cell-types for therapeutic and bioengineering applications, as well as providing powerful models for investigating tissue behavior.
Dries E, Bardi I, Pitoulis F, et al., 2020, A Novel in vitro Model using Organotypic Cardiac Slices Reveals Transmural Heterogeneity in Arrhythmogenic Ca2+ Events after Cardiac Injury, 64th Annual Meeting of the Biophysical-Society, Publisher: CELL PRESS, Pages: 254A-254A, ISSN: 0006-3495
King O, Cruz-Moreira D, Kit-Anan SW, et al., 2020, Vascularized Myocardium-On-A-Chip: Excitation-Contraction Coupling in Perfused Cardiac Co-Cultures, 64th Annual Meeting of the Biophysical-Society, Publisher: CELL PRESS, Pages: 410A-410A, ISSN: 0006-3495
Pitoulis FG, Nunez-Toldra R, Kit-Anan WS, et al., 2020, Exploring Mechanical Load-Induced Cardiac Remodelling Using a Novel Organotypic Myocardial Slice Model, 64th Annual Meeting of the Biophysical-Society, Publisher: CELL PRESS, Pages: 425A-425A, ISSN: 0006-3495
Fourre JD, Bardi I, King O, et al., 2019, Endothelial cell activation by pro-inflammatory cytokines exerts novel paracrine effects on cocultured cardiomyocytes, Publisher: WILEY, Pages: 91-91, ISSN: 1748-1708
Sanzari I, Dinelli F, Humphrey E, et al., 2019, Microstructured hybrid scaffolds for aligning neonatal rat ventricular myocytes, MATERIALS SCIENCE & ENGINEERING C-MATERIALS FOR BIOLOGICAL APPLICATIONS, Vol: 103, ISSN: 0928-4931
Jabbour R, Owen T, Reinsch M, et al., 2019, Development and preclinical testing of upscaled engineered heart tissue for use in translational studies, Congress of the European-Society-of-Cardiology (ESC) / World Congress of Cardiology, Publisher: OXFORD UNIV PRESS, Pages: 3273-3273, ISSN: 0195-668X
Fourre J, Bardi I, Maughan RT, et al., 2019, Endothelial cell activation by pro-inflammatory cytokines exerts novel paracrine effects on co-cultured cardiomyocytes, Congress of the European-Society-of-Cardiology (ESC) / World Congress of Cardiology, Publisher: OXFORD UNIV PRESS, Pages: 3904-3904, ISSN: 0195-668X
Pitoulis F, Perbellini F, Harding SE, et al., 2019, Mechanical heterogeneity across the left ventricular wall - a study using intact multicellular preparations, Congress of the European-Society-of-Cardiology (ESC) / World Congress of Cardiology, Publisher: OXFORD UNIV PRESS, Pages: 3264-3264, ISSN: 0195-668X
Ou Q, Jacobson Z, Abouleisa R, et al., 2019, Physiological Biomimetic Culture System for Pig and Human Heart Slices, Circulation Research, Vol: 125, Pages: 628-642, ISSN: 0009-7330
RATIONALE: Preclinical testing of cardiotoxicity and efficacy of novel heart failure therapies faces a major limitation: the lack of an in situ culture system that emulates the complexity of human heart tissue and maintains viability and functionality for a prolonged time. OBJECTIVE: To develop a reliable, easily reproducible, medium-throughput method to culture pig and human heart slices under physiological conditions for a prolonged period of time. METHODS AND RESULTS: Here, we describe a novel, medium-throughput biomimetic culture system that maintains viability and functionality of human and pig heart slices (300 µm thickness) for 6 days in culture. We optimized the medium and culture conditions with continuous electrical stimulation at 1.2 Hz and oxygenation of the medium. Functional viability of these slices over 6 days was confirmed by assessing their calcium homeostasis, twitch force generation, and response to β-adrenergic stimulation. Temporal transcriptome analysis using RNAseq at day 2, 6, and 10 in culture confirmed overall maintenance of normal gene expression for up to 6 days, while over 500 transcripts were differentially regulated after 10 days. Electron microscopy demonstrated intact mitochondria and Z-disc ultra-structures after 6 days in culture under our optimized conditions. This biomimetic culture system was successful in keeping human heart slices completely viable and functionally and structurally intact for 6 days in culture. We also used this system to demonstrate the effects of a novel gene therapy approach in human heart slices. Furthermore, this culture system enabled the assessment of contraction and relaxation kinetics on isolated single myofibrils from heart slices after culture. CONCLUSIONS: We have developed and optimized a reliable medium-throughput culture system for pig and human heart slices as a platform for testing the efficacy of novel heart failure therapeutics and reliable testing of cardiotoxicity in a 3D heart
Wang BX, Kit-Anan W, Whittaker T, et al., 2019, Regulation of cardiac excitation-contraction coupling by human cardiac fibroblasts in health and disease, British-Pharmacology-Society Meeting (Pharmacology), Publisher: WILEY, Pages: 3034-3035, ISSN: 0007-1188
Watson S, Duff J, Bardi I, et al., 2019, Biomimetic electromechanical stimulation to maintain adult myocardial slices in vitro, Nature Communications, Vol: 10, ISSN: 2041-1723
Adult cardiac tissue undergoes a rapid process of dedifferentiation when cultured outside the body. The in vivo environment, particularly constant electromechanical stimulation, is fundamental to the regulation of cardiac structure and function. We investigated the role of electromechanical stimulation in preventing culture-induced dedifferentiation of adult cardiac tissue using rat, rabbit and human heart failure myocardial slices. Here we report that the application of a preload equivalent to sarcomere length (SL) = 2.2 μm is optimal for the maintenance of rat myocardial slice structural, functional and transcriptional properties at 24 h. Gene sets associated with the preservation of structure and function are activated, while gene sets involved in dedifferentiation are suppressed. The maximum contractility of human heart failure myocardial slices at 24 h is also optimally maintained at SL = 2.2 μm. Rabbit myocardial slices cultured at SL = 2.2 μm remain stable for 5 days. This approach substantially prolongs the culture of adult cardiac tissue in vitro.
Jabbour R, Owen T, Reinsch M, et al., 2019, DEVELOPMENT AND PRECLINICAL TESTING OF A LARGE HEART MUSCLE PATCH, Annual Conference of the British-Cardiovascular-Society (BCS) - Digital Health Revolution, Publisher: BMJ PUBLISHING GROUP, Pages: A157-A158, ISSN: 1355-6037
Kreutzer FP, Meinecke A, Fiedler J, et al., 2019, HFWM: Natural compound-derived small molecules to target fibrosis, Publisher: WILEY, Pages: 319-319, ISSN: 1388-9842
Wang BX, Kit-Anan W, Whittaker T, et al., 2019, Human Cardiac Fibroblast-Secreted Exosomes Improve Efficiency of Human Cardiomyocyte Calcium Cycling, Publisher: SPRINGER, Pages: 269-269, ISSN: 0920-3206
Perbellini F, Watson SA, Thum T, et al., 2019, Adult myocardial slices a highly viable and functional platform to study cardiac biology, Publisher: WILEY, Pages: 42-43, ISSN: 0014-2972
Watson SA, Terracciano CM, Perbellini F, 2019, Myocardial sices: an intermediate complexity platform for translational cardiovascular research, Cardiovascular Drugs and Therapy, Vol: 33, Pages: 239-244, ISSN: 0920-3206
Myocardial slices, also known as "cardiac tissue slices" or "organotypic heart slices," are ultrathin (100-400 μm) slices of living adult ventricular myocardium prepared using a high-precision vibratome. They are a model of intermediate complexity as they retain the native multicellularity, architecture, and physiology of the heart, while their thinness ensures adequate oxygen and metabolic substrate diffusion in vitro. Myocardial slices can be produced from a variety of animal models and human biopsies, thus providing a representative human in vitro platform for translational cardiovascular research. In this review, we compare myocardial slices to other in vitro models and highlight some of the unique advantages provided by this platform. Additionally, we discuss the work performed in our laboratory to optimize myocardial slice preparation methodology, which resulted in highly viable myocardial slices from both large and small mammalian hearts with only 2-3% cardiomyocyte damage and preserved structure and function. Applications of myocardial slices span both basic and translational cardiovascular science. Our laboratory has utilized myocardial slices for the investigation of cardiac multicellularity, visualizing 3D collagen distribution and micro/macrovascular networks using tissue clearing protocols and investigating the effects of novel conductive biomaterials on cardiac physiology. Myocardial slices have been widely used for pharmacological testing. Finally, the current challenges and future directions for the technology are discussed.
King O, Kermani F, Wang B, et al., 2019, Endothelial Cell Regulation of Excitation-Contraction Coupling in Induced Pluripotent Stem Cell Derived Myocardium, 63rd Annual Meeting of the Biophysical-Society, Publisher: CELL PRESS, Pages: 153A-153A, ISSN: 0006-3495
Pitoulis F, Watson SA, Dries E, et al., 2019, Myocardial Slices - A Novel Platform for In Vitro Biomechanical Studies, 63rd Annual Meeting of the Biophysical-Society, Publisher: CELL PRESS, Pages: 30A-30A, ISSN: 0006-3495
Dubey P, Humphrey E, Majid Q, et al., 2019, Polyhydroxyalkanoates, ideal materials for cardiac regeneration, ISSN: 1526-7547
© 2019 Omnipress - All rights reserved. Statement of purpose: Polyhydroxyalkanoates (PHAs), a family of biodegradable and biocompatible polymers with a range of material properties and degradation rates are known to be particularly cardio-regenerative in nature1,2,3. Myocardial infarction results in the generation of scar tissue with limited or no regeneration due to the modest nature of intrinsic myocardial regenerative capability. The concept of a cardiac patch is tailored to meet the unmet medical need of cardiac regeneration where a biomaterial-based patch with/without cells would be used to induce efficient cardiac regeneration. Medium chain length PHAs (MCL-PHAs) with monomer chain length between C6-C16 are highly elastomeric in nature1,2 and have been shown to be excellent substrates for the growth and function of neonatal cardiomyocytes3. This work describes an in-depth study of the potential of MCL-PHAs for the development of functional cardiac patches laden with human pluripotent stem cell derived cardiomyocytes (hiPSC-CMs), providing mechanical support and cell based therapy.
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.