scholarly journals Engineering and Assessing Cardiac Tissue Complexity

2021 ◽  
Vol 22 (3) ◽  
pp. 1479
Author(s):  
Karine Tadevosyan ◽  
Olalla Iglesias-García ◽  
Manuel M. Mazo ◽  
Felipe Prósper ◽  
Angel Raya

Cardiac tissue engineering is very much in a current focus of regenerative medicine research as it represents a promising strategy for cardiac disease modelling, cardiotoxicity testing and cardiovascular repair. Advances in this field over the last two decades have enabled the generation of human engineered cardiac tissue constructs with progressively increased functional capabilities. However, reproducing tissue-like properties is still a pending issue, as constructs generated to date remain immature relative to native adult heart. Moreover, there is a high degree of heterogeneity in the methodologies used to assess the functionality and cardiac maturation state of engineered cardiac tissue constructs, which further complicates the comparison of constructs generated in different ways. Here, we present an overview of the general approaches developed to generate functional cardiac tissues, discussing the different cell sources, biomaterials, and types of engineering strategies utilized to date. Moreover, we discuss the main functional assays used to evaluate the cardiac maturation state of the constructs, both at the cellular and the tissue levels. We trust that researchers interested in developing engineered cardiac tissue constructs will find the information reviewed here useful. Furthermore, we believe that providing a unified framework for comparison will further the development of human engineered cardiac tissue constructs displaying the specific properties best suited for each particular application.

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1756 ◽  
Author(s):  
Angeliqua Sayed ◽  
Mariana Valente ◽  
David Sassoon

Embryonic heart progenitors arise at specific spatiotemporal periods that contribute to the formation of distinct cardiac structures. In mammals, the embryonic and fetal heart is hypoxic by comparison to the adult heart. In parallel, the cellular metabolism of the cardiac tissue, including progenitors, undergoes a glycolytic to oxidative switch that contributes to cardiac maturation. While oxidative metabolism is energy efficient, the glycolytic-hypoxic state may serve to maintain cardiac progenitor potential. Consistent with this proposal, the adult epicardium has been shown to contain a reservoir of quiescent cardiac progenitors that are activated in response to heart injury and are hypoxic by comparison to adjacent cardiac tissues. In this review, we discuss the development and potential of the adult epicardium and how this knowledge may provide future therapeutic approaches for cardiac repair.


Author(s):  
Danielle Pretorius ◽  
Asher M. Kahn-Krell ◽  
Xi Lou ◽  
Vladimir G. Fast ◽  
Joel L. Berry ◽  
...  

Engineered cardiac tissues fabricated from human induced pluripotent stem cells (hiPSCs) show promise for ameliorating damage from myocardial infarction, while also restoring function to the damaged left ventricular (LV) myocardium. For these constructs to reach their clinical potential, they need to be of a clinically relevant volume and thickness, and capable of generating synchronous and forceful contraction to assist the pumping action of the recipient heart. Design prerequisites include a structure thickness sufficient to produce a beneficial contractile force, prevascularization to overcome diffusion limitations and sufficient structural development to allow for maximal cell communication. Previous attempts to meet these prerequisites have been hindered by lack of oxygen and nutrient transport due to diffusion limits (100–200 μm) resulting in necrosis. This study employs a layer-by-layer (LbL) fabrication method to produce cardiac tissue constructs that meet these design prerequisites and mimic normal myocardium in form and function. Thick (>2 mm) cardiac tissues created from hiPSC-derived cardiomyocytes, -endothelial cells (ECs) and -fibroblasts (FBs) were assessed, in vitro, over a 4-week period for viability (<6% necrotic cells), cell morphology and functionality. Functional performance assessment showed enhanced t-tubule network development, gap junction communication as well as previously unseen, physiologically relevant conduction velocities (CVs) (>30 cm/s). These results demonstrate that LbL fabrication can be utilized successfully to create prevascularized, functional cardiac tissue constructs from hiPSCs for potential therapeutic applications.


Biomolecules ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 498
Author(s):  
Mojdeh Khajehlandi ◽  
Lotfali Bolboli ◽  
Marefat Siahkuhian ◽  
Mohammad Rami ◽  
Mohammadreza Tabandeh ◽  
...  

Exercise can ameliorate cardiovascular dysfunctions in the diabetes condition, but its precise molecular mechanisms have not been entirely understood. The aim of the present study was to determine the impact of endurance training on expression of angiogenesis-related genes in cardiac tissue of diabetic rats. Thirty adults male Wistar rats were randomly divided into three groups (N = 10) including diabetic training (DT), sedentary diabetes (SD), and sedentary healthy (SH), in which diabetes was induced by a single dose of streptozotocin (50 mg/kg). Endurance training (ET) with moderate-intensity was performed on a motorized treadmill for six weeks. Training duration and treadmill speed were increased during five weeks, but they were kept constant at the final week, and slope was zero at all stages. Real-time polymerase chain reaction (RT-PCR) analysis was used to measure the expression of myocyte enhancer factor-2C (MEF2C), histone deacetylase-4 (HDAC4) and Calmodulin-dependent protein kinase II (CaMKII) in cardiac tissues of the rats. Our results demonstrated that six weeks of ET increased gene expression of MEF2C significantly (p < 0.05), and caused a significant reduction in HDAC4 and CaMKII gene expression in the DT rats compared to the SD rats (p < 0.05). We concluded that moderate-intensity ET could play a critical role in ameliorating cardiovascular dysfunction in a diabetes condition by regulating the expression of some angiogenesis-related genes in cardiac tissues.


Author(s):  
Li Lin ◽  
Wei Xu ◽  
Yongqing Li ◽  
Ping Zhu ◽  
Wuzhou Yuan ◽  
...  

Wnt/β-catenin signalling plays a key role in pathological cardiac remodelling in adults. The identification of a tissue-specific Wnt/β-catenin interaction factor may realise a tissue-specific clinical targeting strategy. Drosophila Pygo codes for the core interaction factor of Wnt/β-catenin. Two Pygo homologs, Pygo1 and Pygo2, have been identified in mammals. Different from the ubiquitous expression profile of Pygo2, Pygo1is enriched in cardiac tissue. However, the role of Pygo1 in mammalian cardiac disease remains unelucidated. Here, we found that Pygo1 was upregulated in human cardiac tissues with pathological hypertrophy. Cardiac-specific overexpression of Pygo1 in mice spontaneously led to cardiac hypertrophy accompanied by declined cardiac function, increased heart weight/body weight and heart weight/tibial length ratios and increased cell size. The canonical β-catenin/T-cell transcription factor 4 complex was abundant in Pygo1-overexpressingtransgenic(Pygo1-TG) cardiac tissue,and the downstream genes of Wnt signaling, i.e., Axin2, Ephb3, and C-myc, were upregulated. A tail vein injection of β-catenin inhibitor effectively rescued the phenotype of cardiac failure and pathological myocardial remodelling in Pygo1-TG mice. Furthermore, in vivo downregulated pygo1 during cardiac hypertrophic condition antagonized agonist-induced cardiac hypertrophy. Therefore, our study is the first to present in vivo evidence demonstrating that Pygo1 regulates pathological cardiac hypertrophy in a canonical Wnt/β-catenin-dependent manner, which may provide new clues for a tissue-specific clinical treatment targeting this pathway.


2018 ◽  
Vol 38 (3) ◽  
pp. 371-377
Author(s):  
SD Nusair ◽  
AN Joukhan ◽  
AH Bani Rashaid ◽  
AM Rababa’h

Methomyl toxicity has been reported as a cause of several accidental and suicidal fatalities. The study is evaluating the effect of lethal methomyl toxicity on fortilin and S100A1 in serum and cardiac tissues. Adult 96 female Sprague-Dawley rats were divided equally into a control (euthanized by cervical dislocation) and a study group (overdosed with methomyl). The levels of fortilin and S100A1 in serum were measured antemortem (to establish the basal levels in serum) and postmortem (to evaluate changes after methomyl exposure) using enzyme-linked immunoassay. S100A1 was immunostained in sections from cardiac tissues. Both proteins in the control were not significantly different ( p > 0.05) compared with the antemortem levels. On the contrast, both biomarkers levels in the intoxicated group were remarkably higher ( p < 0.001) than the control and the antemortem levels. Ventricular tissues from the intoxicated rats presented depleted S100A1 immunostain in cardiomyocytes localized mainly in the epicardium with deeply stained adjacent cardiac fibroblasts. The cardiomyocytes were damaged with a prominent loss of striations compared to normal cardiac tissues from the control. The present outcomes explain to a certain degree the potential toxic effect of methomyl poisoning on the cardiac tissue. Both proteins could be added to the currently available battery of markers for assessing methomyl toxicity.


2017 ◽  
Vol 131 (13) ◽  
pp. 1393-1404 ◽  
Author(s):  
Anastasia Korolj ◽  
Erika Yan Wang ◽  
Robert A. Civitarese ◽  
Milica Radisic

Engineering functional cardiac tissues remains an ongoing significant challenge due to the complexity of the native environment. However, our growing understanding of key parameters of the in vivo cardiac microenvironment and our ability to replicate those parameters in vitro are resulting in the development of increasingly sophisticated models of engineered cardiac tissues (ECT). This review examines some of the most relevant parameters that may be applied in culture leading to higher fidelity cardiac tissue models. These include the biochemical composition of culture media and cardiac lineage specification, co-culture conditions, electrical and mechanical stimulation, and the application of hydrogels, various biomaterials, and scaffolds. The review will also summarize some of the recent functional human tissue models that have been developed for in vivo and in vitro applications. Ultimately, the creation of sophisticated ECT that replicate native structure and function will be instrumental in advancing cell-based therapeutics and in providing advanced models for drug discovery and testing.


2016 ◽  
Vol 26 (1) ◽  
pp. 5-13
Author(s):  
Branko Đukić

Table tennis is acyclic, polistructural sports activity which requires a high degree of physical, psychological, technical and tactical preparedness of the athlete. In the function of development and maintenance of functional ability high level, variety of methods impose, apply different training means, methods and loads. In this paper are presented laboratory and field testing results of aerobic functional capabilities of best ping pong players of Serbia and Serbian youth team before the European Championships in Bratislava in 2015, as well as exercises that can be applied in the training process of functional abilities development. Dosage, intensity and exercise selection should depend on the level of athletes physical fitness, and the level of adoption and trained kicks, athletes age, training periodization and etc.


2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Akitoshi Inui ◽  
Hidekazu Sekine ◽  
Kazunori Sano ◽  
Izumi Dobashi ◽  
Azumi Yoshida ◽  
...  

The definitive treatment of severe heart failure is heart transplantation; however the number of heart transplantation procedures performed in Japan per year ranges from 30-40 due to donor shortage. Therefore, recently other treatments such as ventricular assist device or regenerative therapy by human cardiac tissue engineering have been developed and are considered as appropriate alternatives. We have developed an original technology, which was named cell-sheet based tissue engineering to fabricate functional three-dimensional tissue by layering cell sheets. The utilization of this technique allowed us to successfully engineer thick rat cardiac tissue with perfusable blood vessels in vitro. Here, we demonstrate a technique to engineer human cardiac tissue with perfusable blood vessels using cardiac cell sheets derived from human induced pluripotent stem cells, and porcine small intestine as a vascular bed for perfusion culture. The small intestine was harvested from with a branch of the superior mesenteric artery and vein and underwent mucosal resection after harvested tissue was cut open. To engineer cardiac tissue with perfusable blood vessels, cardiac cell sheets co-cultured with endothelial cells, were triple-layered and then was overlaid on the vascular bed in the bioreactor system. One day after perfusion culture, overlaid cardiac tissues pulsated spontaneously and were synchronized. The cardiac tissue construct was viable tissue without any observable necrosis. Furthermore we examined the possibility of transplantation of the in vitro engineered human cardiac tissue with the connectable host artery and vein. Engineered cardiac tissue was removed from the bioreactor system after 4-day perfusion, and transplanted to another pig heart. The branch of the superior mesenteric artery and vein of the graft were then reconnected to the host internal thoracic artery and vein. When the cardiac tissue reperfused, it began to beat spontaneously after a few minutes. We believe that this method is useful to fabricate functional cardiac tissue and may become an appropriate treatment for severe heart failure.


1987 ◽  
Vol 253 (5) ◽  
pp. H1089-H1097 ◽  
Author(s):  
H. Nakaya ◽  
N. Tohse ◽  
M. Kanno

Recently it has been postulated that oxygen-derived free radicals may be involved in reperfusion-induced arrhythmias. This study was undertaken to evaluate cellular electrophysiological alterations produced by peroxidation of membrane lipids in isolated cardiac tissues. In retrogradely perfused guinea pig hearts, perfusion of organic hydroperoxides, cumene hydroperoxide (CH), and tert-butyl hydroperoxide (TBH) caused conduction disturbances and arrhythmias, concomitantly with an increase in malondialdehyde (MDA) content of the myocardium. The hydroperoxides decreased the maximum diastolic potential, action potential amplitude, and maximum upstroke velocity of phase 0 in both canine Purkinje fibers and guinea pig papillary muscles. They also induced abnormal automaticity, such as depolarization-induced automaticity, delayed afterdepolarizations, and triggered activity. Mechanical abnormalities including increased resting tension and aftercontractions, presumably resulting from intracellular Ca2+ overload, were produced by the hydroperoxides. Pretreatment with butylated hydroxytoluene, an antioxidant, significantly inhibited the hydroperoxide-induced electrophysiological derangements and MDA accumulation in the myocardium. These results suggest that lipid peroxidation of membranes causes various electrophysiological and mechanical abnormalities and may play a role in the genesis of reperfusion-induced arrhythmias.


2002 ◽  
Vol 92 (2) ◽  
pp. 581-585 ◽  
Author(s):  
Jay M. Edelberg ◽  
Jason T. Jacobson ◽  
David S. Gidseg ◽  
Lilong Tang ◽  
David J. Christini

Biosensors play a critical role in the real-time determination of relevant functional physiological needs. However, typical in vivo biosensors only approximate endogenous function via the measurement of surrogate signals and, therefore, may often lack a high degree of dynamic fidelity with physiological requirements. To overcome this limitation, we have developed an excitable tissue-based implantable biosensor approach, which exploits the inherent electropotential input-output relationship of cardiac myocytes to measure the physiological regulatory inputs of chronotropic demand via the detection of blood-borne signals. In this study, we report the improvement of this application through the modulation of host-biosensor communication via the enhancement of vascularization of chronotropic complexes in mice. Moreover, in an effort to further improve translational applicability as well as molecular plasticity, we have advanced this approach by employing stem cell-derived cardiac myocyte aggregates in place of whole cardiac tissue. Overall, these studies demonstrate the potential of biologically based biosensors to predict endogenous physiological dynamics and may facilitate the translation of this approach for in vivo monitoring.


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