scholarly journals Cardiac Cell Patterning on Customized Microelectrode Arrays for Electrophysiological Recordings

Micromachines ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1351
Author(s):  
Jiaying Ji ◽  
Xiang Ren ◽  
Pinar Zorlutuna
Keyword(s):  
Electrical Activity ◽  
Cardiac Electrophysiology ◽  
Electrical Coupling ◽  
Microelectrode Arrays ◽  
Field Potential ◽  
Induced Pluripotent Stem Cell ◽  
Essential Elements ◽  
Neonatal Rat ◽  
Rat Cardiomyocytes ◽  
Coupling Dynamics

Cardiomyocytes (CMs) and fibroblast cells are two essential elements for cardiac tissue structure and function. The interactions between them can alter cardiac electrophysiology and thus contribute to cardiac diseases, such as arrhythmogenesis. One possible explanation is that fibroblasts can directly affect cardiac electrophysiology through electrical coupling with CMs. Therefore, detecting the electrical activities in the CM-fibroblast network is vital for understanding the coupling dynamics among them. Current commercialized platforms for studying cardiac electrophysiology utilize planar microelectrode arrays (MEAs) to record the extracellular field potential (FP) in real-time, but the prearranged electrode configuration highly limits the measurement capabilities at specific locations. Here, we report a custom-designed MEA device with a novel micropatterning method to construct a controlled network of neonatal rat CMs (rCMs) and fibroblast connections for monitoring the electrical activity of rCM-fibroblast co-cultures in a spatially controlled fashion. For the micropatterning of the co-culture, surface topographical features and mobile blockers were used to control the initial attachment locations of a mixture of neonatal rat cardiomyocytes (rCMs) and fibroblasts, to form separate beating rCM-fibroblast clusters while leaving empty space for fibroblast growth to connect these clusters. Once the blockers are removed, the proliferating fibroblasts connect and couple the separate beating clusters. Using this method, electrical activity of both rCMs and human-induced-pluripotent-stem-cell-derived cardiomyocytes (iCMs) was examined. The coupling dynamics were studied through the extracellular FP and impedance profile recorded from the MEA device, indicating that the fibroblast bridge provided an RC-type coupling of physically separate rCM-containing clusters and enabled synchronization of these clusters.

Abstract 13963: Evidence of Content-Dependent Functional and Electrical Coupling of Human Induced Pluripotent Stem Cell-Derived Engineered Cardiac Tissue With Chronic Infarct Rat Myocardium

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Hiroko Iseoka ◽  
Shigeru Miyagawa ◽  
Satsuki Fukushima ◽  
Shin Yajima ◽  
Atsuhiro Saito ◽  
...  
Keyword(s):  
Stem Cell ◽  
Pluripotent Stem Cell ◽  
Cardiac Tissue ◽  
Electrical Coupling ◽  
Induced Pluripotent Stem Cell ◽  
Neonatal Rat ◽  
Therapeutic Effects ◽  
Rat Cardiomyocytes ◽  
Induced Pluripotent

Background: It has been shown that transplantation of engineered cardiac tissue (ECT) derived from human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) into the infarct heart induces electrical communication between the ECT and the native myocardium; however, factors enhancing the electrical integrity and thus the therapeutic effects are not fully understood. We herein hypothesized that content of cardiomyocytes in the ECT may be a key to achieve efficient electrical coupling and functional contribution in chronic rat myocardial infarction (MI) heart. Methods and Results: Neonatal rat cardiomyocytes (NRCM), mimicking the host myocardium, were partially covered by the ECT containing iPSC-CMs produced by thermoresponsive culture dishes in vitro , to explore electrical communication of the ECT with myocardium. As a result, the NRCM and the ECT showed spontaneous, individual contractions for 2 hours, though they gradually showed electrical and motional synchronization, featuring transmitted electrical pulse from the NRCM to the ECT, as assessed by multi-electrode array. Subsequently, the ECT of different ratios (25, 50, 70, and 90%) of iPSC-CMs were generated by magnetic-activated cell sorting using cardiac specific cell surface marker. As a result, the 70% group exhibited the highest contractile and relaxation properties in vitro , as assessed by high-speed video microscopy image-based motion analysis and Ca transient measurement. Finally, the ECTs including 25, 50, 70% CMs were transplanted to immune deficient rat MI model (n=7 each). As a result, ejection fraction was significantly improved in the 50% (52±10%) and 70% (52±12%) groups, but not in the 25% group (35±5%), as compared to the control (35±10%; P <0.05). Epicardial optical mapping of Langendorff perfused heart on day 3 showed that the ECTs of 50% and the 70% groups exhibited electrical activity and synchronization with the native myocardium. Conclusion: Transplantation of the ECT improved cardiac performance associated with synchronization with the myocardium in rat infarction model, dependent upon content of the cardiomyocytes in the ECT. It was thus suggested that transplanted ECT may behave “working cardiac construct” in the damaged heart.

scholarly journals Cardiomyocyte functional screening: interrogating comparative electrophysiology of high-throughput model cell systems

2019 ◽  
Vol 317 (6) ◽  
pp. C1256-C1267 ◽  
Author(s):  
Simon P. Wells ◽  
Helen M. Waddell ◽  
Choon Boon Sim ◽  
Shiang Y. Lim ◽  
Gabriel B. Bernasochi ◽  
...  
Keyword(s):  
Conduction Velocity ◽  
High Throughput ◽  
Microelectrode Array ◽  
Ventricular Myocytes ◽  
Field Potential ◽  
Induced Pluripotent Stem Cell ◽  
Neonatal Rat ◽  
Functional Screening ◽  
Electrophysiological Properties

Cardiac arrhythmias of both atrial and ventricular origin are an important feature of cardiovascular disease. Novel antiarrhythmic therapies are required to overcome current drug limitations related to effectiveness and pro-arrhythmia risk in some contexts. Cardiomyocyte culture models provide a high-throughput platform for screening antiarrhythmic compounds, but comparative information about electrophysiological properties of commonly used types of cardiomyocyte preparations is lacking. Standardization of cultured cardiomyocyte microelectrode array (MEA) experimentation is required for its application as a high-throughput platform for antiarrhythmic drug development. The aim of this study was to directly compare the electrophysiological properties and responses to isoproterenol of three commonly used cardiac cultures. Neonatal rat ventricular myocytes (NRVMs), immortalized atrial HL-1 cells, and custom-generated human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) were cultured on microelectrode arrays for 48–120 h. Extracellular field potentials were recorded, and conduction velocity was mapped in the presence/absence of the β-adrenoceptor agonist isoproterenol (1 µM). Field potential amplitude and conduction velocity were greatest in NRVMs and did not differ in cardiomyocytes isolated from male/female hearts. Both NRVMs and hiPSC-CMs exhibited longer field potential durations with rate dependence and were responsive to isoproterenol. In contrast, HL-1 cells exhibited slower conduction and shorter field potential durations and did not respond to 1 µM isoproterenol. This is the first study to compare the intrinsic electrophysiologic properties of cultured cardiomyocyte preparations commonly used for in vitro electrophysiology assessment. These findings offer important comparative data to inform methodological approaches in the use of MEA and other techniques relating to cardiomyocyte functional screening investigations of particular relevance to arrhythmogenesis.

scholarly journals Peroxisomes contribute to intracellular calcium dynamics

2020 ◽  
Author(s):  
Yelena Sargsyan ◽  
Uta Bickmeyer ◽  
Katrin Streckfuss-Bömeke ◽  
Ivan Bogeski ◽  
Sven Thoms
Keyword(s):  
Intracellular Calcium ◽  
Hela Cells ◽  
Calcium Influx ◽  
Induced Pluripotent Stem Cell ◽  
Cytosolic Calcium ◽  
Neonatal Rat ◽  
Calcium Handling ◽  
Calcium Stores ◽  
Calcium Dynamics ◽  
Rat Cardiomyocytes

AbstractPeroxisomes communicate with other cellular compartments by transfer of various metabolites. However, whether peroxisomes are sites for calcium handling and exchange has remained contentious. Here we generated sensors for assessment of peroxisomal calcium and applied them for single cell-based calcium imaging in HeLa cells and cardiomyocytes. We found that peroxisomes in HeLa cells take up calcium upon depletion of intracellular calcium stores and upon calcium influx across the plasma membrane. Further, we show that peroxisomes of neonatal rat cardiomyocytes and human induced pluripotent stem cell-derived cardiomyocytes can take up calcium in a controlled manner. Our results indicate that peroxisomal and cytosolic calcium signals are tightly interconnected. Hence, peroxisomes may play an important role in shaping cellular calcium dynamics by serving as buffers or sources of intracellular calcium.

scholarly journals Peroxisomes contribute to intracellular calcium dynamics in cardiomyocytes and non-excitable cells

2021 ◽  
Vol 4 (9) ◽  
pp. e202000987
Author(s):  
Yelena Sargsyan ◽  
Uta Bickmeyer ◽  
Christine S Gibhardt ◽  
Katrin Streckfuss-Bömeke ◽  
Ivan Bogeski ◽  
...  
Keyword(s):  
Intracellular Calcium ◽  
Hela Cells ◽  
Calcium Influx ◽  
Induced Pluripotent Stem Cell ◽  
Cytosolic Calcium ◽  
Neonatal Rat ◽  
Calcium Handling ◽  
Calcium Stores ◽  
Calcium Dynamics ◽  
Rat Cardiomyocytes

Peroxisomes communicate with other cellular compartments by transfer of various metabolites. However, whether peroxisomes are sites for calcium handling and exchange has remained contentious. Here we generated sensors for assessment of peroxisomal calcium and applied them for single cell-based calcium imaging in HeLa cells and cardiomyocytes. We found that peroxisomes in HeLa cells take up calcium upon depletion of intracellular calcium stores and upon calcium influx across the plasma membrane. Furthermore, we show that peroxisomes of neonatal rat cardiomyocytes and human induced pluripotent stem cell–derived cardiomyocytes can take up calcium. Our results indicate that peroxisomal and cytosolic calcium signals are tightly interconnected both in HeLa cells and in cardiomyocytes. Cardiac peroxisomes take up calcium on beat-to-beat basis. Hence, peroxisomes may play an important role in shaping cellular calcium dynamics of cardiomyocytes.

scholarly journals Electrophysiology of hiPSC-Cardiomyocytes Co-Cultured with HEK Cells Expressing the Inward Rectifier Channel

2021 ◽  
Vol 22 (12) ◽  
pp. 6621
Author(s):  
Ana Da Silva Costa ◽  
Peter Mortensen ◽  
Maria P. Hortigon-Vinagre ◽  
Marcel A. G. van der Heyden ◽  
Francis L. Burton ◽  
...  
Keyword(s):  
Electrical Activity ◽  
Cardiac Electrophysiology ◽  
Induced Pluripotent Stem Cell ◽  
Mechanical Activity ◽  
Human Embryonic Kidney ◽  
Minor Variation ◽  
Spontaneous Rate ◽  
Induced Pluripotent ◽  
Electrophysiological Effects ◽  
Kir2.1 Channel

The immature electrophysiology of human-induced pluripotent stem cell-derived cardiomyocytes (hiCMs) complicates their use for therapeutic and pharmacological purposes. An insufficient inward rectifying current (IK1) and the presence of a funny current (if) cause spontaneous electrical activity. This study tests the hypothesis that the co-culturing of hiCMs with a human embryonic kidney (HEK) cell-line expressing the Kir2.1 channel (HEK-IK1) can generate an electrical syncytium with an adult-like cardiac electrophysiology. The mechanical activity of co-cultures using different HEK-IK1:hiCM ratios was compared with co-cultures using wildtype (HEK–WT:hiCM) or hiCM alone on days 3–8 after plating. Only ratios of 1:3 and 1:1 showed a significant reduction in spontaneous rate at days 4 and 6, suggesting that IK1 was influencing the electrophysiology. Detailed analysis at day 4 revealed an increased incidence of quiescent wells or sub-areas. Electrical activity showed a decreased action potential duration (APD) at 20% and 50%, but not at 90%, alongside a reduced amplitude of the aggregate AP signal. A computational model of the 1:1 co-culture replicates the electrophysiological effects of HEK–WT. The addition of the IK1 conductance reduced the spontaneous rate and APD20, 50 and 90, and minor variation in the intercellular conductance caused quiescence. In conclusion, a 1:1 co-culture HEK-IK1:hiCM caused changes in electrophysiology and spontaneous activity consistent with the integration of IK1 into the electrical syncytium. However, the additional electrical effects of the HEK cell at 1:1 increased the possibility of electrical quiescence before sufficient IK1 was integrated into the syncytium.

EFFECTS OF ACUTE HYPERGLYCEMIA AND INSULIN INTERVENTION ON THE SPONTANEOUS FIELD POTENTIAL OF SINOATRIAL NODE TISSUE BY USING MICROELECTRODE ARRAYS

2015 ◽  
Vol 15 (04) ◽  
pp. 1550046
Author(s):  
YU FENG ◽  
HUI CAO ◽  
YANBIN ZHANG
Keyword(s):  
Frequency Domain ◽  
Time Domain ◽  
Cardiac Electrophysiology ◽  
Sinoatrial Node ◽  
Heart Diseases ◽  
Microelectrode Arrays ◽  
Field Potential ◽  
Acute Hyperglycemia ◽  
The Time Domain ◽  
The Impact

Traditional studies on the relationship between hyperglycemia and heart diseases generally focused on the impact of chronic and long-term effect of diabetes on cardiac functions. Most of the methods were culturing myocardial cells and giving outside stimulations. However, recent studies show that acute hyperglycemia might play a significant role in spontaneous cardiac electrophysiology. In this research we applied microelectrode arrays (MEA) to record the spontaneous sinoatrial node field potentials of C57/BL6J mice and analyzed the effects of different glucose concentrations in time domain and frequency domain by using statistical method, vector maps and fast Fourier transform (FFT). Meanwhile, we studied the effects of insulin interference in the experimental process. When the concentration of the glucose solution was greater than 40 mmol/L, the spontaneous sinoatrial node field potential changed markedly. In the time domain, the amplitude decreased rapidly and the conductive characteristics were disordered. In the frequency domain, the two spectrum peaks decreased rapidly. These changes were irreversible. However, insulin preconditioning could inhibit the impact of high glucose.

scholarly journals INVESTIGATION OF MICRO SPIRAL WAVES AT CELLULAR LEVEL USING A MICROELECTRODE ARRAYS TECHNOLOGY

2011 ◽  
Vol 21 (01) ◽  
pp. 209-223 ◽  
Author(s):  
S. JACQUIR ◽  
S. BINCZAK ◽  
B. XU ◽  
G. LAURENT ◽  
D. VANDROUX ◽  
...  
Keyword(s):  
Monolayer Culture ◽  
Microelectrode Arrays ◽  
Spiral Wave ◽  
Cellular Level ◽  
Spiral Waves ◽  
Neonatal Rat ◽  
Cardiac Muscle Cells ◽  
Rat Cardiomyocytes ◽  
Severe Arrhythmia

During cardiac arrhythmia, functional reentries may take the form of spiral waves. The purpose of this study was to induce spiral waves by an electrical stimulation of cultured neonatal rat cardiomyocytes using a microelectrode arrays technology. In basal conditions, cardiac muscle cells in monolayer culture displayed a planar wavefront propagation. External electrical impulse trains induced severe arrhythmia and spiral waves appeared. This in vitro generation of spiral wave opens a new way to test the anti-arrhythmic drugs and for strategies at microscopically scale.

scholarly journals Machine-readable Yin–Yang imbalance: traditional Chinese medicine syndrome computer modeling based on three-dimensional noninvasive cardiac electrophysiology imaging

2019 ◽  
Vol 47 (4) ◽  
pp. 1580-1591 ◽  
Author(s):  
Wei Cen ◽  
Ralph Hoppe ◽  
Aiwu Sun ◽  
Hongyan Ding ◽  
Ning Gu
Keyword(s):  
Chinese Medicine ◽  
Traditional Chinese Medicine ◽  
Electrical Activity ◽  
Computer Modeling ◽  
Cardiac Electrophysiology ◽  
Three Dimensional ◽  
Mathematical Physics ◽  
Syndrome Differentiation ◽  
Physics Model ◽  
Machine Readable

Objectives The principal diagnostic methods of traditional Chinese medicine (TCM) are inspection, auscultation and olfaction, inquiry, and pulse-taking. Treatment by syndrome differentiation is likely to be subjective. This study was designed to provide a basic theory for TCM diagnosis and establish an objective means of evaluating the correctness of syndrome differentiation. Methods We herein provide the basic theory of TCM syndrome computer modeling based on a noninvasive cardiac electrophysiology imaging technique. Noninvasive cardiac electrophysiology imaging records the heart’s electrical activity from hundreds of electrodes on the patient’s torso surface and therefore provides much more information than 12-lead electrocardiography. Through mathematical reconstruction algorithm calculations, the reconstructed heart model is a machine-readable description of the underlying mathematical physics model that reveals the detailed three-dimensional (3D) electrophysiological activity of the heart. Results From part of the simulation results, the imaged 3D cardiac electrical source provides dynamic information regarding the heart’s electrical activity at any given location within the 3D myocardium. Conclusions This noninvasive cardiac electrophysiology imaging method is suitable for translating TCM syndromes into a computable format of the underlying mathematical physics model to offer TCM diagnosis evidence-based standards for ensuring correct evaluation and rigorous, scientific data for demonstrating its efficacy.

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