scholarly journals Arrhythmic Risk Assessment of Hypokalaemia Using Human Pluripotent Stem Cell-Derived Cardiac Anisotropic Sheets

2021 ◽  
Vol 9 ◽  
Author(s):  
Bimal Gurung ◽  
Gary Tse ◽  
Wendy Keung ◽  
Ronald A. Li ◽  
Wing Tak Wong
Keyword(s):  
Stem Cell ◽  
Action Potential ◽  
Pluripotent Stem Cells ◽  
Calcium Transient ◽  
Calcium Handling ◽  
Mapping Technique ◽  
Complex Structures ◽  
Human Pluripotent Stem Cell ◽  
Exact Test ◽  
Refractory Periods

Introduction: Hypokalaemia, defined as an extracellular concentration of K+ below 3.5 mM, can cause cardiac arrhythmias by triggered or re-entrant mechanisms. Whilst these effects have been reported in animal and human stem cell-based models, to date there has been no investigation in more complex structures such as the human ventricular cardiac anisotropic sheet (hvCAS). Here, we investigated arrhythmogenicity, electrophysiological, and calcium transient (CaT) changes induced by hypokalaemia using this bioengineered platform.Methods: An optical mapping technique was applied on hvCAS derived from human pluripotent stem cells to visualize electrophysiological and CaT changes under normokalaemic (5 mM KCl) and hypokalaemic (3 mM KCl) conditions.Results: Hypokalaemia significantly increased the proportion of preparations showing spontaneous arrhythmias from 0/14 to 7/14 (Fisher’s exact test, p = 0.003). Hypokalaemia reduced longitudinal conduction velocity (CV) from 7.81 to 7.18 cm⋅s−1 (n = 9, 7; p = 0.036), transverse CV from 5.72 to 4.69 cm⋅s−1 (n = 12, 11; p = 0.030), prolonged action potential at 90% repolarization (APD90) from 83.46 to 97.45 ms (n = 13, 15; p < 0.001), increased action potential amplitude from 0.888 to 1.195 ΔF (n = 12, 14; p < 0.001) and CaT amplitude from 0.76 to 1.37 ΔF (n = 12, 13; p < 0.001), and shortened effective refractory periods from 242 to 165 ms (n = 12, 13; p < 0.001).Conclusion: Hypokalaemia exerts pro-arrhythmic effects on hvCAS, which are associated with alterations in CV, repolarization, refractoriness, and calcium handling. These preparations provide a useful platform for investigating electrophysiological substrates and for conducting arrhythmia screening.

scholarly journals Intestinal Organoids—Current and Future Applications

2016 ◽  
Author(s):  
Andre M. C. Meneses ◽  
Kerstin Schneeberger ◽  
Hedwig S. Kruitwagen ◽  
Louis C. Penning ◽  
Frank G. van Steenbeek ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Pluripotent Stem Cells ◽  
Disease Modeling ◽  
Three Dimensional ◽  
Intestinal Stem Cells ◽  
Complex Structures ◽  
Technical Advances ◽  
Induced Pluripotent

Recent technical advances in the stem cell field have enabled the in vitro generation of complex structures resembling whole organs termed organoids. Most of these approaches employ culture systems that allow stem cell-derived or tissue progenitor cells to self-organize into three-dimensional (3D)-structures. Since organoids can be grown from various species, organs and from patient-derived induced pluripotent stem cells, they create significant prospects for modelling development and diseases, for toxicology and drug discovery studies, and in the field of regenerative medicine. Here, we report on intestinal stem cells, organoid culture, organoid disease modeling, transplantation, current and future uses of this exciting new insight model to veterinary medicine field.

Sarco/endoplasmic reticulum Ca2+-ATPase is a more effective calcium remover than sodium-calcium exchanger in human embryonic stem cell-derived cardiomyocytes

2019 ◽  
Vol 317 (5) ◽  
pp. H1105-H1115 ◽  
Author(s):  
Sen Li ◽  
Anant Chopra ◽  
Wendy Keung ◽  
Camie W. Y. Chan ◽  
Kevin D. Costa ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Stem Cell ◽  
Embryonic Stem Cell ◽  
Pluripotent Stem Cell ◽  
Human Embryonic Stem Cell ◽  
Embryonic Stem ◽  
Cytosolic Calcium ◽  
Calcium Handling ◽  
Human Pluripotent Stem Cell ◽  
Compensatory Response

Human pluripotent stem cell (hPSCs)-derived ventricular (V) cardiomyocytes (CMs) display immature Ca2+–handing properties with smaller transient amplitudes and slower kinetics due to such differences in crucial Ca2+-handling proteins as the poor sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) pump but robust Na+-Ca2+ exchanger (NCX) activities in human embryonic stem cell (ESC)-derived VCMs compared with adult. Despite their fundamental importance in excitation-contraction coupling, the relative contribution of SERCA and NCX to Ca2+-handling of hPSC-VCMs remains unexplored. We systematically altered the activities of SERCA and NCX in human embryonic stem cell-derived ventricular cardiomyocytes (hESC-VCMs) and their engineered microtissues, followed by examining the resultant phenotypic consequences. SERCA overexpression in hESC-VCMs shortened the decay of Ca2+ transient at low frequencies (0.5 Hz) without affecting the amplitude, SR Ca2+ content and Ca2+ baseline. Interestingly, short hairpin RNA-based NCX suppression did not prolong the transient decay, indicating a compensatory response for Ca2+ removal. Although hESC-VCMs and their derived microtissues exhibited negative frequency-transient/force responses, SERCA overexpression rendered them less negative at high frequencies (>2 Hz) by accelerating Ca2+ sequestration. We conclude that for hESC-VCMs and their microtissues, SERCA, rather than NCX, is the main Ca2+ remover during diastole; poor SERCA expression is the leading cause for immature negative-frequency/force responses, which can be partially reverted by forced expression. Combinatorial approach to mature calcium handling in hESC-VCMs may help shed further mechanistic insights. NEW & NOTEWORTHY In this study of human pluripotent stem cell-derived cardiomyocytes, we studied the role of sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) and Na+-Ca2+ exchanger (NCX) in Ca2+ handling. Our data support the notion that SERCA is more effective in cytosolic calcium removal than the NCX.

scholarly journals Expression of miRNAs from the Imprinted DLK1/DIO3 Locus Signals the Osteogenic Potential of Human Pluripotent Stem Cells

Cells ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 1523 ◽  
Author(s):  
Laetitia Barrault ◽  
Jacqueline Gide ◽  
Tingting Qing ◽  
Lea Lesueur ◽  
Jorg Tost ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Osteogenic Differentiation ◽  
Cell Lines ◽  
Pluripotent Stem Cells ◽  
Pluripotent Stem Cell ◽  
Human Pluripotent Stem Cells ◽  
Osteogenic Potential ◽  
Human Pluripotent Stem Cell ◽  
Stem Cell Lines

Substantial variations in differentiation properties have been reported among human pluripotent cell lines (hPSC), which could affect their utility and clinical safety. We characterized the variable osteogenic capacity observed between different human pluripotent stem cell lines. By focusing on the miRNA expression profile, we demonstrated that the osteogenic differentiation propensity of human pluripotent stem cell lines could be associated with the methylation status and the expression of miRNAs from the imprinted DLK1/DIO3 locus. More specifically, quantitative analysis of the expression of six different miRNAs of that locus prospectively identified human embryonic stem cells and human-induced pluripotent stem cells with differential osteogenic differentiation capacities. At the molecular and functional levels, we showed that these miRNAs modulated the expression of the activin receptor type 2B and the downstream signal transduction, which impacted osteogenesis. In conclusion, miRNAs of the imprinted DLK1/DIO3 locus appear to have both a predictive value and a functional impact in determining the osteogenic fate of human pluripotent stem cells.

Characterizing the contribution of voltage- and calcium-dependent coupling to action potential stability: implications for repolarization alternans

2007 ◽  
Vol 293 (4) ◽  
pp. H2109-H2118 ◽  
Author(s):  
Peter N. Jordan ◽  
David J. Christini
Keyword(s):  
Action Potential ◽  
Calcium Imaging ◽  
Calcium Transient ◽  
Calcium Handling ◽  
Calcium Dependent ◽  
Relative Contribution ◽  
Real Time Measurement ◽  
Transmembrane Voltage ◽  
Voltage Clamping ◽  
Potential Stability

Experiments have provided suggestive but inconclusive insights into the relative contributions of transmembrane voltage and intracellular calcium handling to the development of cardiac electrical instabilities such as repolarization alternans. In this study, we applied a novel combination of techniques (action potential voltage clamping, calcium-transient clamping, and stability analysis) to cardiac cell models to more clearly determine the roles that voltage- and calcium-dependent coupling play in regulating action potential stability and the development of alternans subsequent to the loss of stability. Using these techniques, we are able to demonstrate that voltage- and calcium-dependent coupling exhibit varying degrees of influence on action potential stability across models. Our results indicate that cellular dynamic instabilities such as alternans may be initiated by either voltage- or calcium-dependent mechanisms or by some combination of the two. Based on these modeling results, we propose novel single-cell experiments that incorporate action-potential voltage clamping, calcium imaging, and real-time measurement of action potential stability. These experiments will make it possible to experimentally determine the relative contribution of voltage coupling to the regulation of action potential stability in real cardiac myocytes, thereby providing further insights into the mechanism of alternans.

Convergence of human pluripotent stem cell, organoid, and genome editing technologies

2021 ◽  
pp. 153537022098580
Author(s):  
Lin Wang ◽  
Zhaohui Ye ◽  
Yoon-Young Jang
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Genome Editing ◽  
Pluripotent Stem Cells ◽  
Pluripotent Stem Cell ◽  
Three Dimensional ◽  
Experimental Models ◽  
Human Pluripotent Stem Cell ◽  
Research Areas ◽  
Technological Advances

The last decade has seen many exciting technological breakthroughs that greatly expanded the toolboxes for biological and biomedical research, yet few have had more impact than induced pluripotent stem cells and modern-day genome editing. These technologies are providing unprecedented opportunities to improve physiological relevance of experimental models, further our understanding of developmental processes, and develop novel therapies. One of the research areas that benefit greatly from these technological advances is the three-dimensional human organoid culture systems that resemble human tissues morphologically and physiologically. Here we summarize the development of human pluripotent stem cells and their differentiation through organoid formation. We further discuss how genetic modifications, genome editing in particular, were applied to answer basic biological and biomedical questions using organoid cultures of both somatic and pluripotent stem cell origins. Finally, we discuss the potential challenges of applying human pluripotent stem cell and organoid technologies for safety and efficiency evaluation of emerging genome editing tools.

scholarly journals Remdesivir but not famotidine inhibits SARS-CoV-2 replication in human pluripotent stem cell-derived intestinal organoids

2020 ◽  
Author(s):  
Jana Krüger ◽  
Rüdiger Groß ◽  
Carina Conzelmann ◽  
Janis A. Müller ◽  
Lennart Koepke ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Pluripotent Stem Cells ◽  
Pluripotent Stem Cell ◽  
Gastrointestinal Symptoms ◽  
Cell Types ◽  
Human Pluripotent Stem Cell ◽  
Intestinal Organoids

Gastrointestinal symptoms in COVID-19 are associated with prolonged symptoms and increased severity. We employed human intestinal organoids derived from pluripotent stem cells (PSC-HIOs) to analyze SARS-CoV-2 pathogenesis and to validate efficacy of specific drugs in the gut. Certain, but not all cell types in PSC-HIOs express SARS-CoV-2 entry factors ACE2 and TMPRSS2, rendering them susceptible to SARS-CoV-2 infection. Remdesivir, a promising drug to treat COVID-19, effectively suppressed SARS-CoV-2 infection of PSC-HIOs. In contrast, the histamine-2-blocker famotidine showed no effect. Thus, PSC-HIOs provide an interesting platform to study SARS-CoV-2 infection and to identify or validate drugs.

scholarly journals Optical Investigation of Action Potential and Calcium Handling Maturation of hiPSC-Cardiomyocytes on Biomimetic Substrates

2019 ◽  
Vol 20 (15) ◽  
pp. 3799 ◽  
Author(s):  
Josè Manuel Pioner ◽  
Lorenzo Santini ◽  
Chiara Palandri ◽  
Daniele Martella ◽  
Flavia Lupi ◽  
...  
Keyword(s):  
Action Potential ◽  
Calcium Transient ◽  
Optical Measurements ◽  
Calcium Handling ◽  
Optical Investigation ◽  
Adrenergic Stimulation ◽  
Ventricular Tissue ◽  
Custom Made ◽  
Induced Pluripotent

Cardiomyocytes from human induced pluripotent stem cells (hiPSC-CMs) are the most promising human source with preserved genetic background of healthy individuals or patients. This study aimed to establish a systematic procedure for exploring development of hiPSC-CM functional output to predict genetic cardiomyopathy outcomes and identify molecular targets for therapy. Biomimetic substrates with microtopography and physiological stiffness can overcome the immaturity of hiPSC-CM function. We have developed a custom-made apparatus for simultaneous optical measurements of hiPSC-CM action potential and calcium transients to correlate these parameters at specific time points (day 60, 75 and 90 post differentiation) and under inotropic interventions. In later-stages, single hiPSC-CMs revealed prolonged action potential duration, increased calcium transient amplitude and shorter duration that closely resembled those of human adult cardiomyocytes from fresh ventricular tissue of patients. Thus, the major contribution of sarcoplasmic reticulum and positive inotropic response to β-adrenergic stimulation are time-dependent events underlying excitation contraction coupling (ECC) maturation of hiPSC-CM; biomimetic substrates can promote calcium-handling regulation towards adult-like kinetics. Simultaneous optical recordings of long-term cultured hiPSC-CMs on biomimetic substrates favor high-throughput electrophysiological analysis aimed at testing (mechanistic hypothesis on) disease progression and pharmacological interventions in patient-derived hiPSC-CMs.

Manufacturing human pluripotent stem cell derived endothelial cells in scalable and cell-friendly microenvironments

2019 ◽  
Vol 7 (1) ◽  
pp. 373-388
Author(s):  
Haishuang Lin ◽  
Qian Du ◽  
Qiang Li ◽  
Ou Wang ◽  
Zhanqi Wang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Endothelial Cells ◽  
Stem Cell ◽  
Pluripotent Stem Cells ◽  
Pluripotent Stem Cell ◽  
Human Pluripotent Stem Cells ◽  
Human Pluripotent Stem Cell ◽  
Alginate Hydrogel

Alginate hydrogel tubes are designed for the scalable expansion of human pluripotent stem cells and efficient differentiation into endothelial cells.

scholarly journals Commentary on human pluripotent stem cell-based blood–brain barrier models

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Ethan S. Lippmann ◽  
Samira M. Azarin ◽  
Sean P. Palecek ◽  
Eric V. Shusta
Keyword(s):  
Stem Cell ◽  
Blood Brain Barrier ◽  
Pluripotent Stem Cells ◽  
Research Community ◽  
Brain Barrier ◽  
Current Status ◽  
Human Pluripotent Stem Cell ◽  
Blood Brain ◽  
Published Evidence ◽  
Negative Attributes

Abstract In 2012, we provided the first published evidence that human pluripotent stem cells could be differentiated to cells exhibiting markers and phenotypes characteristic of the blood–brain barrier (BBB). In the ensuing years, the initial protocols have been refined, and the research community has identified both positive and negative attributes of this stem cell-based BBB model system. Here, we give our perspective on the current status of these models and their use in the BBB community, as well as highlight key attributes that would benefit from improvement moving forward.

Sign in / Sign up

Export Citation Format

Share Document