1
|
Salameh S, Guerrelli D, Miller JA, Desai M, Moise N, Yerebakan C, Bruce A, Sinha P, d'Udekem Y, Weinberg SH, Posnack NG. Connecting Transcriptomics with Computational Modeling to Reveal Developmental Adaptations in the Human Pediatric Myocardium. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.19.589826. [PMID: 38712262 PMCID: PMC11071413 DOI: 10.1101/2024.04.19.589826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Background Nearly 1% or 1.3 million babies are born with congenital heart disease (CHD) globally each year - many of whom will require palliative or corrective heart surgery within the first few years of life. A detailed understanding of cardiac maturation can help to expand our knowledge on cardiac diseases that develop during gestation, identify age-appropriate cardiovascular drug therapies, and inform clinical care decisions related to surgical repair, myocardial preservation, or postoperative management. Yet, to date, our knowledge of the temporal changes that cardiomyocytes undergo during postnatal development is largely limited to animal models. Methods Right atrial tissue samples were collected from n=117 neonatal, infant, and pediatric patients undergoing correct surgery due to (acyanotic) CHD. Patients were stratified into five age groups: neonate (0-30 days), infant (31-364 days), toddler to preschool (1-5 years), school age (6-11 years), and adolescent to young adults (12-32 years). We measured age-dependent adaptations in cardiac gene expression, and used computational modeling to simulate action potential and calcium transients. Results Enrichment of differentially expressed genes (DEG) was explored, revealing age-dependent changes in several key biological processes (cell cycle, cell division, mitosis), cardiac ion channels, and calcium handling genes. Gene-associated changes in ionic currents exhibited both linear trends and sudden shifts across developmental stages, with changes in calcium handling ( I NCX ) and repolarization ( I K1 ) most strongly associated with an age-dependent decrease in the action potential plateau potential and increase in triangulation, respectively. We also note a shift in repolarization reserve, with lower I Kr expression in younger patients, a finding likely tied to the increased amplitude of I Ks triggered by elevated sympathetic activation in pediatric patients. Conclusion This study provides valuable insights into age-dependent changes in human cardiac gene expression and electrophysiology among patients with CHD, shedding light on molecular mechanisms underlying cardiac development and function across different developmental stages.
Collapse
|
2
|
Salameh S, Ogueri V, Posnack NG. Adapting to a new environment: postnatal maturation of the human cardiomyocyte. J Physiol 2023; 601:2593-2619. [PMID: 37031380 PMCID: PMC10775138 DOI: 10.1113/jp283792] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 03/16/2023] [Indexed: 04/10/2023] Open
Abstract
The postnatal mammalian heart undergoes remarkable developmental changes, which are stimulated by the transition from the intrauterine to extrauterine environment. With birth, increased oxygen levels promote metabolic, structural and biophysical maturation of cardiomyocytes, resulting in mature muscle with increased efficiency, contractility and electrical conduction. In this Topical Review article, we highlight key studies that inform our current understanding of human cardiomyocyte maturation. Collectively, these studies suggest that human atrial and ventricular myocytes evolve quickly within the first year but might not reach a fully mature adult phenotype until nearly the first decade of life. However, it is important to note that fetal, neonatal and paediatric cardiac physiology studies are hindered by a number of limitations, including the scarcity of human tissue, small sample size and a heavy reliance on diseased tissue samples, often without age-matched healthy controls. Future developmental studies are warranted to expand our understanding of normal cardiac physiology/pathophysiology and inform age-appropriate treatment strategies for cardiac disease.
Collapse
Affiliation(s)
- Shatha Salameh
- Department of Pharmacology & Physiology, George Washington University, Washington, DC, USA
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Hospital, Washington, DC, USA
| | - Vanessa Ogueri
- Children’s National Heart Institute, Children’s National Hospital, Washington, DC, USA
| | - Nikki Gillum Posnack
- Department of Pharmacology & Physiology, George Washington University, Washington, DC, USA
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Hospital, Washington, DC, USA
- Children’s National Heart Institute, Children’s National Hospital, Washington, DC, USA
- Department of Pediatrics, George Washington University, Washington, DC, USA
| |
Collapse
|
3
|
Lin WH, Zhu Z, Ravikumar V, Sharma V, Tolkacheva EG, McAlpine MC, Ogle BM. A Bionic Testbed for Cardiac Ablation Tools. Int J Mol Sci 2022; 23:ijms232214444. [PMID: 36430922 PMCID: PMC9692733 DOI: 10.3390/ijms232214444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 11/03/2022] [Accepted: 11/09/2022] [Indexed: 11/22/2022] Open
Abstract
Bionic-engineered tissues have been proposed for testing the performance of cardiovascular medical devices and predicting clinical outcomes ex vivo. Progress has been made in the development of compliant electronics that are capable of monitoring treatment parameters and being coupled to engineered tissues; however, the scale of most engineered tissues is too small to accommodate the size of clinical-grade medical devices. Here, we show substantial progress toward bionic tissues for evaluating cardiac ablation tools by generating a centimeter-scale human cardiac disk and coupling it to a hydrogel-based soft-pressure sensor. The cardiac tissue with contiguous electromechanical function was made possible by our recently established method to 3D bioprint human pluripotent stem cells in an extracellular matrix-based bioink that allows for in situ cell expansion prior to cardiac differentiation. The pressure sensor described here utilized electrical impedance tomography to enable the real-time spatiotemporal mapping of pressure distribution. A cryoablation tip catheter was applied to the composite bionic tissues with varied pressure. We found a close correlation between the cell response to ablation and the applied pressure. Under some conditions, cardiomyocytes could survive in the ablated region with more rounded morphology compared to the unablated controls, and connectivity was disrupted. This is the first known functional characterization of living human cardiomyocytes following an ablation procedure that suggests several mechanisms by which arrhythmia might redevelop following an ablation. Thus, bionic-engineered testbeds of this type can be indicators of tissue health and function and provide unique insight into human cell responses to ablative interventions.
Collapse
Affiliation(s)
- Wei-Han Lin
- Department of Biomedical Engineering, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA
- Stem Cell Institute, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA
| | - Zhijie Zhu
- Department of Mechanical Engineering, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA
| | - Vasanth Ravikumar
- Department of Electrical Engineering, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA
| | - Vinod Sharma
- Cardiac Rhythm and Heart Failure Division, Medtronic Inc., Minneapolis, MN 55432, USA
| | - Elena G. Tolkacheva
- Department of Biomedical Engineering, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA
- Lillehei Heart Institute, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA
- Institute for Engineering in Medicine, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA
| | - Michael C. McAlpine
- Department of Mechanical Engineering, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA
- Institute for Engineering in Medicine, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA
- Correspondence: (M.C.M.); (B.M.O.)
| | - Brenda M. Ogle
- Department of Biomedical Engineering, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA
- Stem Cell Institute, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA
- Lillehei Heart Institute, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA
- Institute for Engineering in Medicine, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA
- Masonic Cancer Center, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA
- Correspondence: (M.C.M.); (B.M.O.)
| |
Collapse
|
4
|
Swift LM, Burke M, Guerrelli D, Reilly M, Ramadan M, McCullough D, Prudencio T, Mulvany C, Chaluvadi A, Jaimes R, Posnack NG. Age-dependent changes in electrophysiology and calcium handling: implications for pediatric cardiac research. Am J Physiol Heart Circ Physiol 2019; 318:H354-H365. [PMID: 31886723 DOI: 10.1152/ajpheart.00521.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Rodent models are frequently employed in cardiovascular research, yet our understanding of pediatric cardiac physiology has largely been deduced from more simplified two-dimensional cell studies. Previous studies have shown that postnatal development includes an alteration in the expression of genes and proteins involved in cell coupling, ion channels, and intracellular calcium handling. Accordingly, we hypothesized that postnatal cell maturation is likely to lead to dynamic alterations in whole heart electrophysiology and calcium handling. To test this hypothesis, we employed multiparametric imaging and electrophysiological techniques to quantify developmental changes from neonate to adult. In vivo electrocardiograms were collected to assess changes in heart rate, variability, and atrioventricular conduction (Sprague-Dawley rats). Intact, whole hearts were transferred to a Langendorff-perfusion system for multiparametric imaging (voltage, calcium). Optical mapping was performed in conjunction with an electrophysiology study to assess cardiac dynamics throughout development. Postnatal age was associated with an increase in the heart rate (181 ± 34 vs. 429 ± 13 beats/min), faster atrioventricular conduction (94 ± 13 vs. 46 ± 3 ms), shortened action potentials (APD80: 113 ± 18 vs. 60 ± 17 ms), and decreased ventricular refractoriness (VERP: 157 ± 45 vs. 57 ± 14 ms; neonatal vs. adults, means ± SD, P < 0.05). Calcium handling matured with development, resulting in shortened calcium transient durations (168 ± 18 vs. 117 ± 14 ms) and decreased propensity for calcium transient alternans (160 ± 18- vs. 99 ± 11-ms cycle length threshold; neonatal vs. adults, mean ± SD, P < 0.05). Results of this study can serve as a comprehensive baseline for future studies focused on pediatric disease modeling and/or preclinical testing.NEW & NOTEWORTHY This is the first study to assess cardiac electrophysiology and calcium handling throughout postnatal development, using both in vivo and whole heart models.
Collapse
Affiliation(s)
- Luther M Swift
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, District of Columbia.,Children's National Heart Institute, Children's National Health System, Washington, District of Columbia
| | - Morgan Burke
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, District of Columbia.,Children's National Heart Institute, Children's National Health System, Washington, District of Columbia
| | - Devon Guerrelli
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, District of Columbia.,Children's National Heart Institute, Children's National Health System, Washington, District of Columbia
| | - Marissa Reilly
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, District of Columbia
| | - Manelle Ramadan
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, District of Columbia.,Children's National Heart Institute, Children's National Health System, Washington, District of Columbia
| | - Damon McCullough
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, District of Columbia.,Children's National Heart Institute, Children's National Health System, Washington, District of Columbia
| | - Tomas Prudencio
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, District of Columbia
| | - Colm Mulvany
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, District of Columbia
| | - Ashika Chaluvadi
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, District of Columbia
| | - Rafael Jaimes
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, District of Columbia.,Children's National Heart Institute, Children's National Health System, Washington, District of Columbia
| | - Nikki Gillum Posnack
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, District of Columbia.,Children's National Heart Institute, Children's National Health System, Washington, District of Columbia.,Department of Pediatrics and Department of Pharmacology and Physiology, School of Medicine and Health Sciences, George Washington University, Washington, District of Columbia
| |
Collapse
|
5
|
Human atrial cell models to analyse haemodialysis-related effects on cardiac electrophysiology: work in progress. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2014; 2014:291598. [PMID: 25587348 PMCID: PMC4284940 DOI: 10.1155/2014/291598] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 11/05/2014] [Accepted: 11/12/2014] [Indexed: 11/25/2022]
Abstract
During haemodialysis (HD) sessions, patients undergo alterations in the extracellular environment, mostly concerning plasma electrolyte concentrations, pH, and volume, together with a modification of sympathovagal balance. All these changes affect cardiac electrophysiology, possibly leading to an increased arrhythmic risk. Computational modeling may help to investigate the impact of HD-related changes on atrial electrophysiology. However, many different human atrial action potential (AP) models are currently available, all validated only with the standard electrolyte concentrations used in experiments. Therefore, they may respond in different ways to the same environmental changes. After an overview on how the computational approach has been used in the past to investigate the effect of HD therapy on cardiac electrophysiology, the aim of this work has been to assess the current state of the art in human atrial AP models, with respect to the HD context. All the published human atrial AP models have been considered and tested for electrolytes, volume changes, and different acetylcholine concentrations. Most of them proved to be reliable for single modifications, but all of them showed some drawbacks. Therefore, there is room for a new human atrial AP model, hopefully able to physiologically reproduce all the HD-related effects. At the moment, work is still in progress in this specific field.
Collapse
|
6
|
Nguyen DC, Hookway TA, Wu Q, Jha R, Preininger MK, Chen X, Easley CA, Spearman P, Deshpande SR, Maher K, Wagner MB, McDevitt TC, Xu C. Microscale generation of cardiospheres promotes robust enrichment of cardiomyocytes derived from human pluripotent stem cells. Stem Cell Reports 2014; 3:260-8. [PMID: 25254340 PMCID: PMC4175548 DOI: 10.1016/j.stemcr.2014.06.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 05/31/2014] [Accepted: 06/02/2014] [Indexed: 10/26/2022] Open
Abstract
Cardiomyocytes derived from human pluripotent stem cells (hPSCs) are a promising cell source for regenerative medicine, disease modeling, and drug discovery, all of which require enriched cardiomyocytes, ideally ones with mature phenotypes. However, current methods are typically performed in 2D environments that produce immature cardiomyocytes within heterogeneous populations. Here, we generated 3D aggregates of cardiomyocytes (cardiospheres) from 2D differentiation cultures of hPSCs using microscale technology and rotary orbital suspension culture. Nearly 100% of the cardiospheres showed spontaneous contractility and synchronous intracellular calcium transients. Strikingly, from starting heterogeneous populations containing ∼10%-40% cardiomyocytes, the cell population within the generated cardiospheres featured ∼80%-100% cardiomyocytes, corresponding to an enrichment factor of up to 7-fold. Furthermore, cardiomyocytes from cardiospheres exhibited enhanced structural maturation in comparison with those from a parallel 2D culture. Thus, generation of cardiospheres represents a simple and robust method for enrichment of cardiomyocytes in microtissues that have the potential use in regenerative medicine as well as other applications.
Collapse
Affiliation(s)
- Doan C Nguyen
- Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Tracy A Hookway
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30332, USA
| | - Qingling Wu
- Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA 30322, USA; Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30332, USA
| | - Rajneesh Jha
- Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Marcela K Preininger
- Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA 30322, USA; Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30332, USA
| | - Xuemin Chen
- Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Charles A Easley
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Paul Spearman
- Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Shriprasad R Deshpande
- Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Kevin Maher
- Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Mary B Wagner
- Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Todd C McDevitt
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30332, USA; Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332, USA.
| | - Chunhui Xu
- Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA 30322, USA; Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332, USA.
| |
Collapse
|
7
|
Ban K, Wile B, Kim S, Park HJ, Byun J, Cho KW, Saafir T, Song MK, Yu SP, Wagner M, Bao G, Yoon YS. Purification of cardiomyocytes from differentiating pluripotent stem cells using molecular beacons that target cardiomyocyte-specific mRNA. Circulation 2013; 128:1897-909. [PMID: 23995537 DOI: 10.1161/circulationaha.113.004228] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Although methods for generating cardiomyocytes from pluripotent stem cells have been reported, current methods produce heterogeneous mixtures of cardiomyocytes and noncardiomyocyte cells. Here, we report an entirely novel system in which pluripotent stem cell-derived cardiomyocytes are purified by cardiomyocyte-specific molecular beacons (MBs). MBs are nanoscale probes that emit a fluorescence signal when hybridized to target mRNAs. METHOD AND RESULTS Five MBs targeting mRNAs of either cardiac troponin T or myosin heavy chain 6/7 were generated. Among 5 MBs, an MB that targeted myosin heavy chain 6/7 mRNA (MHC1-MB) identified up to 99% of HL-1 cardiomyocytes, a mouse cardiomyocyte cell line, but <3% of 4 noncardiomyocyte cell types in flow cytometry analysis, which indicates that MHC1-MB is specific for identifying cardiomyocytes. We delivered MHC1-MB into cardiomyogenically differentiated pluripotent stem cells through nucleofection. The detection rate of cardiomyocytes was similar to the percentages of cardiac troponin T- or cardiac troponin I-positive cardiomyocytes, which supports the specificity of MBs. Finally, MHC1-MB-positive cells were sorted by fluorescence-activated cell sorter from mouse and human pluripotent stem cell differentiating cultures, and ≈97% cells expressed cardiac troponin T or cardiac troponin I as determined by flow cytometry. These MB-based sorted cells maintained their cardiomyocyte characteristics, which was verified by spontaneous beating, electrophysiological studies, and expression of cardiac proteins. When transplanted in a myocardial infarction model, MB-based purified cardiomyocytes improved cardiac function and demonstrated significant engraftment for 4 weeks without forming tumors. CONCLUSIONS We developed a novel cardiomyocyte selection system that allows production of highly purified cardiomyocytes. These purified cardiomyocytes and this system can be valuable for cell therapy and drug discovery.
Collapse
Affiliation(s)
- Kiwon Ban
- Division of Cardiology, Department of Medicine, Emory University School of Medicine, Atlanta, GA
| | - Brian Wile
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA
| | - Sangsung Kim
- Division of Cardiology, Department of Medicine, Emory University School of Medicine, Atlanta, GA
| | - Hun-Jun Park
- Division of Cardiology, Department of Medicine, Emory University School of Medicine, Atlanta, GA.,Division of Cardiology, Department of Internal Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea
| | - Jaemin Byun
- Division of Cardiology, Department of Medicine, Emory University School of Medicine, Atlanta, GA
| | - Kyu-Won Cho
- Division of Cardiology, Department of Medicine, Emory University School of Medicine, Atlanta, GA
| | - Talib Saafir
- Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA
| | - Ming-Ke Song
- Department of Anesthesiology, Emory University School of Medicine, Atlanta, GA
| | - Shan Ping Yu
- Department of Anesthesiology, Emory University School of Medicine, Atlanta, GA
| | - Mary Wagner
- Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA
| | - Gang Bao
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA
| | - Young-Sup Yoon
- Division of Cardiology, Department of Medicine, Emory University School of Medicine, Atlanta, GA
| |
Collapse
|
8
|
Lieu DK, Fu JD, Chiamvimonvat N, Tung KC, McNerney GP, Huser T, Keller G, Kong CW, Li RA. Mechanism-based facilitated maturation of human pluripotent stem cell-derived cardiomyocytes. Circ Arrhythm Electrophysiol 2013; 6:191-201. [PMID: 23392582 DOI: 10.1161/circep.111.973420] [Citation(s) in RCA: 148] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
BACKGROUND Human embryonic stem cells (hESCs) can be efficiently and reproducibly directed into cardiomyocytes (CMs) using stage-specific induction protocols. However, their functional properties and suitability for clinical and other applications have not been evaluated. METHODS AND RESULTS Here we showed that CMs derived from multiple pluripotent human stem cell lines (hESC: H1, HES2) and types (induced pluripotent stem cell) using different in vitro differentiation protocols (embryoid body formation, endodermal induction, directed differentiation) commonly displayed immature, proarrhythmic action potential properties such as high degree of automaticity, depolarized resting membrane potential, Phase 4- depolarization, and delayed after-depolarization. Among the panoply of sarcolemmal ionic currents investigated (I(Na)(+)/I(CaL)(+)/I(Kr)(+)/I(NCX)(+)/I(f)(+)/I(to)(+)/I(K1)(-)/I(Ks)(-)), we pinpointed the lack of the Kir2.1-encoded inwardly rectifying K(+) current (I(K1)) as the single mechanistic contributor to the observed immature electrophysiological properties in hESC-CMs. Forced expression of Kir2.1 in hESC-CMs led to robust expression of Ba(2+)-sensitive I(K1) and, more importantly, completely ablated all the proarrhythmic action potential traits, rendering the electrophysiological phenotype indistinguishable from the adult counterparts. These results provided the first link of a complex developmentally arrested phenotype to a major effector gene, and importantly, further led us to develop a bio-mimetic culturing strategy for enhancing maturation. CONCLUSIONS By providing the environmental cues that are missing in conventional culturing method, this approach did not require any genetic or pharmacological interventions. Our findings can facilitate clinical applications, drug discovery, and cardiotoxicity screening by improving the yield, safety, and efficacy of derived CMs.
Collapse
Affiliation(s)
- Deborah K Lieu
- Cardiovascular Research Center, Mount Sinai School of Medicine, New York, NY, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Cai B, Mu X, Gong D, Jiang S, Li J, Meng Q, Bai Y, Liu Y, Wang X, Tan X, Yang B, Lu Y. Difference of sodium currents between pediatric and adult human atrial myocytes: evidence for developmental changes of sodium channels. Int J Biol Sci 2011; 7:708-14. [PMID: 21647304 PMCID: PMC3107490 DOI: 10.7150/ijbs.7.708] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Accepted: 05/25/2011] [Indexed: 02/06/2023] Open
Abstract
Voltage-gated calcium currents and potassium currents were shown to undergo developmental changes in postnatal human and animal cardiomocytes. However, so far, there is no evidence whether sodium currents also presented the developmental changes in postnatal human atrial cells. The aim of this study was to observe age-related changes of sodium currents between pediatric and adult atrial myocytes. Human atrial myocytes were acutely isolated and the whole-cell patch clamp technique was used to record sodium currents isolated from pediatric and adult atrial cardiomocytes. The peak amplitude of sodium currents recorded in adult atrial cells was significantly larger than that in pediatric atrial myocytes. However, there was no significant difference of the activation voltage for peak sodium currents between two kinds of atrial myocytes. The time constants for the activation and inactivation of sodium currents were smaller in adult atria than pediatric atria. The further study revealed that the voltage-dependent inactivation of sodium currents were more slow in adult atrial cardiomyocytes than pediatric atrial cells. A significant difference was also observed in the recovery process of sodium channel from inactivation. In summary, a few significant differences were demonstrated in sodium currents characteristics between pediatric and adult atrial myocytes, which indicates that sodium currents in human atria also undergo developmental changes.
Collapse
Affiliation(s)
- Benzhi Cai
- Department of Pharmacology, the State-Province Key Laboratory of Biomedicine, Ministry of Education, Harbin Medical University, and Department of Cardiosurgery, Second Affiliated Hospital of Harbin Medical University, Harbin 150081, China
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Vergleich der Calciumsensitivität und Kontraktilität von infantilen und adulten Kardiomyozyten. ZEITSCHRIFT FUR HERZ THORAX UND GEFASSCHIRURGIE 2006. [DOI: 10.1007/s00398-006-0550-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
11
|
Bassani RA. Transient outward potassium current and Ca2+ homeostasis in the heart: beyond the action potential. Braz J Med Biol Res 2006; 39:393-403. [PMID: 16501819 DOI: 10.1590/s0100-879x2006000300010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The present review deals with Ca2+-independent, K+-carried transient outward current (Ito), an important determinant of the early repolarization phase of the myocardial action potential. The density of total Ito and of its fast and slow components (I(to,f) and I(to,s), respectively), as well as the expression of their molecular correlates (pore-forming protein isoforms Kv4.3/4.2 and Kv1.4, respectively), vary during postnatal development and aging across species and regions of the heart. Changes in Ito may also occur in disease conditions, which may affect the profile of cardiac repolarization and vulnerability to arrhythmias, and also influence excitation-contraction coupling. Decreased Ito density, observed in immature and aging myocardium, as well as during several types of cardiomyopathy and heart failure, may be associated with action potential prolongation, which favors Ca2+ influx during membrane depolarization and limits voltage-dependent Ca2+ efflux via the Na+/Ca2+ exchanger. Both effects contribute to increasing sarcoplasmic reticulum (SR) Ca2+ content (the main source of contraction-activating Ca2+ in mammalian myocardium), which, in addition to the increased Ca2+ influx, should enhance the amount of Ca2+ released by the SR during systole. This change usually takes place under conditions in which SR function is depressed, and may be adaptive since it provides partial compensation for SR deficiency, although possibly at the cost of asynchronous SR Ca2+ release and greater propensity to triggered arrhythmias. Thus, Ito modulation appears to be an additional mechanism by which excitation-contraction coupling in myocardial cells is indirectly regulated.
Collapse
Affiliation(s)
- R A Bassani
- Centro de Engenharia Biomédica, Universidade Estadual de Campinas, Campinas, SP, Brazil.
| |
Collapse
|