On the Road to iPS Cell Cardiovascular Applications

Abstract

HomeCirculation ResearchVol. 105, No. 7On the Road to iPS Cell Cardiovascular Applications Free AccessEditorialPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessEditorialPDF/EPUBOn the Road to iPS Cell Cardiovascular Applications Timothy J. Kamp and Gary E. Lyons Timothy J. KampTimothy J. Kamp From the Departments of Medicine (T.J.K.), Physiology (T.J.K.), and Anatomy (G.E.L.); and Stem Cell and Regenerative Medicine Center (G.E.L.,T.J.K.), University of Wisconsin, Madison. Search for more papers by this author and Gary E. LyonsGary E. Lyons From the Departments of Medicine (T.J.K.), Physiology (T.J.K.), and Anatomy (G.E.L.); and Stem Cell and Regenerative Medicine Center (G.E.L.,T.J.K.), University of Wisconsin, Madison. Search for more papers by this author Originally published25 Sep 2009https://doi.org/10.1161/CIRCRESAHA.109.205740Circulation Research. 2009;105:617–619The ability to generate induced pluripotent stem (iPS) cells from somatic cells by the overexpression of a limited number of stem cell-related genes has generated great excitement and interest in the biomedical research community including cardiovascular researchers. The pioneering study by Yamanaka and colleagues showing that overexpression of Oct3/4, Sox2, Klf4, and c-Myc could reprogram mouse fibroblasts to a pluripotent state similar to that of embryonic stem (ES) cells opened major new avenues of research.1 This epigenetic reprogramming was rapidly extrapolated to the human system using either the same combination of reprogramming factors or a slightly different combination of transgenes (OCT4, NANOG, SOX2, LIN28).2–4 Like embryonic stem (ES) cells, iPS cells can be used for basic developmental biology research and also as a cell source to generate theoretically unlimited quantities of desired cell types such as cardiomyocytes. Such differentiated cells types can be used in a wide range of basic research studies and potentially in clinical applications, which not only include cellular therapies but also drug discovery and safety testing. One appealing aspect of human iPS cells compared to human ES cells is that they can be more readily generated without specialized expertise and access to human embryos, which also avoids the ethical challenges associated with human embryo research. Potentially the most powerful advantage of iPS cells over ES cells is that they can be generated from any patient to produce genetically identical pluripotent cells that can create human disease models or generate patient-specific cells for therapy. Already a number of iPS cell human disease models have been generated,5,6 and proof-of-principle iPS cellular therapies have been pioneered in mouse models.7–9Despite the speed at which the iPS cell field is racing forward, we are just at the beginning of a long road. Many major questions remain regarding iPS cells. Will they prove to be equivalent to ES cells in their properties? In other words, will iPS cells be equally as pluripotent as ES cells and readily generate all cell lineages represented in the 3 embryonic germ layers? Will different iPS cell lines show distinct differentiation profiles which may be an advantage or disadvantage for a given application? For example, will certain iPS cell lines be less able to differentiate into cardiovascular relevant cell types compared to other lines? Another critical question for therapeutic applications is whether reprogrammed iPS cell lines are prone to tumorigenesis. Does the starting cell source matter? How does the technique of reprogramming impact iPS cell behavior? In this issue of Circulation Research, Martinez-Fernandez et al address some of these questions by carefully examining the cardiogenic potential of mouse iPS cells generated from murine fibroblasts using 3 reprogramming factors (OCT4, KLF4, and SOX2).10Most of the detailed understanding of the developmental potential of iPS cells comes from studies using mouse iPS cell lines generated with integrating retroviral vectors encoding 4 reprogramming factors (Oct3/4, Sox2, Klf4, and c-Myc), because this technology has been available the longest, for 3 full years. Some of these 4-factor iPS cells have been demonstrated to be competent to integrate into blastocyst stage embryos and generate chimeric mice which can exhibit germline transmission.11–13 This is strong evidence of pluripotency, but initial efforts at the most rigorous developmental test of pluripotency, what is called tetraploid complementation, failed.12 In tetraploid complementation, an embryo is made tetraploid by fusing cells at the 2-cell stage. The resulting tetraploid blastocyst can develop the cells that become placenta but cannot develop the embryo proper. Stem cells transplanted at the early blastocyst stage of the tetraploid embryo will generate a viable mouse strictly from the donor cells, if the cells are truly pluripotent. Very recently, 2 studies have demonstrated using tetraploid complementation that 4-factor iPS cell lines can support development of full term viable mice.14,15 Thus, some 4-factor iPS cell lines seem to be fully capable of developing all cell types present in the adult mouse, but the hint of caution is that in the limited data available, not all tested iPS cell lines proved successful in tetraploid complementation.15 This could be because of experimental limitations and inadequate testing or fundamental differences in the iPS cell lines. Likewise, in vitro studies of cardiac differentiation of 4-factor mouse iPS cell lines have produced mixed results, with some lines showing comparable cardiogenesis to ES cells and others showing delayed cardiogenesis.16,17 Thus with the oldest of iPS cell technologies, some iPS cell lines seem to meet even the most stringent criteria for pluripotency, but it is unlikely that all 4-factor iPS cell lines will meet this standard.It was quickly recognized that chimeric animals generated from 4-factor iPS cells were at increased risk for tumorigenesis attributable to reactivation of the c-Myc transgene,11 which clearly represents a safety concern for translation of this technology to humans. However, c-Myc was soon found not to be essential for generation of iPS cells, which could be generated using 3 virally encoded factors: Oct3/4, Sox2, and Klf4 (3F iPS cells).18,19 These 3F iPS cells expressed the standard markers of pluripotency in culture and could generate chimeric offspring following blastocyst injection, providing the first developmental assay supporting pluripotency and, importantly, they did not display any evident increase in risk for tumorigenesis.18 However, at this stage, it remains to be determined whether these 3F iPS cells are fully pluripotent like ES cells and apparently like some 4-factor iPS cell lines.To address this question with a focus on cardiac differentiation, in this issue of Circulation Research,10 Martinez-Fernandez and colleagues present an elegant study of 3F mouse iPS cells focused on their ability to undergo cardiogenesis. These authors began their studies by transducing mouse embryonic fibroblasts using lentiviral delivered human transgenes for SOX2, OCT4, and KLF4 to produce 3F iPS cells. The first test of the cardiogenic potential of the 3F iPS cells was performed by subjecting them to in vitro differentiation in embryoid bodies. The anticipated temporal change in expression of genes indicative of cardiac differentiation was observed, with an upregulation of cardiac transcription factors followed by myofilament proteins and the presence of contracting cardiomyocytes in the embryoid bodies. The cardiomyocytes exhibited organized myofibrils and were electrically coupled based on the presence of gap junction and synchronized multicellular contraction patterns. Furthermore, they demonstrated spontaneous cardiac-like action potentials and Ca2+ transients. Initial voltage-clamp experiments showed that the iPS cell-derived cardiomyocytes exhibited some of the anticipated ionic currents expected in cardiomyocytes.Although this in vitro characterization convincingly demonstrates the ability of the 3F iPS cells to generate functional cardiomyocytes, it is only a beginning study of these cardiomyocytes. How do these iPS cell cardiomyocytes compare to ES cell cardiomyocytes under the authors’ same experimental conditions? For example, is there evidence (from the action potentials or other markers) for different types of cardiomyocytes developing, eg, atrial, ventricular, and nodal-like? Likewise, the authors see primarily Ca2+ inward currents without evidence for Na+ current in these cardiomyocytes despite using a ramp protocol that should allow measurement of Na+ current. Mouse ES cell-derived cardiomyocytes in contrast express voltage-dependent Na+ channels and inward Na+ currents at comparable stages of maturation.20 In addition, the authors demonstrate Ca2+ transients, but do these transient exhibit properties typical of cardiac muscle such as robust intracellular Ca2+ stores with Ca2+-induced Ca2+ release?Despite these unresolved questions, the authors provide evidence that these 3F iPS cells can robustly undergo cardiogenesis based on their embryonic developmental studies. The authors take a slightly different route by aggregating the 3F iPS cells to morula stage embryos using a technique called noncoerced diploid aggregation. If the iPS cells are fully pluripotent, they would be anticipated to contribute to the generation of a chimeric blastocyst which develops into a chimeric mouse. Because the iPS cells include a lacZ transgene, they can be readily tracked, and the study demonstrates a mosaic distribution of lacZ-positive iPS cell progeny in the developing mouse embryos. The iPS cells were found to be clearly present in the heart at all stages of development studied, and live-born chimeric mice exhibited normal cardiac function. Although these observations do not quite reach the pluripotency-defining bar of tetraploid complementation, at least for the focused analysis on cardiac development, it seems likely that the 3F iPS cells generated by the Martinez-Fernandez can undergo normal cardiac development. Furthermore, the authors did not observe tumors in the chimeric offspring from the 3F iPS cells, but the number of mice studied was relatively small. Overall, the study of Martinez-Fernandez provides the most detailed analysis of cardiogenesis of 3F iPS cells to date, and the news is good thus far in that these cells are readily able differentiate to form cardiac muscle.However, we have not reached our desired destination with current 3F iPS cells because reprogramming without c-Myc reduces but does not eliminate the risk of tumorigenesis. A recent safety study of iPS cell lines examining their potential to generate teratomas from differentiated progeny revealed that secondary neurospheres differentiated from iPS cells could form teratomas when transplanted into mouse brains regardless of the presence or absence of the c-Myc transgene.21 Another clear risk for oncogenic transformation of iPS cells is related to the uncontrolled integration of the transgenes into the genomes of the reprogrammed cells. Unfortunately, the potential for insertional mutagenesis to activate protooncogenes has been demonstrated to be a real risk in the case of some gene therapy protocols. Hence, integrating lentiviral 3F iPS cells are only one more stop on the road of perfecting iPS cell technology.The approaches to generate iPS cells are changing at a remarkable pace. Small molecules have been used to increase the efficiency of generating iPS cell lines and have enabled the use of only 2 transgenes to generate iPS cell lines.22,23 Mouse iPS cells have now been generated using adenovirus or plasmid-mediated transfections, which avoid the potential problems associated with viral integration of transgenes.24,25 Generation of mouse iPS cells using only recombinant proteins without transgenes has also been described.26 Furthermore, techniques using nonintegrating transgenes have succeeded in generating iPS cells from human cells.27 This exponential growth in technologies to produce iPS cells has, however, outpaced the ability to thoroughly investigate the properties of the resulting iPS cells. Careful studies like those of Martinez-Fernandez are needed for next generation iPS cells.The groundbreaking studies done with mouse iPS cells have greatly advanced the field, but ultimately, for clinical applications, human iPS cells need the closest scrutiny. How can we demonstrate that human iPS cells are pluripotent without access to embryological studies? In vitro studies will certainly play an important role in characterizing lineage potential development.28 What will be the best way to assess tumor risk in the human iPS cells? What human iPS cell technologies will provide cells optimal for repair of the injured myocardium? We are on the road to powerful cardiovascular applications of iPS cells, but this remains a largely unmapped route that requires us to proceed expeditiously but cautiously. Table 1. Non-standard Abbreviations and AcronymsESembryonic stemiPSinduced pluripotent stemThe opinions expressed in this editorial are not necessarily those of the editors or of the American Heart Association.Sources of FundingSupported by NIH grants R01 HL0846150 and NIH R01 EB007534; National Science Foundation grant EFRI-0735903; and WiCell Research Institute.DisclosuresT.J.K. is a founding shareholder in Cellular Dynamics International Inc.FootnotesCorrespondence to Timothy J. Kamp, University of Wisconsin School of Medicine and Public Health, H6/370 Clinical Science Center-MC 3248, 600 Highland Ave, Madison, WI 53792. E-mail [email protected] References 1 Takahashi K, Yamanaka S. Induction of pluripotent stem cells from mouse embryonic and adult fibroblast cultures by defined factors. Cell. 2006; 126: 663–676.CrossrefMedlineGoogle Scholar2 Takahashi K, Tanabe K, Ohnuki M, Narita M, Ichisaka T, Tomoda K, Yamanaka S. Induction of pluripotent stem cells from adult human fibroblasts by defined factors. Cell. 2007; 131: 861–872.CrossrefMedlineGoogle Scholar3 Yu J, Vodyanik MA, Smuga-Otto K, Antosiewicz-Bourget J, Frane JL, Tian S, Nie J, Jonsdottir GA, Ruotti V, Stewart R, Slukvin II, Thomson JA. Induced pluripotent stem cell lines derived from human somatic cells. Science. 2007; 318: 1917–1920.CrossrefMedlineGoogle Scholar4 Park IH, Zhao R, West JA, Yabuuchi A, Huo H, Ince TA, Lerou PH, Lensch MW, Daley GQ. Reprogramming of human somatic cells to pluripotency with defined factors. Nature. 2008; 451: 141–146.CrossrefMedlineGoogle Scholar5 Park IH, Arora N, Huo H, Maherali N, Ahfeldt T, Shimamura A, Lensch MW, Cowan C, Hochedlinger K, Daley GQ. Disease-specific induced pluripotent stem cells. Cell. 2008; 134: 877–886.CrossrefMedlineGoogle Scholar6 Ebert AD, Yu J, Rose FF Jr, Mattis VB, Lorson CL, Thomson JA, Svendsen CN. Induced pluripotent stem cells from a spinal muscular atrophy patient. Nature. 2009; 457: 277–280.CrossrefMedlineGoogle Scholar7 Nelson TJ, Martinez-Fernandez A, Yamada S, Perez-Terzic C, Ikeda Y, Terzic A. Repair of acute myocardial infarction by human stemness factors induced pluripotent stem cells. Circulation. 2009; 120: 408–416.LinkGoogle Scholar8 Hanna J, Wernig M, Markoulaki S, Sun CW, Meissner A, Cassady JP, Beard C, Brambrink T, Wu LC, Townes TM, Jaenisch R. Treatment of sickle cell anemia mouse model with iPS cells generated from autologous skin. Science. 2007; 318: 1920–1923.CrossrefMedlineGoogle Scholar9 Wernig M, Zhao JP, Pruszak J, Hedlund E, Fu D, Soldner F, Broccoli V, Constantine-Paton M, Isacson O, Jaenisch R. Neurons derived from reprogrammed fibroblasts functionally integrate into the fetal brain and improve symptoms of rats with Parkinson’s disease. Proc Natl Acad Sci U S A. 2008; 105: 5856–5861.CrossrefMedlineGoogle Scholar10 Martinez-Fernandez A, Nelson TJ, Yamada S, Reyes S, Alekseev AE, Perez-Terzic C, Ikeda Y, Terzic A. iPS programmed without c-MYC yield proficient cardiogenesis for functional heart chimerism. Circ Res. 2009; 105: 648–656.LinkGoogle Scholar11 Okita K, Ichisaka T, Yamanaka S. Generation of germline-competent induced pluripotent stem cells. Nature. 2007; 448: 313–317.CrossrefMedlineGoogle Scholar12 Wernig M, Meissner A, Foreman R, Brambrink T, Ku M, Hochedlinger K, Bernstein BE, Jaenisch R. In vitro reprogramming of fibroblasts into a pluripotent ES-cell-like state. Nature. 2007; 448: 318–324.CrossrefMedlineGoogle Scholar13 Maherali N, Sridharan R, Xie W, Utikal J, Eminli S, Arnold K, Stadtfeld M, Yachechko R, Tchieu J, Jaenisch R, Plath K, Hochedlinger K. Directly reprogrammed fibroblasts show global epigenetic remodeling and widespread tissue contribution. Cell Stem Cell. 2007; 1: 55–70.CrossrefMedlineGoogle Scholar14 Kang L, Wang J, Zhang Y, Kou Z, Gao S. iPS cells can support full-term development of tetraploid blastocyst-complemented embryos. Cell Stem Cell. 2009; 5: 135–138.CrossrefMedlineGoogle Scholar15 Zhao XY, Li W, Lv Z, Liu L, Tong M, Hai T, Hao J, Guo CL, Ma QW, Wang L, Zeng F, Zhou Q. iPS cells produce viable mice through tetraploid complementation. Nature. 2009; 461: 86–90.CrossrefMedlineGoogle Scholar16 Mauritz C, Schwanke K, Reppel M, Neef S, Katsirntaki K, Maier LS, Nguemo F, Menke S, Haustein M, Hescheler J, Hasenfuss G, Martin U. Generation of functional murine cardiac myocytes from induced pluripotent stem cells. Circulation. 2008; 118: 507–517.LinkGoogle Scholar17 Narazaki G, Uosaki H, Teranishi M, Okita K, Kim B, Matsuoka S, Yamanaka S, Yamashita JK. Directed and systematic differentiation of cardiovascular cells from mouse induced pluripotent stem cells. Circulation. 2008; 118: 498–506.LinkGoogle Scholar18 Nakagawa M, Koyanagi M, Tanabe K, Takahashi K, Ichisaka T, Aoi T, Okita K, Mochiduki Y, Takizawa N, Yamanaka S. Generation of induced pluripotent stem cells without Myc from mouse and human fibroblasts. Nat Biotechnol. 2008; 26: 101–106.CrossrefMedlineGoogle Scholar19 Wernig M, Meissner A, Cassady JP, Jaenisch R. c-Myc is dispensable for direct reprogramming of mouse fibroblasts. Cell Stem Cell. 2008; 2: 10–12.CrossrefMedlineGoogle Scholar20 Maltsev VA, Wobus AM, Rohwedel J, Bader M, Hescheler J. Cardiomyocytes differentiated in vitro from embryonic stem cells developmentally express cardiac-specific genes and ionic currents. Circ Res. 1994; 75: 233–244.CrossrefMedlineGoogle Scholar21 Miura K, Okada Y, Aoi T, Okada A, Takahashi K, Okita K, Nakagawa M, Koyanagi M, Tanabe K, Ohnuki M, Ogawa D, Ikeda E, Okano H, Yamanaka S. Variation in the safety of induced pluripotent stem cell lines. Nat Biotechnol. 2009; 27: 743–745.CrossrefMedlineGoogle Scholar22 Huangfu D, Osafune K, Maehr R, Guo W, Eijkelenboom A, Chen S, Muhlestein W, Melton DA. Induction of pluripotent stem cells from primary human fibroblasts with only Oct4 and Sox2. Nat Biotechnol. 2008; 26: 1269–1275.CrossrefMedlineGoogle Scholar23 Shi Y, Desponts C, Do JT, Hahm HS, Scholer HR, Ding S. Induction of pluripotent stem cells from mouse embryonic fibroblasts by Oct4 and Klf4 with small-molecule compounds. Cell Stem Cell. 2008; 3: 568–574.CrossrefMedlineGoogle Scholar24 Stadtfeld M, Nagaya M, Utikal J, Weir G, Hochedlinger K. Induced pluripotent stem cells generated without viral integration. Science. 2008; 322: 945–949.CrossrefMedlineGoogle Scholar25 Okita K, Nakagawa M, Hyenjong H, Ichisaka T, Yamanaka S. Generation of mouse induced pluripotent stem cells without viral vectors. Science. 2008; 322: 949–953.CrossrefMedlineGoogle Scholar26 Zhou H, Wu S, Joo JY, Zhu S, Han DW, Lin T, Trauger S, Bien G, Yao S, Zhu Y, Siuzdak G, Scholer HR, Duan L, Ding S. Generation of induced pluripotent stem cells using recombinant proteins. Cell Stem Cell. 2009; 4: 381–384.CrossrefMedlineGoogle Scholar27 Yu J, Hu K, Smuga-Otto K, Tian S, Stewart R, Slukvin II, Thomson JA. Human induced pluripotent stem cells free of vector and transgene sequences. Science. 2009; 324: 797–801.CrossrefMedlineGoogle Scholar28 Zhang J, Wilson GF, Soerens AG, Koonce CH, Yu J, Palecek SP, Thomson JA, Kamp TJ. Functional cardiomyocytes derived from human induced pluripotent stem cells. Circ Res. 2009; 104: e30–e41.LinkGoogle Scholar Previous Back to top Next FiguresReferencesRelatedDetailsCited By Davis J, Chouman A, Creech J, Monteiro da Rocha A, Ponce-Balbuena D, Jimenez Vazquez E, Nichols R, Lozhkin A, Madamanchi N, Campbell K and Herron T (2021) In vitro model of ischemic heart failure using human induced pluripotent stem cell–derived cardiomyocytes, JCI Insight, 10.1172/jci.insight.134368, 6:10, Online publication date: 24-May-2021. Li J and Lee J (2021) Protocol for Morphological and Functional Phenotype Analysis of hiPS-Derived Pluripotent Stem-Cell Derived Cardiomyocytes, 10.1007/978-1-0716-1484-6_10, (91-100), . Herron T (2018) Highly Mature Human iPSC–Derived Cardiomyocytes as Models for Cardiac Electrophysiology and Drug Testing Cardiac Electrophysiology: From Cell to Bedside, 10.1016/B978-0-323-44733-1.00057-2, (541-551), . Herron T, Rocha A, Campbell K, Ponce-Balbuena D, Willis B, Guerrero-Serna G, Liu Q, Klos M, Musa H, Zarzoso M, Bizy A, Furness J, Anumonwo J, Mironov S and Jalife J (2016) Extracellular Matrix–Mediated Maturation of Human Pluripotent Stem Cell–Derived Cardiac Monolayer Structure and Electrophysiological Function, Circulation: Arrhythmia and Electrophysiology, 9:4, Online publication date: 1-Apr-2016. Lee S, Lee H, Choi S, Kim S and Kim K (2016) Evaluation of nefazodone-induced cardiotoxicity in human induced pluripotent stem cell-derived cardiomyocytes, Toxicology and Applied Pharmacology, 10.1016/j.taap.2016.01.015, 296, (42-53), Online publication date: 1-Apr-2016. Caballero M, Espinoza-Lewis R and Candiracci M (2016) Application of Stem Cells and iPS Cells in Toxicology Stem Cells in Toxicology and Medicine, 10.1002/9781119135449.ch2, (5-25) Herron T (2016) Calcium and voltage mapping in hiPSC-CM monolayers, Cell Calcium, 10.1016/j.ceca.2016.02.004, 59:2-3, (84-90), Online publication date: 1-Mar-2016. Doerr L, Thomas U, Guinot D, Bot C, Stoelzle-Feix S, Beckler M, George M and Fertig N (2015) New Easy-to-Use Hybrid System for Extracellular Potential and Impedance Recordings, SLAS Technology, 10.1177/2211068214562832, 20:2, (175-188), Online publication date: 1-Apr-2015. Zhao Y, Du J, Chen Y, Tang Y, Qin G, Lv G, Zhuang S and Zhao T (2015) Inhibition of Oct 3/4 mitigates the cardiac progenitor-derived myocardial repair in infarcted myocardium, Stem Cell Research & Therapy, 10.1186/s13287-015-0252-5, 6:1, Online publication date: 1-Dec-2015. Martins A, Vunjak-Novakovic G and Reis R (2014) The Current Status of iPS Cells in Cardiac Research and Their Potential for Tissue Engineering and Regenerative Medicine, Stem Cell Reviews and Reports, 10.1007/s12015-013-9487-7, 10:2, (177-190), Online publication date: 1-Apr-2014. Ieda M (2013) Direct Reprogramming into Desired Cell Types by Defined Factors, The Keio Journal of Medicine, 10.2302/kjm.2012-0017-RE, 62:3, (74-82), . Harris K, Aylott M, Cui Y, Louttit J, McMahon N and Sridhar A (2013) Comparison of Electrophysiological Data From Human-Induced Pluripotent Stem Cell–Derived Cardiomyocytes to Functional Preclinical Safety Assays, Toxicological Sciences, 10.1093/toxsci/kft113, 134:2, (412-426), Online publication date: 1-Aug-2013., Online publication date: 1-Aug-2013. Ieda M (2013) Induced Cardiomyocytes Cardiac Regeneration using Stem Cells, 10.1201/b14990-16, (258-275), Online publication date: 10-Apr-2013. Ieda M (2012) Cellular Reprogramming and Fate Conversion Advances in Stem Cell Research, 10.1007/978-1-61779-940-2_12, (211-225), . Kawaguchi N, Hayama E, Furutani Y and Nakanishi T (2012) Prospective In Vitro Models of Channelopathies and Cardiomyopathies , Stem Cells International, 10.1155/2012/439219, 2012, (1-10), . Abassi Y, Xi B, Li N, Ouyang W, Seiler A, Watzele M, Kettenhofen R, Bohlen H, Ehlich A, Kolossov E, Wang X and Xu X (2012) Dynamic monitoring of beating periodicity of stem cell-derived cardiomyocytes as a predictive tool for preclinical safety assessment, British Journal of Pharmacology, 10.1111/j.1476-5381.2011.01623.x, 165:5, (1424-1441), Online publication date: 1-Mar-2012. Bai X, Zheng H, Fang R, Wang T, Hou X, Li Y, Chen X and Tian W (2011) Fabrication of engineered heart tissue grafts from alginate/collagen barium composite microbeads, Biomedical Materials, 10.1088/1748-6041/6/4/045002, 6:4, (045002), Online publication date: 1-Aug-2011. Pesce M, Pompilio G, Gambini E and Capogrossi M (2011) Cardiac Stem Cells: Tales, Mysteries and Promises in Heart Generation and Regeneration Regenerative Medicine, 10.1007/978-90-481-9075-1_12, (265-286), . Yang K, Shih H, How C, Chen C, Hsu H, Yang C, Lee Y, Perng R, Peng C, Li H, Chang C, Mou C and Chiou S (2011) IV Delivery of Induced Pluripotent Stem Cells Attenuates Endotoxin-Induced Acute Lung Injury in Mice, Chest, 10.1378/chest.11-0539, 140:5, (1243-1253), Online publication date: 1-Nov-2011. Xi B, Wang T, Li N, Ouyang W, Zhang W, Wu J, Xu X, Wang X and Abassi Y (2011) Functional Cardiotoxicity Profiling and Screening Using the xCELLigence RTCA Cardio System, JALA: Journal of the Association for Laboratory Automation, 10.1016/j.jala.2011.09.002, 16:6, (415-421), Online publication date: 1-Dec-2011. Pesce M, Burba I, Gambini E, Prandi F, Pompilio G and Capogrossi M (2011) Endothelial and cardiac progenitors: Boosting, conditioning and (re)programming for cardiovascular repair, Pharmacology & Therapeutics, 10.1016/j.pharmthera.2010.10.003, 129:1, (50-61), Online publication date: 1-Jan-2011. Cheng J, Morales A, Siegfried J, Li D, Norton N, Song J, Gonzalez-Quintana J, Makielski J and Hershberger R (2010) SCN5A Rare Variants in Familial Dilated Cardiomyopathy Decrease Peak Sodium Current Depending on the Common Polymorphism H558R and Common Splice Variant Q1077del, Clinical and Translational Science, 10.1111/j.1752-8062.2010.00249.x, 3:6, (287-294), Online publication date: 1-Dec-2010. Chen S, Chang C, Tsai S, Chang Y, Chou S, Huang S, Tai L, Chen Y, Ku H, Li H and Chiou S (2010) Functional Improvement of Focal Cerebral Ischemia Injury by Subdural Transplantation of Induced Pluripotent Stem Cells with Fibrin Glue, Stem Cells and Development, 10.1089/scd.2009.0452, 19:11, (1757-1767), Online publication date: 1-Nov-2010. Taylor D (2009) From stem cells and cadaveric matrix to engineered organs, Current Opinion in Biotechnology, 10.1016/j.copbio.2009.10.016, 20:5, (598-605), Online publication date: 1-Oct-2009. Schmitz-Rixen T and Lang W (2009) Entwicklung der Gefäß- und Endovaskularchirurgie in den nächsten 20 JahrenDevelopment of vascular and endovascular surgery over the next 20 years, Der Chirurg, 10.1007/s00104-009-1776-y, 80:12, (1126-1131), Online publication date: 1-Dec-2009. September 25, 2009Vol 105, Issue 7 Advertisement Article InformationMetrics https://doi.org/10.1161/CIRCRESAHA.109.205740PMID: 19797193 Originally publishedSeptember 25, 2009 Keywordscardiac developmentstem cellsiPS cellscardiac differentiationcardiomyocytescardiogenesisPDF download Advertisement