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Differences in Contractile Function of Myofibrils within Human Embryonic Stem Cell-Derived Cardiomyocytes vs. Adult Ventricular Myofibrils Are Related to Distinct Sarcomeric Protein Isoforms

التفاصيل البيبلوغرافية
العنوان: Differences in Contractile Function of Myofibrils within Human Embryonic Stem Cell-Derived Cardiomyocytes vs. Adult Ventricular Myofibrils Are Related to Distinct Sarcomeric Protein Isoforms
المؤلفون: Bogdan Iorga, Kristin Schwanke, Natalie Weber, Meike Wendland, Stephan Greten, Birgit Piep, Cristobal G. dos Remedios, Ulrich Martin, Robert Zweigerdt, Theresia Kraft, Bernhard Brenner
المصدر: Frontiers in Physiology, Vol 8 (2018)
بيانات النشر: Frontiers Media S.A., 2018.
سنة النشر: 2018
المجموعة: LCC:Physiology
مصطلحات موضوعية: human pluripotent stem cell-derived cardiomyocytes, human embryonic stem cell-derived cardiomyocytes, hiPSC-CMs maturation, human cardiomyocytes development, adult human ventricular myofibrils, cardiac contractile function, Physiology, QP1-981
الوصف: Characterizing the contractile function of human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) is key for advancing their utility for cellular disease models, promoting cell based heart repair, or developing novel pharmacological interventions targeting cardiac diseases. The aim of the present study was to understand whether steady-state and kinetic force parameters of β-myosin heavy chain (βMyHC) isoform-expressing myofibrils within human embryonic stem cell-derived cardiomyocytes (hESC-CMs) differentiated in vitro resemble those of human ventricular myofibrils (hvMFs) isolated from adult donor hearts. Contractile parameters were determined using the same micromechanical method and experimental conditions for both types of myofibrils. We identified isoforms and phosphorylation of main sarcomeric proteins involved in the modulation of force generation of both, chemically demembranated hESC-CMs (d-hESC-CMs) and hvMFs. Our results indicate that at saturating Ca2+ concentration, both human-derived contractile systems developed forces with similar rate constants (0.66 and 0.68 s−1), reaching maximum isometric force that was significantly smaller for d-hESC-CMs (42 kPa) than for hvMFs (94 kPa). At submaximal Ca2+-activation, where intact cardiomyocytes normally operate, contractile parameters of d-hESC-CMs and hvMFs exhibited differences. Ca2+ sensitivity of force was higher for d-hESC-CMs (pCa50 = 6.04) than for hvMFs (pCa50 = 5.80). At half-maximum activation, the rate constant for force redevelopment was significantly faster for d-hESC-CMs (0.51 s−1) than for hvMFs (0.28 s−1). During myofibril relaxation, kinetics of the slow force decay phase were significantly faster for d-hESC-CMs (0.26 s−1) than for hvMFs (0.21 s−1), while kinetics of the fast force decay were similar and ~20x faster. Protein analysis revealed that hESC-CMs had essentially no cardiac troponin-I, and partially non-ventricular isoforms of some other sarcomeric proteins, explaining the functional discrepancies. The sarcomeric protein isoform pattern of hESC-CMs had features of human cardiomyocytes at an early developmental stage. The study indicates that morphological and ultrastructural maturation of βMyHC isoform-expressing hESC-CMs is not necessarily accompanied by ventricular-like expression of all sarcomeric proteins. Our data suggest that hPSC-CMs could provide useful tools for investigating inherited cardiac diseases affecting contractile function during early developmental stages.
نوع الوثيقة: article
وصف الملف: electronic resource
اللغة: English
تدمد: 1664-042X
49442988
Relation: http://journal.frontiersin.org/article/10.3389/fphys.2017.01111/full; https://doaj.org/toc/1664-042X
DOI: 10.3389/fphys.2017.01111
URL الوصول: https://doaj.org/article/2141cbe2b4944298869c2089b299ca9a
رقم الأكسشن: edsdoj.2141cbe2b4944298869c2089b299ca9a
قاعدة البيانات: Directory of Open Access Journals
الوصف
تدمد:1664042X
49442988
DOI:10.3389/fphys.2017.01111