Local control of excitation-contraction coupling in human embryonic stem cell-derived cardiomyocytes.
We investigated the mechanisms of excitation-contraction (EC) coupling in human embryonic stem cell-derived cardiomyocytes (hESC-CMs) and fetal ventricular myocytes (hFVMs) using patch-clamp electrophysiology and confocal microscopy. We tested the hypothesis that Ca(2+) influx via voltage-gated L-ty...
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2009-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC2671137?pdf=render |
| _version_ | 1818198616736530432 |
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| author | Wei-Zhong Zhu Luis F Santana Michael A Laflamme |
| author_facet | Wei-Zhong Zhu Luis F Santana Michael A Laflamme |
| author_sort | Wei-Zhong Zhu |
| collection | DOAJ |
| description | We investigated the mechanisms of excitation-contraction (EC) coupling in human embryonic stem cell-derived cardiomyocytes (hESC-CMs) and fetal ventricular myocytes (hFVMs) using patch-clamp electrophysiology and confocal microscopy. We tested the hypothesis that Ca(2+) influx via voltage-gated L-type Ca(2+) channels activates Ca(2+) release from the sarcoplasmic reticulum (SR) via a local control mechanism in hESC-CMs and hFVMs. Field-stimulated, whole-cell [Ca(2+)](i) transients in hESC-CMs required Ca(2+) entry through L-type Ca(2+) channels, as evidenced by the elimination of such transients by either removal of extracellular Ca(2+) or treatment with diltiazem, an L-type channel inhibitor. Ca(2+) release from the SR also contributes to the [Ca(2+)](i) transient in these cells, as evidenced by studies with drugs interfering with either SR Ca(2+) release (i.e. ryanodine and caffeine) or reuptake (i.e. thapsigargin and cyclopiazonic acid). As in adult ventricular myocytes, membrane depolarization evoked large L-type Ca(2+) currents (I(Ca)) and corresponding whole-cell [Ca(2+)](i) transients in hESC-CMs and hFVMs, and the amplitude of both I(Ca) and the [Ca(2+)](i) transients were finely graded by the magnitude of the depolarization. hESC-CMs exhibit a decreasing EC coupling gain with depolarization to more positive test potentials, "tail" [Ca(2+)](i) transients upon repolarization from extremely positive test potentials, and co-localized ryanodine and sarcolemmal L-type Ca(2+) channels, all findings that are consistent with the local control hypothesis. Finally, we recorded Ca(2+) sparks in hESC-CMs and hFVMs. Collectively, these data support a model in which tight, local control of SR Ca(2+) release by the I(Ca) during EC coupling develops early in human cardiomyocytes. |
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| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-12T02:08:42Z |
| publishDate | 2009-01-01 |
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| spelling | doaj.art-f5195646e0304fa5926a5066fd85914d2022-12-22T00:41:58ZengPublic Library of Science (PLoS)PLoS ONE1932-62032009-01-0144e540710.1371/journal.pone.0005407Local control of excitation-contraction coupling in human embryonic stem cell-derived cardiomyocytes.Wei-Zhong ZhuLuis F SantanaMichael A LaflammeWe investigated the mechanisms of excitation-contraction (EC) coupling in human embryonic stem cell-derived cardiomyocytes (hESC-CMs) and fetal ventricular myocytes (hFVMs) using patch-clamp electrophysiology and confocal microscopy. We tested the hypothesis that Ca(2+) influx via voltage-gated L-type Ca(2+) channels activates Ca(2+) release from the sarcoplasmic reticulum (SR) via a local control mechanism in hESC-CMs and hFVMs. Field-stimulated, whole-cell [Ca(2+)](i) transients in hESC-CMs required Ca(2+) entry through L-type Ca(2+) channels, as evidenced by the elimination of such transients by either removal of extracellular Ca(2+) or treatment with diltiazem, an L-type channel inhibitor. Ca(2+) release from the SR also contributes to the [Ca(2+)](i) transient in these cells, as evidenced by studies with drugs interfering with either SR Ca(2+) release (i.e. ryanodine and caffeine) or reuptake (i.e. thapsigargin and cyclopiazonic acid). As in adult ventricular myocytes, membrane depolarization evoked large L-type Ca(2+) currents (I(Ca)) and corresponding whole-cell [Ca(2+)](i) transients in hESC-CMs and hFVMs, and the amplitude of both I(Ca) and the [Ca(2+)](i) transients were finely graded by the magnitude of the depolarization. hESC-CMs exhibit a decreasing EC coupling gain with depolarization to more positive test potentials, "tail" [Ca(2+)](i) transients upon repolarization from extremely positive test potentials, and co-localized ryanodine and sarcolemmal L-type Ca(2+) channels, all findings that are consistent with the local control hypothesis. Finally, we recorded Ca(2+) sparks in hESC-CMs and hFVMs. Collectively, these data support a model in which tight, local control of SR Ca(2+) release by the I(Ca) during EC coupling develops early in human cardiomyocytes.http://europepmc.org/articles/PMC2671137?pdf=render |
| spellingShingle | Wei-Zhong Zhu Luis F Santana Michael A Laflamme Local control of excitation-contraction coupling in human embryonic stem cell-derived cardiomyocytes. PLoS ONE |
| title | Local control of excitation-contraction coupling in human embryonic stem cell-derived cardiomyocytes. |
| title_full | Local control of excitation-contraction coupling in human embryonic stem cell-derived cardiomyocytes. |
| title_fullStr | Local control of excitation-contraction coupling in human embryonic stem cell-derived cardiomyocytes. |
| title_full_unstemmed | Local control of excitation-contraction coupling in human embryonic stem cell-derived cardiomyocytes. |
| title_short | Local control of excitation-contraction coupling in human embryonic stem cell-derived cardiomyocytes. |
| title_sort | local control of excitation contraction coupling in human embryonic stem cell derived cardiomyocytes |
| url | http://europepmc.org/articles/PMC2671137?pdf=render |
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