Abstract
Cardiomyocytes (CMs) are nonregenerative. Self-renewable pluripotent human embryonic stem cells (hESCs) can differentiate into CMs for cell-based therapies. We recently reported that Ca2+ handling, crucial to excitation-contraction coupling of hESC-derived CMs (hESC-CMs), is functional but immature. Such immature properties as smaller cytosolic Ca2+ transient amplitudes, slower kinetics, and reduced Ca2+ content of sarcoplasmic reticulum (SR) can be attributed to the differential developmental expression profiles of specific Ca2+ handling and regulatory proteins in hESC-CMs and their adult counterparts. In particular, calsequestrin (CSQ), the most abundant, high-capacity but low-affinity, Ca2+-binding protein in the SR that is anchored to the ryanodine receptor, is robustly expressed in adult CMs but completely absent in hESCCMs. Here we hypothesized that gene transfer of CSQ in hESC-CMs suffices to induce functional improvement of SR. Transduction of hESC-CMs by the recombinant adenovirus Ad-CMV-CSQ-IRES-GFP (Ad-CSQ) significantly increased the transient amplitude, upstroke velocity, and transient decay compared with the control Ad-CMV-GFP (Ad-GFP) and Ad-CMV-CSQΔ-IRES-GFP (Ad-CSQΔ, which mediated the expression of a nonfunctional, truncated version of CSQ) groups. Ad-CSQ increased the SR Ca2+ content but did not alter L-type Ca 2+ current. Pharmacologically, untransduced wildtype, Ad-GFP-, Ad-CSQΔ-, and Ad-CSQ-transduced hESC-CMs behaved similarly. Whereas ryanodine significantly reduced the Ca2+ transient amplitude and slowed the upstroke, thapsigargin slowed the decay. Neither triadin nor junctin was affected. We conclude that CSQ expression in hESC-CMs facilitates Ca 2+ handling maturation. Our results shed insights into the suitability of hESC-CMs for therapies and as certain heart disease models for drug screening.
| Original language | English (US) |
|---|---|
| Journal | American Journal of Physiology - Cell Physiology |
| Volume | 297 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jul 2009 |
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Keywords
- Adenovirus
- Calcium transients
- Ryanodine receptor
ASJC Scopus subject areas
- Cell Biology
- Physiology
- Medicine(all)
Cite this
Facilitated maturation of Ca2+ handling properties of human embryonic stem cell-derived cardiomyocytes by calsequestrin expression. / Liu, Jing; Lieu, Deborah; Siu, Chung Wah; Fu, Ji Dong; Tse, Hung Fat; Li, Ronald A.
In: American Journal of Physiology - Cell Physiology, Vol. 297, No. 1, 07.2009.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Facilitated maturation of Ca2+ handling properties of human embryonic stem cell-derived cardiomyocytes by calsequestrin expression
AU - Liu, Jing
AU - Lieu, Deborah
AU - Siu, Chung Wah
AU - Fu, Ji Dong
AU - Tse, Hung Fat
AU - Li, Ronald A.
PY - 2009/7
Y1 - 2009/7
N2 - Cardiomyocytes (CMs) are nonregenerative. Self-renewable pluripotent human embryonic stem cells (hESCs) can differentiate into CMs for cell-based therapies. We recently reported that Ca2+ handling, crucial to excitation-contraction coupling of hESC-derived CMs (hESC-CMs), is functional but immature. Such immature properties as smaller cytosolic Ca2+ transient amplitudes, slower kinetics, and reduced Ca2+ content of sarcoplasmic reticulum (SR) can be attributed to the differential developmental expression profiles of specific Ca2+ handling and regulatory proteins in hESC-CMs and their adult counterparts. In particular, calsequestrin (CSQ), the most abundant, high-capacity but low-affinity, Ca2+-binding protein in the SR that is anchored to the ryanodine receptor, is robustly expressed in adult CMs but completely absent in hESCCMs. Here we hypothesized that gene transfer of CSQ in hESC-CMs suffices to induce functional improvement of SR. Transduction of hESC-CMs by the recombinant adenovirus Ad-CMV-CSQ-IRES-GFP (Ad-CSQ) significantly increased the transient amplitude, upstroke velocity, and transient decay compared with the control Ad-CMV-GFP (Ad-GFP) and Ad-CMV-CSQΔ-IRES-GFP (Ad-CSQΔ, which mediated the expression of a nonfunctional, truncated version of CSQ) groups. Ad-CSQ increased the SR Ca2+ content but did not alter L-type Ca 2+ current. Pharmacologically, untransduced wildtype, Ad-GFP-, Ad-CSQΔ-, and Ad-CSQ-transduced hESC-CMs behaved similarly. Whereas ryanodine significantly reduced the Ca2+ transient amplitude and slowed the upstroke, thapsigargin slowed the decay. Neither triadin nor junctin was affected. We conclude that CSQ expression in hESC-CMs facilitates Ca 2+ handling maturation. Our results shed insights into the suitability of hESC-CMs for therapies and as certain heart disease models for drug screening.
AB - Cardiomyocytes (CMs) are nonregenerative. Self-renewable pluripotent human embryonic stem cells (hESCs) can differentiate into CMs for cell-based therapies. We recently reported that Ca2+ handling, crucial to excitation-contraction coupling of hESC-derived CMs (hESC-CMs), is functional but immature. Such immature properties as smaller cytosolic Ca2+ transient amplitudes, slower kinetics, and reduced Ca2+ content of sarcoplasmic reticulum (SR) can be attributed to the differential developmental expression profiles of specific Ca2+ handling and regulatory proteins in hESC-CMs and their adult counterparts. In particular, calsequestrin (CSQ), the most abundant, high-capacity but low-affinity, Ca2+-binding protein in the SR that is anchored to the ryanodine receptor, is robustly expressed in adult CMs but completely absent in hESCCMs. Here we hypothesized that gene transfer of CSQ in hESC-CMs suffices to induce functional improvement of SR. Transduction of hESC-CMs by the recombinant adenovirus Ad-CMV-CSQ-IRES-GFP (Ad-CSQ) significantly increased the transient amplitude, upstroke velocity, and transient decay compared with the control Ad-CMV-GFP (Ad-GFP) and Ad-CMV-CSQΔ-IRES-GFP (Ad-CSQΔ, which mediated the expression of a nonfunctional, truncated version of CSQ) groups. Ad-CSQ increased the SR Ca2+ content but did not alter L-type Ca 2+ current. Pharmacologically, untransduced wildtype, Ad-GFP-, Ad-CSQΔ-, and Ad-CSQ-transduced hESC-CMs behaved similarly. Whereas ryanodine significantly reduced the Ca2+ transient amplitude and slowed the upstroke, thapsigargin slowed the decay. Neither triadin nor junctin was affected. We conclude that CSQ expression in hESC-CMs facilitates Ca 2+ handling maturation. Our results shed insights into the suitability of hESC-CMs for therapies and as certain heart disease models for drug screening.
KW - Adenovirus
KW - Calcium transients
KW - Ryanodine receptor
UR - http://www.scopus.com/inward/record.url?scp=67650033077&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=67650033077&partnerID=8YFLogxK
U2 - 10.1152/ajpcell.00060.2009
DO - 10.1152/ajpcell.00060.2009
M3 - Article
C2 - 19357236
AN - SCOPUS:67650033077
VL - 297
JO - American Journal of Physiology - Renal Fluid and Electrolyte Physiology
JF - American Journal of Physiology - Renal Fluid and Electrolyte Physiology
SN - 1931-857X
IS - 1
ER -