Contractile abnormalities and altered drug response in engineered heart tissue from Mybpc3-targeted knock-in mice
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Contractile abnormalities and altered drug response in engineered heart tissue from Mybpc3-targeted knock-in mice. / Stöhr, Andrea; Friedrich, Felix W; Flenner, Frederik; Geertz, Birgit; Eder, Alexandra; Schaaf, Sebastian; Hirt, Marc N; Uebeler, June; Schlossarek, Saskia; Carrier, Lucie; Hansen, Arne; Eschenhagen, Thomas.
In: J MOL CELL CARDIOL, Vol. 63, 01.10.2013, p. 189-98.Research output: SCORING: Contribution to journal › SCORING: Journal article › Research › peer-review
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TY - JOUR
T1 - Contractile abnormalities and altered drug response in engineered heart tissue from Mybpc3-targeted knock-in mice
AU - Stöhr, Andrea
AU - Friedrich, Felix W
AU - Flenner, Frederik
AU - Geertz, Birgit
AU - Eder, Alexandra
AU - Schaaf, Sebastian
AU - Hirt, Marc N
AU - Uebeler, June
AU - Schlossarek, Saskia
AU - Carrier, Lucie
AU - Hansen, Arne
AU - Eschenhagen, Thomas
N1 - © 2013. Published by Elsevier Ltd. All rights reserved.
PY - 2013/10/1
Y1 - 2013/10/1
N2 - Myosin-binding protein C (Mybpc3)-targeted knock-in mice (KI) recapitulate typical aspects of human hypertrophic cardiomyopathy. We evaluated whether these functional alterations can be reproduced in engineered heart tissue (EHT) and yield novel mechanistic information on the function of cMyBP-C. EHTs were generated from cardiac cells of neonatal KI, heterozygous (HET) or wild-type controls (WT) and developed without apparent morphological differences. KI had 70% and HET 20% lower total cMyBP-C levels than WT, accompanied by elevated fetal gene expression. Under standard culture conditions and spontaneous beating, KI EHTs showed more frequent burst beating than WT and occasional tetanic contractions (14/96). Under electrical stimulation (6Hz, 37°C) KI EHTs exhibited shorter contraction and relaxation times and a twofold higher sensitivity to external [Ca(2+)]. Accordingly, the sensitivity to verapamil was 4-fold lower and the response to isoprenaline or the Ca(2+) sensitizer EMD 57033 2- to 4-fold smaller. The loss of EMD effect was verified in 6-week-old KI mice in vivo. HET EHTs were apparently normal under basal conditions, but showed similarly altered contractile responses to [Ca(2+)], verapamil, isoprenaline and EMD. In contrast, drug-induced changes in intracellular Ca(2+) transients (Fura-2) were essentially normal. In conclusion, the present findings in auxotonically contracting EHTs support the idea that cMyBP-C's normal role is to suppress force generation at low intracellular Ca(2+) and stabilize the power-stroke step of the cross bridge cycle. Pharmacological testing in EHT unmasked a disease phenotype in HET. The altered drug response may be clinically relevant.
AB - Myosin-binding protein C (Mybpc3)-targeted knock-in mice (KI) recapitulate typical aspects of human hypertrophic cardiomyopathy. We evaluated whether these functional alterations can be reproduced in engineered heart tissue (EHT) and yield novel mechanistic information on the function of cMyBP-C. EHTs were generated from cardiac cells of neonatal KI, heterozygous (HET) or wild-type controls (WT) and developed without apparent morphological differences. KI had 70% and HET 20% lower total cMyBP-C levels than WT, accompanied by elevated fetal gene expression. Under standard culture conditions and spontaneous beating, KI EHTs showed more frequent burst beating than WT and occasional tetanic contractions (14/96). Under electrical stimulation (6Hz, 37°C) KI EHTs exhibited shorter contraction and relaxation times and a twofold higher sensitivity to external [Ca(2+)]. Accordingly, the sensitivity to verapamil was 4-fold lower and the response to isoprenaline or the Ca(2+) sensitizer EMD 57033 2- to 4-fold smaller. The loss of EMD effect was verified in 6-week-old KI mice in vivo. HET EHTs were apparently normal under basal conditions, but showed similarly altered contractile responses to [Ca(2+)], verapamil, isoprenaline and EMD. In contrast, drug-induced changes in intracellular Ca(2+) transients (Fura-2) were essentially normal. In conclusion, the present findings in auxotonically contracting EHTs support the idea that cMyBP-C's normal role is to suppress force generation at low intracellular Ca(2+) and stabilize the power-stroke step of the cross bridge cycle. Pharmacological testing in EHT unmasked a disease phenotype in HET. The altered drug response may be clinically relevant.
KW - Adrenergic beta-Agonists
KW - Animals
KW - Calcium
KW - Calcium Channel Blockers
KW - Cardiomyopathy, Hypertrophic
KW - Carrier Proteins
KW - Disease Models, Animal
KW - Gene Targeting
KW - Intracellular Space
KW - Isoproterenol
KW - Mice
KW - Mice, Transgenic
KW - Myocardial Contraction
KW - Myocardium
KW - Tissue Engineering
KW - Transcriptome
KW - Verapamil
U2 - 10.1016/j.yjmcc.2013.07.011
DO - 10.1016/j.yjmcc.2013.07.011
M3 - SCORING: Journal article
C2 - 23896226
VL - 63
SP - 189
EP - 198
JO - J MOL CELL CARDIOL
JF - J MOL CELL CARDIOL
SN - 0022-2828
ER -