Details
| Original language | English |
|---|---|
| Pages (from-to) | 112-125 |
| Number of pages | 14 |
| Journal | Journal of Molecular and Cellular Cardiology |
| Volume | 198 |
| Early online date | 7 Dec 2024 |
| Publication status | Published - Jan 2025 |
Abstract
Hypertrophic Cardiomyopathy (HCM) is often caused by heterozygous mutations in β-myosin heavy chain (MYH7, β-MyHC). In addition to hyper- or hypocontractile effects of HCM-mutations, heterogeneity in contractile function (contractile imbalance) among individual cardiomyocytes was observed in end-stage HCM-myocardium. Contractile imbalance might be induced by burst-like transcription, leading to unequal fractions of mutant versus wildtype mRNA and protein in individual cardiomyocytes (allelic imbalance). Until now it is not known if allelic and contractile imbalance are present early in HCM-development or rather occur in response to disease-associated remodeling. To address this question, we used patient-specific human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) with heterozygous MYH7-mutations R723G and G741R as models of early-stage HCM without secondary adaptions upon disease progression. R723G-hiPSC-CMs showed typical HCM-markers like hypertrophy and myofibrillar disarray. Using RNA-FISH and allele-specific single-cell-PCR, we show for both cell lines that MYH7 is transcribed in bursts. Highly variable mutant vs. wildtype MYH7-mRNA fractions in individual HCM-hiPSC-CMs indicated allelic imbalance. HCM-hiPSC-CM-lines showed functional alterations like slowed twitch contraction kinetics and reduced calcium sensitivity of myofibrillar force generation. A significantly larger variability in force generation or twitch parameters of individual HCM-hiPSC-CMs compared to WT-hiPSC-CMs indicated contractile imbalance. Our results with early-stage hiPSC-CMs strongly suggest that burst-like transcription and allelic imbalance are general features of CMs, which together with mutation-induced changes of sarcomere contraction could induce contractile imbalance in heterozygous CMs, presumably aggravating development of HCM. Genetic or epigenetic approaches targeting functional heterogeneity in HCM could lead to promising future therapies, in addition to myosin modulation.
Keywords
- Allelic imbalance, Contractile imbalance, hiPSC-derived cardiomyocytes, Hypertrophic cardiomyopathy, R723G myosin mutation
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Molecular Biology
- Medicine(all)
- Cardiology and Cardiovascular Medicine
Sustainable Development Goals
Cite this
- Standard
- Harvard
- Apa
- Vancouver
- BibTeX
- RIS
In: Journal of Molecular and Cellular Cardiology, Vol. 198, 01.2025, p. 112-125.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Patient-specific hiPSC-derived cardiomyocytes indicate allelic and contractile imbalance as pathogenic factor in early-stage Hypertrophic Cardiomyopathy
AU - Weber, Natalie
AU - Montag, Judith
AU - Kowalski, Kathrin
AU - Iorga, Bogdan
AU - de la Roche, Jeanne
AU - Holler, Tim
AU - Wojciechowski, Daniel
AU - Wendland, Meike
AU - Radocaj, Ante
AU - Mayer, Anne Kathrin
AU - Brunkhorst, Anja
AU - Osten, Felix
AU - Burkart, Valentin
AU - Piep, Birgit
AU - Bodenschatz, Alea
AU - Gibron, Pia
AU - Schwanke, Kristin
AU - Franke, Annika
AU - Thiemann, Stefan
AU - Koroleva, Anastasia
AU - Pfanne, Angelika
AU - Konsanke, Maike
AU - Fiedler, Jan
AU - Hegermann, Jan
AU - Wrede, Christoph
AU - Mühlfeld, Christian
AU - Chichkov, Boris
AU - Fischer, Martin
AU - Thum, Thomas
AU - Francino, Antonio
AU - Martin, Ulrich
AU - Meißner, Joachim
AU - Zweigerdt, Robert
AU - Kraft, Theresia
N1 - Publisher Copyright: © 2024 The Author(s)
PY - 2025/1
Y1 - 2025/1
N2 - Hypertrophic Cardiomyopathy (HCM) is often caused by heterozygous mutations in β-myosin heavy chain (MYH7, β-MyHC). In addition to hyper- or hypocontractile effects of HCM-mutations, heterogeneity in contractile function (contractile imbalance) among individual cardiomyocytes was observed in end-stage HCM-myocardium. Contractile imbalance might be induced by burst-like transcription, leading to unequal fractions of mutant versus wildtype mRNA and protein in individual cardiomyocytes (allelic imbalance). Until now it is not known if allelic and contractile imbalance are present early in HCM-development or rather occur in response to disease-associated remodeling. To address this question, we used patient-specific human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) with heterozygous MYH7-mutations R723G and G741R as models of early-stage HCM without secondary adaptions upon disease progression. R723G-hiPSC-CMs showed typical HCM-markers like hypertrophy and myofibrillar disarray. Using RNA-FISH and allele-specific single-cell-PCR, we show for both cell lines that MYH7 is transcribed in bursts. Highly variable mutant vs. wildtype MYH7-mRNA fractions in individual HCM-hiPSC-CMs indicated allelic imbalance. HCM-hiPSC-CM-lines showed functional alterations like slowed twitch contraction kinetics and reduced calcium sensitivity of myofibrillar force generation. A significantly larger variability in force generation or twitch parameters of individual HCM-hiPSC-CMs compared to WT-hiPSC-CMs indicated contractile imbalance. Our results with early-stage hiPSC-CMs strongly suggest that burst-like transcription and allelic imbalance are general features of CMs, which together with mutation-induced changes of sarcomere contraction could induce contractile imbalance in heterozygous CMs, presumably aggravating development of HCM. Genetic or epigenetic approaches targeting functional heterogeneity in HCM could lead to promising future therapies, in addition to myosin modulation.
AB - Hypertrophic Cardiomyopathy (HCM) is often caused by heterozygous mutations in β-myosin heavy chain (MYH7, β-MyHC). In addition to hyper- or hypocontractile effects of HCM-mutations, heterogeneity in contractile function (contractile imbalance) among individual cardiomyocytes was observed in end-stage HCM-myocardium. Contractile imbalance might be induced by burst-like transcription, leading to unequal fractions of mutant versus wildtype mRNA and protein in individual cardiomyocytes (allelic imbalance). Until now it is not known if allelic and contractile imbalance are present early in HCM-development or rather occur in response to disease-associated remodeling. To address this question, we used patient-specific human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) with heterozygous MYH7-mutations R723G and G741R as models of early-stage HCM without secondary adaptions upon disease progression. R723G-hiPSC-CMs showed typical HCM-markers like hypertrophy and myofibrillar disarray. Using RNA-FISH and allele-specific single-cell-PCR, we show for both cell lines that MYH7 is transcribed in bursts. Highly variable mutant vs. wildtype MYH7-mRNA fractions in individual HCM-hiPSC-CMs indicated allelic imbalance. HCM-hiPSC-CM-lines showed functional alterations like slowed twitch contraction kinetics and reduced calcium sensitivity of myofibrillar force generation. A significantly larger variability in force generation or twitch parameters of individual HCM-hiPSC-CMs compared to WT-hiPSC-CMs indicated contractile imbalance. Our results with early-stage hiPSC-CMs strongly suggest that burst-like transcription and allelic imbalance are general features of CMs, which together with mutation-induced changes of sarcomere contraction could induce contractile imbalance in heterozygous CMs, presumably aggravating development of HCM. Genetic or epigenetic approaches targeting functional heterogeneity in HCM could lead to promising future therapies, in addition to myosin modulation.
KW - Allelic imbalance
KW - Contractile imbalance
KW - hiPSC-derived cardiomyocytes
KW - Hypertrophic cardiomyopathy
KW - R723G myosin mutation
UR - http://www.scopus.com/inward/record.url?scp=85211017594&partnerID=8YFLogxK
U2 - 10.1016/j.yjmcc.2024.11.007
DO - 10.1016/j.yjmcc.2024.11.007
M3 - Article
C2 - 39647438
AN - SCOPUS:85211017594
VL - 198
SP - 112
EP - 125
JO - Journal of Molecular and Cellular Cardiology
JF - Journal of Molecular and Cellular Cardiology
SN - 0022-2828
ER -