Deficient cMyBP-C protein expression during cardiomyocyte differentiation underlies human hypertrophic cardiomyopathy cellular phenotypes in disease specific human ES cell derived cardiomyocytes.
OBJECTIVE
Mutations of cardiac sarcomere genes have been identified to cause HCM, but the molecular mechanisms that lead to cardiomyocyte hypertrophy and risk for sudden death are uncertain. The aim of this study was to examine HCM disease mechanisms at play during cardiac differentiation of human HCM specific pluripotent stem cells.


RESULTS
We generated a human embryonic stem cell (hESC) line carrying a naturally occurring mutation of MYPBC3 (c.2905 +1 G >A) to study HCM pathogenesis during cardiac differentiation. HCM-specific hESC-derived cardiomyocytes (hESC-CMs) displayed hallmark aspects of HCM including sarcomere disarray, hypertrophy and impaired calcium impulse propagation. HCM hESC-CMs presented a transient haploinsufficiency of cMyBP-C during cardiomyocyte differentiation, but by day 30 post-differentiation cMyBP-C levels were similar to control hESC-CMs. Gene transfer of full-length MYBPC3 during differentiation prevented hypertrophy, sarcomere disarray and improved calcium impulse propagation in HCM hESC-CMs.


CONCLUSIONS
These findings point to the critical role of MYBPC3 during sarcomere assembly in cardiac myocyte differentiation and suggest developmental influences of MYBPC3 truncating mutations on the mature hypertrophic phenotype.
Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI 48109, United States; Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, MI 48109, United States.
Andre
A
Monteiro da Rocha
Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI 48109, United States.
Guadalupe
G
Guerrero-Serna
Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI 48109, United States.
Adam
A
Helms
Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI 48109, United States.
Carly
C
Luzod
Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI 48109, United States.
Sergey
S
Mironov
Department of Pediatrics, University of Michigan, Ann Arbor, MI 48109, United States.
Mark
M
Russell
Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI 48109, United States.
José
J
Jalife
Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI 48109, United States.
Sharlene M
SM
Day
Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, MI 48109, United States. Electronic address: smithgd@umich.edu.
Gary D
GD
Smith
Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI 48109, United States. Electronic address: toddherr@umich.edu.
Todd J
TJ
Herron
D002118:Calcium / Q000378:metabolism; D002312:Cardiomyopathy, Hypertrophic / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism*; D002454:Cell Differentiation / Q000235:genetics*; D004252:DNA Mutational Analysis; D053595:Embryonic Stem Cells / Q000166:cytology*; D015870:Gene Expression; D006801:Humans; D059785:Karyotype; D009154:Mutation; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000378:metabolism*; D038081:Organogenesis; D010641:Phenotype; D012518:Sarcomeres / Q000378:metabolism; D014158:Transcription, Genetic; D014161:Transduction, Genetic; D000099163:Myosin Binding Protein C
D002118:Calcium; D002352:Carrier Proteins; D000099163:Myosin Binding Protein C
Cardiac differentiation; Cardiomyopathy; Hypertrophy; Optical mapping; Stem cell derived cardiomyocytes; Stem cells