Abstract 17931: Auxotonic MyoPod® Engineered Heart Tissues Enable Longitudinal Tracking of in vitro Development of Hypertrophic Cardiomyopathy
Cassady Rupert, Benjamin Archer, Viet Dau, Shannon Cirilli, xia li, Stuart G Campbell- Physiology (medical)
- Cardiology and Cardiovascular Medicine
Introduction: Engineered heart tissues (EHTs) formed from human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes carrying relevant mutations are a valuable tool for in vitro disease modeling and therapeutic testing. Tracking the emergence of a phenotype in vitro is key to targeting the optimal window to test therapeutic intervention. We hypothesized that auxotonic MyoPod® EHTs would enable longitudinal characterization with video analysis.
Methods: Four auxotonic MyoPod® scaffold designs of decellularized porcine ventricular myocardium were seeded with wild type (WT) hiPSC-cardiomyocytes and human cardiac fibroblasts and cultured for 3 weeks. Mechanical testing was then performed on a MyoLab® instrument to obtain the contractile phenotype. One auxotonic MyoPod® design was then selected to form EHTs with WT or MYH7 R403Q +/- hiPSC-cardiomyocytes and fibroblasts. Videos of spontaneous contractions were obtained every 2-3 days.
Results: All auxotonic MyoPod® scaffold designs tested (A-D) formed spontaneously contracting EHTs. In optimization studies, design C auxotonic MyoPod® EHTs were not significantly different from isometric control in any of the contractile metrics measured including twitch force (256.2 ± 25.8 μN vs 214.7 ± 78.1 μN) and time from peak force to 50% relaxation (103.8 ± 6.6 ms vs 111.2 ± 7.6 ms; control vs C, n=3 EHTs/group). When design C MyoPod® EHTs were seeded with WT and MYH7 R403Q +/- cardiomyocytes, video analysis showed slower relaxation time in MYH7 R403Q +/- EHTs that was significantly longer compared to WT control by one week of culture. Time to 90% relaxation (RT90) was lengthened by 38.8% ± 2.2% in MYH7 R403Q +/- (WT: n=7, MYH7 R403Q +/- : n=6; p<0.01). These video analysis results agree with MyoLab® testing data of isometric WT and MYH7 R403Q +/- EHTs where RT90 was slowed by 36.8% ± 0.1% in MYH7 R403Q +/- (WT: n=8, MYH7 R403Q +/- : n=5; p<0.01).
Conclusion: In these studies, an auxotonic MyoPod® scaffold design was identified that does not alter the baseline contractile phenotype of EHTs, and it was used to track the development of relaxation deficit in MYH7 R403Q +/- EHTs over one week in culture. This technology can be used to track both the development of a disease phenotype and its response to therapies delivered in vitro.