Table 2 Major differences between human iPSC-CMs and adult cardiomyocytes
| Â | iPSC-CMs | Adult cardiomyocytes |
|---|---|---|
Cellular morphology | Smaller in size, roundish in shape | Larger in size, elongated in shape |
Disorganized sarcomeres | Organized sarcomeres | |
Sarcomeric protein isoforms | Slow skeletal troponin I (ssTnI) | Cardiac troponin I (cTnI) |
Higher ratios of α-MHC/β-MHC | Lower ratios of α-MHC/β-MHC | |
Titin N2BA isoform | Titin N2B isoform | |
Electrophysiology | Smaller maximum diastolic potential | Larger maximum diastolic potential |
Slower upstroke velocity | Faster upstroke velocity | |
Automaticity in ventricular-like iPSC-CMs | No automaticity in adult ventricular myocytes | |
Undetectable or significantly smaller IK1 | Larger IK1 | |
Calcium handling | Poor calcium handling | Improved calcium handling |
No or few T-tubules | Abundant T-tubules | |
Mitochondrial function | Few and underdeveloped mitochondria | Dense, developed, and well-distributed mitochondria |
Metabolic characteristics | Glycolysis as major energy source | Fatty acid β-oxidation as major energy source |