Background:
Diabetic cardiomyopathy (DCM) is one of the major cardiac complications in diabetic patients. However, the underlying mechanisms and pathogenesis of diabetic cardiomyopathy are only partially understood and the specific therapeutic target remains unknown. Here, we developed an
in vitro
diabetic cardiomyopathy model through simple metabolic manipulation using human induced pluripotent stem cell (iPSC)-derived cardiomyocytes (iPSC-CMs).
Methods:
After 30 days from initial differentiation, iPSC-CMs were cultured with maturation medium (containing fatty acid but no glucose) for 3 days to obtain matured cardiomyocyte properties. Maturation extent of iPSC-CMs was analyzed using patch-clamp to analyze electrophysiological properties and RT-PCR to analyze cardiomyocyte-specific structure proteins and ion channel expression. Matured iPSC-CMs were then treated with 11 mM glucose for 2 days. 11 mM glucose represents mild glucose conditions in diabetic patients. Cardiomyopathy phenotype of iPSC-CMs was evaluated by analyzing brain natriuretic peptide (BNP) secretion from iPSC-CMs using ELISA.
Result:
Differentiated iPSCs-CMs were immature. Following 3 day culture in maturation medium, iPSC-CMs exhibited the cardiomyocyte maturation characteristics: 1) an increase of contractility with diminished automaticity, suggesting progressive maturation toward adult cardiomyocytes, 2) the lower maximal diastolic potential and increased amplitude, indicating functional maturation, and 3) an upregulation of the following gene expression: sarcomeric proteins (e.g., TNNI3, MYL2 and MYL3) and potassium channel α-subunit genes (KCNJ12 and KCNJ4). Matured iPSC-CMs treated with 11 mM glucose showed increase in cell size and BNP secretion (17-fold increase vs. control cells without glucose, p<0.01). These results suggested that cardiomyocytes exposure to the maturation medium followed by diabetic milieu of glucose recapitulate DCM
in vitro
.
Conclusion:
We conclude that the phenotype of DCM can be modeled using cultured iPSC-derived cardiomyocytes through diabetic extracellular milieu. This clinically relevant stem cell model would be a powerful platform to study novel mechanisms of DCM and the specific therapeutic targets.
Diabetic Cardiomyopathy Modelling Using Induced Pluripotent Stem Cell Derived Cardiomyocytes: Recent Advances and Emerging Models