Cryopreservation alters contractile function of human induced pluripotent stem cell-derived cardiomyocytes

Area of Science:

• Cardiovascular Research
• Stem Cell Biology
• Cell Cryopreservation

Background:

• Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are crucial for disease modeling and drug discovery.
• Batch-to-batch variability and immature phenotypes in hiPSC-CMs present challenges for data reproducibility.
• Cryopreservation offers a solution for long-term storage, potentially enhancing consistency and maturation.

Purpose of the Study:

• To compare the effects of cryopreservation on hiPSC-CMs using different media.
• To assess the comparability of fresh versus cryopreserved hiPSC-CMs in terms of recovery, morphology, and function.
• To evaluate the impact of cryopreservation on hiPSC-CM structure and contractile parameters.

Main Methods:

• Comparison of two cryopreservation media: CryoStor® CS10 and KnockOut Serum Replacement.
• Assessment of hiPSC-CM recovery rates and proportion in long-term culture post-thaw.
• Analysis of cell morphology, sarcomere length, and contractile parameters (time to peak, half relaxation time, contraction amplitude).
• Evaluation of sarcomeric gene and protein expression changes.

Main Results:

• Both CryoStor® CS10 and KnockOut Serum Replacement showed comparable recovery rates (39% and 46%, respectively) and similar proportions of cardiomyocytes in culture.
• Cryopreservation altered hiPSC-CM morphology, including increased cell area and variable sarcomere length.
• Contractile parameters were affected, with faster time to peak and half relaxation, and altered contraction amplitude.
• Minimal changes were observed in sarcomeric gene and protein expression, though some differential effects of cryo-media were noted.

Conclusions:

• Cryopreservation influences hiPSC-CM morphology and contractile function, which must be considered in experimental design.
• While cryopreservation impacts cellular characteristics, it provides a viable method for improving consistency and reproducibility of hiPSC-CM data.
• Differential effects of cryopreservation media on hiPSC-CM structure and function warrant further investigation.