Evaluation Of Cardioplegia With Hypertrophic Cardiomyopathy By Induction Of Pluripotent Stem Cells

Aim:Hypertrophic cardiomyopathy (HCM) is estimated to be the most prevalent hereditary heart disease and is an autosomal dominant heart disease. Open-heart surgical repair is one of the most effective approach for the treatment of HCM. Nowadays over 1000 identification of specific mutations have been defined the genetic causes of HCM, but the pathways and mechanism that these mutations lead to hypertrophy are still not well understood. Induced pluripotent stem cells (iPSCs) is a novel technique which is possible to reprogram differentiated cells into an undifferentiated state. We generated induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) from patients with hypertrophic cardiomyopathy. With these iPSC-CMs, we investigated the mechanism underlying pathogenesis of HCM, and evaluated cardiac protective effect of cardioplegia solution on HCM at the cell level.Method:23 patients with cardiac surgery were recruited and dermal fibroblasts were collected. With nucleotide sequence analysis, two patient with HCM mutation on β-myosin heavy chain (MYH7) gene, which cause an Arginine to Histidine substitution at position 663, were demonstrated. Patient-specific iPSCs of these two patients were generated as well as two healthy volunteers. Genome-editing techniques are then used to correct the mutation thus providing a Rescue iPSC clone. Established iPSC lines were differentiated into cardiomyocytes using standard small molecular monolayer method. Calcium handling was then tested, and ischemia-reperfusion injury in iPSC-CMs model was used to evaluate cardiac protective effect of blood cardioplegia, HTK solution and St. Thomas solution.Results:All of three genotypes iPSCs exhibited positive immunostaining for stem cell markers OCT4, NANOG, SOX2 and SSEA4. Karyotyping analyses showed stable chromosomal integrity in all iPSC lines. Cardiomyocytes from Arg663His Mutation iPSCs were bigger in cell size, and exhibited disorder myofibril and abnormal calcium transients. With ischemia-reperfusion injury, HTK solution exhibited better protective effect on reducing oxygen radical and improving calcium handling, which lead to less arrhythmia and apoptosis. Conclusion:We established and characterized three genotypes of iPSC lines from HCM patients, healthy volunteers and genome-rescue iPSCs. iPSC-CMs derived from Arg663His Mutation iPSCs exhibited features of HCM like cellular enlargement and calcium handling disorder. After ischemia-reperfusion injury, HCM iPSC-CMs with HTK solution exhibited less arrhythmia and apoptosis. As a result, HTK solution is the recommendation cardioplegia for HCM.