Strategies to Promote Maturation in Human Induced Pluripotent Stem Cell - Derived Cardiomyocytes
hiPSC-CMs are highly relevant in cell and tissue engineering, helping to understand cardiovascular development, as well as being highly impactful in the arena of regenerative medicine. While protocols have been established to obtain a relatively pure population of hiPSC-CMs, immaturity limits their usage for drug development, and disease modeling. Recent strategies to induce hiPSC-CM maturation include long-term culture, mechanical/electrical stimulation, and metabolic media formulations, however, very few have considered the signaling networks involved in the maturation process. Our previous data using bulk-RNAseq analysis in neonatal mouse cardiomyocytes showed that inhibition of GLI-signaling promotes CM maturation. Here we utilized early stage hiPSC-CMs and inhibited GLI-signaling to elucidate its impact in their maturation. We found that Gant61-mediated GLI inhibition led to increased striated sarcomeres, and reduced circularity index, indicating promotion of hiPSC-CM maturation. Next, we utilized MLC2v-GFP hiPSC-CM to monitor the maturation status. Our preliminary data using FACS-analysis showed that inhibition of GLI-signaling resulted in an increased number of MLC2v-GFP cells, with rod-like morphology and increased sarcomeric striations as compared to controls. Further, transcript analysis revealed increased expression of Phospholamban (PLN) and increase in MYH7-MYH6 ratio. These results indicated that modulation of GLI-signaling plays an important role in hiPSC-CMs and fine-tuning with other signaling pathways could significantly promote hiPSC-CM maturation.