ERRγ enhances cardiac maturation with T-tubule formation in human iPSC-derived cardiomyocytes

Abstract

One of the earliest maturation steps in cardiomyocytes (CMs) is the sarcomere protein isoform switch between TNNI1 and TNNI3 (fetal and neonatal/adult troponin I). Here, we generate human induced pluripotent stem cells (hiPSCs) carrying a TNNI1EmGFP and TNNI3mCherry double reporter to monitor and isolate mature sub-populations during cardiac differentiation. Extensive drug screening identifies two compounds, an estrogen-related receptor gamma (ERRγ) agonist and an S-phase kinase-associated protein 2 inhibitor, that enhances cardiac maturation and a significant change to TNNI3 expression. Expression, morphological, functional, and molecular analyses indicate that hiPSC-CMs treated with the ERRγ agonist show a larger cell size, longer sarcomere length, the presence of transverse tubules, and enhanced metabolic function and contractile and electrical properties. Here, we show that ERRγ-treated hiPSC-CMs have a mature cellular property consistent with neonatal CMs and are useful for disease modeling and regenerative medicine.

Recent progress of iPSC technology in cardiac diseases

“…In addition to these factors, Sakamoto et al demonstrated that ERR signaling plays an essential role in postnatal cardiac maturation in mice (Sakamoto et al 2020 ). Coincident with this finding, we recently reported that an ERRγ agonist enhanced maturation with T-tube formation in iPSC cardiomyocytes in vitro (Miki et al 2021 ). Garbern et al demonstrated that the inhibition of mTOR signaling, which acts as a nutrient sensor and a cell cycle regulator, by a small compound, Torin 1, enhanced the maturation of iPSC cardiomyocytes via p53-induced quiescence (Garbern et al 2020 ).…”

The nuclear receptor ERR cooperates with the cardiogenic factor GATA4 to orchestrate cardiomyocyte maturation

“…For example, an hiPSC-CM engineered heart model exibited increased expression of ESRRA and PPARGC1A 51 . In addition, an ERRγ agonist was recently identified as an inducer to drive hiPSC-CM maturation in an unbiased screen using a TNNI3 reporter hiPSC line 52 . These collective results suggest that strategies aimed at activation of ERR signaling may enhance cardiomyocyte maturation in culture and in vivo.…”

Metabolism in Human Pluripotent Stem Cells and Cardiomyocytes for Regenerative Therapy

“…Recently, an estrogen-related receptor gamma agonist was shown to induce hiPSC-CMs to promote maturation in terms of cardiac gene expression, morphology, and function. 49,50 Overall, these findings underscore the importance of metabolism and the need to optimize culture conditions to promote the maturation of hiPSC-CMs (Fig. 3).…”