Functional and molecular effects of TNF-alpha on human iPSC-derived cardiomyocytes

• Authors: Anita Saraf, Emory University; Antonio Rampoldi, Emory University; Myra Chao, Emory University; Dong Li, Emory University; Lawrence Armand, Emory University; Hyun Hwang, Emory University; Rui Liu, Emory University; Rajneesh Jha, Emory University; Haian Fu, Emory University; Joshua Maxwell, Emory University; Chunhui Xu, Emory University
• Journal Title: Stem Cell Research
• Volume: Volume 52
• Publisher: Elsevier | 2021-02-13, Pages 102218-102218
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1016/j.scr.2021.102218
• Subjects: Biology, Cell; Health Sciences, Medicine and Surgery; Chemistry, Biochemistry
• Keywords: Science & Technology; Life Sciences & Biomedicine; Cell & Tissue Engineering; Biotechnology & Applied Microbiology; Cell Biology; Human iPSC; Cardiomyocytes; Cytokines; Ca2+ transients; TNF alpha; Ca2+ propagation; Tumor-necrosis-factor; Heart failure; Connexin expression; Cardiac myocytes; GAP-Junctions; Cell death; Cytokines; Activation; Contractility

Abstract

Proinflammatory molecule tumor necrosis factor alpha (TNF-α) is predominantly elevated in cytokine storm as well as worsening cardiac function. Here we model the molecular and functional effects of TNF-α in cardiomyocytes (CMs) derived from human induced pluripotent stem cells (hiPSC). We found that treatment of hiPSC-CMs with TNF-α increased reactive oxygen species (ROS) and caspase 3/7 activity and caused cell death and apoptosis. TNF-α treatment also resulted in dysregulation of cardiomyocyte function with respect to the increased abnormal calcium handling, calcium wave propagation between cells and excitation–contraction coupling. We also uncovered significant changes in gene expression and protein localization caused by TNF-α treatment. Notably, TNF-α treatment altered the expression of ion channels, dysregulated cadherins, and affected the localization of gap-junction protein connexin-43. In addition, TNF-α treatment up-regulated IL-32 (a human specific cytokine, not present in rodents and an inducer of TNF-α) and IL-34 and down-regulated glutamate receptors and cardiomyocyte contractile proteins. These findings provide insights into the molecular and functional consequences from the exposure of human cardiomyocytes to TNF-α. Our study provides a model to incorporate inflammatory factors into hiPSC-CM-based studies to evaluate mechanistic aspects of heart disease.