A Multi-omic approach reveals iron availability influences hepatocyte cell fate II

Recent evidence has highlighted the importance of employing cell culture media designed to reproduce the physiological metabolic environment in vitro. Here, we utilize the physiological medium Plasmax to examine the impact of nutrient availability on the model human hepatocyte cell line, HepG2. Incubation of HepG2 cells in Plasmax suppressed a transcriptional program driven by Hepatocyte Nuclear Factor 4 (HNF4A), a master regulator of hepatocyte identity. Given that HepG2 cells were originally isolated from a patient with hepatoblastoma, this suggests reversion to the native state in physiological media. Importantly, exclusion of the trace element iron from Plasmax reinstated the HNF4A-driven transcriptional program. Taken together, these studies suggest a relationship between iron availability and regulation of hepatocyte cell fate and highlight the importance of more faithfully recapitulating in vivo metabolite availability in vitro. Overall design: RNA-Seq profiling of HepG2 cells incubated in EMEM, Plasmax, Plasmax without trace elements (Plasmax-TE), and Plasmax without trace elements and with iron supplementation (Plasmax-TE+Fe) for 96 hours.