Morphological and Functional Characterization and Assessment of iPSC-Derived Hepatocytes forIn VitroToxicity Testing

Abstract

Drug-induced liver injury (DILI) remains a great challenge and a major concern during late-stage drug development. Induced pluripotent stem cells (iPSC) represent an exciting alternative in vitro model system to explore the role of genetic diversity in DILI, especially when derived from patients who have experienced drug-induced hepatotoxicity. The development and validation of the iPSC-derived hepatocytes as an in vitro cell-based model of DILI is an essential first step in creating more predictive tools for understanding patient-specific hepatotoxic responses to drug treatment. In this study, we performed extensive morphological and functional analyses on iPSC-derived hepatocytes from a commercial source. iPSC-derived hepatocytes exhibit many of the key morphological and functional features of primary hepatocytes, including membrane polarity and production of glycogen, lipids, and key hepatic proteins, such as albumin, asialoglycoprotein receptor and α1-antitrypsin. They maintain functional activity for many drug-metabolizing enzyme pathways and possess active efflux capacity of marker substrates into bile canalicular compartments. Whole genome-wide array analysis of multiple batches of iPSC-derived cells showed that their transcriptional profiles are more similar to those from neonatal and adult hepatocytes than those from fetal liver. Results from experiments using prototype DILI compounds, such as acetaminophen and trovafloxacin, indicate that these cells are able to reproduce key characteristic metabolic and adaptive responses attributed to the drug-induced hepatotoxic effects in vivo. Overall, this novel system represents a promising new tool for understanding the underlying mechanisms of idiosyncratic DILI and for screening new compounds for DILI-related liabilities.

Comparative transcriptomics of hepatic differentiation of human pluripotent stem cells and adult human liver tissue

“…Freshly isolated human hepatocytes are currently the gold standard cell type for transplantation as well as for cell modeling for drug discovery and development, and various toxicity tests (15,16,21,25,34). However, limited availability, short life span, loss of functionality upon isolation and culturing in vitro, dedifferentiation, and failing to represent the polymorphic population urge the development of alternative cell sources that do not have these drawbacks (15,25,31,34).…”

“…Moreover, human induced pluripotent stem cells (hiPSCs) generated from the transfection of somatic cells with pluripotency factors, may be employed in drug discovery as disease models (1,4,20,31). In addition, these cells can also be utilized for patient specific treatment (1,20).…”

Requirements for human iPS cell-derived hepatocytes as an alternative to primary human hepatocytes for assessing absorption, distribution, metabolism, excretion and toxicity of pharmaceuticals

“…The other is the large varia- tions between lots due to their different genetic and environmental backgrounds. HiPSC-derived hepatocytes have been anticipated to be used in in vitro ADMET studies as alternatives to PHHs because researchers are able to obtain the hiPSC-derived hepatocytes from the same origin repeatedly (Holmgren et al, 2014;Lu et al, 2015;Sirenko et al, 2014). PHHs were often used as controls in the studies of hiPSC-derived hepatocytes.…”

Human hepatocytes derived from pluripotent stem cells: a promising cell model for drug hepatotoxicity screening

“…This scenario suggests the feasibility of modeling the metabolic differences observed frequently in the human population. Recently, Lu et al (2015) demonstrated the ability of iPSCs-derived HLCs to reproduce key characteristic metabolic and adaptive responses can be attributed to the hepatotoxic effects of APAP and trovafloxacin in vivo (Lu et al 2015). Takayama et al (2012) used the transduction with an adenovirus encoding HNF4-α to promote hepatic maturation of both ESCs and iPSCs, and studied whether their HLCs could be used to predict metabolism-mediated toxicity (Takayama et al 2012).…”