Mouse Embryonic Stem cell-derived Insulin-producing Cell Line: A Surrogate for the Investigation of Beta Cell Biology and Pathogenesis

Abstract

Chronic hyperglycemia results in beta cell dysfunction, which leads to type 2 diabetes. Compared to animal models, cell models are more amenable to molecular manipulation, thereby facilitating the elucidation of beta cell glucotoxicity. However, this would require physiologically relevant beta cell surrogates. We have previously derived clonal insulin-producing cell lines from mouse embryos and embryonic stem cells (ESCs) via intermediate progenitors and demonstrated that they display salient features of beta cells. Herein, we characterized their physiology through a comparative gene expression analysis against their progenitors. Pentose phosphate pathway, clathrin-mediated endocytosis and PPAR signaling were predicted to be important to the insulin-producing cells and this was validated using cell-based assays. The identification of these pathways that are also highly relevant to beta cell physiology reaffirms the suitability of these cells as surrogates. We subsequently treated ESC-derived ERoSHK cells with high glucose and observed reduced glucose-stimulated insulin secretion. Comparative gene expression profiling between low and high glucose-treated cells identified aberrations to cell survival and structure in the latter, which was corroborated with increased apoptosis, altered colony morphology, depolymerized actin cytoskeleton and reduced E-cadherin-mediated cell-cell contact. These alterations were partly attributed to constitutive ERK phosphorylation that causes actin to exist predominantly in the depolymerized state, suggesting that chronic high glucose compromised beta cell survival and function by disrupting actin dynamics.