Myotubes derived from human-induced pluripotent stem cells mirror in vivo insulin resistance

Abstract

Induced pluripotent stem cells (iPS cells) represent a unique tool for the study of the pathophysiology of human disease, because these cells can be differentiated into multiple cell types in vitro and used to generate patient- and tissue-specific disease models. Given the critical role for skeletal muscle insulin resistance in whole-body glucose metabolism and type 2 diabetes, we have created a novel cellular model of human muscle insulin resistance by differentiating iPS cells from individuals with mutations in the insulin receptor (IR-Mut) into functional myotubes and characterizing their response to insulin in comparison with controls. Morphologically, IR-Mut cells differentiated normally, but had delayed expression of some muscle differentiation-related genes. Most importantly, whereas control iPS-derived myotubes exhibited in vitro responses similar to primary differentiated human myoblasts, IR-Mut myotubes demonstrated severe impairment in insulin signaling and insulin-stimulated 2-deoxyglucose uptake and glycogen synthesis. Transcriptional regulation was also perturbed in IR-Mut myotubes with reduced insulin-stimulated expression of metabolic and early growth response genes. Thus, iPS-derived myotubes from individuals with genetically determined insulin resistance demonstrate many of the defects observed in vivo in insulin-resistant skeletal muscle and provide a new model to analyze the molecular impact of muscle insulin resistance.

Differentiation of diabetic foot ulcer–derived induced pluripotent stem cells reveals distinct cellular and tissue phenotypes

“…This "convergence" may possibly be linked to epigenetic alterations that occur upon iPSC reprogramming. Although it has been previously shown that iPSCs and iPSC-derived cells from patients with genetic insulinresistance model in vivo defects observed in patients with type 2 diabetes (53,54), it is known that epigenetic mechanisms occurring during reprogramming can remove epigenetic marks associated with disease phenotypes (55). Our findings are supported by recent studies showing a similar "phenotypic convergence" in iPSC-derived dopaminergic neurons reprogrammed from sporadic Parkinson's disease (56) and iPSC-derived fibroblasts reprogrammed from scleroderma (57).…”

Gut microbiome catabolites as novel modulators of muscle cell glucose metabolism

“…Human immortalized LHCN-M2 myoblast differentiation to myotubes was accompanied by increased troponin T expression (33), while a-actinin protein, which increases with Z-line formation but not before, was unchanged (40), both as expected. The myotubes were responsive to insulin, a characteristic of skeletal muscle (41). GLUT4 increased with differentiation while GLUT1 decreased, consistent with previous data (42).…”

Diabetes through a 3D lens: organoid models

“…These cultures have the potential to model insulin resistance in 3D but have only been studied in 2D. Iovino et al generated myotubes from healthy volunteers and individuals with Donohue syndrome, a genetic disorder associated with mutations in the insulin receptor [78]. The myotubes derived from individuals with Donohue syndrome exhibited defects in insulin signalling, glucose uptake and glycogen accumulation, as well as insulin-regulated gene expression.…”