Assessment of the in vitro function of human stem cell-derived β cells
Insulin-producing human embryonic stem cell-derived {beta} (SC-{beta}) cells are a promising cell source for diabetes cell replacement therapy. We have recently reported a differentiation strategy that produces SC-{beta} cells in islet organoids that not only undergo glucose-stimulated insulin secretion but also have an islet-like dynamic insulin release profile, displaying both first and second phase insulin secretion. The goal of this study was to further characterize the functional profile of these SC-{beta} cells in vitro. We utilized a Seahorse extracellular flux analyzer to measure mitochondrial respiration of SC-{beta} cells at low and high glucose. We also used photolithography to fabricate a microfluidic device containing microwells to immobilize SC-{beta} cells for perfusional analysis, monitoring cytoplasmic calcium using Fluo-4 AM at low and high glucose. Here we find that in addition to increased insulin secretion, SC-{beta} cells have increased cellular respiration and cytoplasmic calcium ion concentration in response to a high glucose stimulation. Our results indicate that SC-{beta} cells have similar function to that reported for islets, providing further performance characterization that could help with eventual development for diabetes cell therapy and drug screening.