Zinc dynamics in the pluripotent stem cells during maintenance of pluripotency and pancreatic differentiation

We previously reported that pluripotent stem cells (PSCs) are highly dependent on methionine metabolism and that S-adenosyl methionine (SAM) acts as a key metabolite in sustaining the pluripotency of PSCs. We reported that zinc signaling is one of the downstream pathways for methionine metabolism and that zinc is crucial in regulating the self-renewal and differentiation of PSCs. An interdependent relationship exists between methionine metabolism and zinc dynamics. Here, we aim to reveal the zinc dynamics in the pluripotent PSCs and during pancreatic differentiation. Using a 67Zn-stable isotope-replaced medium, we measured zinc uptake into cells in undifferentiated iPSCs and during pancreatic differentiation. We observed that undifferentiated iPS cells take up zinc from the medium, increasing the intracellular 67Zn ratio. At 48 h, the intracellular 67Zn ratio approached the medium’s zinc profile, but remained slightly lower. By 5 days, the intracellular 67Zn ratio had fully converged to the medium level. A comparison of iPS cells and cells at multiple stages of pancreatic differentiation revealed that Zn intake varies with differentiation stage.