Cell Rep. 2017 Nov 21;21(8):2058-2065. doi: 10.1016/j.celrep.2017.10.098.

Biological Significance of the Suppression of Oxidative Phosphorylation in Induced Pluripotent Stem Cells.

Zhang C¹, Skamagki M², Liu Z³, Ananthanarayanan A², Zhao R⁴, Li H⁵, Kim K⁶.

Abstract

We discovered that induced pluripotent stem cell (iPSC) clones generated from aged tissue donors (A-iPSCs) fail to suppress oxidative phosphorylation. Compared to embryonic stem cells (ESCs) and iPSCs generated from young donors (Y-iPSCs), A-iPSCs show poor expression of the pluripotent stem cell-specific glucose transporter 3 (GLUT3) and impaired glucose uptake, making them unable to support the high glucose demands of glycolysis. Persistent oxidative phosphorylation in A-iPSCs generates higher levels of reactive oxygen species (ROS), which leads to excessive elevation of glutathione (a ROS-scavenging metabolite) and a blunted DNA damage response. These phenotypes were recapitulated in Y-iPSCs by inhibiting pyruvate dehydrogenase kinase (PDK) or supplying citrate to activate oxidative phosphorylation. In addition, oxidative phosphorylation in A-iPSC clones depletes citrate, a nuclear source of acetyl group donors for histone acetylation; this consequently alters histone acetylation status. Expression of GLUT3 in A-iPSCs recovers the metabolic defect, DNA damage response, and histone acetylation status.