LIF-activated Jak signaling determines Esrrb expression during late-stage reprogramming.

The regulatory process of naïve-state induced pluripotent stem cell (iPSC) generation is not well understood. Leukemia inhibitory factor (LIF)-activated Janus kinase/signal transducer and activator of transcription 3 (Jak/Stat3) is the master regulator for naïve-state pluripotency achievement and maintenance. The estrogen-related receptor beta () serves as a naïve-state marker gene regulating self-renewal of embryonic stem cells (ESCs). However, the interconnection between and LIF signaling for pluripotency establishment in reprogramming is unclear. We screened the marker genes critical for complete reprogramming during mouse iPSC generation, and identified genes including that are responsive to LIF/Jak pathway signaling. Overexpression of resumes the reprogramming halted by inhibition of Jak activity in partially reprogrammed cells (pre-iPSCs), and leads to the generation of pluripotent iPSCs. We further show that neither overexpression of nor stimulation of Wnt signaling, two upstream regulators of in ESCs, stimulates the expression of in reprogramming when LIF or Jak activity is blocked. Our study demonstrates that is a specific reprogramming factor regulated downstream of the LIF/Jak signaling pathway. These results shed new light on the regulatory role of LIF pathway on complete pluripotency establishment during iPSC generation.