FGF2 Supports NANOG Expression via Pyruvate Dehydrogenase–Dependent Histone Acetylation under Low Oxygen Conditions

Petr Fojtík^1,2,3Martin Šenfluk⁴Katerina Holomkova⁴Anton Salykin⁴Jana Gregorova⁵Pavel Smak⁵Ondrej Pes⁵Jan Raska^2,6Monika Stetkova⁴Petr Skladal⁷Miroslava Sedlackova⁶Ales Hampl⁶Dasa Bohaciakova^2,6Stjepan Uldrijan^2,4Vladimir Rotrekl^2,4*

• ¹Masaryk University, Faculty of Medicine, Department of Biology, Brno, Czechia
• ²International Clinical Research Center (FNUSA-ICRC), Brno, Czechia
• ³Masaryk University, Faculty of Mediciine, Department of Histology and Embryology, Brno, Czechia
• ⁴Masaryk University, Faculty of Medicine, Department of Biology, Brno, Czechia
• ⁵Masaryk University, Faculty of Medicine, Department of Biochemistry, Brno, Czechia
• ⁶Masaryk University, Faculty of Medicine, Department of Histology and Embryology, Brno, Czechia
• ⁷Masaryk University, Faculty of Science, Department of Biochemistry, Brno, Czechia

The safe and effective application of human pluripotent stem cells (hPSCs) in research and regenerative medicine requires precise control over pluripotency and cell fate. Pluripotency is characterized by high levels of histone acetylation and aerobic glycolysis, while differentiation is associated with metabolic shifts and reduced histone acetylation. These transitions are driven, in part, by the availability of metabolic substrates that influence epigenetic regulation. A central enzyme in this process is pyruvate dehydrogenase (PDH), which converts glycolytic pyruvate into acetyl coenzyme A (Ac-CoA), the essential donor for histone acetylation. Here, we investigate how PDH activity regulates histone acetylation and pluripotency maintenance under physiologically relevant oxygen conditions (5% and 21% O₂), in response to FGF2 signaling and changes in reactive oxygen species (ROS) levels. We show that active PDH promotes global histone H3 acetylation and upregulates the expression of the key pluripotency factor NANOG, specifically under 5% O₂. Mechanistically, we identify a novel FGF2–MEK1/2–ERK1/2–ROS axis that modulates PDH activity via redox-dependent regulation. Notably, this effect is oxygen-sensitive and absent at atmospheric oxygen levels (21% O₂). Our findings position PDH as a redox-sensitive metabolic switch that connects energy metabolism with epigenetic control of pluripotency by regulating Ac-CoA availability. This work highlights the critical role of oxygen tension, ROS homeostasis, and growth factor signaling in shaping the metabolic–epigenetic landscape of hPSCs, with implications for optimizing stem cell culture and differentiation protocols.