Metabolic Reprogramming, Autophagy, and Reactive Oxygen Species Are Necessary for Primordial Germ Cell Reprogramming...

Area of Science:

• Cell Biology
• Metabolic Regulation
• Stem Cell Biology

Background:

• Cellular reprogramming involves a metabolic shift from oxidative phosphorylation (OXPHOS) to glycolysis.
• Hypoxia-inducible factor 1 (HIF1) mediates hypoxia-induced reprogramming of primordial germ cells (PGCs) into pluripotent cells.

Purpose of the Study:

• To determine if a metabolic switch to glycolysis is solely responsible for PGC reprogramming.
• To investigate the roles of autophagy, reactive oxygen species (ROS), and mitochondrial activity in PGC reprogramming.

Main Methods:

• PGCs were cultured with pyruvate kinase M2 (PKM2) activators or by manipulating PPARγ to promote glycolysis.
• OXPHOS was stimulated by inhibiting PDK1 activity under normoxic or hypoxic conditions.
• Autophagy and ROS production were modulated to assess their contribution to reprogramming.

Main Results:

• A metabolic shift towards glycolysis, autophagy, and mitochondrial inactivation is necessary for PGC reprogramming.
• An early increase in ROS levels is observed during reprogramming.
• These processes are regulated by the balance of HIF1/HIF2 and Oct4 levels, with histone acetylation playing a role.

Conclusions:

• Metabolic reprogramming, autophagy, and ROS production are critical for PGC reprogramming into a pluripotent state.
• The generated pluripotent cells exhibit limited self-renewal capacity due to insufficient Blimp1 downregulation and lack of Klf4/cMyc expression.