Mitochondrial fission produces a Warburg effect via the oxidative inhibition of prolyl hydroxylase domain-2

Abstract

Excessive mitochondrial fission and a shift to a Warburg phenotype are hallmarks of pulmonary hypertension (PH), although the mechanistic link between these processes remains unclear. We show that in pulmonary arterial endothelial cells (PAEC), Drp1 overexpression induces mitochondrial fission and increases glycolytic ATP production and glycolysis. This is due to mitochondrial reactive oxygen species (mito-ROS)-mediated activation of hypoxia-inducible factor-1α (HIF-1α) signaling, and this is linked to hydrogen peroxide (H₂O₂)-mediated inhibition of prolyl hydroxylase domain-2 (PHD2) due to its cysteine 326 oxidation and dimerization. Furthermore, these findings are validated in PAEC isolated from a lamb model of PH, which are glycolytic (Shunt PAEC), exhibit increases in both H₂O₂ and PHD2 dimer levels. The overexpression of catalase reversed the PHD2 dimerization, decreased HIF-1α levels, and attenuated glycolysis in Shunt PAEC. Our data suggest that reducing PHD2 dimerization could be a potential therapeutic target for PH.

Keywords: Drp1; HIF-1 alpha; Hydrogen peroxide; Mitochondrial fission; PHD2; ROS; Warburg effect.