Molecular hydrogen induces metabolic reprogramming to promote differentiation of glioma stem cells

Abstract

Background: Our previous study showed that molecular hydrogen could effectively suppress glioblastoma multiforme (GBM) tumor growth via induction of glioblastoma stem cells (GSCs) differentiation. Metabolic reprogramming has been demonstrated to delicately regulate the stemness of cancer stem cells. In the present study, we explored whether metabolic reprogramming is involved in the hydrogen-induced GSCs differentiation. Methods: Immunofluorescence staining was conducted to determine the expression of cell surface markers. Glucose uptake and lactate secretion was determined by spectrophotometric method. Untargeted metabolomics analyses were conducted to investigate the metabolic alteration in GSCs after hydrogen treatment. 13 C-labeled metabolic flux analysis was performed to explore the regulatory effects of molecular hydrogen on the glucose metabolism of GSCs. Results: Immunofluorescence staining showed the up-regulated expression of oligodendroglial markers in hydrogen-treated GSCs. Both glucose uptake and lactate production in GSCs were significantly inhibited by hydrogen treatment. Untargeted metabolomics analyses showed hydrogen-induced promotion of de novo synthesis of nucleotides in GSCs. Metabolic flux analysis showed decreased glucose metabolism in GSCs induced by hydrogen. Conversely, the content of glycerol 3-phosphate, glutamate and glutamine were increased by hydrogen treatment. Conclusions: Results from this study demonstrated that molecular hydrogen could inhibit glucose metabolism and promote de novo synthesis of nucleotides in GSCs, suggesting the involvement of metabolic reprogramming in the hydrogen-induced GSCs differentiation. Our study also provides important new clues to seek the target of molecular hydrogen.