Defining the mechanisms and consequences of glycolytic metabolism in human pluripotent stem cells

The balance between glycolytic and oxidative metabolism shifts during differentiation of human embryonic stem cells (hESCs) and during reprogramming of somatic cells into pluripotent stem cells. However the contribution of glycolytic metabolism to various stages of pluripotency is not well understood. Additionally, few tools have been developed that modulate pluripotent stem cell glycolytic metabolism to influence self-renewal or differentiation. Here we show that the degree of human pluripotency is associated with glycolytic rate, whereby naive hESCs exhibit higher glycolytic flux, increased MYC transcriptional activity, and elevated nuclear N-MYC levels relative to primed hESCs. Consistently, the inner cell mass of human blastocysts also exhibits increased MYC transcriptional activity relative to primed hESCs and elevated nuclear N-MYC levels. Expression of the lactate transporter, monocarboxylate transporter 1 (MCT1), is strongly associated with the pluripotent state, and reduction of glycolysis using a small molecule inhibitor towards MCT1 decreases self-renewal of nave hESCs and feeder-free cultured primed hESCs, but not that of primed hESCs grown in feeder-supported conditions. Lastly, reduction of glycolytic metabolism via MCT1 inhibition in feeder-free primed hESCs enhances neural lineage specification. These findings validate the association between glycolytic metabolism and pluripotency, reveal differences in the glucose metabolism of feeder- versus feeder-free cultured hESCs, and show that pharmacologic regulation of glycolysis can influence self-renewal and initial cell fate specification of human pluripotent stem cells.

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Gu W, Gaeta X, Sahakyan A, Chan AB, Hong CS, Kim R, Braas D, Plath K, Lowry WE, Christofk HR