Fructose induces gluconeogenesis and lipogenesis through a SIRT1-dependent mechanism.

Consumption of a fructose-rich diet leads to insulin resistance and dyslipidemia in part due to elevated gluconeogenesis and lipogenesis. SIRT1, an NAD(+)-dependent protein deacetylase, can induce gluconeogenesis and lipogenesis. The aim of this study was to determine whether fructose increased hepatic SIRT1, leading to induction of gluconeogenesis and lipogenesis.

Metformin suppresses hepatic gluconeogenesis through induction of SIRT1 and GCN5.

Abnormal elevation of hepatic gluconeogenesis is central to the onset of hyperglycaemia in patients with type 2 diabetes mellitus (T2DM). Metformin corrects hyperglycaemia through inhibition of gluconeogenesis, but its mechanism of action is yet to be fully described. SIRT1 and GCN5 (listed as KAT2A in the MGI Database) have recently been identified as regulators of gluconeogenic gene expression through modulation of levels and activity of the coactivators cAMP-response element binding protein-regulated transcription coactivator 2 (TORC2 or CRTC2 as listed in the MGI Database) and peroxisome proliferator-activated receptor-gamma coactivator-1alpha (PGC1alpha or PPARGC1A as listed in the MGI Database).

Endotoxin induced hyperlactatemia and hypoglycemia is linked to decreased mitochondrial phosphoenolpyruvate carboxykinase.

Aims: Phosphoenolpyruvate carboxykinase (PEPCK) is the rate limiting enzyme for gluconeogenesis, and plays a key role in recycling lactate for glucose production. It is synthesized as two separate isoforms; cytosolic (PEPCK-C, gene code; PCK1) and mitochondrial (PEPCK-M, gene code; PCK2). Previous studies of gluconeogenesis in endotoxemia have focused solely on PCK1.