Hepatic gluconeogenic pathway enzymes and flux (GNG)

Hepatic gluconeogenesis is the metabolic pathway responsible for the de novo synthesis of glucose from non-carbohydrate precursors, including lactate, glycerol, and glucogenic amino acids like alanine [10, 12]. This process occurs primarily in the liver and is critical for maintaining systemic glucose homeostasis during periods of fasting or intense exercise [10, 16]. In conditions such as Type 2 Diabetes Mellitus, the flux through this pathway is pathologically elevated, leading to excessive hepatic glucose production and fasting hyperglycemia [1, 12]. The pathway is governed by four key rate-limiting enzymes: pyruvate carboxylase, phosphoenolpyruvate carboxykinase (PEPCK), fructose-1,6-bisphosphatase (FBPase), and glucose-6-phosphatase [3, 9].\n\nPharmacological targeting of these enzymes or their regulatory signals aims to reduce excessive glucose production in diabetic patients [1, 3]. Metformin is the most widely used drug that suppresses this pathway, acting through multiple mechanisms including AMPK activation and inhibition of mitochondrial glycerophosphate dehydrogenase [3, 10, 11]. Novel therapeutic candidates, such as specific inhibitors of FBPase, are also under clinical investigation [3]. However, therapeutic modulation of hepatic gluconeogenesis carries significant risks, most notably hypoglycemia and lactic acidosis, which necessitate careful patient monitoring and dose titration [10, 15].

Other names

Hepatic glucose productionDe novo glucose synthesisGluconeogenesis pathwayHGP

Inhibition of rate-limiting gluconeogenic enzymes (e.g., FBPase), suppression of gluconeogenic gene expression (e.g., PEPCK, G6Pase) via modulation of AMPK or glucagon signaling, and reduction of substrate flux.