AMPK Regulation of Glucose, Lipid and Protein Metabolism: Mechanisms and Nutritional Significance.

AMP-activated protein kianse (AMPK) is a master sensor of cellular energy levels and a crucial regulator of nutrient metabolism such as the synthesis of fatty acids, glucose and protein as well as their oxidation to CO2 and water . Thus, AMPK signaling has important implications for fat deposition and glucose homeostasis in animals and humans. Much experimental and clinical evidence show that AMPK is a key therapeutic target for the prevention of diseases such as obesity, diabetes, cancer, inflammation and cardiac dysfunction. In this review we highlight recent advances on the upstream and downstream targets of AMPK, as well as the specific mechanisms whereby AMPK regulates digestive functions and chronic energy balance in animals and humans.

The Physiological Basis and Nutritional Function of Alpha-ketoglutarate.

Alpha-Ketoglutarate (AKG) is a biological substance that plays important roles in cell metabolism and physiology. AKG is synthesized from glucose or oxaloacetate plus pyruvate. As an intermediate of the tricarboxylic acid cycle, AKG is essential for the oxidation of fatty acids, amino acids, and glucose. Extracellular AKG is a significant source of energy for cells of the gastrointestinal tract. As a precursor for the synthesis of glutamate and glutamine in multiple tissues (including liver, skeletal muscle, heart, brain, and white adipose tissue), AKG bridges carbohydrate and nitrogen metabolism for both conservation of amino acids and ammonia detoxification. Additionally, emerging evidence shows that AKG is a regulator of gene expression and cell signaling pathways (including the mammalian target of rapamycin and AMPactivated protein kinase). Thus, AKG is an attractive dietary supplement in animal and human nutrition to improve cellular energy status, immunity, and health.