Hyperglycemia Stimulates the Irreversible Catabolism of Branched-Chain Amino Acids and Generation of Ketone Bodies by Cultured Human Astrocytes.

Astrocytes are considered to possess a noticeable role in brain metabolism and, as a partners in neuron-glia cooperation, to contribute to the synthesis, bioconversion, and regulation of the flux of substrates for neuronal metabolism. With the aim of investigating to what extent human astrocytes are metabolizing amino acids and by which compounds are they enriching their surroundings, we employed a metabolomics analysis of their culture media by H-NMR. In addition, we compared the composition of media with either 5 mM or 25 mM glucose.

Application of the Hydrophilic Interaction Liquid Chromatography (HILIC-MS) Novel Protocol to Study the Metabolic Heterogeneity of Glioblastoma Cells.

Glioblastoma is a highly malignant brain tumor consisting of a heterogeneous cellular population. The transformed metabolism of glioblastoma cells supports their growth and division on the background of their milieu. One might hypothesize that the transformed metabolism of a primary glioblastoma could be well adapted to limitations in the variety and number of substrates imported into the brain parenchyma and present it their microenvironment.

Both Enantiomers of 2-Hydroxyglutarate Modulate the Metabolism of Cultured Human Neuroblastoma Cells.

Elevated levels of D-2-hydroxyglutarate (D-2HG) and L-2-hydroxyglutarate (L-2HG) in the brain are associated with various pathological conditions, potentially contributing to neurological symptoms and neurodegeneration. Previous studies on animal models have revealed their capability to interfere with several cellular processes, including mitochondrial metabolism. Both enantiomers competitively inhibit the enzymatic activity of 2-oxoglutarate-dependent dioxygenases.

Application of Liquid Chromatography Coupled to Mass Spectrometry for Direct Estimation of the Total Levels of Adenosine and Its Catabolites in Human Blood.

Adenosine is a multifunctional nucleoside with several roles across various levels in organisms. Beyond its intracellular involvement in cellular metabolism, extracellular adenosine potently influences both physiological and pathological processes. In relation to its blood level, adenosine impacts the cardiovascular system, such as heart beat rate and vasodilation.

The presence of pyruvate carboxylase in the human brain and its role in the survival of cultured human astrocytes.

Pyruvate carboxylase (PC) is a mitochondrial, biotin-containing enzyme catalyzing the ATP-dependent synthesis of oxaloacetate from pyruvate and bicarbonate, with a critical anaplerotic role in sustaining the brain metabolism. Based on the studies performed on animal models, PC expression was assigned to be glia-specific. To study PC distribution among human neural cells, we probed the cultured human astrocytes and brain sections with antibodies against PC.