Evasion of complement-mediated killing is a common phenotype for many different types of pathogens, but the mechanism is still poorly understood. Most of the clinic isolates of Edwardsiella tarda, an important pathogen infecting both of human and fish, are commonly found serum-resistant. To explore the potential mechanisms, we applied gas chromatography-mass spectrometry (GC-MS)-based metabolom...

Elevated plasma branched-chain amino acids (BCAA) in the setting of insulin resistance have been relevant in predicting type 2 diabetes mellitus (T2DM) onset, but their role in the etiology of hepatic insulin resistance remains uncertain. We determined the link between BCAA and dysfunctional hepatic tricarboxylic acid (TCA) cycle, which is a central feature of hepatic insulin resistance and non...

A novel approach for the mathematical modeling of (13)C label incorporation into amino acids via the TCA cycle that eliminates the explicit calculation of the labeling of the TCA cycle intermediates is described, resulting in one differential equation per measurable time course of labeled amino acid. The equations demonstrate that both glutamate C4 and C3 labeling depend in a predictable manner...

The effect of different carbon sources on the expression of tricarboxylic acid (TCA) cycle genes, along with glyoxylate bypass genes, in Corynebacterium glutamicum was determined. All TCA cycle genes were coordinately expressed in medium containing acetate. Growth in the presence of acetate gave rise to abundant expression of most TCA cycle genes, with the level of gltA transcript being the hig...

Conversion of lactate to glucose was examined in myotubes, minced muscle tissue, and rats exposed to 2H2O or 13C-enriched substrates. Myotubes or minced skeletal muscle incubated with [U-(13)C3]lactate released small amounts of [1,2,3-(13)C3]- or [4,5,6-(13)C3]glucose. This labeling pattern is consistent with direct transfer from lactate to glucose without randomization in the tricarboxylic aci...

There have been numerous studies indicating that the tricarboxylic acid (TCA) cycle functions as the terminal respiratory pathway in various microorganisms. The existence of this cycle in shigella organisms, however, has not been reported. This report presents evidence that strains of Shigella flexneri 3 also have a TCA cycle. These data were obtained during a study of the metabolic behavior of...

Muscle glutamate is central to reactions producing 2-oxoglutarate, a tricarboxylic acid (TCA) cycle intermediate that essentially expands the TCA cycle intermediate pool during exercise. Paradoxically, muscle glutamate drops approximately 40-80% with the onset of exercise and 2-oxoglutarate declines in early exercise. To investigate the physiological relationship between glutamate, oxidative me...

BACKGROUND In comparison to the comprehensive analyses performed on virulence gene expression, regulation and action, the intracellular metabolism of Salmonella during infection is a relatively under-studied area. We investigated the role of the tricarboxylic acid (TCA) cycle in the intracellular replication of Salmonella Typhimurium in resting and activated macrophages, epithelial cells, and d...

Quantitative determination of trans-cinnamaldehyde (TCA) was conducted by reversed-phase HPLC from young and mature leaves, and leaf branches of Cinnamomum osmophloeum, a Taiwan endemic plant. The results showed that highest yield, 23.79 mg/g of TCA (the tree’s age was three years) was obtained in the two year old mature leaves. In addition, cytotoxic and inhibitory effects of TCA was evaluated...