Evaluation of Oxidative Stress Parameters and Energy Metabolism in Cerebral Cortex of Rats Subjected to Sarcosine Administration

Blood metabolomics and impacted cellular mechanisms during transition into lactation in dairy cows that develop metritis

The objective of this study was to identify metabolites associated with metritis and use them for identification of cellular mechanisms affected during transition into lactation. Holstein cows (n = 104) had blood collected in the prepartum period (d -14 ± 6 relative to calving), at calving (d 0), and at the day of metritis diagnosis (d 7 ± 2 after calving). Cows with reddish or brownish, watery, and fetid discharge were diagnosed with metritis (n = 52). Cows with metritis were paired with herdmates without metritis (n = 52) based on days in milk. The metabolome of plasma samples was evaluated using untargeted gas chromatography time-of-flight mass spectrometry. Univariate analyses included t-tests and fold change analyses. Metabolites with false discovery rate adjusted P ≤ 0.10 on t-tests were used for partial least squares discriminant analysis coupled with permutational analysis using 2,000 permutations. Metabolites with false discovery rate adjusted P ≤ 0.10 on t-tests were also used for enriched pathway analyses and identification of cellular processes. Cows that developed metritis had affected cellular processes associated with lower amino acid metabolism in the prepartum period, greater lipolysis, cell death, and oxidative stress at calving and at metritis diagnosis, and greater leukocyte activation at calving, but lower immune cell activation at metritis diagnosis. In summary, cows that developed metritis had plasma metabolomic changes associated with greater lipolysis, oxidative stress, and a dysregulated immune response which may predispose cows to metritis development.

l-Carnitine prevents oxidative stress in striatum of glutaryl-CoA dehydrogenase deficient mice submitted to lysine overload

The deficiency of the enzyme glutaryl-CoA dehydrogenase leads to predominant accumulation of glutaric acid (GA) in the organism and is known as glutaric acidemia type I (GA1). Despite the mechanisms of brain damage involved in GA1 are not fully understood, oxidative stress may be involved in this process. Treatment is based on protein/lysine (Lys) restriction and l-carnitine (L-car) supplementation. L-car was recently shown to have an important antioxidant role. A knockout mice model (Gcdh^-/-) submitted to a dietary overload of Lys was developed to better understand the GA1 pathogenesis. In this study, we evaluated L-car and glutarylcarnitine levels, the lipid and protein damage, reactive oxygen species (ROS) production and antioxidant enzymes activities in striatum of Gcdh^-/- and wild-type (WT) mice. We also determined the effect of the L-car treatment on these parameters. Thirty-day-old Gcdh^-/- and WT mice were fed a normal chow (0.9% Lys) or submitted to a high Lys diet (4.7%) for 72 h. Additionally, these animals were administered with three intraperitoneal injections of saline or L-car in different times. Gcdh^-/- mice were deficient in L-car and presented a higher glutarylcarnitine levels. They also presented lipid and protein damage, an increased ROS production and altered antioxidant enzymes compared to WT mice. Additionally, mice exposed to Lys overload presented higher alterations in these parameters than mice under normal diet, which were significantly decreased or normalized in those receiving L-car. Thus, we demonstrated a new beneficial effect of the L-car treatment attenuating or abolishing the oxidative stress process in Gcdh^-/- mice.

A comparative study of using free radical generators in the testing of chosen oxidative stress parameters in the different types of cells

The aim of this study was to assess whether there are differences between the results of determining oxidative stress markers obtained from different origin cell lines after exposure to chemicals generating free radicals. The studies considered two markers of oxidative stress: the level of thiobarbituric acid reactive substances (TBARS) and superoxide dismutase activity. The evaluation was performed in five cell lines: Chinese hamster ovary (CHO-9) cells, lung adenocarcinoma A549, macrophages RAW264.7, skin carcinoma cells A431, and keratinocytes HaCaT. Three compounds generating free radicals were used as a source of reactive oxygen/nitrogen: 2,2'-azobis-2-methyl-propanimidamide dihydrochloride (AAPH), sodium persulfate (SP), and 3-morpholinosydnonimine hydrochloride (SIN-1). The most appropriate cell line to assess the level of TBARS proved to be the murine macrophage cell line RAW 264.7. Equally, good performance was observed in the lung cancer cell line A549, but only when tested with AAPH and SP. In the case of measuring superoxide dismutase activity, it appeared that the most suitable cell line was also the RAW 264.7 line, although dispersion increased significantly at the highest concentrations of AAPH and SP measurements. When choosing a cell line to determine oxidative stress, the specificity of the stress-inducing compound and the parameter determined should be taken into consideration.

Hypoxanthine Induces Neuroenergetic Impairment and Cell Death in Striatum of Young Adult Wistar Rats

Hypoxanthine is the major purine involved in the salvage pathway of purines in the brain. High levels of hypoxanthine are characteristic of Lesch-Nyhan Disease. Since hypoxanthine is a purine closely related to ATP formation, the aim of this study was to investigate the effect of intrastriatal hypoxanthine administration on neuroenergetic parameters (pyruvate kinase, succinate dehydrogenase, complex II, cytochrome c oxidase, and ATP levels) and mitochondrial function (mitochondrial mass and membrane potential) in striatum of rats. We also evaluated the effect of cell death parameters (necrosis and apoptosis). Wistar rats of 60 days of life underwent stereotactic surgery and were divided into two groups: control (infusion of saline 0.9%) and hypoxanthine (10 μM). Intrastriatal hypoxanthine administration did not alter pyruvate kinase activity, but increased succinate dehydrogenase and complex II activities and diminished cytochrome c oxidase activity and immunocontent. Hypoxanthine injection decreased the percentage of cells with mitochondrial membrane label and increased mitochondrial membrane potential labeling. There was a decrease in the number of live cells and an increase in the number of apoptotic cells by caused hypoxanthine. Our findings show that intrastriatal hypoxanthine administration altered neuroenergetic parameters, and caused mitochondrial dysfunction and cell death by apoptosis, suggesting that these processes may be associated, at least in part, with neurological symptoms found in patients with Lesch-Nyhan Disease.