Coordinate cis-[Cr(C₂O₄)(pm)(OH₂)₂]⁺ Cation as Molecular Biosensor of Pyruvate's Protective Activity Against Hydrogen Peroxide Mediated Cytotoxity

Estrogen metabolites and hydrogen peroxide - Missing elements in the pathophysiology and possible treatment of treatment-resistant depression?

The pathogenesis of depression is complex and heterogeneous, and the management of this disease remains unsatisfactory, so mechanisms and therapeutic strategies are constantly being sought. This study aimed to determine the potential role of estrogen metabolites in the pathogenesis of treatment-resistant depression (TRD) based on the determination of concentrations of estrogens and their metabolites and hydrogen peroxide (H202) in the biological material of patients with TRD. In this study, we observed for the first time an association between unbalanced estrogen metabolism and elevated H202 levels in TRD patients. Reduced concentrations of 2-methoxyestradiol (2-ME2), 17α-estradiol (α-E2) and 17β-estradiol (β-E2) may be due to abnormal estrogen metabolism toward neurotoxic semiquinones and quinones which are a potential as yet undescribed mechanism responsible for generating oxidative stress (OS) in TRD.

2-Methoxyestradiol and Hydrogen Peroxide as Promising Biomarkers in Parkinson's Disease

Estrogens function in numerous physiological processes including controlling brain cell growth and differentiation. 2-Methoxestradiol (2-ME2), a 17β-estradiol (E2) metabolite, is known for its anticancer effects as observed both in vivo and in vitro. 2-ME2 affects all actively dividing cells, including neurons. The study aimed to determine whether 2-ME2 is a potentially cancer-protective or rather neurodegenerative agent in a specific tissue culture model as well as a clinical setup. In this study, 2-ME2 activity was determined in a Parkinson's disease (PD) in vitro model based on the neuroblastoma SH-SY5Y cell line. The obtained results suggest that 2-ME2 generates nitro-oxidative stress and controls heat shock proteins (HSP), resulting in DNA strand breakage and apoptosis. On the one hand, it may affect intensely dividing cells preventing cancer development; however, on the other hand, this kind of activity within the central nervous system may promote neurodegenerative diseases like PD. Thus, the translational value of 2-ME2's neurotoxic activity in a PD in vitro model was also investigated. LC-MS/MS technique was used to evaluate estrogens and their derivatives, namely, hydroxy and methoxyestrogens, in PD patients' blood, whereas the stopped-flow method was used to assess hydrogen peroxide (H2O2) levels. Methoxyestrogens and H2O2 levels were increased in patients' blood as compared to control subjects, but hydoxyestrogens were simultaneously decreased. From the above, we suggest that the determination of plasma levels of methoxyestrogens and H2O2 may be a novel PD biomarker. The presented research is the subject of the pending patent application "The use of hydrogen peroxide and 17β-estradiol and its metabolites as biomarkers in the diagnosis of neurodegenerative diseases," no. P.441360.

Dietary calcium pyruvate could improve growth performance and reduce excessive lipid deposition in juvenile golden pompano (Trachinotus ovatus) fed a high fat diet

Excessive lipid deposition in farmed fish is a challenge in the aquaculture industry. To study the effect of dietary calcium pyruvate (CaP) on lipid accumulation in fish, we used a high fat diet (HFD) to establish a lipid accumulation model in juvenile golden pompano (Trachinotus ovatus) and supplemented with 0%, 0.25%, 0.50%, 0.75% and 1.0% CaP (diets D0-D4, respectively). After 8-week feeding in floating cages, dietary CaP significantly improved growth performance, which peaked in fish fed diet D3. Supplementation of CaP significantly decreased whole body lipid content in fish fed D2-D4 and hepatosomatic index and liver lipid content in fish fed D3 and D4. Serum and hepatic antioxidant indices, including glutathione, catalase and superoxide dismutase, showed generally increasing trends in fish fed diets with CaP. In addition, increasing dietary CaP increasingly reduced hepatic activities of hexokinase, phosphofructokinase and pyruvate kinase involved in glycolysis, and increased glycogen contents of the liver and muscle. Dietary CaP up-regulated the liver mRNA expression of pparα, cpt1, hsl and fabp1, but down-regulated expression of srebp-1, fas and acc. In conclusion, 0.75% CaP improved growth performance and reduced excessive lipid deposition by affecting fatty acid synthesis and lipolysis in juvenile T. ovatus fed HFD.

Genomic insights into antioxidant activities of Pyruvatibacter mobilis CGMCC 1.15125T, a pyruvate-requiring bacterium isolated from the marine microalgae culture

Pyruvate is a well-known scavenger of reactive oxygen species (ROS) like hydrogen peroxide and could prevent cells from oxidative damage. A pyruvate-requiring marine bacterium, Pyruvatibacter mobilis CGMCC 1.15125^T (=KCTC 42509^T), was isolated from the culture broth of a photosynthetic marine microalga. Here we report the complete genome sequence of Pyruvatibacter mobilis, which contained a circular chromosome of 3,333,914 bp with a mean G + C content of 63.9%. Through genomic analysis, we revealed that strain CGMCC 1.15125^T encodes genes for some antioxidants like superoxide dismutase, glutathione, rubrerythrin and globin to relieve cellular oxidative stress, while pyruvate added to the medium may reduce extracellular ROS. The genome features of P. mobilis provide further insights into the antioxidant activities of bacteria surviving in oxygen-enriched habitats.

Sodium pyruvate pre-treatment prevents cell death due to localised, damaging mechanical strains in the context of pressure ulcers

We demonstrate sodium pyruvate (NaPy) pre-treatment as a successful approach for pressure ulcer (PU) prevention by averting their aetiological origin-cell-level damage and death by large, sustained mechanical loads. We evaluated the NaPy pre-treatment effect on permeability changes in the cell's plasma membrane (PM) following application of in vitro damaging-level strains. Fibroblasts or myoblasts, respectively, models for superficial or deep-tissue damage were grown in 0 or 1 mM NaPy, emulating typical physiological or cell culture conditions. Cells were pre-treated for 4 hours with 0 to 5 mM NaPy prior to 3-hour sustained, damaging-level loads (12% strain). PM permeability was quantified by the cell uptake of small (4 kDa), fluorescent dextran compared with unstrained control using fluorescence-activated cell sorting (FACS). Pre-treatment with 1 mM, and especially 5 mM, NaPy significantly reduces damage to PM integrity. Long-term NaPy pre-exposure can improve protective treatment, affecting fibroblasts and myoblasts differently. Pre-treating with NaPy, a natural cell metabolite, allows cells under damaging-level mechanical loads to maintain their PM integrity, that is, to avoid loss of homeostasis and inevitable, eventual cell death, by preventing initial, microscale stages of PU formation. This pre-treatment may be applied prior to planned periods of immobility, for example, planned surgery or transport, to prolong safe time in a position by preventing initial cell damage that can cascade and lead to PU formation.

Method for detection of hydrogen peroxide in HT22 cells

We have proposed a new method which can be applied in assessing the intracellular production of hydrogen peroxide. Using this assay we have examined the hydrogen peroxide generation during the L-glutamate induced oxidative stress in the HT22 hippocampal cells. The detection of hydrogen peroxide is based on two crucial reagents cis-[Cr(C₂O₄)(pm)(OH₂)₂]⁺ (pm denotes pyridoxamine) and 2-ketobutyrate. The results obtained indicate that the presented method can be a promising tool to detect hydrogen peroxide in biological samples, particularly in cellular experimental models.

Cis-[Cr(C2O4)(pm)(OH2)2]+ coordination ion as a specific sensing ion for H2O2 detection in HT22 cells

The purpose of this study was to examine the application of the coordinated cis-[Cr(C₂O₄)(pm)(OH)₂]⁺ cation where pm denotes pyridoxamine, as a specific sensing ion for the detection of hydrogen peroxide (H₂O₂). The proposed method for H₂O₂ detection includes two key steps. The first step is based on the nonenzymatic decarboxylation of pyruvate upon reaction with H₂O₂, while the second step is based on the interaction of cis-[Cr(C₂O₄)(pm)(OH₂)₂]⁺ with the CO₂ released in the previous step. Using this method H₂O₂ generated during glutamate-induced oxidative stress was detected in HT22 hippocampal cells. The coordination ion cis-[Cr(C₂O₄)(pm)(OH₂)₂]⁺ and the spectrophotometric stopped-flow technique were applied to determine the CO₂ concentration in cell lysates, supernatants and cell-free culture medium. Prior to CO₂ assessment pyruvate was added to all samples studied. Pyruvate reacts with H₂O₂ with 1:1 stoichiometry, and consequently the amount of CO₂ released in this reaction is equivalent to the amount of H₂O₂.

Acute oxidative stress affects IL-8 and TNF-α expression in IPEC-J2 porcine epithelial cells

Reactive oxygen species are implicated in cell and tissue damage in a number of diseases including acute and chronic inflammation of the gut. Effects of H(2)O(2) exposure on non-carcinogenic porcine epithelial cell line, IPEC-J2 cells cultured on collagen-coated membrane inserts were monitored based on transepithelial electrical resistance (TER) change, extent of necrotic cell damage, gene expression of inflammatory cytokines IL-8 and TNF-α. Furthermore, the junction proteins claudin-1 and E-cadherin were also investigated by immunohistochemistry. Peroxide (1mM) increased IL-8 and TNF-α gene expression levels significantly allowing 1 h recovery time without affecting the cellular distribution of junction proteins, TER and cell survival rate. In conclusion, the IPEC-J2 cell line on membrane insert was introduced as a fast and reliable investigation tool for oxidative stimuli-triggered intestinal inflammation and in the future as a screening method for antioxidant and probiotic candidates.