Katarzyna Wejksza

Learn More
The present study characterizes the synthesis of kynurenic acid (KYNA) from exogenously added kynurenine and its regulation by extrinsic factors, in cultured cerebral cortical neurons and, for comparison, in astrocytes incubated under identical conditions. The neuronal culture showed positive immunostaining for both kynurenic acid aminotransferase (KAT)(More)
In the present study we demonstrate for the first time that both kynurenine aminotransferase (KAT) isoforms I and II are present in the permanent immature rat oligodendrocytes cell line (OLN-93). Moreover, we provide evidence that OLN-93 cells are able to synthesize kynurenic acid (KYNA) from exogenously added L-kynurenine and we characterize its regulation(More)
(1) There is increasing evidence that the cerebral endothelium and the blood-brain barrier (BBB) plays an important role in the oxidative stress-induced brain damage. The aim of the present study was to investigate the role of interendothelial junctional proteins in the BBB permeability increase induced by oxidative stress. (2) For the experiments, we have(More)
Mannitol, which is a cell-impermeable and nontoxic polyalcohol, has been shown to be a useful tool for reversible opening of the blood-brain barrier (BBB). Despite successful clinical trials, the molecular mechanism of the mannitol-induced changes in cerebral endothelial cells (CECs) are poorly understood. For our experiments, we used CECs in culture, which(More)
Kynurenic acid (KYNA) is an endogenous antagonist of alpha7 nicotinic receptors and all ionotropic glutamate receptors. Its neuroprotective activity has been suggested. In this study, the presence of KYNAin human saliva and its potential bactericidal role was investigated. KYNAwas found in all samples of human saliva with mean concentration of 3.4 nM. The(More)
The synthesis of the NMDA receptor glycine site antagonist kynurenic acid (KYNA) from exogenously added kynurenine was measured in cultured cerebral cortical neurons, cortical astrocytes and an oligodendroglial cell line OLN-93, incubated for 2 h in the presence or absence of ammonium acetate ("ammonia") at 0.1-10 mM concentration. In neurons ammonia(More)
Betulin and betulinic acid, plant-derived triterpenoid compounds, have been described to possess anti-inflammatory activity. In this paper, we examine the ability of both compounds to induce and modulate cytokine production in human whole blood cell cultures. The results indicate that betulin is a modest TNF-alpha inducer and also an enhancer of(More)
Kynurenic acid (KYNA) is a tryptophan metabolite produced in the kynurenine pathway. In the central nervous system, KYNA exerts neuroprotective and anticonvulsant effects by mechanisms associated with its antagonist activity against the ionotropic glutamate and alpha-7 nicotinic receptors. Its presence has been documented not only in cerebrospinal fluid and(More)
Kynurenic acid (KYNA) is a broad-spectrum antagonist at all subtypes of ionotropic glutamate receptors, but is preferentially active at the strychnine-insensitive glycine allosteric site of the N-methyl-D-aspartate (NMDA) receptor and is also a non-competitive antagonist at the alpha7 nicotinic receptor. KYNA occurs in the CNS, urine, serum and amniotic(More)
  • 1