E. Pileblad

Bio: E. Pileblad is an academic researcher. The author has contributed to research in topics: Astrocyte & Cerebral cortex. The author has an hindex of 1, co-authored 1 publications receiving 32 citations.

The presence of glutathione in primary neuronal and astroglial cultures from rat cerebral cortex and brain stem.

Abstract: The concentration of the tripeptide glutathione (GSH) was measured in primary cultures of neurons and astroglial cells from rat cerebral cortex and brain stem The concentration of GSH was found to be approximately 20 nmol/ mg protein in the neuronal culture from the cerebral cortex and ca 40 nmol/ mg protein in the neuronal brain stem cultures A GSH concentration of approximately 20 nmol/mg was observed in the astrocyte cultures from both brain regions The possibility to increase the GSH concentration was tested by incubating the cultures in the presence of the GSH precursor γ-glutamylcysteine (γ-GC) In the cultured astrocytes γ-GC produced a dose-dependent increase in GSH A similar increase was observed in the neuronal cultures, but this effect failed to reach statistical significance

Synthesis of the antioxidant glutathione in neurons: supply by astrocytes of CysGly as precursor for neuronal glutathione.

Abstract: Deficiency of the antioxidant glutathione in brain appears to be connected with several diseases characterized by neuronal loss. To study neuronal glutathione metabolism and metabolic interactions between neurons and astrocytes in this respect, neuron-rich primary cultures and transient cocultures of neurons and astroglial cells were used. Coincubation of neurons with astroglial cells resulted within 24 hr of incubation in a neuronal glutathione content twice that of neurons incubated in the absence of astroglial cells. In cultured neurons, the availability of cysteine limited the cellular level of glutathione. During a 4 hr incubation in a minimal medium lacking all amino acids except cysteine, the amount of neuronal glutathione was doubled. Besides cysteine, also the dipeptides CysGly and γGluCys were able to serve as glutathione precursors and caused a concentration-dependent increase in glutathione content. Concentrations giving half-maximal effects were 5, 5, and 200 μm for cysteine, CysGly, and γGluCys, respectively. In the transient cocultures, the astroglia-mediated increase in neuronal glutathione was suppressed by acivicin, an inhibitor of the astroglial ectoenzyme γ-glutamyl transpeptidase, which generates CysGly from glutathione. These data suggest the following metabolic interaction in glutathione metabolism of brain cells: the ectoenzyme γ-glutamyl transpeptidase uses as substrate the glutathione released by astrocytes to generate the dipeptide CysGly that is subsequently used by neurons as precursor for glutathione synthesis.

Vitamin E, Ascorbate, Glutathione, Glutathicne Disulfide, and Enzymes of Glutathione Metabolism in Cultures of Chick Astrocytes and Neurons: Evidence that Astrocytes Play an Important Role in Antioxidative Processes in the Brain

Abstract: GSH, GSSG, vitamin E, and ascorbate were measured in 14-day cultures of chick astrocytes and neurons and compared with levels in the forebrains of chick embryos of comparable age Activities of enzymes involved in GSH metabolism were also measured These included -γ-glutamylcysteine synthetase, GSH synthetase, γ-glutamyl cyclotransferase, γ-glutamyltranspeptidase, glutathione transferase (GST), GSH peroxidase, and GSSG reductase The concentration of lipid-soluble vitamin E in the cultured neurons was found to be comparable with that in the forebrain On the other hand, the concentration of vitamin E in the astrocytes was significantly greater in the cultured astrocytes than in the neurons, suggesting that the astrocytes are able to accumulate exogenous vitamin E more extensively than neurons The concentrations of major fatty acids were higher in the cell membranes of cultured neurons than those in the astrocytes Ascorbate was not detected in cultured cells although the chick forebrains contained appreciable levels of this antioxidant GSH, total glutathione (ie, GSH and GSSG), and GST activity were much higher in cultured astrocytes than in neurons γ-Glutamylcysteine synthetase activity was higher in the cultured astrocytes than in the cultured neurons GSH reductase and GSH peroxidase activities were roughly comparable in cultured astrocytes and neurons The high levels of GSH and GST in cultured astrocytes appears to reflect the situation in vivo The data suggest that astrocytes are resistant to reactive oxygen species (and potentially toxic xenobiotics) and may play a protective role in the brain Because enzymes of GSH metabolism are generally well represented in cultured astrocytes and neurons these cells may be ideally suited as probes for manipulating GSH levels in neural tissues in vitro Cultured astrocytes and neurons should be amenable to the study of the effects of various metabolic insults on the GSH system Such studies may provide insights into the design of therapeutic strategies to combat oxidative and xenobiotic stresses

Alterations in the distribution of glutathione in the substantia nigra in Parkinson's disease.

Abstract: Depletion of reduced glutathione occurs in the substantia nigra in Parkinson's disease and in incidental Lewy body disease (presymptomatic Parkinson's disease) which may implicate oxidative stress in the neurode-generative process. In this study mercury orange fluorescent staining and immunostaining with an antibody to reduced glutathione have been used to determine the distribution of reduced glutathione in the substantia nigra in Parkinson's disease compared with normal individuals.