Ebselen increases cytosolic free Ca2+ concentration, stimulates glutamate release and increases GFAP content in rat hippocampal astrocytes.
We have investigated the effect of the seleno-organic compound and radical scavenger ebselen on rat hippocampal astrocytes in culture. Throughout our study we carried out determinations of [Ca2+](c) in fura-2-loaded cells by single cell imaging, glutamate secretion employing an enzymatic-based assay and GFAP expression, which was monitorized by immunocytochemistry and confocal microscopy. Our results show that ebselen (1-20microM) dose dependently increases [Ca2+](c), stimulates glutamate release and increases GFAP content, a hallmark of astrocyte reactivity. Ebselen did not alter significantly cell viability as assayed by determination of LDH release into the extracellular medium. Ebselen-evoked glutamate release and increase in GFAP content were Ca2+-dependent, because incubation of astrocytes in the absence of extracellular Ca2+ (medium containing 0.5mM EGTA) and in the presence of the intracellular Ca2+ chelator BAPTA (10microM) significantly reduced ebselen-evoked changes in these parameters. The effects of ebselen we have observed may underline various signalling pathways which are important for cell proliferation, differentiation and function. However, aberrations in astroglial physiology could significantly compromise brain function, due to their role as modulators of neuron activity. Therefore, we consider that careful attention should be paid when employing ebselen as a prophylactic agent against brain damage.
Salazar
Miguel
M
Department of Physiology (Cell Physiology Research Group), University of Extremadura, Avenida Universidad s/n, E-10071 Cáceres, Spain.
Pariente
José Antonio
JA
Salido
Ginés María
GM
González
Antonio
A
D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism*; D001393:Azoles / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism*; D018698:Glutamic Acid / Q000378:metabolism*; D006624:Hippocampus / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D007150:Immunohistochemistry; D054833:Isoindoles; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D018696:Neuroprotective Agents / Q000494:pharmacology*; D016566:Organoselenium Compounds / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
D001393:Azoles; D005904:Glial Fibrillary Acidic Protein; D054833:Isoindoles; D018696:Neuroprotective Agents; D016566:Organoselenium Compounds; D018698:Glutamic Acid; C042986:ebselen; D007770:L-Lactate Dehydrogenase; D002118:Calcium