title: Inhibition of arachidonic acid release by cytosolic phospholipase A2 is involved in the antiapoptotic effect of FK506 and cyclosporin a on astrocytes exposed to simulated ischemia in vitro.
abstract: In the present study, we investigated whether the protective effect of FK506 and cyclosporin A (CsA) against in vitro ischemic injury of astrocytes might be mediated through attenuation of cytosolic isoform of phospholipase A(2) (cPLA(2)) expression and activity as well as inhibition of arachidonic acid (AA) release. On the 21st day in vitro, cultures of rat astrocytes were subjected to ischemia-simulating conditions (combined oxygen glucose deprivation) for 8 h and exposed to FK506 (10 - 1,000 nM) and CsA (0.25 - 10 microM). Obtained data suggest the cross-talk between the action of 0.25 - 10 microM CsA as well as 1 microM FK506 on calcineurin (CaN) and cPLA(2) in anti-apoptotic signal transduction pathways. Moreover, we have shown that immunosuppressants at these concentrations protected glial cells against ischemia-induced apoptosis through the increase of cell viability, mitochondrial function restoration, and attenuation of oxidative stress. Finally, in our study, low concentrations of FK506 (10 and 100 nM) exerted limited effects on the assessed parameters. Our findings document a key role either for CaN or cPLA(2) expression attenuation and AA release inhibition in the antiapoptotic effect of FK506 and CsA in ischemic astrocytes.
authors.affiliation: Department of Pharmacology, Medical University of Silesia, Poland. bgabryel@interia.pl
authors.forename: Bozena
authors.initials: B
authors.lastname: Gabryel
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Chalimoniuk
authors.forename: Anna
authors.initials: A
authors.lastname: Stolecka
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Waniek
authors.forename: Jozef
authors.initials: J
authors.lastname: Langfort
authors.forename: Andrzej
authors.initials: A
authors.lastname: Malecki
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000975:Antioxidants / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects*; D016718:Arachidonic Acid / Q000378:metabolism*; D001253:Astrocytes / Q000187:drug effects*; D015153:Blotting, Western; D002545:Brain Ischemia / Q000473:pathology*; D019703:Calcineurin / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D016572:Cyclosporine / Q000494:pharmacology*; D003600:Cytosol / Q000201:enzymology* / Q000378:metabolism*; D020104:Immunophilins / Q000494:pharmacology; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D008564:Membrane Potentials / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D010741:Phospholipases A / Q000378:metabolism*; D054467:Phospholipases A2; D051381:Rats; D017208:Rats, Wistar; D020239:Receptor Cross-Talk / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects; D016559:Tacrolimus / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D007166:Immunosuppressive Agents; D016718:Arachidonic Acid; D016572:Cyclosporine; D010741:Phospholipases A; D054467:Phospholipases A2; D019703:Calcineurin; D020104:Immunophilins; D016559:Tacrolimus