title: Serofendic acid, a neuroprotective substance derived from fetal calf serum, inhibits mitochondrial membrane depolarization and caspase-3 activation.
abstract: We have previously reported that a neuroprotective substance, serofendic acid, was purified and isolated from fetal calf serum. Here, we investigated the effect of serofendic acid on glutamate-induced apoptosis using rat primary cultures of cortical neurons. Exposure of the cortical cultures to relatively low concentration of glutamate (100 microM) induced neuronal death and nuclear fragmentation. Glutamate exposure also induced a transient increase in caspase-3 activity. A membrane-permeable inhibitor of caspase-3 (DEVD-CHO) prevented the glutamate neurotoxicity. Serofendic acid (0.01-10 microM) markedly prevented glutamate-induced apoptotic neuronal death and nuclear fragmentation. To elucidate the protective mechanism of serofendic acid, we first examined the effect on the glutamate-induced increase in intracellular Ca2+ concentration. Glutamate-induced increase in intracellular Ca2+ concentration was significantly inhibited by MK-801, a NMDA receptor antagonist, but not by serofendic acid. Next, we investigated the effect of serofendic acid on the loss of mitochondrial membrane potential induced by glutamate by using a fluorescence indicator, tetramethylrhodamine methyl ester (TMRM). Glutamate exposure resulted in a rapid reduction of TMRM fluorescence, indicating that mitochondrial membrane was depolarized by glutamate. Serofendic acid prevented the loss of mitochondrial membrane potential following glutamate exposure. Moreover, serofendic acid reduced the activation of caspase-3 induced by glutamate. Finally, serofendic acid directly inhibited the activity of recombinant human caspase-3, -7 and -8 at higher concentrations. These results indicate that serofendic acid prevents glutamate-induced apoptosis in cultured cortical neurons by the prevention of loss of mitochondrial membrane potential and the reduction of the process of caspase-3 activation.
authors.affiliation: Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Kume
authors.forename: Ryota
authors.initials: R
authors.lastname: Taguchi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Katsuki
authors.forename: Masaharu
authors.initials: M
authors.lastname: Akao
authors.forename: Hachiro
authors.initials: H
authors.lastname: Sugimoto
authors.forename: Shuji
authors.initials: S
authors.lastname: Kaneko
authors.forename: Akinori
authors.initials: A
authors.lastname: Akaike
mesh_terms: D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002118:Calcium / Q000378:metabolism; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism*; D053179:Caspase 7 / Q000235:genetics / Q000378:metabolism; D053181:Caspase 8 / Q000235:genetics / Q000378:metabolism; D061945:Caspase Inhibitors; D002417:Cattle; D002478:Cells, Cultured; D002540:Cerebral Cortex; D004224:Diterpenes / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D005312:Fetal Blood / Q000737:chemistry; D005333:Fetus; D005971:Glutamates / Q000633:toxicity; D006801:Humans; D007424:Intracellular Fluid / Q000187:drug effects / Q000378:metabolism; D008564:Membrane Potentials / Q000187:drug effects; D051336:Mitochondrial Membranes / Q000187:drug effects* / Q000502:physiology; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D018696:Neuroprotective Agents / Q000494:pharmacology*; D009842:Oligopeptides / Q000494:pharmacology; D051381:Rats; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D000590:Amino Acid Chloromethyl Ketones; D061945:Caspase Inhibitors; D004224:Diterpenes; D005971:Glutamates; D018696:Neuroprotective Agents; D009842:Oligopeptides; D011994:Recombinant Proteins; C108637:aspartyl-glutamyl-valyl-aspartal; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; C452642:serofendic acid; D053148:Caspase 3; D053179:Caspase 7; D053181:Caspase 8; D002118:Calcium