title: A three amino acid peptide, Gly-Pro-Arg, protects and rescues cell death induced by amyloid beta-peptide.
abstract: Amyloid beta-peptide (Abeta) contributes to the pathogenesis of Alzheimer's disease (AD), causing neuronal death through apoptosis. In this study, the neuroprotective role of small peptides, Gly-Pro-Glu (GPE), Gly-Glu (GE), Gly-Pro-Asp (GPD), and Gly-Pro-Arg (GPR) were examined against Abeta-induced toxicity in cultured rat hippocampal neurons. We report here that GPR (10-100 microM) prevented Abeta-mediated increase in lactate dehydrogenase (LDH) release and Abeta inhibition of MTT reduction, even in neurons that were pre-exposed to Abeta for 24 or 48 h. Since GPR prevented Abeta inhibition of MTT reduction, the anti-apoptotic effect of GPR was studied by examining activation of caspase-3 and expression of p53 protein. Caspase-3 was significantly activated by 20 microM Abeta25-35 and 5 microM Abeta1-40, but GPR effectively prevented the Abeta-mediated activation of caspase-3. Similarly, Abeta increased numbers of p53-positive cells, but GPR prevented this Abeta effect. Our findings suggest that GPR can rescue cultured rat hippocampal neurons from Abeta-induced neuronal death by inhibiting caspase-3/p53-dependent apoptosis.
authors.affiliation: Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA.
authors.forename: Marina
authors.initials: M
authors.lastname: Ioudina
authors.forename: Etsuro
authors.initials: E
authors.lastname: Uemura
mesh_terms: D016229:Amyloid beta-Peptides / Q000633:toxicity*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002478:Cells, Cultured; D004151:Dipeptides / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects / Q000473:pathology; D007150:Immunohistochemistry; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D009474:Neurons / Q000187:drug effects* / Q000473:pathology; D018696:Neuroprotective Agents / Q000494:pharmacology*; D009842:Oligopeptides / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013778:Tetrazolium Salts / Q000378:metabolism; D013844:Thiazoles / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000187:drug effects
chemical_list: D016229:Amyloid beta-Peptides; D004151:Dipeptides; D018696:Neuroprotective Agents; D009842:Oligopeptides; D013778:Tetrazolium Salts; D013844:Thiazoles; D016159:Tumor Suppressor Protein p53; C035024:glycyl-prolyl-arginine; C046223:N-glycylglutamic acid; D007770:L-Lactate Dehydrogenase; C505410:Casp3 protein, rat; D053148:Caspase 3; D020169:Caspases; C022616:thiazolyl blue; C062053:glycyl-prolyl-glutamic acid