title: Estrogen blocks neurotoxic effects of beta-amyloid (1-42) and induces neurite extension on B103 cells.
abstract: Clinical studies have shown that estrogen replacement therapy is associated with reduced risk of Alzheimer's disease (AD). We tested whether or not estrogen blocks neurotoxic effects of beta-amyloid (1-42) (A beta1-42) on cultured B103 cells. A beta1-42 (1 microM) induced typical necrotic cell death, as revealed by light and electron microscopic examinations. Co-administration of estrogen not only blocked A beta1-42 toxicity to a large degree, but also enhanced neurite extension. Pretreatment with estrogen was even more effective in blocking A beta1-42 toxicity. When added 18 h after the beginning of A beta1-42 treatment, estrogen was still effective in halting the progress of cell death and enhancing neurite extension. The protection against A beta1-42-induced neuronal death by estrogen was unlikely due to a blockade of lipid peroxidation injury, since estrogen completely failed to attenuate ferrous chloride-induced cell death. These results demonstrate that estrogen blocks A beta1-42-induced neurotoxicity and enhances neurite extension on B103 cells, both of which may well be underlying mechanisms of beneficial effects of estrogen in AD.
authors.affiliation: Department of Neurology, School of Medicine, Institute for Medical Sciences, Ajou University, Suwon, South Korea. inhee@skull.ajou.ac.kr
authors.forename: I
authors.initials: I
authors.lastname: Mook-Jung
authors.forename: I
authors.initials: I
authors.lastname: Joo
authors.forename: S
authors.initials: S
authors.lastname: Sohn
authors.forename: H J
authors.initials: HJ
authors.lastname: Kwon
authors.forename: K
authors.initials: K
authors.lastname: Huh
authors.forename: M W
authors.initials: MW
authors.lastname: Jung
mesh_terms: D016229:Amyloid beta-Peptides / Q000037:antagonists & inhibitors / Q000633:toxicity*; D000818:Animals; D001921:Brain / Q000166:cytology / Q000187:drug effects*; D002460:Cell Line; D004967:Estrogens / Q000494:pharmacology*; D016501:Neurites / Q000187:drug effects*; D009474:Neurons / Q000187:drug effects* / Q000648:ultrastructure; D009498:Neurotoxins / Q000633:toxicity*; D010446:Peptide Fragments / Q000037:antagonists & inhibitors / Q000633:toxicity*; D051381:Rats
chemical_list: D016229:Amyloid beta-Peptides; D004967:Estrogens; D009498:Neurotoxins; D010446:Peptide Fragments; C075222:amyloid beta-protein (1-42)