title: Bax-inhibiting peptide protects glutamate-induced cerebellar granule cell death by blocking Bax translocation.
abstract: Glutamate-induced excitotoxicity has been implicated in the pathogenesis of various neurological damages and disorders. In the brain damage of immature animals such as neonatal hypoxic-ischemic brain injury, the excitotoxicity appears to be more intimately involved through apoptosis. Bax, a member of the Bcl-2 family proteins, plays a key role in the promotion of apoptosis by translocation from the cytosol to the mitochondria and the release of apoptogenic factors such as cytochrome c. Recently, Bax-inhibiting peptide (BIP), a novel membrane-permeable peptide which can bind Bax in the cytosol and inhibit its translocation to the mitochondria, was developed. To investigate the possibility of a new neuroprotection strategy targeting Bax translocation in glutamate-induced neuronal cell death, cerebellar granule neurons (CGNs) were exposed to glutamate with or without BIP. Pretreatment of CGNs with BIP elicited a dose-dependent reduction of glutamate-induced neuronal cell death as measured by MTT assay. BIP significantly suppressed both the number of TUNEL-positive cells and the increase in caspases 3 and 9 activities induced by glutamate. In addition, immunoblotting after subcellular fractionation revealed that BIP prevented the glutamate-induced Bax translocation to the mitochondria and the release of cytochrome c from the mitochondria. These results suggest that agents capable of inhibiting Bax activity such as BIP might lead to new drugs for glutamate-related diseases in the future.
authors.affiliation: Department of Obstetrics and Gynecology, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Iriyama
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Kamei
authors.forename: Shiro
authors.initials: S
authors.lastname: Kozuma
authors.forename: Yuji
authors.initials: Y
authors.lastname: Taketani
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D020169:Caspases / Q000187:drug effects / Q000378:metabolism; D002531:Cerebellum; D045304:Cytochromes c / Q000378:metabolism; D019610:Cytoprotection / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D018698:Glutamic Acid / Q000378:metabolism / Q000633:toxicity*; D020925:Hypoxia-Ischemia, Brain / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D020287:In Situ Nick-End Labeling; D007202:Indicators and Reagents; D008297:Male; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D018696:Neuroprotective Agents / Q000494:pharmacology / Q000627:therapeutic use; D009842:Oligopeptides / Q000494:pharmacology* / Q000627:therapeutic use; D010455:Peptides / Q000494:pharmacology* / Q000627:therapeutic use; D021381:Protein Transport / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013778:Tetrazolium Salts; D051028:bcl-2-Associated X Protein / Q000037:antagonists & inhibitors* / Q000378:metabolism
chemical_list: C539791:Bax-inhibiting peptide, BIP; D007202:Indicators and Reagents; D018696:Neuroprotective Agents; D009842:Oligopeptides; D010455:Peptides; D013778:Tetrazolium Salts; D051028:bcl-2-Associated X Protein; D018698:Glutamic Acid; D045304:Cytochromes c; D020169:Caspases