title: Bax siRNA promotes survival of cultured and allografted granule cell precursors through blockade of caspase-3 cleavage.
abstract: Transplantation of neuronal precursor cells (NPCs) into the central nervous system could represent a powerful therapeutical tool against neurodegenerative diseases. Unfortunately, numerous NPCs die shortly after transplantation, predominantly due to caspase-dependent apoptosis. Using a culture of cerebellar neuronal precursors, we have previously demonstrated protective effect of the neuropeptide PACAP, which suppresses ceramide-induced apoptosis by blockade of the mitochondrial apoptotic pathway. The main objective of this study was to determine whether Bax repression can promote survival of NPCs allotransplanted into a host animal. In vivo and ex vivo experiments revealed that C2-ceramide increases Bax expression, while PACAP reverses this effect. In vitro tests using cerebellar NPCs demonstrated that the Bax-specific small interfering RNA (siRNA) could reduce their death and caspase-3 cleavage within the first 24 h. BrdU-labelled NPCs were subjected to transfection procedure with or without siRNA introduction before using for in vivo transplantation. Twenty-four hours after, the allografted NPCs containing siRNA showed significantly reduced level of caspase-3 cleavage, and the volume of their implants was almost twofold higher than in the case of empty-transfected precursors. These data evidence an important role of Bax in life/death decision of grafted NPCs and suggest that RNA interference strategy may be applicable for maintaining NPCs survival within the critical first hours after their transplantation.
authors.affiliation: INSERM U413, Laboratory of Cellular and Molecular Neuroendocrinology, Laboratoire International Associé Samuel de Champlain, European Institute for Peptide Research (IFRMP 23), University of Rouen, Mont-Saint-Aignan, France.
authors.forename: S S
authors.initials: SS
authors.lastname: Zhokhov
authors.forename: A
authors.initials: A
authors.lastname: Desfeux
authors.forename: N
authors.initials: N
authors.lastname: Aubert
authors.forename: A
authors.initials: A
authors.lastname: Falluel-Morel
authors.forename: A
authors.initials: A
authors.lastname: Fournier
authors.forename: V
authors.initials: V
authors.lastname: Laudenbach
authors.forename: H
authors.initials: H
authors.lastname: Vaudry
authors.forename: B J
authors.initials: BJ
authors.lastname: Gonzalez
mesh_terms: D000818:Animals; D053148:Caspase 3 / Q000378:metabolism; D061945:Caspase Inhibitors; D002470:Cell Survival; D002478:Cells, Cultured; D002531:Cerebellum / Q000166:cytology*; D009474:Neurons / Q000166:cytology*; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide / Q000494:pharmacology; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013110:Sphingosine / Q000031:analogs & derivatives / Q000494:pharmacology; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D014184:Transplantation, Homologous; D051028:bcl-2-Associated X Protein / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism
chemical_list: D061945:Caspase Inhibitors; C064769:N-acetylsphingosine; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D034741:RNA, Small Interfering; D051028:bcl-2-Associated X Protein; D053148:Caspase 3; D013110:Sphingosine