title: Ethanol influences on Bax associations with mitochondrial membrane proteins in neonatal rat cerebellum.
abstract: These studies investigated interactions taking place at the mitochondrial membrane in neonatal rat cerebellum following ethanol exposure and focused on interactions between proapoptotic Bax and proteins of the permeability transition pore (PTP), voltage-dependent anion channel (VDAC) and adenine nucleotide translocator (ANT) of the outer and inner mitochondrial membranes, respectively. Cultured cerebellar granule cells were used to assess the role of these interactions in ethanol neurotoxicity. Analyses were made at the age of maximal cerebellar ethanol vulnerability (P4), compared to the later age of relative resistance (P7), to determine whether differential ethanol sensitivity was mirrored by differences in these molecular interactions. We found that, following ethanol exposure, Bax proapoptotic associations with both VDAC and ANT were increased, particularly at the age of greater ethanol sensitivity, and these interactions were sustained at this age for at least 2 h postexposure. Since Bax:VDAC interactions disrupt protective VDAC interactions with mitochondrial hexokinase (HXK), we also assessed VDAC:HXK associations following ethanol treatment and found such interactions were altered by ethanol treatment, but only at 2 h postexposure and only in the P4, ethanol-sensitive cerebellum. Ethanol neurotoxicity in cultured neuronal preparations was abolished by pharmacological inhibition of both VDAC and ANT interactions with Bax but not by a Bax channel blocker. Therefore, we conclude that, at this age, within the constraints of our experimental model, a primary mode of Bax-induced initiation of the apoptosis cascade following ethanol insult involves interactions with proteins of the PTP complex and not channel formation independent of PTP constituents.
authors: Department of Neuroscience, University of Florida College of Medicine, Gainesville, Florida 32610-0244, USA. heaton@mbi.ufl.edu
authors: Marieta Barrow
authors: MB
authors: Heaton
authors: Kendra
authors: K
authors: Siler-Marsiglio
authors: Michael
authors: M
authors: Paiva
authors: Alexandra
authors: A
authors: Kotler
authors: Jonathan
authors: J
authors: Rogozinski
authors: Stacey
authors: S
authors: Kubovec
authors: Mary
authors: M
authors: Coursen
authors: Vladimir
authors: V
authors: Madorsky
mesh_terms: D000280:Administration, Inhalation; D000818:Animals; D000831:Animals, Newborn; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002492:Central Nervous System Depressants / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D002531:Cerebellum / Q000378:metabolism*; D018920:Coculture Techniques; D004396:Coloring Agents; D004797:Enzyme-Linked Immunosorbent Assay; D000431:Ethanol / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D005260:Female; D063647:Fetal Alcohol Spectrum Disorders / Q000473:pathology; D006593:Hexokinase / Q000378:metabolism; D008297:Male; D000226:Mitochondrial ADP, ATP Translocases / Q000037:antagonists & inhibitors; D024101:Mitochondrial Proteins / Q000378:metabolism*; D011247:Pregnancy; D011487:Protein Conformation; D051381:Rats; D020318:Rats, Long-Evans; D013347:Subcellular Fractions / Q000201:enzymology / Q000378:metabolism; D013778:Tetrazolium Salts; D013844:Thiazoles; D050994:Voltage-Dependent Anion Channels / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D051028:bcl-2-Associated X Protein / Q000378:metabolism*
chemical_list: D002492:Central Nervous System Depressants; D004396:Coloring Agents; D024101:Mitochondrial Proteins; D013778:Tetrazolium Salts; D013844:Thiazoles; D050994:Voltage-Dependent Anion Channels; D051028:bcl-2-Associated X Protein; D000431:Ethanol; D000226:Mitochondrial ADP, ATP Translocases; D006593:Hexokinase; C022616:thiazolyl blue