The Proapoptotic BH3-Only, Bcl-2 Family Member, Puma Is Critical for Acute Ethanol-Induced Neuronal Apoptosis

• Published in: Journal of neuropathology and experimental neurology 2009-07, Vol.68 (7), p.747-756
• Main Authors: Ghosh, Arindam P, Walls, Ken C, Klocke, Barbara J, Toms, Rune, Strasser, Andreas, Roth, Kevin A
• Format: Article
• Language: English
• Subjects: Animals; Apoptosis - drug effects; Apoptosis - physiology; Apoptosis Regulatory Proteins - metabolism; bcl-2-Associated X Protein - genetics; bcl-2-Associated X Protein - metabolism; Bcl-2-Like Protein 11; Biological and medical sciences; Blotting, Western; Caspase 3 - metabolism; Errors of metabolism; Ethanol - toxicity; Immunohistochemistry; Lipids (lysosomal enzyme disorders, storage diseases); Medical sciences; Membrane Proteins - metabolism; Metabolic diseases; Mice; Mice, Inbred C57BL; Mice, Knockout; Neurology; Neurons - drug effects; Neurons - physiology; Neuropeptides - metabolism; Proto-Oncogene Proteins - metabolism; Proto-Oncogene Proteins c-bcl-2 - genetics; Proto-Oncogene Proteins c-bcl-2 - metabolism; Time Factors; Tumor Suppressor Protein p53 - genetics; Tumor Suppressor Protein p53 - metabolism; Tumor Suppressor Proteins - genetics; Tumor Suppressor Proteins - metabolism
• ISSN: 0022-3069; 1554-6578
• DOI: 10.1097/NEN.0b013e3181a9d524

Synaptogenesis in humans occurs in the last trimester of gestation and in the first few years of life, whereas it occurs in the postnatal period in rodents. A single exposure of neonatal rodents to ethanol during this period evokes extensive neuronal apoptosis. Previous studies indicate that ethanol triggers the intrinsic apoptotic pathway in neurons, and that this requires the multi-BH domain, proapoptotic Bcl-2 family member Bax. To define the upstream regulators of this apoptotic pathway, we examined the possible roles of p53 and a subclass of proapoptotic Bcl-2 family members (i.e. the BH3 domain-only proteins) in neonatal wild-type and gene-targeted mice that lack these cell death inducers. Acute ethanol exposure produced greater caspase-3 activation and neuronal apoptosis in wild-type mice than in saline-treated littermate controls. Loss of p53-upregulated mediator of apoptosis (Puma) resulted in marked protection from ethanol-induced caspase-3 activation and apoptosis. Although Puma expression has been reported to be regulated by p53, p53-deficient mice exhibited a similar extent of ethanol-induced caspase-3 activation and neuronal apoptosis as wild-type mice. Mice deficient in other proapoptotic BH3-only proteins, including Noxa, Bim, or Hrk, showed no significant protection from ethanol-induced neuronal apoptosis. Collectively, these studies indicate a p53-independent, Bax- and Puma-dependent mechanism of neuronal apoptosis and identify Puma as a possible molecular target for inhibiting the effects of intrauterine ethanol exposure in humans.