Nuclear Clusterin Is Associated with Neuronal Apoptosis in the Developing Rat Brain upon Ethanol Exposure

• Published in: Alcoholism, clinical and experimental research Vol. 36; no. 1; pp. 72 - 82
• Main Authors: Kim, Nayoung, Han, Jae Y., Roh, Gu S., Kim, Hyun J., Kang, Sang S., Cho, Gyeong J., Park, Jae Y., Choi, Wan S.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.01.2012; Wiley; Wiley Subscription Services, Inc
• Subjects: Alcoholism; Alcoholism and acute alcohol poisoning; Animals; Animals, Newborn; Apoptosis; Apoptosis - drug effects; Bcl-x protein; Bcl-XL; Biological and medical sciences; Brain; Brain - drug effects; Brain - growth & development; Brain - metabolism; Caspase-3; Cell Nucleus - metabolism; Cell Survival - drug effects; Cells, Cultured; Cerebral Cortex; Cerebral Cortex - drug effects; Cerebral Cortex - metabolism; Clusterin; Clusterin - metabolism; Confocal microscopy; Cortex; Drug abuse; Ethanol; Ethanol - administration & dosage; Fetal Alcohol Spectrum Disorder; Fetal alcohol syndrome; Hippocampus; Hippocampus - cytology; Immunoblotting; Immunofluorescence; Immunohistochemistry; Immunoprecipitation; Medical sciences; Mice; Microscopy; Protein interaction; Rats; Rats, Sprague-Dawley; Rodents; siRNA; Toxicology; Up-Regulation; Western blotting; Fetal alcohol syndrome; Cerebral cortex; Ethanol; Rat; Rodentia; Central nervous system; Exposure; Clusterin; Encephalon; Alcoholic beverage; Newborn diseases; Vertebrata; Bcl-XL; Mammalia; Neuron; Cell death; Fetal Alcohol Spectrum Disorder; Animal; Apoptosis
• ISSN: 0145-6008; 1530-0277
• DOI: 10.1111/j.1530-0277.2011.01588.x

Background:  Fetal alcohol spectrum disorder (FASD) is often accompanied by reduced brain volumes, reflecting brain cell death induced by ethanol, but the molecular mechanisms were less elucidated. This study was set up to investigate whether clusterin (Clu) was involved in neuronal cell death in developing rats. Methods:  Seven‐day‐old rats were subcutaneously injected with 20% ethanol in normal saline at 3 g/kg twice. The upregulation of Clu and cell death was detected by immunohistochemistry, immunofluorescence microscopy, and/or Western blotting. Protein–protein interaction was detected by immunoprecipitation and immunoblotting. To identify the isoform interacting with Bcl‐XL, HT22 mouse hippocampal cells were transfected with nuclear Clu(nClu)‐ or secretory Clu‐expressing vector, and confocal microscopy was performed. Clu transcripts were knocked down in primary cortical cells using siRNA. Results:  We found that Clu increased in the cerebral cortex following acute ethanol treatment. The Clu upregulation was related to increased cell death, which was assessed by activated caspase‐3 and TUNEL staining. The upregulated Clu was a nuclear isoform that was nuclear translocated upon ethanol exposure and interacted with Bcl‐XL, mediating apoptosis. Conclusions:  This study shows that nClu plays a pro‐apoptotic role in ethanol‐induced cell death in the developing brain, providing new insights for development of FASD.