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AMELIORATION OF ETHANOL-INDUCED DYSMORPHOGENESIS BY ADENOVIRAL-MEDIATED CU,ZN-SOD AND MN-SOD EXPRESSION IN NEURULATION STAGED MOUSE EMBRYOS IN VITRO
Citation:
Smith, J. B., P C. Hartig, M R. Blanton, K. K. Sulik, AND E S. Hunter III. AMELIORATION OF ETHANOL-INDUCED DYSMORPHOGENESIS BY ADENOVIRAL-MEDIATED CU,ZN-SOD AND MN-SOD EXPRESSION IN NEURULATION STAGED MOUSE EMBRYOS IN VITRO. Presented at Society for Developmental Biology, Asheville, NC, May 23-25, 2001.
Description:
AMELIORATION OF ETHANOL-INDUCED DYSMORPHOGENESIS BY ADENOVIRAL-MEDIATED Cu,Zn-SOD AND Mn-SOD EXPRESSION IN NEURULATION STAGED MOUSE EMBRYOS IN VITRO. JB Smith1, PC Hartig3, MR Blanton3, KK Sulik1,2, and ES Hunter3. 1Department of Cell and Developmental Biology and 2Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina and 3NHEERL, USEPA, RTP, North Carolina.
Prenatal ethanol exposure is associated with a variety of malformations and developmental delays collectively termed alcohol-related birth defects. The teratogenicity of ethanol may be due in part to the generation of reactive oxygen species (ROS), as previous research has shown that the antioxidant enzyme superoxide dismutase (SOD) can ameliorate ethanol-induced dysmorphogenesis in C57BL/6J mouse embryos. In the present study, protection from ethanol-induced malformations in cultured CD-1 mouse embryos was evaluated by adding SOD protein to the culture medium and by embryonic expression of cytosolic Cu,Zn-SOD (SOD1) or mitochondrial Mn-SOD (SOD2) mediated by an adenoviral vector. Exposure of embryos to 500 mg/dl ethanol for 24h resulted in characteristic craniofacial defects. Embryonic dysmorphogenesis was not ameliorated by addition of 1500 U/ml SOD protein to the culture medium. In contrast, adenoviral-mediated expression of SOD2 significantly decreased first arch hypoplasia, prosencephalic hypoplasia, and heart malformations. Expression of SOD1 resulted in amelioration of first arch hypoplasia only. All SOD treatments decreased ethanol-induced cell death as detected by whole-mount TUNEL. Staining with 3-(4,5 dimethylthiazol-2-yl)-2,5 diphenyl-tetrazolium bromide (MTT) after 6, 12, or 24 h revealed increased levels of ROS in ethanol-treated embryos as compared to controls, and that adenoviral-mediated SOD2 expression reduced ROS levels resulting from 24h of ethanol exposure. The induction of prosencephalic, first arch, and heart malformations by ethanol suggests that the neural crest cells are damaged by ethanol exposure, and the ability of SOD2 to modulate these defects indicates that ROS damage to the neural crest cells is a critical step in ethanol-induced dysmorphogenesis. Furthermore, differences in the ameliorative effects of SOD1 and SOD2 suggests that free radical damage to the mitochondria is involved in ethanol-induced teratogenesis. Supported by NIAAA-AA11605 and Grant for Predoctoral Training in Research on Drug Abuse, T-32 DA 07244. This abstract does not represent EPA policy.