ETHANOL CEREBELLAR PATHOLOGY--RETINOIDS AND GLYCOLIPIDS

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DESCRIPTION: (Adapted from the Investigator's Abstract) Cerebellar pathology in fetal alcohol syndrome (FAS) is a detrimental effect of ethanol exposure during development in humans and rats. Our in vivo data show that ethanol administered intragastrically increases cerebellar levels of retinoic acid (RA), a potent morphogen. Further, our in vitro data from cultures of cerebellar granule cells, cerebellar astrocytes, or co-cultures of the two show that both ethanol and exogenous RA decrease the production of fucosylated stage-specific embryonic antigen-1 (SSEA-1) and 9-O-acetyl gangliosides (JONES); antigens thought to be essential glycoconjugates for cell adhesion to and migration along glial processes in the developing cerebellum. Further, both ethanol and exogenous RA in these cultures decrease expression of fucosyltransferase mRNA, likely the rate-determining enzyme in the SSEA-1 biosynthetic pathway. These data imply that ethanol neuropathology involves an increase in cerebellar RA levels which alter cell surface expression of glycoconjugates critical to cell adhesion, migration, and survival. This is further supported by the observations that exogenous RA administrated to postnatal rats delays or prevents cerebellar granule cell migration and/or survival and that SSEA-1 specific antibodies prevent granule cell adhesion to glial processes in vitro. Our hypothesis is that ethanol cerebellar pathology involves an increase in RA which decreases cell surface expression of glycoconjugates. Our specific aims are to determine: 1) The postnatal levels of cerebellar RA and its synthetic enzymes, and receptors in neonatal rats treated in vivo with ethanol or RA; 2) The postnatal levels of 9-O-acetyl gangliosides, GD3-9-O-acetyltransferase activity, SSEA-1 glycoconjugates, fucosyltransferase activity, fucosyltransferase mRNA, and to evaluate Purkinje cell survival, granule cell survival/migration, and glial cell content in postnatal rats treated in vivo with ethanol or RA; 3) The RA levels, synthetic enzymes, and expression of RA receptors in ethanol-exposed cultures of cerebellar granule cells, astroglial cells, and co-cultures of the two cell types; 4) Alterations in cell survival and cell adhesion of these cells in the presence of exogenous RA, or antibodies specific to SSEA-1 or 9-O-acetyl gangliosides; 5) The content and expression of 9-O-acetylgangliosides, SSEA-1 glycoconjugates, fucosyltransferase activity and fucosyltransferase mRNA in ethanol- or RA-exposed cultures of these cells.