NEURONAL DEATH IN CULTURED MURINE CORTICAL-CELLS IS INDUCED BY INHIBITION OF GAPDH AND TRIOSEPHOSPHATE ISOMERASE

Polyglutamine-containing proteins expressed in the CAG repeat diseases Huntington's disease and dentatorubralpallidoluyisian atrophy have re cently been suggested to inhibit the key glycolytic enzyme glyceraldeh yde-3-phosphate dehydrogenase (GAPDH). To examine the consequences of GAPDH inhibition upon neuronal survival, we exposed murine neocortical cell cultures to the inhibitor of GAPDH and triosephosphate isomerase , alpha-monochlorohydrin. Cultures exposed to 6-15 mM alpha-monochloro hydrin for 48 h exhibited an increase in dihydroxyacetone phosphate an d a decrease in neuronal ATP that was followed by progressive neuronal death; some glial death occurred at high drug concentrations. The neu ronal death was characterized by cell body shrinkage and chromatin con densation and was sensitive to cycloheximide and to the caspase inhibi tors Z-Val-Ala-Asp fluoromethylketone and tert-butoxycarbonyl-Asp fluo romethylketone. Neurons in striatal cell cultures were more vulnerable to death induced by exposure to alpha-monochlorohydrin, except that N ADPH-diaphorase(+) neurons were selectively spared. Repeated addition of the glycolytic endpoint metabolite pyruvate to the bathing medium a ttenuated both the drop in neuronal ATP and the neuronal cell death, ( C) 1998 Academic Press.