INCREASES IN FRAGMENTED GLIAL FIBRILLARY ACIDIC PROTEIN-LEVELS IN THESPINAL-CORDS OF PATIENTS WITH AMYOTROPHIC-LATERAL-SCLEROSIS

Using one-dimensional polyacrylamide gel electrophoresis, we analyzed protein fractions extracted from the spinal cords of patients with amy otrophic lateral sclerosis (ALS). Several protein bands with molecular weights of 35-55 kDa were stained with Coomassie brilliant blue much more intensely in the ALS than in the non-ALS spinal cord. Glial fibri llary acidic protein (GFAP) immunoreactivity showed a significant decr ease of 50 and 45 kDa band and increase in fragmented 36 and 37 kDa ba nds, which represented GFAP fragments devoid of 59 and 40 residues fro m the N-terminal, respectively, as determined by protein sequence anal ysis. Immunohistochemical examination of ALS spinal cord transections demonstrated increased GFAP-stained astrocytes in the shrunken ventral horn with massive degeneration of motoneurons. These results will pro vide new insight into the possible role of astrocytes in the pathophys iology and/or pathogenesis of ALS.