GLIAL TAU-POSITIVE STRUCTURES LACK THE SEQUENCE ENCODED BY EXON-3 OF THE TAU-PROTEIN GENE

Tau protein comprises six distinct isoforms defined by the presence or absence of sequences encoded by alternatively spliced exon 2, 3 and 1 0. We have investigated immunohistochemically the expression of exon 3 -derived fragment (E-3) of tau protein in brains of patients with Alzh eimer's disease (AD) and other neurodegenerative diseases in which the abnormal accumulation of tau protein takes place. In AD, a subset of neurofibrillary tangles, neuropil threads and dystrophic neurites in s enile plaques were stained positively with an anti-E-3 antibody. In sh arp contrast, glial tau-positive structures, such as astrocytic plaque s and oligodendroglial coiled bodies, were negative for E3 in all case s examined in this study. This is the first report to discriminate tau -positive inclusions in glial cells from those in neurons at the molec ular level. (C) 1997 Elsevier Science Ireland Ltd.