EXPRESSION OF THE HUMAN GROEL STRESS-PROTEIN HOMOLOG IN THE BRAIN ANDSPINAL-CORD

A monoclonal antibody (ML30), previously shown to identify a human mit ochondrial protein epitope homologous with the groEL heat-shock protei n of bacteria (hsp60), was used in an immunohistochemical survey of th e central nervous system in patients dying with no evidence of neurolo gical disease and in tissue from patients dying with various neurologi cal disorders. Staining was performed on frozen tissue sections and on formalin fixed, paraffin embedded tissue. Astrocytes in all areas sho wed a strong pattern of punctate granular staining, which was increase d in astrocytes showing reactive changes. Oligodendrocytes stained lig htly in a diffuse granular pattern as did most neurons. Ependymal cell s showed apical granular positivity. Expression of the hsp60 epitope r ecognised by MI-30 was not seen in ubiquitinated inclusion bodies in m otor neuron disease, neurofibrillary tangles in Alzheimer's disease or Lewy bodies in Parkinson's disease. The epitope recognised by ML30 wa s stable after formalin fixation and in post mortem tissue up to 96 h after death. Expression of the human groEL stress-protein homologue in brain and spinal cord is consistent with a mitochondrial location and may provide a morphological indicator of the functional or metabolic state of cells, especially glial cells.