EXPRESSION OF INTERLEUKIN-1 RECEPTOR ANTAGONIST PROTEIN IN POSTMORTEMHUMAN BRAIN-TISSUES OF ALZHEIMERS-DISEASE AND CONTROL CASES

The immunohistochemical localization of interleukin-1 receptor antagon ist protein (Il-1ra) was examined in brain tissues of neurologically n ormal controls as well as in cases of Alzheimer's disease (AD) and Pic k's disease. In all control cases, immunoreactivity was observed in so me normal-appearing neurons in the neocortex and hippocampus. In AD, t here appeared to be increased numbers of positively staining neurons, and the staining of individual neurons was somewhat more intense. Il-1 ra was additionally expressed in globular deposits in senile plaques a nd, weakly, in some extracellular neurofibrillary tangles. In Pick's d isease, there was similar staining of normal-appearing neurons and int ense staining in some degenerating neurons, Using reverse transcriptas e-polymerase chain reaction techniques, the mRNA for IL-1ra was detect ed in cultured IMR-32 human neuroblastoma cells following differentiat ion with dibutyryl cAMP and bromodeoxyuridine. Taken together, these d ata suggest that IL-1ra is a product of normal neurons which may be up regulated in some pathological circumstances.