Expression of stress proteins alpha B-crystallin, ubiquitin, and hsp27 in pallido-nigral spheroids of aged rhesus monkeys

Ubiquitin and alpha B-crystallin belong to a class of proteins which are ov erexpressed in a variety of human neuropathological conditions associated w ith increased cellular stress. In this study we have examined the brains of aged rhesus monkeys (Macaca mulatta; n = 10, mean age: 39.7 years) using a ntibodies against the stress proteins ubiquitin, alpha B-crystallin. and he at shock protein 27 (hsp27). Here, we demonstrate an increased expression o f ubiquitin, alpha B-crystallin, and hsp27 in spheroid bodies predominantly localized in the globus pallidus and pars reticulata of the substantia nig ra. A portion of the pallido-nigral spheroids also contained ferric iron as highlighted by Perls' staining. On the basis of these findings we advance the hypothesis that expression of ubiquitin, alpha B-crystallin, and hsp27 in pallido-nigral spheroids of aged rhesus monkeys represents a stress resp onse possibly related to increased iron-mediated oxidative stress. (C) 2001 Elsevier Science Inc. All rights reserved.