The distribution and localization of hsp110 in brain

Hsp110 is one of the few, major heat shock proteins of mammalian cells and was one of the earliest heat shock proteins described. However, it has only recently been cloned and studied at the molecular level. It has been noted that of all tissues examined, brain expresses the highest level of hsp110, with expression levels in unstressed brain being similar to the levels see n in heat shocked cells. The present report describes a combined Northern a nd Western blot analysis of hsp110 expression in various regions of mouse a nd human brain. These observations are further expanded by an immunohistoch emical characterization of hsp110 cellular localization in mouse brain. It is seen that although hsp110 is an abundant protein in most regions of the brain, its expression is heterogeneous, with little being detectable in the cerebellum. Within the cerebral hemispheres, hsp110 is present in neurons in all regions including the cerebral cortex, the hippocampus, the thalamus and the hypothalamus. In contrast, in the cerebellum, the Purkinje cells a re the major hsp110 containing cells while the more abundant granule cells show little if any hsp110 labeling. Since hsp110 has been shown to protect cells and proteins from thermal damage, this differential pattern of expres sion may have ramifications in the pathophysiology of brain, specifically i nvolving cerebellar sequelae. (C) 2000 Elsevier Science BN. All rights rese rved.