Cell-specific expression of heat shock transcription factors 1 and 2 in unstressed rat spinal cord

We investigated the intracellular distribution of heat shock factors 1 and 2 (HSF1, HSF2) in rat spinal cord by immunoblotting and immunohistochemistr y using selective policlonal antibodies. Our results showed that both HSF1 and HSF2 were expressed in spinal cord cells (both neurons and glia) but at different intensity and cell localization. HSF1 was unusually distributed in the perinuclear compartment of selected neurons of the gray matter while astrocytes, oligodendrocytes and ependymal cells were predominantly staine d in the nucleus. HSF2 was expressed at lower levels than HSF1 and was scat tered in both nucleus and cytoplasm of the motoneurons of the ventral horns while glial cells again showed a nuclear positivity. This study suggested that the different ability of neurons vs. glial cells to react against adve rse conditions might well be correlated with the different constitutive loc alization of HSFs. (C) 1999 Elsevier Science Ireland Ltd. All rights reserv ed.