Expression and distribution of hsp71 and hsc73 messenger RNAs in rat brain following heat shock: effect of dizocilpine maleate

Abstract

Induction of hsp71 mRNA, coding for the inducible heat shock protein HSP71, and the constitutively expressed, hsc73 mRNA coding for the heat shock cognate protein HSC73 were studied after heat shock using northern blotting and in situ hybridization. Two cDNA oligonucleotides complementary to the messenger RNAs for hsp71 and hsc73 and suitable for in situ hybridization were designed and shown to hybridize selectively to their respective mRNAs. The inducible hsp71 was rapidly synthesized in brain after heat shock and disappeared in 6 h. A high level of expression was observed first in the dentate granule cell layer and then slightly later in the hippocampal pyramidal cell layer. There was also a dramatic increase in the granular layer of the cerebellar cortex. There was a more modest increase in expression of hsc73 after heat shock in forebrain and in cerebellum (granular layer). The N-methyl-D-aspartate receptor antagonist dizocilpine maleate (0.5 mg/kg, i.p.), given 15 min before heat shock, significantly reduced the expression of hsp71 but had no effect on hsc73. These results suggest that glutamate plays a role in heat shock-induced expression of hsp71 in brain.