10 kD mitochondrial matrix heat shock protein mRNA is induced following global brain ischemia in the rat

Heat shock proteins (HSP's) are a family of highly conserved proteins whose expression is increased by stress. The expression of many HSP's is induced in neurons by ischemia; however, the response of the 10 kDa mitochondrial matrix HSP (HSP10) is less well characterized. To address this issue, asphyxial cardiac arrest was induced in 28 male Sprague-Dawley rats. Northern blot analysis revealed that hsp10 mRNA was increased 2.7-fold in asphyxiated rats compared to sham-operated controls. In situ hybridization demonstrated increased mRNA in the cortex, septal nuclei, hippocampus, thalamic nuclei, purkinje cell layer of the cerebellum, and isolated brainstem nuclei of asphyxiated rats. The increase of mRNA was most robust 8 h after the injury but remained increased for 72 h. These results show that hsp10 mRNA is increased following asphyxial cardiac arrest in rats and suggest that hsp10 could be another determinate of neuronal survival after ischemia.