BACKGROUND - Deoxyribonucleic acid microarray analyses of dorsolateral prefrontal cortex (DLPFC) area 9 from 10 matched pairs of schizophrenic and control subjects revealed a consistent and significant decrease (p = .001; mean log2 signal difference = -.58) in transcript expression for a gene clone KIAA0417. This database entry has been recently annotated as two highly homologous members of a heat-shock protein family (HSPA12A and HSPA12B).
METHODS - We followed up our initial results by in situ hybridization in subjects with schizophrenia, major depression, and a chronic haloperidol-treated nonhuman primate model. Furthermore, we investigated the distribution of HSPA12A and HSPA12B transcripts across the human and nonhuman primate brain.
RESULTS - We found that HSPA12A (but not HSPA12B) is highly expressed in the human brain and shows a neuron- and region-specific transcript distribution, with strongest expression in the frontal and occipital cortical regions. HSPA12A messenger ribonucleic acid was significantly reduced (p < .01; mean log2 optical density difference = -.84) across subjects with schizophrenia but not in the DLPFC of subjects with major depression or in monkeys chronically treated with haloperidol.
CONCLUSIONS - The data are consistent with metabolic alterations in schizophrenia, reflected in selective changes in the expression of certain genes encoding proteins involved in cellular metabolism or metabolic responsiveness.