Myelin-associated mRNA and protein expression deficits in the anterior cingulate cortex and hippocampus in elderly schizophrenia patients

Microarray and other studies have reported oligodendrocyte and myelin-related (OMR) deficits in schizophrenia. Here, we employed a quantitative approach to determine the magnitude of OMR gene expression deficits and their brain-region specificity. In addition, we examined how expression levels among the studied OMR genes are interrelated. mRNA of MAG, CNP, SOX10, CLDN11, and PMP22, but not MBP and MOBP, was reduced in the hippocampus and anterior cingulate cortex but not in the putamen of patients with schizophrenia. Expression of the only protein examined (CNP) was decreased in the hippocampus but not in the putamen. Correlation and factor analyses revealed that mRNA levels for genes that did exhibit differential expression in schizophrenia (MAG, CNP, SOX10, CLDN11, and PMP2), as opposed to those that did not (MOBP and MBP), loaded on separate factors. Thus, OMR gene and protein expression deficits in schizophrenia are brain-region specific, and the affected components may share regulatory elements. (C) 2005 Elsevier Inc. All rights reserved.