microRNA expression in the prefrontal cortex of individuals with schizophrenia and schizoaffective disorder
1 Department of Psychiatry, University of North Carolina at Chapel Hill, CB 7160, Chapel Hill, NC 27599, USA
2 School of Pharmacy, University of North Carolina at Chapel Hill, CB 7360, Chapel Hill, NC 27599, USA
3 Renaissance Computing Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
4 Department of Cell and Developmental Biology, University of North Carolina at Chapel Hill, CB 7090, Chapel Hill, NC 27599, USA
5 Constella Group, LLC, Meridian Parkway, Durham, NC 27713, USA
6 Department of Molecular Biology, University of North Carolina at Chapel Hill, CB 7104, Chapel Hill, NC 27599, USA
Genome Biology 2007, 8:R27 doi:10.1186/gb-2007-8-2-r27Published: 27 February 2007
microRNAs (miRNAs) are small, noncoding RNA molecules that are now thought to regulate the expression of many mRNAs. They have been implicated in the etiology of a variety of complex diseases, including Tourette's syndrome, Fragile × syndrome, and several types of cancer.
We hypothesized that schizophrenia might be associated with altered miRNA profiles. To investigate this possibility we compared the expression of 264 human miRNAs from postmortem prefrontal cortex tissue of individuals with schizophrenia (n = 13) or schizoaffective disorder (n = 2) to tissue of 21 psychiatrically unaffected individuals using a custom miRNA microarray. Allowing a 5% false discovery rate, we found that 16 miRNAs were differentially expressed in prefrontal cortex of patient subjects, with 15 expressed at lower levels (fold change 0.63 to 0.89) and 1 at a higher level (fold change 1.77) than in the psychiatrically unaffected comparison subjects. The expression levels of 12 selected miRNAs were also determined by quantitative RT-PCR in our lab. For the eight miRNAs distinguished by being expressed at lower microarray levels in schizophrenia samples versus comparison samples, seven were also expressed at lower levels with quantitative RT-PCR.
This study is the first to find altered miRNA profiles in postmortem prefrontal cortex from schizophrenia patients.