MK4MDD

Study Report

Reference
CitationKlok, 2010 PubMed
Full InfoKlok, M.D., Alt, S.R., Irurzun Lafitte, A.J., Turner, J.D., Lakke, E.A., Huitinga, I., Muller, C.P., Zitman, F.G., Ronald de Kloet, E. and Derijk, R.H. (2010) Decreased expression of mineralocorticoid receptor mRNA and its splice variants in postmortem brain regions of patients with major depressive disorder. J Psychiatr Res.

Study
Hypothesis or Background Appropriate signaling in the brain by the glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) is critical in regulation of the hypothalamic-pituitary-adrenal (HPA) axis, emotional arousal and cognitive performance. To date, few data exist on MR (and GR) expression in the brain of patients suffering from major depressive disorder (MDD).
Sample Informationsix MDD patients and six non-depressed subjects
Method DetailWith the help of quantitative PCR we assessed MR and GR mRNA expression, including the splice variants MR¦Á and MR¦Â, in tissue samples from the hippocampus, amygdala, inferior frontal gyrus, cingulate gyrus and nucleus accumbens. Expression levels were compared between tissue samples from six MDD patients and six non-depressed subjects.
Method Keywordspostmortem study; Q-PCR
ResultRelative to total GR, total MR mRNA expression was higher in hippocampus and lower in the amygdala, inferior frontal gyrus and nucleus accumbens. Both MR¦Á and MR¦Â could be detected in all brain regions that were analyzed, although MR¦Â expression was low. Significantly lower expression levels (30-50%) were detected for MR or GR in hippocampal, inferior frontal gyrus and cingulate gyrus tissue from MDD patients (p < .05), while no differences were found in the amygdala or nucleus accumbens. The data show that both MR¦Á and MR¦Â mRNA are expressed throughout the human limbic brain with highest expressions in the hippocampus.
ConclusionsA decreased expression of corticosteroid receptors in specific brain regions of MDD patients could underlie HPA hyperactivity, mood and cognitive disturbances often observed in patients suffering from stress-related psychopathologies.

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