An analysis of choroid plexus gene expression in major depressive disorder

Turner CA, Thompson RC, Bunney WE, Schatzberg AF, Barchas JD, Myers RM, Akil H, Watson SJ
Society for Neuroscience. 2012.


The choroid plexus (CP) functions to produce cerebrospinal fluid, remove byproducts, provide structural support for the brain and affect neuroendocrine signaling. Moreover, it is important to understand the CP gene expression, as this structure is present in hippocampal dissections. However, its characterization in the human post-mortem brain, as well as the role that this structure may play in Major Depressive Disorder (MDD) is relatively unknown. To investigate which of the many functions of the choroid plexus may be altered in MDD, we analyzed the post-mortem choroid plexus of six controls (5 males and 1 female) and six MDDs (4 males and 2 females). We performed laser capture microscopy of the choroid plexus at the level of the dentate gyrus. Next, we extracted, amplified, labeled and hybridized the cRNA to Illumina BeadChips to assess gene expression. We also analyzed the results using Ingenuity Pathway Analysis. In controls, the most highly abundant transcript was transthyretin. There were also six ribosomal proteins among the 14 most abundantly expressed transcripts. Using BeadStudio software, we identified 169 transcripts differentially expressed between controls and MDDs. There were 43 transcripts upregulated and 126 transcripts downregulated in MDDs. Using pathway analysis (Ingenuity) to examine these altered mRNAs, we noted that the top network included multiple members of the extracellular matrix. These results suggest that a large amount of protein synthesis may naturally occur in the choroid plexus. Finally, the extracellular matrix of the choroid plexus may be altered in MDDs, suggesting an altered blood-CSF-brain barrier.