Gene expression profiles in microdissected neurons from human hippocampal subregions

• Published in: Brain research. Molecular brain research. Vol. 127; no. 1; pp. 105 - 114
• Main Authors: Torres-Muñoz, Jorge E, Van Waveren, Corina, Keegan, Martha G, Bookman, Richard J, Petito, Carol K
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 23.08.2004; Elsevier
• Subjects: Amplified mRNA; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Gene Expression; Gene Expression Profiling; Hippocampus - cytology; Human hippocampus; Humans; Laser capture microdissection; Microarrays; Microdissection - methods; Neurons - metabolism; Oligonucleotide Array Sequence Analysis - methods; Postmortem Changes; Reverse Transcriptase Polymerase Chain Reaction - methods; RNA, Messenger - metabolism; Selective vulnerability; Staining and Labeling - methods; Time Factors; Vertebrates: nervous system and sense organs; Selective vulnerability; Cellular and molecular biology; Laser capture microdissection; Amplified mRNA; Human hippocampus; Microarrays; Human; Neuron; Central nervous system; Gene expression; Hippocampus; Encephalon
• ISSN: 0169-328X; 1872-6941
• DOI: 10.1016/j.molbrainres.2004.05.017

Pyramidal neurons in hippocampal subregions are selectively vulnerable in certain disease states. To investigate, we tested the hypothesis that selective vulnerability in human hippocampus is related to regional differences in neuronal cell death and cell receptor gene expression in CA1 vs. CA3 subregions. We used laser capture microdissection to remove approximately 600 CA1 and 600 CA3 pyramidal neurons each from five fresh-frozen normal post-mortem brains, extracted total RNA and double-amplified mRNA. This was reverse transcribed and labeled for hybridization onto human cDNA array chips containing probes to 10,174 genes and unknown ESTs. RNA from additional microdissections was pooled for replicate hybridizations and quantitative RT-PCR validation. Gene expression differences were few (<1%). We found 43 enriched genes in CA1 neuronal samples that included peripheral benzodiazipine receptor-associated protein, nicotinic cholinergic receptor, two chemokine receptors (CCR1 and CCR5) and several transcriptional factors. We found 17 enriched genes in the CA3 neuronal samples that included fibroblast growth factor receptor and prostaglandin-endoperoxide synthase 1. We found no differential gene expression for 23 calcium channel proteins; nine transporter proteins; 55 cell death and apoptotic regulator proteins; and an additional 497 cell receptors, including 24 glutamate receptors. Quantitative RT-PCR of four differentially expressed genes confirmed the microarray data. The results confirm the ability to examine gene expression profiles in microdissected neurons from human autopsy brain. They show only minor gene expression differences between two distinct neuronal populations in the hippocampus and suggest that selective hippocampal vulnerability is due to factors other than intrinsic differential expression in glutamate receptors and cell death genes.