Homo sapiens Transcriptome or Gene expression. Homo sapiens

Background: The trigeminal ganglion contains neurons that relay sensations of pain, touch, pressure, and many other somatosensory modalities from the body to the central nervous system. The ganglion is also a reservoir for latent herpes virus 1 infection. To gain a better understanding of molecular factors contributing to migraine and headache, transcriptome analyses were performed on postmortem human trigeminal ganglia.Methods: RNA-Seq measurements of gene expression were performed on small subregions of 16 human trigeminal ganglia. The samples were also characterized for viral, and bacterial genomic transcripts. Herpes simplex virus 1 (HSV-1) antibodies in blood were measured using the luciferase immunoprecipitation assay.Results: Molecular heterogeneity across the samples was prominent and could be explained by sampling of anatomically distinct sub-regions of the excised ganglia consistent with neurally-enriched and non-neural, i.e. Schwann, cell enriched regions. The levels of HSV-1 transcripts detected in trigeminal ganglia correlated with levels of HSV-1 antibodies in blood. Multiple migraine susceptibility genes are strongly expressed in neurally-enriched trigeminal samples and in blood vessels.Conclusions: These data provide a comprehensive description of the trigeminal transcriptome and a framework for evaluation of the parameters impinging on post-mortem studies in inhomogeneous tissues by proposing an extensive quality control and refined downstream analyses for RNA-Seq methodologies. Expression profiling of migraine susceptibility genes from genetic association studies appears to emphasize the blood vessel component of the trigeminovascular system.Keywords: RNA-Seq, transcriptome, trigeminal ganglion, herpes simplex virus, post-mortem, migraine