title: Patterns of pain: meta-analysis of microarray studies of pain.
abstract: Existing microarray gene expression profiling studies of tonic/chronic pain were subjected to meta-analysis to identify genes found to be regulated by these pain states in multiple, independent experiments. Twenty studies published from 2002 to 2008 were identified, describing the statistically significant regulation of 2254 genes. Of those, a total of 79 genes were found to be statistically significant "hits" in 4 or more independent microarray experiments, corresponding to a conservative P<0.01 overall. Gene ontology-based functional annotation clustering analyses revealed strong evidence for regulation of immune-related genes in pain states. A multi-gene quantitative real-time polymerase chain reaction experiment was run on dorsal root ganglion (DRG) and spinal cord tissue from rats and mice given nerve (sciatic chronic constriction; CCI) or inflammatory (complete Freund's adjuvant) injury. We independently confirmed the regulation of 43 of these genes in the rat-CCI-DRG condition; the genetic correlates in all other conditions were largely and, in some cases, strikingly, independent. However, a handful of genes were identified whose regulation bridged etiology, anatomical locus, and/or species. Most notable among these were Reg3b (regenerating islet-derived 3 beta; pancreatitis-associated protein) and Ccl2 (chemokine [C-C motif] ligand 2), which were significantly upregulated in every condition in the rat.
authors.affiliation: Department of Psychology, McGill University, Montreal, QC, Canada H3A 1B1 Department of Anesthesia Research, Faculty of Dentistry, McGill University, Montreal, QC, Canada H3A 1B1 Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC, Canada H3A 1B1.
authors.forename: Michael L
authors.initials: ML
authors.lastname: LaCroix-Fralish
authors.forename: Jean-Sebastien
authors.initials: JS
authors.lastname: Austin
authors.forename: Felix Y
authors.initials: FY
authors.lastname: Zheng
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Levitin
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Mogil
mesh_terms: D000818:Animals; D020869:Gene Expression Profiling / Q000379:methods; D005786:Gene Expression Regulation; D006801:Humans; D051379:Mice; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D010146:Pain / Q000145:classification / Q000453:epidemiology / Q000235:genetics; D000073718:Pancreatitis-Associated Proteins; D039781:PubMed / Q000706:statistics & numerical data; D051381:Rats