title: Dynamic changes in the microRNA expression profile reveal multiple regulatory mechanisms in the spinal nerve ligation model of neuropathic pain.
abstract: Neuropathic pain resulting from nerve lesions or dysfunction represents one of the most challenging neurological diseases to treat. A better understanding of the molecular mechanisms responsible for causing these maladaptive responses can help develop novel therapeutic strategies and biomarkers for neuropathic pain. We performed a miRNA expression profiling study of dorsal root ganglion (DRG) tissue from rats four weeks post spinal nerve ligation (SNL), a model of neuropathic pain. TaqMan low density arrays identified 63 miRNAs whose level of expression was significantly altered following SNL surgery. Of these, 59 were downregulated and the ipsilateral L4 DRG, not the injured L5 DRG, showed the most significant downregulation suggesting that miRNA changes in the uninjured afferents may underlie the development and maintenance of neuropathic pain. TargetScan was used to predict mRNA targets for these miRNAs and it was found that the transcripts with multiple predicted target sites belong to neurologically important pathways. By employing different bioinformatic approaches we identified neurite remodeling as a significantly regulated biological pathway, and some of these predictions were confirmed by siRNA knockdown for genes that regulate neurite growth in differentiated Neuro2A cells. In vitro validation for predicted target sites in the 3'-UTR of voltage-gated sodium channel Scn11a, alpha 2/delta1 subunit of voltage-dependent Ca-channel, and purinergic receptor P2rx ligand-gated ion channel 4 using luciferase reporter assays showed that identified miRNAs modulated gene expression significantly. Our results suggest the potential for miRNAs to play a direct role in neuropathic pain.
authors.affiliation: Biological Technologies, Pfizer Global Research and Development, Cambridge, Massachusetts, United States of America.
authors.forename: David
authors.initials: D
authors.lastname: von Schack
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Agostino
authors.forename: B Stuart
authors.initials: BS
authors.lastname: Murray
authors.forename: Yizheng
authors.initials: Y
authors.lastname: Li
authors.forename: Padmalatha S
authors.initials: PS
authors.lastname: Reddy
authors.forename: Jin
authors.initials: J
authors.lastname: Chen
authors.forename: Sung E
authors.initials: SE
authors.lastname: Choe
authors.forename: Brian W
authors.initials: BW
authors.lastname: Strassle
authors.forename: Christine
authors.initials: C
authors.lastname: Li
authors.forename: Brian
authors.initials: B
authors.lastname: Bates
authors.forename: Lynn
authors.initials: L
authors.lastname: Zhang
authors.forename: Huijuan
authors.initials: H
authors.lastname: Hu
authors.forename: Smita
authors.initials: S
authors.lastname: Kotnis
authors.forename: Brendan
authors.initials: B
authors.lastname: Bingham
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Garth T
authors.initials: GT
authors.lastname: Whiteside
authors.forename: Tarek A
authors.initials: TA
authors.lastname: Samad
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Kennedy
authors.forename: Seena K
authors.initials: SK
authors.lastname: Ajit
mesh_terms: D000818:Animals; D057225:Data Mining; D004195:Disease Models, Animal; D057075:Enzyme Assays; D005727:Ganglia, Spinal / Q000378:metabolism / Q000473:pathology; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D055785:Gene Knockdown Techniques; D017930:Genes, Reporter; D008026:Ligation; D008156:Luciferases / Q000378:metabolism; D008297:Male; D051379:Mice; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism / Q000592:standards; D009437:Neuralgia / Q000235:genetics* / Q000473:pathology; D011786:Quality Control; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012015:Reference Standards; D015203:Reproducibility of Results; D013127:Spinal Nerves / Q000378:metabolism* / Q000473:pathology*
chemical_list: D035683:MicroRNAs; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D008156:Luciferases