title: Osteopontin expression and function within the dorsal root ganglion.
abstract: Osteopontin expression has previously been demonstrated in the adult rat dorsal root ganglion, although its function remains unclear. Here, we demonstrate, using real-time reverse transcription-polymerase (RT-PCR) chain reaction, that osteopontin mRNA expression is increased 1 and 3 weeks following sciatic nerve section (axotomy). Further, immunohistochemical staining suggests that this increase is restricted to neurons already expressing the protein. Osteopontin knock-out animals have significantly increased mechanosensory thresholds in the intact adult compared with the wild-type controls; however no differences in allodynia are noted between genotypes using a model of neuropathic pain. Lastly, exogenous recombinant osteopontin has no effect on neurite outgrowth from adult wild-type sensory neurons, nor were differences in neurite outgrowth observed in osteopontin knock-out animals compared with wild-type controls.
authors.affiliation: Department of Pharmacology at South Bristol, University of Bristol, Bristol, UK.
authors.forename: Barnaby C L
authors.initials: BC
authors.lastname: Marsh
authors.forename: Niall C
authors.initials: NC
authors.lastname: Kerr
authors.forename: Nathalie
authors.initials: N
authors.lastname: Isles
authors.forename: David T
authors.initials: DT
authors.lastname: Denhardt
authors.forename: David
authors.initials: D
authors.lastname: Wynick
mesh_terms: D000367:Age Factors; D000818:Animals; D019771:Axotomy; D005260:Female; D005727:Ganglia, Spinal / Q000166:cytology / Q000502:physiology*; D015870:Gene Expression / Q000502:physiology; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D018345:Mice, Knockout; D009437:Neuralgia / Q000378:metabolism / Q000503:physiopathology*; D016501:Neurites / Q000502:physiology; D009475:Neurons, Afferent / Q000502:physiology / Q000648:ultrastructure; D009619:Nociceptors / Q000502:physiology; D053495:Osteopontin / Q000235:genetics* / Q000378:metabolism*; D017288:Pain Threshold / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012584:Sciatic Nerve / Q000502:physiology
chemical_list: D012333:RNA, Messenger; D053495:Osteopontin