1. Fibroblast growth factor homologous factor 1 (FHF1) is expressed in a subpopulation of calcitonin gene-related peptide-positive nociceptive neurons in the murine dorsal root ganglia
- Author
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Jean Valmier, Stéphanie Ventéo, Patrick Carroll, Agnès Fichard-Carroll, Sylvie Puech, Ilana Mechaly, Thomas Hubert, Steeve Bourane, Hamel, Christian, Physiopathologie et thérapie des déficits sensoriels et moteurs, and Université Montpellier 2 - Sciences et Techniques (UM2)-IFR76-Institut National de la Santé et de la Recherche Médicale (INSERM)
- Subjects
MESH: Neurons ,Fluorescent Antibody Technique ,MESH: Neuropeptides ,Fibroblast growth factor ,Sodium Channels ,Mice ,Neurotrophic factors ,MESH: Reverse Transcriptase Polymerase Chain Reaction ,Ganglia, Spinal ,MESH: Animals ,MESH: Nociceptors ,MESH: Fluorescent Antibody Technique ,In Situ Hybridization ,Neurons ,Sodium channel activity ,Reverse Transcriptase Polymerase Chain Reaction ,General Neuroscience ,MESH: Receptor, trkA ,Nociceptors ,Axotomy ,Peripherin ,Immunohistochemistry ,Cell biology ,Nociception ,MESH: Ganglia, Spinal ,[SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC] ,MESH: Fibroblast Growth Factors ,Neurofilament ,Calcitonin Gene-Related Peptide ,Blotting, Western ,MESH: Axotomy ,Calcitonin gene-related peptide ,Biology ,MESH: Sodium Channels ,MESH: In Situ Hybridization ,MESH: Mice, Inbred C57BL ,MESH: Blotting, Western ,MESH: Calcitonin Gene-Related Peptide ,Animals ,[SDV.NEU] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC] ,RNA, Messenger ,Receptor, trkA ,MESH: Mice ,NAV1.9 Voltage-Gated Sodium Channel ,MESH: RNA, Messenger ,Sodium channel ,Neuropeptides ,MESH: Immunohistochemistry ,Fibroblast Growth Factors ,Mice, Inbred C57BL ,nervous system ,Neuroscience - Abstract
International audience; Dorsal root ganglia (DRG) neurons exhibit a wide molecular heterogeneity in relation to the various sensory modalities (mechanoception, thermoception, nociception) that they subserve. Finding markers of subpopulations is an important step in understanding how these neurons convey specific information. We identified fibroblast growth factor homologous factor 1 (FHF1) in a search for markers of subpopulations of DRG neurons. FHFs constitute a family of four factors that share some structural properties with fibroblast growth factors (FGFs) but are functionally distinct. They are expressed in specific subsets of neurons and are involved in the modulation of sodium channel activity. The pattern of expression of FHF1 in the DRG was determined during development, in the adult and after axotomy. We show that in the adult, FHF1 is expressed in two populations, one composed of nociceptors and another in which no neurotrophic factor receptors were detected (panTrk-/c-Ret-). Interestingly, in the nociceptors, FHF1 expression was restricted to a subset of TrkA+/calcitonin gene-related peptide (CGRP)-positive neurons. Neurofilament 200 (NF-200) and peripherin labeling indicates that 70% of the FHF1-expressing neurons contribute to A-fibers and 30% to C-fibers. FHF1 interacts with the Na(v)1.9 sodium channel isoform, which is strongly expressed in cRet+/isolectin-B4 binding neurons, but we show that FHF1 is not expressed in the cRet+/IB4+ subclass and that it does not colocalize with Na(v)1.9. Our results argue strongly against the possibility that FHF1 has a modulatory effect on this channel in cRet+/IB4+ neurons, but FHF1 could play a role in a distinct subset of TrkA+/CGRP+ nociceptors.
- Published
- 2008