title: Location is everything: let-7b microRNA and TLR7 signaling results in a painful TRP.
abstract: Extracellular let-7b, a microRNA found in the central nervous system, affects neurons through its interaction with Toll-like receptor 7 (TLR7), but with divergent outcomes in different neurons. Lehmann et al. found that let-7b stimulation of cortical and hippocampal neurons led to neuronal apoptosis, whereas Park et al. report that let-7b activation of TLR7 stimulated the cation channel transient receptor potential A1 (TRPA1) on dorsal root ganglia sensory neurons and induced pain responses. The primary difference that may influence these distinct responses to let-7b is the localization of TLR7 to the endosome in the cortical and hippocampal neurons or the plasma membrane in the sensory neurons. These studies suggest that different types of neurons traffic TLR7 to distinct membrane locations, affecting the functional response of neurons to let-7b stimulation.
authors.affiliation: Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840, USA.
authors.forename: Clayton W
authors.initials: CW
authors.lastname: Winkler
authors.affiliation: Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840, USA.
authors.forename: Katherine G
authors.initials: KG
authors.lastname: Taylor
authors.affiliation: Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840, USA. petersonka@niaid.nih.gov.
authors.forename: Karin E
authors.initials: KE
authors.lastname: Peterson
mesh_terms: D017209:Apoptosis / Q000502:physiology; D015220:Calcium Channels / Q000378:metabolism; D002490:Central Nervous System / Q000502:physiology*; D006801:Humans; D035683:MicroRNAs / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009474:Neurons / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D000074025:TRPA1 Cation Channel; D051199:Toll-Like Receptor 7 / Q000378:metabolism*; D050051:Transient Receptor Potential Channels / Q000378:metabolism
chemical_list: D015220:Calcium Channels; D035683:MicroRNAs; D009419:Nerve Tissue Proteins; C495348:TLR7 protein, human; D000074025:TRPA1 Cation Channel; C473350:TRPA1 protein, human; D051199:Toll-Like Receptor 7; D050051:Transient Receptor Potential Channels; C487931:mirnlet7 microRNA, human