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Identification of precursor micro RNA s within distal axons of sensory neuron
Author(s) -
Kim Hak Hee,
Kim Paul,
Phay Monichan,
Yoo Soonmoon
Publication year - 2015
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/jnc.13140
Subject(s) - drosha , dicer , microrna , biology , growth cone , axotomy , neuroscience , neuron , sensory system , microbiology and biotechnology , in situ hybridization , sensory neuron , axon , rna , messenger rna , central nervous system , gene , biochemistry , rna interference
A set of specific precursor micro RNA s (pre‐mi RNA s) are reported to localize into neuronal dendrites, where they could be processed locally to control synaptic protein synthesis and plasticity. However, it is not clear whether specific pre‐mi RNA s are also transported into distal axons to autonomously regulate intra‐axonal protein synthesis. Here, we show that a subset of pre‐mi RNA s, whose mature mi RNA s are enriched in axonal compartment of sympathetic neurons, are present in axons of neurons both in vivo and in vitro by quantitative PCR and by in situ hybridization. Some pre‐mi RNA s (let 7c‐a and pre‐miRs‐16, 23a, 25, 125b‐1, 433, and 541) showed elevated axonal levels, while others (pre‐miRs‐138‐2, 185, and 221) were decreased in axonal levels following injury. Dicer and KSRP proteins are also present in distal axons, but Drosha is found restricted to the cell body. These findings suggest that specific pre‐mi RNA s are selected for localization into distal axons of sensory neurons and are presumably processed to mature mi RNA s in response to extracellular stimuli. This study supports the notion that local mi RNA biogenesis effectively provides another level of temporal control for local protein synthesis in axons.We showed that a subset of specific precursor miRNAs are transported into distal axons of sensory neurons and that the levels of these precursor miRNAs change in response to injury. We proposed that injury could invoke a change in axonal miRNA levels, effectively providing a means to turn translation of specific mRNAs on or off within the spatial confines of the distal axon.