title: Increase of transcription factor EB (TFEB) and lysosomes in rat DRG neurons and their transportation to the central nerve terminal in dorsal horn after nerve injury.
abstract: In the spinal dorsal horn (DH), nerve injury activates microglia and induces neuropathic pain. Several studies clarified an involvement of adenosine triphosphate (ATP) in the microglial activation. However, the origin of ATP together with the release mechanism is unclear. Recent in vitro study revealed that an ATP marker, quinacrine, in lysosomes was released from neurite terminal of dorsal root ganglion (DRG) neurons to extracellular space via lysosomal exocytosis. Here, we demonstrate a possibility that the lysosomal ingredient including ATP released from DRG neurons by lysosomal-exocytosis is an additional source of the glial activation in DH after nerve injury. After rat L5 spinal nerve ligation (SNL), mRNA for transcription factor EB (TFEB), a transcription factor controlling lysosomal activation and exocytosis, was induced in the DRG. Simultaneously both lysosomal protein, LAMP1- and vesicular nuclear transporter (VNUT)-positive vesicles were increased in L5 DRG neurons and ipsilateral DH. The quinacrine staining in DH was increased and co-localized with LAMP1 immunoreactivity after nerve injury. In DH, LAMP1-positive vesicles were also co-localized with a peripheral nerve marker, Isolectin B4 (IB4) lectin. Injection of the adenovirus encoding mCherry-LAMP1 into DRG showed that mCherry-positive lysosomes are transported to the central nerve terminal in DH. These findings suggest that activation of lysosome synthesis including ATP packaging in DRG, the central transportation of the lysosome, and subsequent its exocytosis from the central nerve terminal of DRG neurons in response to nerve injury could be a partial mechanism for activation of microglia in DH. This lysosome-mediated microglia activation mechanism may provide another clue to control nociception and pain.
authors.affiliation: Department of Anatomy and Neurobiology, School of Medicine, Kyung Hee University, Heogi-Dong 1, Dongdaemun-Gu, Seoul 130-701, Republic of Korea; Core Research for Evolutional Science and Technology (CREST) of the Japan Science and Technology Agency (JST), Saitama, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Jung
authors.affiliation: Department of Functional Anatomy & Neuroscience, Nagoya University, Graduate School of Medicine, 65 Tsurumaicho, Showa-ku, Nagoya 466-8550, Japan; Core Research for Evolutional Science and Technology (CREST) of the Japan Science and Technology Agency (JST), Saitama, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Uesugi
authors.affiliation: Department of Anatomy and Cell Biology and Mitochondria, Hub Regulation Center, Dong-A University College of Medicine, 3-1 Dongdaesin-dong, Seo-gu, Busan 602-714, Republic of Korea.
authors.forename: N Y
authors.initials: NY
authors.lastname: Jeong
authors.affiliation: Department of Anatomy and Neurobiology, School of Medicine, Kyung Hee University, Heogi-Dong 1, Dongdaemun-Gu, Seoul 130-701, Republic of Korea.
authors.forename: B S
authors.initials: BS
authors.lastname: Park
authors.affiliation: Department of Functional Anatomy & Neuroscience, Nagoya University, Graduate School of Medicine, 65 Tsurumaicho, Showa-ku, Nagoya 466-8550, Japan; Core Research for Evolutional Science and Technology (CREST) of the Japan Science and Technology Agency (JST), Saitama, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Konishi
authors.affiliation: Department of Functional Anatomy & Neuroscience, Nagoya University, Graduate School of Medicine, 65 Tsurumaicho, Showa-ku, Nagoya 466-8550, Japan; Core Research for Evolutional Science and Technology (CREST) of the Japan Science and Technology Agency (JST), Saitama, Japan. Electronic address: kiyama@med.nagoya-u.ac.jp.
authors.forename: H
authors.initials: H
authors.lastname: Kiyama
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000378:metabolism*; D004195:Disease Models, Animal; D005089:Exocytosis / Q000502:physiology; D005727:Ganglia, Spinal / Q000378:metabolism* / Q000473:pathology; D005822:Genetic Vectors; D006023:Glycoproteins / Q000378:metabolism; D037102:Lectins / Q000378:metabolism; D008159:Lumbar Vertebrae; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D051907:Lysosomal Membrane Proteins / Q000235:genetics / Q000378:metabolism; D008247:Lysosomes / Q000378:metabolism*; D008297:Male; D017628:Microglia / Q000378:metabolism; D009474:Neurons / Q000378:metabolism* / Q000473:pathology; D033704:Nucleotide Transport Proteins / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D017208:Rats, Wistar; D013127:Spinal Nerves / Q000293:injuries* / Q000378:metabolism; D053675:Versicans; D000097573:Red Fluorescent Protein; D052118:Lysosomal-Associated Membrane Protein 1
chemical_list: D000255:Adenosine Triphosphate; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D006023:Glycoproteins; D037102:Lectins; D008164:Luminescent Proteins; D051907:Lysosomal Membrane Proteins; D033704:Nucleotide Transport Proteins; D012333:RNA, Messenger; D053675:Versicans; D000097573:Red Fluorescent Protein; C489117:Lamp1 protein, rat; D052118:Lysosomal-Associated Membrane Protein 1; C000595299:Slc17a9 protein, rat; C574124:TFEB protein, rat; C508324:Vcan protein, rat
keywords: dorsal horn; dorsal root ganglion neurons; lysosomal exocytosis; microglia; spinal nerve injury