title: The long non-coding RNA nuclear-enriched abundant transcript 1_2 induces paraspeckle formation in the motor neuron during the early phase of amyotrophic lateral sclerosis.
abstract: BACKGROUND
  A long non-coding RNA (lncRNA), nuclear-enriched abundant transcript 1_2 (NEAT1_2), constitutes nuclear bodies known as "paraspeckles". Mutations of RNA binding proteins, including TAR DNA-binding protein-43 (TDP-43) and fused in sarcoma/translocated in liposarcoma (FUS/TLS), have been described in amyotrophic lateral sclerosis (ALS). ALS is a devastating motor neuron disease, which progresses rapidly to a total loss of upper and lower motor neurons, with consciousness sustained. The aim of this study was to clarify the interaction of paraspeckles with ALS-associated RNA-binding proteins, and to identify increased occurrence of paraspeckles in the nucleus of ALS spinal motor neurons.
  
  
  RESULTS
  In situ hybridization (ISH) and ultraviolet cross-linking and immunoprecipitation were carried out to investigate interactions of NEAT1_2 lncRNA with ALS-associated RNA-binding proteins, and to test if paraspeckles form in ALS spinal motor neurons. As the results, TDP-43 and FUS/TLS were enriched in paraspeckles and bound to NEAT1_2 lncRNA directly. The paraspeckles were localized apart from the Cajal bodies, which were also known to be related to RNA metabolism. Analyses of 633 human spinal motor neurons in six ALS cases showed NEAT1_2 lncRNA was upregulated during the early stage of ALS pathogenesis. In addition, localization of NEAT1_2 lncRNA was identified in detail by electron microscopic analysis combined with ISH for NEAT1_2 lncRNA. The observation indicating specific assembly of NEAT1_2 lncRNA around the interchromatin granule-associated zone in the nucleus of ALS spinal motor neurons verified characteristic paraspeckle formation.
  
  
  CONCLUSIONS
  NEAT1_2 lncRNA may act as a scaffold of RNAs and RNA binding proteins in the nuclei of ALS motor neurons, thereby modulating the functions of ALS-associated RNA-binding proteins during the early phase of ALS. These findings provide the first evidence of a direct association between paraspeckle formation and a neurodegenerative disease, and may shed light on the development of novel therapeutic targets for the treatment of ALS.
authors.affiliation: Department of Physiology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan. ynishimo@2003.jukuin.keio.ac.jp
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Nishimoto
authors.forename: Shinichi
authors.initials: S
authors.lastname: Nakagawa
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Hirose
authors.forename: Hirotaka James
authors.initials: HJ
authors.lastname: Okano
authors.forename: Masaki
authors.initials: M
authors.lastname: Takao
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Shibata
authors.forename: Satoshi
authors.initials: S
authors.lastname: Suyama
authors.forename: Ken-Ichiro
authors.initials: K
authors.lastname: Kuwako
authors.forename: Takao
authors.initials: T
authors.lastname: Imai
authors.forename: Shigeo
authors.initials: S
authors.lastname: Murayama
authors.forename: Norihiro
authors.initials: N
authors.lastname: Suzuki
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Okano
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000690:Amyotrophic Lateral Sclerosis / Q000378:metabolism* / Q000473:pathology*; D000818:Animals; D016022:Case-Control Studies; D022003:Cell Nucleus Structures / Q000378:metabolism* / Q000648:ultrastructure; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000378:metabolism; D005260:Female; D006367:HeLa Cells; D006801:Humans; D008297:Male; D051379:Mice; D008954:Models, Biological; D009046:Motor Neurons / Q000378:metabolism* / Q000473:pathology / Q000648:ultrastructure; D011485:Protein Binding; D062085:RNA, Long Noncoding / Q000378:metabolism*; D034702:RNA-Binding Protein FUS / Q000378:metabolism; D013116:Spinal Cord / Q000378:metabolism / Q000473:pathology
chemical_list: D004268:DNA-Binding Proteins; C577276:NEAT1 long non-coding RNA, human; C577275:NEAT1 long non-coding RNA, mouse; D062085:RNA, Long Noncoding; D034702:RNA-Binding Protein FUS