Acta Neuropathologica

, Volume 120, Issue 1, pp 75–84 | Cite as

TDP-43 pathology in sporadic ALS occurs in motor neurons lacking the RNA editing enzyme ADAR2

  • Hitoshi Aizawa
  • Jun Sawada
  • Takuto Hideyama
  • Takenari Yamashita
  • Takayuki Katayama
  • Naoyuki Hasebe
  • Takashi Kimura
  • Osamu Yahara
  • Shin Kwak
Original Paper


Both the appearance of cytoplasmic inclusions containing phosphorylated TAR DNA-binding protein (TDP-43) and inefficient RNA editing at the GluR2 Q/R site are molecular abnormalities observed specifically in motor neurons of patients with sporadic amyotrophic lateral sclerosis (ALS). The purpose of this study is to determine whether a link exists between these two specific molecular changes in ALS spinal motor neurons. We immunohistochemically examined the expression of adenosine deaminase acting on RNA 2 (ADAR2), the enzyme that specifically catalyzes GluR2 Q/R site-editing, and the expression of phosphorylated and non-phosphorylated TDP-43 in the spinal motor neurons of patients with sporadic ALS. We found that all motor neurons were ADAR2-positive in the control cases, whereas more than half of them were ADAR2-negative in the ALS cases. All ADAR2-negative neurons had cytoplasmic inclusions that were immunoreactive to phosphorylated TDP-43, but lacked non-phosphorylated TDP-43 in the nucleus. Our results suggest a molecular link between reduced ADAR2 activity and TDP-43 pathology.


Amyotrophic lateral sclerosis Adenosine deaminase acting on RNA 2 TDP-43 RNA editing Motor neuron 

Supplementary material

401_2010_678_MOESM1_ESM.ppt (2.2 mb)
Supplementary Figure 1ADAR2 immunostaining in degenerating neurons in other neurological diseases. Neurons in the pontine nuclei of an ALS patient exhibit slight ADAR2 immunoreactivity in the cytoplasm (a). The neurons in the pontine nuclei in both multiple system atrophy (b) and spinocerebellar atrophy type 1 (c) showed faint ADAR2 immunoreactivity, although these neurons were atrophic and reduced in number. These results suggested that the alteration of ADAR2 activity was not involved in the process of neuronal death in the pontine nucleus of MSA or SCA1. Bar indicates 20 μm (PPT 2238 kb)
401_2010_678_MOESM2_ESM.ppt (1.8 mb)
Supplementary Figure 2Immunohistochemistry with two anti-ADAR2 antibodies. Both RED1 (a) and C-15 (b) stained specifically the cytoplasm but not the nucleus of motor neurons. Non-specific lipofuscin staining is observed in (b) (PPT 1858 kb)
401_2010_678_MOESM3_ESM.doc (24 kb)
Supplementary material 3 (DOC 24 kb)


  1. 1.
    Akbarian S, Smith MA, Jones EG (1995) Editing for an AMPA receptor subunit RNA in prefrontal cortex and striatum in Alzheimer’s disease, Huntington’s disease and schizophrenia. Brain Res 699:297–304CrossRefPubMedGoogle Scholar
  2. 2.
    Amador-Ortiz C, Lin WL, Ahmed Z et al (2007) TDP-43 immunoreactivity in hippocampal sclerosis and Alzheimer’s disease. Ann Neurol 61:435–445CrossRefPubMedGoogle Scholar
  3. 3.
    Arai T, Hasegawa M, Akiyama H et al (2006) TDP-43 is a component of ubiquitin-positive tau-negative inclusions in frontotemporal lobar degeneration and amyotrophic lateral sclerosis. Biochem Biophys Res Commun 351:602–611CrossRefPubMedGoogle Scholar
  4. 4.
    Buratti E, Baralle FE (2008) Multiple roles of TDP-43 in gene expression, splicing regulation, and human disease. Front Biosci 13:867–878CrossRefPubMedGoogle Scholar
  5. 5.
    Burnashev N, Monyer H, Seeburg PH, Sakmann B (1992) Divalent ion permeability of AMPA receptor channels is dominated by the edited form of a single subunit. Neuron 8:189–198CrossRefPubMedGoogle Scholar
  6. 6.
    Carriedo SG, Yin HZ, Weiss JH (1996) Motor neurons are selectively vulnerable to AMPA/kainate receptor-mediated injury in vitro. J Neurosci 16:4069–4079PubMedGoogle Scholar
  7. 7.
    Chen YZ, Bennett CL, Huynh HM et al (2004) DNA/RNA helicase gene mutations in a form of juvenile amyotrophic lateral sclerosis (ALS4). Am J Hum Genet 74:1128–1135CrossRefPubMedGoogle Scholar
  8. 8.
    Geser F, Winton MJ, Kwong LK et al (2008) Pathological TDP-43 in parkinsonism-dementia complex and amyotrophic lateral sclerosis of Guam. Acta Neuropathol 115:133–145CrossRefPubMedGoogle Scholar
  9. 9.
    Gitcho MA, Baloh RH, Chakraverty S et al (2008) TDP-43 A315T mutation in familial motor neuron disease. Ann Neurol 63:535–538CrossRefPubMedGoogle Scholar
  10. 10.
    Hadano S, Hand CK, Osuga H et al (2001) A gene encoding a putative GTPase regulator is mutated in familial amyotrophic lateral sclerosis 2. Nat Genet 29:166–173CrossRefPubMedGoogle Scholar
  11. 11.
    Hasegeawa M, Arai T, Akiyama H et al (2007) TDP-43 is deposited in the Guam Parkinsonism-dementia complex brains. Brain 130:1386–1394CrossRefGoogle Scholar
  12. 12.
    Hasegawa M, Arai T, Nonaka T et al (2008) Phosphorylated TDP-43 in frontotemporal lobar degeneration and amyotrophic lateral sclerosis. Ann Neurol 64:60–70CrossRefPubMedGoogle Scholar
  13. 13.
    Higashi S, Iseki E, Yamamoto R et al (2007) Concurrence of TDP-43, tau and alpha-synuclein pathology in brains of Alzheimer’s disease and dementia with Lewy diseases. Brain Res 1184:284–394CrossRefPubMedGoogle Scholar
  14. 14.
    Higuchi M, Maas S, Single FN et al (2000) Point mutation in an AMPA receptor gene rescues lethality in mice deficient in the RNA-editing enzyme ADAR2. Nature 406:78–81CrossRefPubMedGoogle Scholar
  15. 15.
    Kabashi E, Valdmanis PN, Dion P et al (2008) TARDBP mutations in individuals with sporadic and familial amyotrophic lateral sclerosis. Nat Genet 40:572–574CrossRefPubMedGoogle Scholar
  16. 16.
    Kawahara Y, Ito K, Sun H et al (2004) Glutamate receptors: RNA editing and death of motor neurons. Nature 427:801CrossRefPubMedGoogle Scholar
  17. 17.
    Kawahara Y, Ito K, Ito M, Tsuji S, Kwak S (2005) Novel splice variants of human ADAR2 mRNA: skipping of the exon encoding the dsRNA-binding domains, and multiple C-terminal splice sites. Gene 363:193–201CrossRefPubMedGoogle Scholar
  18. 18.
    Kawahara Y, Kwak S (2005) Excitotoxicity and ALS: what is unique about the AMPA receptors expressed on spinal motor neurons? Amyotroph Lateral Scler Other Motor Neuron Disord 6:131–144CrossRefPubMedGoogle Scholar
  19. 19.
    Kawahara Y, Sun H, Ito K et al (2006) Underediting of GluR2 mRNA, a neuronal death inducing molecular change in sporadic ALS, does not occur in motor neurons in ALS1 or SBMA. Neurosci Res 54:11–14CrossRefPubMedGoogle Scholar
  20. 20.
    Kwak S, Kawahara Y (2005) Deficient RNA editing of GluR2 and neuronal death in amyotropic lateral sclerosis. J Mol Med 83:110–120CrossRefPubMedGoogle Scholar
  21. 21.
    Kwak S, Weiss JH (2006) Calcium-permeable AMPA channels in neurodegenerative disease and ischemia. Curr Opin Neurobiol 16:281–287CrossRefPubMedGoogle Scholar
  22. 22.
    Kwiatkowski TJ Jr, Bosco DA, Leclerc AL et al (2009) Mutations in the FUS/TLS gene on chromosome 16 cause familial amyotrophic lateral sclerosis. Science 323:1205–1208CrossRefPubMedGoogle Scholar
  23. 23.
    Mackenzie IR, Bigio EH, Ince PG et al (2007) Pathological TDP-43 distinguishes sporadic amyotrophic lateral sclerosis from amyotrophic lateral sclerosis with SOD1 mutations. Ann Neurol 61:427–434CrossRefPubMedGoogle Scholar
  24. 24.
    Nakashima-Yasuda H, Uryu K, Robinson J et al (2007) Co-morbidity of TDP-43 proteinopathy in Lewy body related diseases. Acta Neuropathol 114:221–229CrossRefPubMedGoogle Scholar
  25. 25.
    Neumann M, Sampathu DM, Kwong LK et al (2006) Ubiquitinated TDP-43 in frontotemporal lobar degeneration and amyotrophic lateral sclerosis. Science 314:130–133CrossRefPubMedGoogle Scholar
  26. 26.
    Neumann M, Kwong LK, Lee EB et al (2009) Phosphorylation of S409/410 of TDP-43 is a consistent feature in all sporadic and familial forms of TDP-43 proteinopathies. Acta Neuropathol 117:137–149CrossRefPubMedGoogle Scholar
  27. 27.
    Nishimura AL, Mitne-Neto M, Silva HC et al (2004) A mutation in the vesicle-trafficking protein VAPB causes late-onset spinal muscular atrophy and amyotrophic lateral sclerosis. Am J Hum Genet 75:822–831CrossRefPubMedGoogle Scholar
  28. 28.
    Ou SH, Wu F, Harrich D et al (1995) Cloning and characterization of a novel cellular protein, TDP-43, that binds to human immunodeficiency virus type 1 TAR DNA sequence motifs. J Virol 69:3584–3596PubMedGoogle Scholar
  29. 29.
    Paschen W, Hedreen JC, Ross CA (1994) RNA editing of the glutamate receptor subunits GluR2 and GluR6 in human brain tissue. J Neurochem 63:1596–1602PubMedCrossRefGoogle Scholar
  30. 30.
    Rosen DR, Siddique T, Patterson D et al (1993) Mutations in Cu/Zn superoxide dismutase gene are associated with familial amyotrophic lateral sclerosis. Nature 362:59–62CrossRefPubMedGoogle Scholar
  31. 31.
    Sommer B, Köhler M, Sprengel R, Seeburg PH (1991) RNA editing in brain controls a determinant of ion flow in glutamate-gated channels. Cell 67:11–19CrossRefPubMedGoogle Scholar
  32. 32.
    Sreedharan J, Blair IP, Tripathi VB et al (2008) TDP-43 mutations in familial and sporadic amyotrophic lateral sclerosis. Science 319:1668–1672CrossRefPubMedGoogle Scholar
  33. 33.
    Suzuki T, Tsuzuki K, Kameyama K, Kwak S (2003) Recent advances in the study of AMPA receptors. Nippon Yakurigaku Zasshi 122:515–526PubMedGoogle Scholar
  34. 34.
    Takuma H, Kwak S, Yoshizawa T, Kanazawa I (1999) Reduction of GluR2 RNA editing, a molecular change that increases calcium influx through AMPA receptors, selective in the spinal ventral gray of patients with amyotrophic lateral sclerosis. Ann Neurol 46:806–815CrossRefPubMedGoogle Scholar
  35. 35.
    Tan CF, Eguchi H, Tagawa A et al (2007) TDP-43 immunoreactivity in neuronal inclusions in familial amyotrophic lateral sclerosis with or without SOD1 gene mutation. Acta Neuropathol 113:535–542CrossRefPubMedGoogle Scholar
  36. 36.
    Uryu K, Nakashima-Yasuda H, Forman MS et al (2008) Concomitant TAR-DNA-binding protein 43 pathology is present in Alzheimer disease and corticobasal degeneration but not in other tauopathies. J Neuropathol Exp Neurol 67:555–564CrossRefPubMedGoogle Scholar
  37. 37.
    Van Deerlin VM, Leverenz JB, Bekris LM et al (2008) TARDBP mutations in amyotrophic lateral sclerosis with TDP-43 neuropathology: a genetic and histopathological analysis. Lancet Neurol 7:409–416CrossRefPubMedGoogle Scholar
  38. 38.
    Vance C, Rogelj B, Hortobágyi T et al (2009) Mutations in FUS, an RNA processing protein, cause familial amyotrophic lateral sclerosis type 6. Science 323:1208–1211CrossRefPubMedGoogle Scholar
  39. 39.
    Yang Y, Hentati A, Deng HX et al (2001) The gene encoding alsin, a protein with three guanine-nucleotide exchange factor domains, is mutated in a form of recessive amyotrophic lateral sclerosis. Nat Genet 29:160–165CrossRefPubMedGoogle Scholar
  40. 40.
    Yokoseki A, Shiga A, Tan CF et al (2008) TDP-43 mutation in familial amyotrophic lateral sclerosis. Ann Neurol 63:538–542CrossRefPubMedGoogle Scholar

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • Hitoshi Aizawa
    • 1
  • Jun Sawada
    • 1
  • Takuto Hideyama
    • 2
  • Takenari Yamashita
    • 2
  • Takayuki Katayama
    • 1
  • Naoyuki Hasebe
    • 1
  • Takashi Kimura
    • 3
  • Osamu Yahara
    • 3
  • Shin Kwak
    • 2
  1. 1.Division of Neurology, Department of Internal MedicineAsahikawa Medical CollegeAsahikawaJapan
  2. 2.CREST, Japan Science and Technology Agency, Department of Neurology, Graduate School of MedicineThe University of TokyoTokyoJapan
  3. 3.Department of NeurologyDouhoku National HospitalAsahikawaJapan

Personalised recommendations