title: [Molecular dissection of TDP-43 in ALS and FTLD].
abstract: Proteomic and immunochemical analyses have shown that hyperphosphorylated TDP-43 is a major component of ubiquitin-positive inclusions from brain of frontotemporal lobar degeneration (FTLD) patients. In 2008, TDP-43 gene mutations were discovered in familial and sporadic amyotrophic lateral sclerosis (ALS), indicating that TDP-43 protein abnormality is associated with neurodegeneration. We raised antibodies against 36 synthetic phosphopeptides and demonstrated that abnormal phosphorylation takes place in the C-terminal region of TDP-43. One antibody, pS409/410, stained the inclusions in both FTLD and ALS brains, with no nuclear staining. Immunoblotting revealed the presence of hyperphosphorylated 45 kDa band, smearing substances and 18-26 kDa fragments in deposits, and the band patterns were different between FTLD and ALS. Overexpression of TDP-43 C-terminal fragments as GFP-fusions resulted in formation of inclusions positive for antibodies to phosphorylated TDP-43 and ubiquitin. We further investigated the protease-resistant TDP-43 and found that it is also different between ALS and FTLD, supporting the idea that the different band patterns reflect different conformations of abnormal TDP-43. Interestingly, the C-terminal band pattern is indistinguishable among brain regions and spinal cord in each individual patient. These results suggest that abnormal TDP-43 produced in a cell may be transferred to different regions and propagated during disease progression.
authors.affiliation: Department of Molecular Neurobiology, Tokyo Institute of Psychiatry.
authors.forename: Masato
authors.initials: M
authors.lastname: Hasegawa
authors.forename: Tetsuaki
authors.initials: T
authors.lastname: Arai
authors.forename: Takashi
authors.initials: T
authors.lastname: Nonaka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tsuji
authors.forename: Makiko
authors.initials: M
authors.lastname: Yamashita
authors.forename: Masato
authors.initials: M
authors.lastname: Hosokawa
authors.forename: Fuyuki
authors.initials: F
authors.lastname: Kametani
authors.forename: Akira
authors.initials: A
authors.lastname: Tamaoka
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Akiyama
mesh_terms: D000690:Amyotrophic Lateral Sclerosis / Q000235:genetics*; D000818:Animals; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000276:immunology; D004195:Disease Models, Animal; D057174:Frontotemporal Lobar Degeneration / Q000235:genetics*; D006801:Humans; D051379:Mice; D009154:Mutation; D010766:Phosphorylation; D057177:TDP-43 Proteinopathies; D054875:Ubiquitination
chemical_list: D004268:DNA-Binding Proteins