lunedì 2 giugno 2008

TDP-43 : interessante nuova scoperta
Di seguito 3 studi da Pub-Med
1° studio
Ann Neurol. 2008 Apr;63(4):538-42.
Links
TDP-43 mutation in familial amyotrophic lateral sclerosis.
Yokoseki A, Shiga A, Tan CF, Tagawa A, Kaneko H, Koyama A, Eguchi H, Tsujino A, Ikeuchi T, Kakita A, Okamoto K, Nishizawa M, Takahashi H, Onodera O.
Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan.
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder. Accumulating evidence has shown that 43kDa TAR-DNA-binding protein (TDP-43) is the disease protein in ALS and frontotemporal lobar degeneration. We previously reported a familial ALS with Bumina bodies and TDP-43-positive skein-like inclusions in the lower motor neurons; these findings are indistinguishable from those of sporadic ALS. In three affected individuals in two generations of one family, we found a single base-pair change from A to G at position 1028 in TDP-43, which resulted in a Gln-to-Arg substitution at position 343. Our findings provide a new insight into the molecular pathogenesis of ALS.
PMID: 18438952 [PubMed - in process]
2° studio
A90V TDP-43 variant results in the aberrant localization of TDP-43 in vitro.
Winton MJ, Van Deerlin VM, Kwong LK, Yuan W, Wood EM, Yu CE, Schellenberg GD, Rademakers R, Caselli R, Karydas A, Trojanowski JQ, Miller BL, Lee VM.
Center for Neurodegenerative Disease Research, Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.
TAR DNA-binding protein-43 (TDP-43) is a highly conserved, ubiquitously expressed nuclear protein that was recently identified as the disease protein in frontotemporal lobar degeneration with ubiquitin-positive inclusions (FTLD-U) and amyotrophic lateral sclerosis (ALS). Pathogenic TDP-43 gene (TARDBP) mutations have been identified in familial ALS kindreds, and here we report a TARDBP variant (A90V) in a FTLD/ALS patient with a family history of dementia. Significantly, A90V is located between the bipartite nuclear localization signal sequence of TDP-43 and the in vitro expression of TDP-43-A90V led to its sequestration with endogenous TDP-43 as insoluble cytoplasmic aggregates. Thus, A90V may be a genetic risk factor for FTLD/ALS because it predisposes nuclear TDP-43 to redistribute to the cytoplasm and form pathological aggregates.
PMID: 18505686 [PubMed - as supplied by publisher]
3° studio
Lancet Neurol. 2008 May;7(5):409-16. Epub 2008 Apr 7.
Links
TARDBP mutations in amyotrophic lateral sclerosis with TDP-43 neuropathology: a genetic and histopathological analysis.
Van Deerlin VM, Leverenz JB, Bekris LM, Bird TD, Yuan W, Elman LB, Clay D, Wood EM, Chen-Plotkin AS, Martinez-Lage M, Steinbart E, McCluskey L, Grossman M, Neumann M, Wu IL, Yang WS, Kalb R, Galasko DR, Montine TJ, Trojanowski JQ, Lee VM, Schellenberg GD, Yu CE.
Center for Neurodegenerative Disease Research, Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, USA; Institute on Aging, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
BACKGROUND: TDP-43 is a major component of the ubiquitinated inclusions that characterise amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) with ubiquitin inclusions (FTLD-U). TDP-43 is an RNA-binding and DNA-binding protein that has many functions and is encoded by the TAR DNA-binding protein gene (TARDBP) on chromosome 1. Our aim was to investigate whether TARDBP is a candidate disease gene for familial ALS that is not associated with mutations in superoxide dismutase 1 (SOD1). METHODS: TARDBP was sequenced in 259 patients with ALS, FTLD, or both. We used TaqMan-based SNP genotyping to screen for the identified variants in control groups matched to two kindreds of patients for age and ethnic origin. Additional clinical, genetic, and pathological assessments were made in these two families. FINDINGS: We identified two variants in TARDBP, which would encode Gly290Ala and Gly298Ser forms of TDP-43, in two kindreds with familial ALS. The variants seem to be pathogenic because they co-segregated with disease in both families, were absent in controls, and were associated with TDP-43 neuropathology in both members of one of these families for whom CNS tissue was available. INTERPRETATION: The Gly290Ala and Gly298Ser mutations are located in the glycine-rich domain of TDP-43, which regulates gene expression and mediates protein-protein interactions such as those with heterogeneous ribonucleoproteins. Owing to the varied and important cellular functions of TDP-43, these mutations might cause neurodegeneration through both gains and losses of function. The finding of pathogenic mutations in TARDBP implicates TDP-43 as an active mediator of neurodegeneration in TDP-43 proteinopathies, a class of disorder that includes ALS and FTLD-U. FUNDING: National Institutes of Health (AG10124, AG17586, AG005136-22, PO1 AG14382), Department of Veterans Affairs, Friedrich-Baur Stiftung (0017/2007), US Public Health Service, ALS Association, and Fundació 'la Caixa'.
PMID: 18396105 [PubMed - in process]

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