Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0002736 (amyotrophic lateral sclerosis)
 19,048 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

TAR DNA-binding protein of about 43 kDa (TDP-43) is the main ubiquitinated peptide in tau-negative frontotemporal lobar degeneration (FTLD). TDP-43 is typically a nuclear protein, and its aggregation and cytoplasmic translocation are thought to represent major steps in the pathogenesis of FTLD due to TDP-43 proteinopathy (FTLD-TDP). Certain clinical syndromes of frontotemporal dementia are preferentially associated with pathologic findings of FTLD-TDP, and TDP-43 pathology represents the connection between FTLD-TDP and amyotrophic lateral sclerosis. Recent advances in clinical, genetic, and pathologic studies of FTLD-TDP and amyotrophic lateral sclerosis have shed light on the potentially pathogenic role of TDP-43 and identified TDP-43 itself as a candidate biomarker for antemortem diagnosis of FTLD-TDP.
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PMID:TDP-43 and frontotemporal dementia. 1966 64

Frontotemporal dementia (FTD) is a clinical syndrome with a heterogeneous molecular basis. The neuropathology associated with most FTD is characterized by abnormal cellular aggregates of either transactive response DNA-binding protein with Mr 43 kDa (TDP-43) or tau protein. However, we recently described a subgroup of FTD patients, representing around 10%, with an unusual clinical phenotype and pathology characterized by frontotemporal lobar degeneration with neuronal inclusions composed of an unidentified ubiquitinated protein (atypical FTLD-U; aFTLD-U). All cases were sporadic and had early-onset FTD with severe progressive behavioural and personality changes in the absence of aphasia or significant motor features. Mutations in the fused in sarcoma (FUS) gene have recently been identified as a cause of familial amyotrophic lateral sclerosis, with these cases reported to have abnormal cellular accumulations of FUS protein. Because of the recognized clinical, genetic and pathological overlap between FTD and amyotrophic lateral sclerosis, we investigated whether FUS might also be the pathological protein in aFTLD-U. In all our aFTLD-U cases (n = 15), FUS immunohistochemistry labelled all the neuronal inclusions and also demonstrated previously unrecognized glial pathology. Immunoblot analysis of protein extracted from post-mortem aFTLD-U brain tissue demonstrated increased levels of insoluble FUS. No mutations in the FUS gene were identified in any of our patients. These findings suggest that FUS is the pathological protein in a significant subgroup of sporadic FTD and reinforce the concept that FTD and amyotrophic lateral sclerosis are closely related conditions.
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PMID:A new subtype of frontotemporal lobar degeneration with FUS pathology. 2069 41

Both, amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration with ubiquitin-positive inclusions (FTLD-U), and their combination (FTLD-U/MND) are principally sporadic diseases that are rarely familial. Cytoplasmic ubiquitinated proteinaceous inclusions in motor and extra-motor neurons are the pathological hallmark of all three forms. In 2006, the TAR DNA-binding protein of 43 kDa (TDP-43) was both identified as the key protein component of the ubiquitinated inclusions and recognised as the key protein of a spectrum of diseases that have since been consolidated as TDP-43 proteinopathies. TDP-43 as a nuclear protein contributes to the regulation of gene expression, and associated with neurodegeneration, it has been found to be truncated, hyperphosphorylated, and mislocalized. It is unclear whether the loss of the TDP-43's nuclear function or the gain of a toxic function outside its nucleus is disease causing. Since 2008, several TARDBP-mutations have been identified as leading to the autosomal-dominant familial ALS (ALS 10), although no TARDBP-mutations have yet to be linked to FTLD.
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PMID:[TDP-43 proteinopathies: ALS and frontotemporal dementias]. 1968 86

The mechanisms underlying selective motor neuron degeneration in amyotrophic lateral sclerosis (ALS) remain unknown. There have been several important clinical trials on the treatment of ALS and treatment efficacy studies using mouse (SOD1) models of ALS. The latter revealed that diminished mutant SOD1 expression in the astrocytes delayed microglial activation and slowed disease progression. Dyslipidemia has been reported to have a protective effect in ALS patients. Current evidence has implicated a 43-kDa TAR DNA-binding protein (TDP-43) in the pathologenesis of ALS. Several mutations in TDP-43 were discovered in families with inherited motor neuron disease. Although phase III trials revealed that creatine monohydrate and IGF-1 was not beneficial for patients with ALS, favorable outcomes in SOD1 mice were reported with lithium, NADPH oxidase inhibitor, free-radical scavenger, and ammonium tetrathiomolybdate. Spinal and bulbar muscular atrophy (SBMA) is an adult-onset motor neuron disease affecting only males. Animal studies have revealed that the pathogenesis of SBMA depends on the serum testosterone level and that androgen deprivation mitigates neurodegeneration through inhibition of nuclear accumulation of the pathogenic androgen receptor (AR). Our studies have also identified several candidates for the treatment of SBMA. Selective inhibition of heat shock protein (HSP) facilitates the proteasomal degradation of pathogenic AR, leading to improvements in the signs and symptoms of SBMA mice. Oral administration of sodium butyrate--a histone deacetylase inhibitor--resulted in the improvement of neurological dysfunction in the SBMA mouse model, although its therapeutic dose range is narrow.
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PMID:[Molecular-targeted therapy for motor neuron disease]. 1969 78

Transactive response DNA-binding protein 43 (TDP-43) forms abnormal ubiquitinated and phosphorylated inclusions in brain tissues from patients with amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration. TDP-43 is a DNA/RNA-binding protein involved in RNA processing, such as transcription, pre-mRNA splicing, mRNA stabilization and transport to dendrites. We found that in response to oxidative stress and to environmental insults of different types TDP-43 is capable to assemble into stress granules (SGs), ribonucleoprotein complexes where protein synthesis is temporarily arrested. We demonstrated that a specific aminoacidic interval (216-315) in the C-terminal region and the RNA-recognition motif 1 domain are both implicated in TDP-43 participation in SGs as their deletion prevented the recruitment of TDP-43 into SGs. Our data show that TDP-43 is a specific component of SGs and not of processing bodies, although we proved that TDP-43 is not necessary for SG formation, and its gene silencing does not impair cell survival during stress. The analysis of spinal cord tissue from ALS patients showed that SG markers are not entrapped in TDP-43 pathological inclusions. Although SGs were not evident in ALS brains, we speculate that an altered control of mRNA translation in stressful conditions may trigger motor neuron degeneration at early stages of the disease.
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PMID:TDP-43 is recruited to stress granules in conditions of oxidative insult. 1976 85

TDP-43 is an RNA/DNA-binding protein implicated in transcriptional repression and mRNA processing. Inclusions of TDP-43 are hallmarks of frontotemporal dementia and amyotrophic lateral sclerosis. Besides aggregation of TDP-43, loss of nuclear localization is observed in disease. To identify relevant targets of TDP-43, we performed expression profiling. Thereby, histone deacetylase 6 (HDAC6) downregulation was discovered on TDP-43 silencing and confirmed at the mRNA and protein level in human embryonic kidney HEK293E and neuronal SH-SY5Y cells. This was accompanied by accumulation of the major HDAC6 substrate, acetyl-tubulin. HDAC6 levels were restored by re-expression of TDP-43, dependent on RNA binding and the C-terminal protein interaction domains. Moreover, TDP-43 bound specifically to HDAC6 mRNA arguing for a direct functional interaction. Importantly, in vivo validation in TDP-43 knockout Drosophila melanogaster confirmed the specific downregulation of HDAC6. HDAC6 is necessary for protein aggregate formation and degradation. Indeed, HDAC6-dependent reduction of cellular aggregate formation and increased cytotoxicity of polyQ-expanded ataxin-3 were found in TDP-43 silenced cells. In conclusion, loss of functional TDP-43 causes HDAC6 downregulation and might thereby contribute to pathogenesis.
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PMID:Knockdown of transactive response DNA-binding protein (TDP-43) downregulates histone deacetylase 6. 1991 Sep 24

Findings of clinical, neuropathological and biochemical studies have supported the idea that frontotemporal lobar degeneration with ubiquitin inclusions (FTLD-U) and amyotrophic lateral sclerosis (ALS) are part of a neurological disease spectrum. This concept is now further strengthened by the recent discovery of a 43-kDa transactivating responsive sequence DNA-binding protein (TDP-43) as a key component of the underlying neuropathology of FTLD-U, ALS with dementia (ALS-D) and ALS. Here we describe the clinicopathological features of selected autopsy cases belonging to this disease spectrum, and discuss the neuropathological similarities and differences between FTLD-U and ALS-D, with special reference to the morphology, distribution and density of ubiquitin/TDP-43-positive abnormal structures, along with a review of the literature.
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PMID:[Neuropathological similarities and differences between frontotemporal lobar degeneration with ubiquitin inclusions and amyotrophic lateral sclerosis with dementia]. 1993 89

Transactive response (TAR) DNA-binding protein 43 (TDP-43) is a major protein component within ubiquitin-positive inclusions of frontotemporal lobar degeneration and amyotrophic lateral sclerosis. Although TDP-43 is a nuclear DNA/RNA-binding protein, in pathological conditions, TDP-43 has been reported to redistribute to the cytoplasm where it is cleaved and forms insoluble, ubiquitinated, and phosphorylated inclusions. Here we present a cellular model in which full-length human TDP-43 or a splicing isoform (TDP-S6) that lacks the C terminus is overexpressed in a human cell line and mouse primary neurons. Whereas recombinant and endogenous TDP-43 was primarily localized in the nucleus, the shorter TDP-S6 formed highly insoluble cytoplasmic and nuclear inclusions reminiscent of disease-specific pathology. Western blot analysis of detergent-insoluble extracts showed an increase in high molecular weight immunoreactive species for TDP-S6 compared with TDP-43, consistent with ubiquitination or ubiquitin-like modifications. We used a multiplex stable isotope labeling with amino acids in cell culture approach to compare the detergent-insoluble proteome from mock-, TDP-43-, and TDP-S6-transfected cells. TDP-S6 overexpression caused a concomitant increase in both ubiquitin (Ub) and the small Ub-like modifier-2/3 (SUMO-2/3) within the insoluble proteome. Similarly, full-length TDP-43 overexpression also resulted in the elevation of SUMO-2/3. Immunofluorescence showed strong co-localization of endogenous Ub with both cytoplasmic and nuclear TDP-S6 inclusions, whereas SUMO-2/3 was co-localized mainly with the nuclear inclusions. Quantitative mass spectrometry further revealed that mixed Lys-48 and Lys-63 polyUb linkages were associated with the TDP insoluble fractions. Together our data indicate that expression of a TDP-43 splice variant lacking a C terminus recapitulates many of the cellular and biochemical features associated with disease pathology and that the interplay of ubiquitination and SUMOylation may have an important role in TDP-43 regulation.
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PMID:Multiplex SILAC analysis of a cellular TDP-43 proteinopathy model reveals protein inclusions associated with SUMOylation and diverse polyubiquitin chains. 2004 51

It is now established that pathological transactive response DNA-binding protein with a Mr of 43 kD (TDP-43) on sodium dodecyl sulfate-polyacrylamide gel electrophoresis is the major disease protein in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) with ubiquitin-positive inclusions (now known as FTLD-TDP). In fact, the discovery of pathological TDP-43 solidified the idea that these disorders are multi-system diseases and this led to the concept of a TDP-43 proteinopathy as a spectrum of disorders comprised of different clinical and pathological entities extending from ALS to ALS with cognitive impairment/dementia and FTLD-TDP without or with motor neuron disease (FTLD-MND). These align along a broad disease continuum sharing similar pathogenetic mechanisms linked to pathological TDP-43. We here review salient findings in the development of a concept of TDP-43 proteinopathy as a novel group of neurodegenerative diseases similar in concept to alpha-synucleinopathies and tauopathies.
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PMID:Amyotrophic lateral sclerosis and frontotemporal lobar degeneration: a spectrum of TDP-43 proteinopathies. 2010 19

Transactivation response (TAR) DNA-binding protein of Mr 43 kDa (TDP-43) is a major component of the tau-negative and ubiquitin-positive inclusions that characterize amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration which is now referred to as FTLD-TDP. Concurrent TDP-43 pathology has been reported in a variety of other neurodegenerative disorders such as Alzheimer's disease, forming a group of TDP-43 proteinopathy. Accumulated TDP-43 is characterized by phosphorylation and fragmentation. There is a close relationship between the pathological subtypes of FTLD-TDP and the immunoblot pattern of the C-terminal fragments of phosphorylated TDP-43. These results suggest that proteolytic processing of accumulated TDP-43 may play an important role for the pathological process. In cultured cells, transfected C-terminal fragments of TDP-43 are more prone to form aggregates than full-length TDP-43. Transfecting the C-terminal fragment of TDP-43 harboring pathogenic mutations of TDP-43 gene identified in familial and sporadic ALS cases into cells enhanced the aggregate formation. Furthermore, we found that methylene blue and dimebon inhibit aggregation of TDP-43 in these cellular models. Understanding the mechanism of phosphorylation and truncation of TDP-43 and aggregate formation may be crucial for clarifying the pathogenesis of TDP-43 proteinopathy and for developing useful therapeutics.
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PMID:Phosphorylated and cleaved TDP-43 in ALS, FTLD and other neurodegenerative disorders and in cellular models of TDP-43 proteinopathy. 2010 22


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