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

Tau-negative and ubiquitin-positive inclusions (UPI) are the pathological hallmarks of frontotemporal lobar degeneration (FTLD-U) and amyotrophic lateral sclerosis (ALS). Recently, TDP-43, a heterogeneous nuclear ribonucleoprotein was identified as a component of these UPI. However, it remains to be determined whether TDP-43 is the major component of UPI, because only antibodies recognizing both normal and abnormal TDP-43 have been available. We raised antibodies to phosphopeptides representing 36 out of 64 candidate phosphorylation sites of human TDP-43. Of the generated antibodies, pS379, pS403/404, pS409, pS410 and pS409/410 clearly labeled UPI and glial cytoplasmic inclusions but not the nuclei. Immunoblot analyses of sarkosyl insoluble fractions demonstrated that the phosphorylation-specific antibodies recognized TDP-43 at -45 kDa, smearing substances and the -25 kDa fragment, all of which were present in the brains of FTLD-U and ALS but not controls. These antibodies did not recognize normal TDP-43 at 43 kDa. These results clearly indicate that abnormally phosphorylated full-length TDP-43 and the C-terminal fragments are the major component of UPI in FTLD-U and ALS. These findings together with recent discovery of mutations in the TDP-43 gene in ALS strongly suggest that TDP-43 is the
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PMID:[Significance of the TDP-43 deposition in FTLD-U and ALS]. 1919 42

Ever since the significance of pathological 43-kDa transactivating responsive sequence DNA-binding protein (TDP-43) for human disease has been recognized in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration with ubiquitin positive inclusions (FTLD-U), a number of publications have emerged reporting on this pathology in a variety of neurodegenerative diseases. Given the heterogeneous and, in part, conflicting nature of the recent findings, we here review pathological TDP-43 and its relationship to human disease with a special focus on ALS and FTLD-U. To this end, we propose a classification scheme in which pathological TDP-43 is the major disease defining pathology in one group, or is present in addition to other neurodegenerative hallmark pathologies in a second category. We conclude that the TDP-43 proteinopathies represent a novel class of neurodegenerative disorders akin to alpha-synucleinopathies and tauopathies, with the concept of ALS and FTLD-U to be widened to a broad clinico-pathological multisystem disease, i.e., TDP-43 proteinopathy.
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PMID:Amyotrophic lateral sclerosis, frontotemporal dementia and beyond: the TDP-43 diseases. 1927 Nov 5

Patients presenting with left-sided FTLD syndromes sometimes develop a new preoccupation with art, greater attention to visual stimuli, and increased visual creativity. We describe the case of a 53-year-old, right-handed man with a history of bipolar disorder who presented with language and behavior impairments characteristic of FTLD, then developed motor symptoms consistent with a second diagnosis of amyotrophic lateral sclerosis. Though the patient had never created visual art before, he developed a compulsion for painting beginning at the earliest stages of his disease, and continued producing art daily until he could no longer lift a paintbrush because of his motor deficits. Upon autopsy, he was found to have ubiquitin and TDP43-positive inclusions with MND pathology. This case study details the patient's longitudinal neuropsychological, emotional, behavioral, and motor symptoms, along with structural imaging, neurologic, and neuropathologic findings. Multiple examples of the patient's art are depicted throughout all stages of his illness, and the possible cognitive, behavioral, and neurologic correlates of his new-onset visual artistry are discussed.
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PMID:A case study of an emerging visual artist with frontotemporal lobar degeneration and amyotrophic lateral sclerosis. 1927 73

The identification of TDP-43 as the major component of the pathologic inclusions in most forms of sporadic and familial frontotemporal lobar degeneration with ubiquitin-positive inclusions (FTLD-U) and amyotrophic lateral sclerosis (ALS) resolved a long-standing enigma concerning the nature of the ubiquitinated disease protein under these conditions. Anti-TDP-43 immunohistochemistry and the recent development of novel tools, such as phosphorylation-specific TDP-43 antibodies, have increased our knowledge about the spectrum of pathological changes associated with FTLD-U and ALS and moreover, facilitated the neuropathological routine diagnosis of these conditions. This review summarizes the recent advances in our understanding on the molecular neuropathology and pathobiology of TDP-43 in FTLD and ALS.
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PMID:Molecular neuropathology of TDP-43 proteinopathies. 1933 44

Inclusions of TAR DNA-binding protein-43 (TDP-43), a nuclear protein that regulates transcription and RNA splicing, are the defining histopathological feature of frontotemporal lobar degeneration with ubiquitin-positive inclusions (FTLD-Us) and sporadic and familial forms of amyotrophic lateral sclerosis (ALS). In ALS and FTLD-U, aggregated, ubiquitinated, and N-terminally truncated TDP-43 can be isolated from brain tissue rich in neuronal and glial cytoplasmic inclusions. The loss of TDP-43 function resulting from inappropriate cleavage, translocation from the nucleus, or its sequestration into inclusions could play important roles in neurodegeneration. However, it is not known whether TDP-43 fragments directly mediate toxicity and, more specifically, whether their abnormal aggregation is a cause or consequence of pathogenesis. We report that the ectopic expression of a approximately 25-kDa TDP-43 fragment corresponding to the C-terminal truncation product of caspase-cleaved TDP-43 leads to the formation of toxic, insoluble, and ubiquitin- and phospho-positive cytoplasmic inclusions within cells. The 25-kDa C-terminal fragment is more prone to phosphorylation at S409/S410 than full-length TDP-43, but phosphorylation at these sites is not required for inclusion formation or toxicity. Although this fragment shows no biological activity, its exogenous expression neither inhibits the function nor causes the sequestration of full-length nuclear TDP-43, suggesting that the 25-kDa fragment can induce cell death through a toxic gain-of-function. Finally, by generating a conformation-dependent antibody that detects C-terminal fragments, we show that this toxic cleavage product is specific for pathologic inclusions in human TDP-43 proteinopathies.
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PMID:Aberrant cleavage of TDP-43 enhances aggregation and cellular toxicity. 1938 87

Initially, trans activation responsive region (TAR)-DNA-binding protein 43 (TDP-43) was considered to be a disease-specific component of ubiquitin-positive and tau-negative inclusions in the brains of patients with frontotemporal lobar degeneration with ubiquitin-positive inclusions (FTLD-U) and amyotrophic lateral sclerosis (ALS); however, it is now widely known that this protein also abnormally accumulates in neurons in other neurodegenerative diseases. On the basis of observation mainly in the medial temporal lobe, TDP-43-immunoreactive neuronal inclusions have been detected in 20-30% of Alzheimer disease (AD) brains. However, it is controversial whether these cases represent a combined disease, that is, mixed AD/FTLD-U. To address this issue, it is necessary to obtain more knowledge on the region-specific distribution of TDP-43 immunoreactivity and also about its relationship to AD common pathology. Here, we describe abnormal TDP-43 immunoreactivity in the medial temporal lobe in 5/16 AD patients (31%). Most of the depositions were cytoplasmic inclusions, mainly located in the subiculum and parahippocampal gyrus and rarely in dentate granular cells of the hippocampus. TDP-43-positive inclusions and senile plaque/neurofibrillary tangle distribution were not always identical, and intracellular colocalizations of TDP-43 and phospho-tau were also infrequent. The cases showing TDP-43-positive inclusions in the medial temporal lobe also showed abnormally highly dense TDP-43 immunoreactivity in the frontal, but not in the parietal and occipital cortices. Intracellularly, TDP-43-positive inclusions were highly ubiquitinated and colocalized with p62 immunoreactivity as well. Our findings suggest that abnormal TDP-43 deposition and AD pathology (formation of senile plaques and neurofibrillary tangles) might occur independently. However, taken together with the results of previous reports, the distribution of TDP-43 immunoreactivity in the hippocampus and frontal cortex in AD appear to be varying. We consider that it is still too early to determine that the TDP-43 accumulation is a part of AD pathology or result from a completely independent pathology.
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PMID:Regional distribution of TDP-43 inclusions in Alzheimer disease (AD) brains: their relation to AD common pathology. 1942 39

Non-amyloid, ubiquitinated cytoplasmic inclusions containing TDP-43 and its C-terminal fragments are pathological hallmarks of amyotrophic lateral sclerosis (ALS), a fatal motor neuron disorder, and frontotemporal lobar degeneration with ubiquitin-positive inclusions (FTLD-U). Importantly, TDP-43 mutations are linked to sporadic and non-SOD1 familial ALS. However, TDP-43 is not the only protein in disease-associated inclusions, and whether TDP-43 misfolds or is merely sequestered by other aggregated components is unclear. Here, we report that, in the absence of other components, TDP-43 spontaneously forms aggregates bearing remarkable ultrastructural similarities to TDP-43 deposits in degenerating neurons of ALS and FTLD-U patients [corrected] . The C-terminal domain of TDP-43 is critical for spontaneous aggregation. Several ALS-linked TDP-43 mutations within this domain (Q331K, M337V, Q343R, N345K, R361S, and N390D) increase the number of TDP-43 aggregates and promote toxicity in vivo. Importantly, mutations that promote toxicity in vivo accelerate aggregation of pure TDP-43 in vitro. Thus, TDP-43 is intrinsically aggregation-prone, and its propensity for toxic misfolding trajectories is accentuated by specific ALS-linked mutations.
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PMID:TDP-43 is intrinsically aggregation-prone, and amyotrophic lateral sclerosis-linked mutations accelerate aggregation and increase toxicity. 1946 77

The transactive response (TAR) DNA binding protein 43 (TDP-43) has been recently implicated as a major component of ubiquitinated inclusions in amyotrophic lateral sclerosis (ALS, motor neuron disease: MND) and ALS-related disorders. In this study, we examined abnormal TDP-43 pathology in 13 sporadic ALS (SALS), six familial ALS (FALS) with and without Cu/Zn superoxide dismutase (SOD1) mutations (SOD1-FALS and non-SOD1-FALS), Guam ALS, two frontotemporal lobar degeneration with MND/ALS (FTLD-MND/ALS), one FTLD with ubiquitin-only-immunoreactive inclusions (FTLD-U) and two progressive supranuclear palsy (PSP). Sections from the spinal cord were processed for immunohistochemistry using antibodies against TDP-43, ubiquitin, p62, cystatin C, phosphorylated tau protein (P-tau; AT8), alpha-synuclein and phosphorylated neurofilament protein (P-NF). In 12 out of 13 SALS and both Guam ALS cases ubiquitin and p62-immunoreactive (IR) neuronal inclusions co-localized with TDP-43. In three out of four SOD1-FALS and one of two non-SOD1-FALS cases, TDP-43-IR inclusions were absent despite the presence of p62 and/or ubiquitin-IR inclusions. However, a single TDP-43-IR neuronal inclusion co-localized with p62 and ubiquitin in one SOD1-FALS (His48Gln) case. Except for one neuron in a Guam case, all TDP-43-IR neuronal inclusions were negative for P-tau (AT8). TDP-43-IR glial inclusions and neurites were also demonstrated. The TDP-43 is a consistent component of the ubiquitinated inclusions in SALS and Guam ALS, but TDP-43-IR inclusions are absent or scarce in SOD1-FALS.
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PMID:TDP-43 is consistently co-localized with ubiquitinated inclusions in sporadic and Guam amyotrophic lateral sclerosis but not in familial amyotrophic lateral sclerosis with and without SOD1 mutations. 1949 40

TAR DNA binding protein of 43 kDa (TDP-43) is a major component of the ubiquitin-positive inclusions found in the brain of patients with frontotemporal lobar degeneration (FTLD-U) and amyotrophic lateral sclerosis (ALS). Here, we report that expression of TDP-43 C-terminal fragments as green fluorescent protein (GFP) fusions in SH-SY5Y cells results in the formation of abnormally phosphorylated and ubiquitinated inclusions that are similar to those found in FTLD-U and ALS. Co-expression of DsRed-tagged full-length TDP-43 with GFP-tagged C-terminal fragments of TDP-43 causes formation of cytoplasmic inclusions positive for both GFP and DsRed. Cells with GFP and DsRed positive inclusions lack normal nuclear staining for endogenous TDP-43. These results suggest that GFP-tagged C-terminal fragments of TDP-43 are bound not only to transfected DsRed-full-length TDP-43 but also to endogenous TDP-43. Endogenous TDP-43 may be recruited to cytoplasmic aggregates of TDP-43 C-terminal fragments, which results in the failure of its nuclear localization and function. Interestingly, expression of GFP-tagged TDP-43 C-terminal fragments harboring pathogenic mutations that cause ALS significantly enhances the formation of inclusions. We also identified cleavage sites of TDP-43 C-terminal fragments deposited in the FTLD-U brains using mass spectrometric analyses. We propose that generation and aggregation of phosphorylated C-terminal fragments of TDP-43 play a primary role in the formation of inclusions and resultant loss of normal TDP-43 localization, leading to neuronal degeneration in TDP-43 proteinopathy.
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PMID:Truncation and pathogenic mutations facilitate the formation of intracellular aggregates of TDP-43. 1951 51

Neuronal and glial deposition of misfolded, proteolytically processed, polyubiquitinated and abnormally phosphorylated C-terminal fragments (CTFs) of the TAR DNA binding protein-43 (TDP-43) is a pathological hallmark of frontotemporal lobar degeneration with ubiquitin positive inclusions (FTLD-U) and certain cases of amyotrophic lateral sclerosis. We demonstrate that TDP-43 can be proteolytically processed by caspases upon induction of apoptosis to a major 35 kDa and a minor 25 kDa CTF. These fragments are initially soluble, but over time they accumulate as insoluble and pathologically phosphorylated derivatives. However, proteolytic processing appears not to be absolutely required for the deposition of insoluble TDP-43 species, since a caspase resistant mutant of TDP-43 is also converted into insoluble species. Phosphorylation at S409/410 apparently occurs late during the conversion of soluble to insoluble TDP-43, suggesting that phosphorylation is not a prerequisite for aggregation. Loss of function of the progranulin (PGRN) gene causes FTLD-U with TDP-43 positive inclusions and has been suggested to lead to caspase activation and subsequent TDP-43 processing. However, siRNA-mediated knockdown of PGRN in cell culture as well as a PGRN gene knockout in mice failed to cause the formation of the disease characterizing CTFs of TDP-43. Our findings therefore suggest that caspase-mediated processing generates CTFs of similar biochemical properties as those occurring in nuclear and cytoplasmic deposits of FTLD-U patients independent of PGRN levels.
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PMID:Proteolytic processing of TAR DNA binding protein-43 by caspases produces C-terminal fragments with disease defining properties independent of progranulin. 1952 33


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