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)

There is an overlap between amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Some 5-10% of ALS patients show changes in their behaviour and personality that are characteristic of FTD and about 10% of FTD patients develop ALS. Mild cognitive impairment occurs in 30% of ALS patients. The progressive decline of muscle strength in ALS patients and social skills in FTD patients places severe demands on the patient and his or her contacts. In some ALS and FTD patients, ubiquitin-positive inclusions have been found in the hippocampus and anterior horn cells. In patients with familial FTD who have ubiquitin-positive inclusions, mutations have been found in the progranulin (PGRN) gene. TAR-DNA-binding protein-43, encoded by the TARDBP gene, has recently been identified as a constituent of the ubiquitin inclusions. TARDBP and PGRN mutations are found in patients with ALS. The overlapping characteristics provide clues for further research into the pathogenesis of ALS and FTD.
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PMID:[Amyotrophic lateral sclerosis and frontotemporal dementia: overlapping characteristics]. 2017 58

Cytoplasmic ubiquitin-positive inclusions containing TAR-DNA-binding protein-43 (TDP-43) within motor neurons are the hallmark pathology of sporadic amyotrophic lateral sclerosis (ALS). TDP-43 is a nuclear protein and the mechanisms by which it becomes mislocalized and aggregated in ALS are not properly understood. A mutation in the vesicle-associated membrane protein-associated protein-B (VAPB) involving a proline to serine substitution at position 56 (VAPBP56S) is the cause of familial ALS type-8. To gain insight into the molecular mechanisms by which VAPBP56S induces disease, we created transgenic mice that express either wild-type VAPB (VAPBwt) or VAPBP56S in the nervous system. Analyses of both sets of mice revealed no overt motor phenotype nor alterations in survival. However, VAPBP56S but not VAPBwt transgenic mice develop cytoplasmic TDP-43 accumulations within spinal cord motor neurons that were first detected at 18 months of age. Our results suggest a link between abnormal VAPBP56S function and TDP-43 mislocalization.
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PMID:Amyotrophic lateral sclerosis mutant vesicle-associated membrane protein-associated protein-B transgenic mice develop TAR-DNA-binding protein-43 pathology. 2018 46

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.
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PMID:TDP-43 pathology in sporadic ALS occurs in motor neurons lacking the RNA editing enzyme ADAR2. 2037 15

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder caused by loss of motor neurons both in the brain and spinal cord, which dramatically reduces life expectancy. ALS occurs either in familial ALS or, more frequently, in sporadic ALS forms. Several mechanisms have been postulated to underlie motor neuron death. In the present paper, starting from some of the genes related to familial ALS, we overview and discuss their potential role in modifying of the physiological clearance of altered proteins and organelles in motor neurons. Special emphasis is placed on the role of autophagy, which seems to prevail as a protein clearing system over other multienzymatic pathways such as the proteasome within motor neurons. The evidence which links an altered autophagy to the onset of motor neuron death proposes that this biochemical pathway might represent a final common mechanism underlying both inherited and sporadic forms of ALS. In light of these findings we also analyze the potential significance of a novel association between ALS, altered autophagy, and mutations of nuclear proteins such as TAR-DNA-Binding Protein 43 and fused in sarcoma/translated in liposarcoma. Such an association appears to be critical since it is now well demonstrated that all sporadic and most familiar forms of ALS are characterized by altered deposition and mislocalization of TAR-DNA-Binding Protein 43. These novel insights into the pathogenesis of ALS may lead to the identification of novel strategies to promote motor neuron survival.
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PMID:The role of autophagy: what can be learned from the genetic forms of amyotrophic lateral sclerosis. 2040 84

Frontotemporal lobar degeneration (FTLD) is a clinical syndrome characterized by behavioral and language difficulties, which refers to a clinically, genetically, and neuropathologically heterogeneous group of neurodegenerative disorders. Familial FTLD has been linked to mutations in several genes: the microtubule-associated protein tau (MAPT), progranulin (GRN), valosin-containing protein (VCP) and charged multivescicular body protein 2B (CHMP2B), and genetic locus on chromosome 9p linked to familial amyotrophic lateral sclerosis (ALS) and frontotemporal dementia. The associated neuropathology is characterized by selective degeneration of the frontal and temporal lobes with the neuronal and/or glial inclusions. The current classification of FTLD neuropathology is based on the major constituent protein of them: tau, TAR DNA-binding protein of 43 kD (TDP-43), and fused in sarcoma (FUS). Abnormal phosphorylation, ubiquitination, and proteolytic cleavage are the common pathologic signature of tau and TDP-43 accumulated in diseased brains. Recent findings of TDP-43 and FUS reveal that FTLD and ALS share a common mechanism of pathogenesis. This review focuses on the current understanding of the molecular neuropathology of FTLD, and their relevance to the development of the therapeutics.
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PMID:[The molecular pathology of frontotemporal lobar degeneration]. 2049 55

Inclusion body myopathy associated with Paget's disease of bone and frontotemporal dementia (IBMPFD) is a dominantly inherited degenerative disorder caused by mutations in the valosin-containing protein (VCP7) gene. VCP (p97 in mouse, TER94 in Drosophila melanogaster, and CDC48 in Saccharomyces cerevisiae) is a highly conserved AAA(+) (ATPases associated with multiple cellular activities) ATPase that regulates a wide array of cellular processes. The mechanism of IBMPFD pathogenesis is unknown. To elucidate the pathogenic mechanism, we developed and characterized a Drosophila model of IBMPFD (mutant-VCP-related degeneration). Based on genetic screening of this model, we identified three RNA-binding proteins that dominantly suppressed degeneration; one of these was TBPH, the Drosophila homolog of TAR (trans-activating response region) DNA-binding protein 43 (TDP-43). Here we demonstrate that VCP and TDP-43 interact genetically and that disease-causing mutations in VCP lead to redistribution of TDP-43 to the cytoplasm in vitro and in vivo, replicating the major pathology observed in IBMPFD and other TDP-43 proteinopathies. We also demonstrate that TDP-43 redistribution from the nucleus to the cytoplasm is sufficient to induce cytotoxicity. Furthermore, we determined that a pathogenic mutation in TDP-43 promotes redistribution to the cytoplasm and enhances the genetic interaction with VCP. Together, our results show that degeneration associated with VCP mutations is mediated in part by toxic gain of function of TDP-43 in the cytoplasm. We suggest that these findings are likely relevant to the pathogenic mechanism of a broad array of TDP-43 proteinopathies, including frontotemporal lobar degeneration and amyotrophic lateral sclerosis.
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PMID:TDP-43 mediates degeneration in a novel Drosophila model of disease caused by mutations in VCP/p97. 2051 48

We report a 52-year-old Japanese man showing both upper and lower motor neuron signs with familial amyotrophic lateral sclerosis (ALS). Analysis of the TAR DNA-binding protein of 43 kDa (TDP-43) gene (TARDBP) revealed a glycine-to-serine substitution at position 298 (G298S). Cerebrospinal fluid (CSF) level of total tau protein (CSF-tau) of our patient was found to be highly elevated compared with those of sporadic ALS cases and controls. The elevated CSF-tau level might be related to the damage of neurons exhibiting a large number of TDP-43 inclusions in familial ALS with this mutation.
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PMID:Familial ALS with G298S mutation in TARDBP: a comparison of CSF tau protein levels with those in sporadic ALS. 2055 45

TAR DNA-binding protein (TDP-43) and fused in sarcoma (FUS) are two highly conserved ribonucleoproteins. Pathogenic mutations of the TDP-43 or the FUS gene are all linked to amyotrophic lateral sclerosis (ALS) that is characterized by progressive degeneration of motor neurons. To better understand the correlation of ALS disease genes with the selectivity of chronic motor neuron degeneration, we examined the longitudinal expression of the TDP-43 and the FUS genes in C57BL6 mice and in Sprague-Dawley rats. TDP-43 and FUS were robustly and ubiquitously expressed in the postnatal mice and rats, but were markedly decreased in the adult rodents. In adulthood, TDP-43 and FUS proteins were even undetectable in peripheral organs including skeletal muscles, liver, and kidney, but were constantly expressed at substantial levels in the central nervous system. Motor neurons expressed the TDP-43 and the FUS genes at robust levels throughout rodent's lifetime. Moreover, TDP-43 and FUS were accumulated in the cytoplasm of motor neurons in aged animals. Our findings suggest that TDP-43 and FUS play an important role in development and that constant and robust expression of the genes in motor neurons may render the neurons vulnerable to pathogenic mutation of the TDP-43 or the FUS gene. To faithfully model the pathology of TDP-43- or FUS gene mutations in rodents, we must replicate the expression patterns of the TDP-43 and the FUS gene in animals.
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PMID:Sustained expression of TDP-43 and FUS in motor neurons in rodent's lifetime. 2061 80

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the progressive loss of upper and lower motor neurons. As with other age-dependent neurodegenerative disorders, ALS is linked to the presence of misfolded proteins that may perturb several intracellular mechanisms and trigger neurotoxicity. Misfolded proteins aggregate intracellularly generating insoluble inclusions that are a key neuropathological hallmark of ALS. Proteins involved in the intracellular degradative systems, signaling pathways and the human TAR DNA-binding protein TDP-43 are major components of these inclusions. While their role and cytotoxicity are still largely debated, aggregates represent a powerful marker to follow protein misfolding in the neurodegenerative processes. Using in vitro and in vivo models of mutant SOD1 associated familial ALS (fALS), we and other groups demonstrated that protein misfolding perturbs one of the major intracellular degradative pathways, the ubiquitin proteasome system, giving rise to a vicious cycle that leads to the further deposit of insoluble proteins and finally to the formation of inclusions. The aberrant response to mutated SOD1 thus leads to the activation of the cascade of events ultimately responsible for cell death. Hence, our idea is that, by assisting protein folding, we might reduce protein aggregation, restore a fully functional proteasome activity and/or other cascades of events triggered by the mutant proteins responsible for motor neuron death in ALS. This could be obtained by stimulating mutant protein turnover, using an alternative degradative pathway that could clear mutant SOD1, namely autophagy.
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PMID:A role of small heat shock protein B8 (HspB8) in the autophagic removal of misfolded proteins responsible for neurodegenerative diseases. 2069 40

Amyotrophic lateral sclerosis (ALS) is an incurable neurodegenerative disease that preferentially targets motor neurons. It was recently found that dominant mutations in two related RNA-binding proteins, TDP-43 (43-kDa TAR DNA-binding domain protein) and FUS/TLS (fused in sarcoma/translated in liposarcoma) cause a subset of ALS. The convergent ALS phenotypes associated with TDP-43 and FUS/TLS mutations are suggestive of a functional relationship; however, whether or not TDP-43 and FUS/TLS operate in common biochemical pathways is not known. Here we show that TDP-43 and FUS/TLS directly interact to form a complex at endogenous expression levels in mammalian cells. Binding was mediated by an unstructured TDP-43 C-terminal domain and occurred within the context of a 300-400-kDa complex that also contained C-terminal cleavage products of TDP-43 linked to neuropathology. TDP-43 C-terminal fragments were excluded from large molecular mass TDP-43 ribonucleoprotein complexes but retained FUS/TLS binding activity. The functional significance of TDP-43-FUS/TLS complexes was established by showing that RNAi silencing of either TDP-43 or FUS/TLS reduced the expression of histone deacetylase (HDAC) 6 mRNA. TDP-43 and FUS/TLS associated with HDAC6 mRNA in intact cells and in vitro, and competition experiments suggested that the proteins occupy overlapping binding sites. The combined findings demonstrate that TDP-43 and FUS/TLS form a functional complex in intact cells and suggest that convergent ALS phenotypes associated with TDP-43 and FUS/TLS mutations may reflect their participation in common biochemical processes.
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PMID:Amyotrophic lateral sclerosis-associated proteins TDP-43 and FUS/TLS function in a common biochemical complex to co-regulate HDAC6 mRNA. 2072 6


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