Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0030567 (Parkinson's disease)
 63,064 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Alzheimer's disease (AD) and Parkinson's disease (PD) are the two most common neurodegenerative diseases that occur either in relatively rare, familial forms or in common, sporadic forms. The genetic defects underlying several monogenic familial forms of AD and PD have recently been identified, however, the causes of other AD and PD cases, particularly sporadic cases, remain unclear. To gain insights into the pathogenic mechanisms involved in AD and PD, we used a proteomic approach to identify proteins with altered expression levels and/or oxidative modifications in idiopathic AD and PD brains. Here, we report that the protein level of ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1), a neuronal de-ubiquitinating enzyme whose mutation has been linked to an early-onset familial PD, is down-regulated in idiopathic PD as well as AD brains. By using a combination of two-dimensional gel electrophoresis and mass spectrometry, we have identified three human brain UCH-L1 isoforms, a full-length form and two amino-terminally truncated forms. Our proteomic analyses reveal that the full-length UCH-L1 is a major target of oxidative damage in AD and PD brains, which is extensively modified by carbonyl formation, methionine oxidation, and cysteine oxidation. Furthermore, immunohistochemical studies show that prominent UCH-L1 immunostaining is associated with neurofibrillary tangles and that the level of soluble UCH-L1 protein is inversely proportional to the number of tangles in AD brains. Together, these results provide evidence supporting a direct link between oxidative damage to the neuronal ubiquitination/de-ubiquitination machinery and the pathogenesis of sporadic AD and PD.
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PMID:Oxidative modifications and down-regulation of ubiquitin carboxyl-terminal hydrolase L1 associated with idiopathic Parkinson's and Alzheimer's diseases. 1472 78

The synuclein family includes three isoforms, termed alpha, beta and gamma. alpha-Synuclein accumulates in various pathological lesions resulting from neurodegenerative disorders including Parkinson's disease (PD), dementia with Lewy bodies (DLB) and multiple system atrophy. However, neither beta- nor gamma-synuclein has been detected in Lewy bodies, and thus it is unclear whether these isoforms contribute to neurological pathology. In the present study, we used immunohistochemistry to demonstrate accelerated accumulation of beta- and gamma-synucleins in axonal spheroids in gracile axonal dystrophy (gad) mice, which do not express ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1). gamma-Synuclein immunoreactivity in the spheroids appeared in the gracile nucleus at 3 weeks of age and was maintained until 32 weeks. beta-Synuclein immunoreactivity appeared in spheroids around 12 weeks of age. In contrast, alpha-synuclein immunoreactivity was barely detectable in spheroids. Immunoreactivity for synaptophysin and ubiquitin were either faint or undetectable in spheroids. Given that UCH-L1 deficiency results in axonal degeneration and spheroid formation, our findings suggest that beta- and gamma-synuclein participate in the pathogenesis of axonal swelling in gad mice.
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PMID:Accumulation of beta- and gamma-synucleins in the ubiquitin carboxyl-terminal hydrolase L1-deficient gad mouse. 1530 32

Here, we illustrated that the morphological structures of ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1) variants and Parkinson's disease (PD) exhibit good pathological correlation by a small-angle neutron scattering (SANS). UCH-L1 is a neuro-specific multiple functional enzyme, deubiquitinating, ubiquityl ligase, and also involved in stabilization of mono-ubiquitin. To examine the relationship between multiple functions of UCH-L1 and the configuration of its variants [wild-type, I93M (linked to familial Parkinson's disease), and S18Y (linked to reduced risk of Parkinson's disease)], in this report, we proposed that these were all self-assembled dimers by an application of a rotating ellipsoidal model; the configurations of these dimers were quite different. The wild-type was a rotating ellipsoidal. The globular form of the monomeric component deformed by the I93M mutation. Conversely, the S18Y polymorphism promoted the globularity. Thus, the multiple functional balance is closely linked to the intermolecular interactions between the UCH-L1 monomer and the final dimeric configuration.
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PMID:Characterization of multimetric variants of ubiquitin carboxyl-terminal hydrolase L1 in water by small-angle neutron scattering. 1631 32

The I93M mutation in ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1) was reported in one German family with autosomal dominant Parkinson's disease (PD). The causative role of the mutation has, however, been questioned. We generated transgenic (Tg) mice carrying human UCHL1 under control of the PDGF-B promoter; two independent lines were generated with the I93M mutation (a high- and low-expressing line) and one line with wild-type human UCH-L1. We found a significant reduction in the dopaminergic neurons in the substantia nigra and the dopamine content in the striatum in the high-expressing I93M Tg mice as compared with non-Tg mice at 20 weeks of age. Although these changes were absent in the low-expressing I93M Tg mice, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treatment profoundly reduced dopaminergic neurons in this line as compared with wild-type Tg or non-Tg mice. Abnormal neuropathologies were also observed, such as silver staining-positive argyrophilic grains in the perikarya of degenerating dopaminergic neurons, in I93M Tg mice. The midbrains of I93M Tg mice contained increased amounts of insoluble UCH-L1 as compared with those of non-Tg mice, perhaps resulting in a toxic gain of function. Collectively, our data represent in vivo evidence that expression of UCHL1(I93M) leads to the degeneration of dopaminergic neurons.
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PMID:Dopaminergic neuronal loss in transgenic mice expressing the Parkinson's disease-associated UCH-L1 I93M mutant. 1696 39

The identification of mutations that cause familial Parkinson's disease (PD) provides a framework for studies into pathways that may be perturbed also in the far more common, non-familial form of the disorder. Following this hypothesis, we have examined the gene regulatory network that links alpha-synuclein and parkin pathways with dopamine metabolism in neuropathologically verified cases of sporadic PD. By means of an in silico approach using a database of eukaryotic molecular interactions and a whole genome transcriptome dataset validated by qRT-PCR and histological methods, we found parkin and functionally associated genes to be up-regulated in the lateral substantia nigra (SN). In contrast, alpha-synuclein and ubiquitin carboxyl-terminal hydrolase L1 (UCHL1) gene expression levels were significantly reduced in both the lateral and medial SN in PD. Gene expression for Septin 4, a member of the GTP-binding protein family involved in alpha-synuclein metabolism was elevated in the lateral parkinsonian SN. Additionally, catalase and mitogen-activated protein kinase 8 and poly(ADP-ribose) polymerase family member 1 (PARP1) known to function in DNA repair and cell death induction, all members of the dopamine synthesis pathway, were up-regulated in the lateral SN. In contrast, two additional PD-linked genes, glucocerebrosidase and nuclear receptor subfamily 4, group A, member 2 (NR4A2) showed reduced expression. We show that in sporadic PD, parkin, alpha-synuclein and dopamine pathways are co-deregulated. Alpha-synuclein is a member of all three gene regulatory networks. Our analysis results support the view that alpha-synuclein has a central role in the familial as well as the non-familial form of the disease and provide steps towards a pathway definition of PD.
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PMID:Analysis of alpha-synuclein, dopamine and parkin pathways in neuropathologically confirmed parkinsonian nigra. 1720 91

Local axonal degeneration is a common pathological feature of peripheral neuropathies and neurodegenerative disorders of the central nervous system, including Alzheimer's disease, Parkinson's disease, and stroke; however, the underlying molecular mechanism is not known. Here, we analyzed the gracile axonal dystrophy (gad) mouse, which displays the dying-back-type of axonal degeneration in sensory neurons, to find the molecules involved in the mechanism of axonal degeneration. The gad mouse is analogous to a null mutant of ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1). UCH-L1 is a deubiquitinating enzyme expressed at high levels in neurons, as well as testis and ovary. In addition, we recently discovered a new function of UCH-L1-namely to bind to and stabilize mono-ubiquitin in neurons, and found that the level of mono-ubiquitin was decreased in neurons, especially in axons of the sciatic nerve, in gad mice. The low level of ubiquitin suggests that the target proteins of the ubiquitin proteasome system are not sufficiently ubiquitinated and thus degraded in the gad mouse; therefore, these proteins may be the key molecules involved in axonal degeneration. To identify molecules involved in axonal degeneration in gad mice, we compared protein expression in sciatic nerves between gad and wild-type mice at 2 and 12 weeks old, using two-dimensional difference gel electrophoresis. As a result, we found age-dependent accumulation of several proteins, including glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and 14-3-3, in gad mice compared with wild-type mice. Histochemical analyses demonstrated that GAPDH and 14-3-3 were localized throughout axons in both gad and wild-type mice, but GAPDH accumulated in the axons of gad mice. Recently, it has been suggested that a wide range of neurodegenerative diseases are characterized by the accumulation of intracellular and extracellular protein aggregates, and it has been reported that oxidative stress causes the aggregation of GAPDH. Furthermore, histochemical analysis demonstrated that sulfonated GAPDH, a sensor of oxidative stress that elicits cellular dysfunction, was expressed in the axons of gad mice, and 4-hydroxy-2-nonenal, a major marker of oxidative stress, was also only detected in gad mice. Our findings suggest that GAPDH may participate in a process of the dying-back-type of axonal degeneration in gad mice and may provide valuable insight into the mechanisms of axonal degeneration.
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PMID:Proteomic and histochemical analysis of proteins involved in the dying-back-type of axonal degeneration in the gracile axonal dystrophy (gad) mouse. 1915 71

Neuroprotective effects of alpha(2)-adrenergic receptor (AR) agonists are mediated via the alpha(2A)AR subtype, but the molecular mechanisms underlying these actions are still not elucidated. A two-hybrid screen was performed to identify new proteins that may control alpha(2)AR receptor function and trafficking. This screen identified the ubiquitin carboxyl-terminal hydrolase-L1 (Uch-L1), a protein associated with Parkinson's disease, as alpha(2)AR interacting protein. This interaction was confirmed and evaluated by GST pull down assays demonstrating that Uch-L1 binds preferentially to the alpha(2A)AR subtype and only with less affinity to alpha(2B)AR and alpha(2C)AR. Co-immunoprecipitation of epitope-tagged proteins confirmed the specificity of this interaction in vivo. Moreover, co-transfection of a truncated G-protein coupled receptor kinase-DNA preventing alpha(2)AR phosphorylation led to an increased signal-strength of coimmunoprecipitated Uch-L1. Confocal laser microscopy showed that interaction of alpha(2A)AR and Uch-L1 occurred in the cytoplasm. alpha(2)AR agonist mediated activation of p44/42 MAP Kinase was drastically decreased in the presence of Uch-L1 indicating a functional relevance of this interaction. These findings may present a mechanism contributing to subtype-specific alpha(2)AR trafficking and a potential pathway for the neuroprotective effects of alpha(2)AR agonists.
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PMID:Interaction of the ubiquitin carboxyl terminal esterase L1 with alpha(2)-adrenergic receptors inhibits agonist-mediated p44/42 MAP kinase activation. 1947 70

DNA methylation occurs predominantly at cytosines that precede guanines in dinucleotide CpG sites; it is one of the most important mechanisms for epigenetic DNA regulation during normal development and for aberrant DNA in cancer. To determine the feasibility of DNA methylation studies in the postmortem human brain, we evaluated brain samples with variable postmortem artificially increased delays up to 48 hours. DNA methylation was analyzed in selected regions of MAPT, APP, and PSEN1 in the frontal cortex and hippocampus of controls (n=26) and those with Alzheimer disease at Stages I to II (n=17); Alzheimer disease at Stages III to IV (n=15); Alzheimer disease at Stages V to VI (n=12); argyrophilic grain disease (n=10); frontotemporal lobar degeneration linked to tau mutations (n=6); frontotemporal lobar degeneration with ubiquitin-immunoreactive inclusions (n=4); frontotemporal lobar degeneration with motor neuron disease (n=3); Pick disease (n=3); Parkinson disease (n=8); dementia with Lewy bodies, pure form (n=5); and dementia with Lewy bodies, common form (n=15). UCHL1 (ubiquitin carboxyl-terminal hydrolase 1 gene) was analyzed in the frontal cortex of controls and those with Parkinson disease and related synucleinopathies. DNA methylation sites were very reproducible in every case. No differences in the percentage of CpG methylation were found between control and disease samples or among the different pathological entities in any region analyzed. Because small changes in methylation of DNA promoters in vulnerable cells might have not been detected in total homogenates, however, these results should be interpreted with caution, particularly as they relate to chronic degenerative diseases in which small modifications may be sufficient to modulate disease progression.
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PMID:DNA methylation of Alzheimer disease and tauopathy-related genes in postmortem brain. 1960 65

UCHL1/PGP 9.5 (also known as UCHL1 and PGP 9.5) was first detected as a "brain-specific protein" over 28 years ago. The protein is highly conserved and localized in neurones and neuroendocrine cells in vertebrates, forming an estimated 5-10% of cytoplasmic protein. A minor proportion in brain is tightly membrane-bound and the protein is also found in human oocytes and spermatogonia. A few specialised neurones lack UCHL1/PGP 9.5 and possibly replaceable neurones have low levels of the protein. UCHL1/PGP 9.5 shows sequence homology with UCHL3 (ubiquitin carboxyl-terminal hydrolase L3) and will similarly hydrolyse C-terminal adducts of ubiquitin. Both proteins show an unusual highly knotted structure with five "crossovers" but there are differences in substrate specificity, amino-acid sequence, and tissue distribution between them. There is no convincing evidence that UCHL1/PGP 9.5 can remove ubiquitin from proteins destined for proteasomal degradation, rather the substrate(s) of the enzyme appear to be one or more as yet unidentified short ubiquitin C-terminal extensions. Other suggested functions of the protein are plausible but largely unconfirmed. Isolated loss of UCHL1/PGP 9.5 function seen in the gracile axonal dystrophy (GAD) mouse due to a deletion in its gene results in a failure of axonal transport and a "dying-back" axonopathy beginning distally in long axons. The evidence that mutations in the UCHL1/PGP 9.5 gene lead to either significant susceptibility to or protection from Parkinson's disease (or other human neurodegenerative disorders) is weak. Antibodies to the protein have found remarkably widespread application in the detection of fine nerves in peripheral tissues of many vertebrate species.
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PMID:UCHL1 (PGP 9.5): neuronal biomarker and ubiquitin system protein. 1987 17

Hypothalamic tuberoinfundibular dopamine (TIDA) neurons remain unaffected in Parkinson disease (PD) while there is significant degeneration of midbrain nigrostriatal dopamine (NSDA) neurons. A similar pattern of susceptibility is observed in acute and chronic 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse and rotenone rat models of degeneration. It is not known if the resistance of TIDA neurons is a constitutive or induced cell-autonomous phenotype for this unique subset of DA neurons. In the present study, treatment with a single injection of MPTP (20 mg/kg; s.c.) was employed to examine the response of TIDA versus NSDA neurons to acute injury. An acute single dose of MPTP caused an initial loss of DA from axon terminals of both TIDA and NSDA neurons, with recovery occurring solely in TIDA neurons by 16 h post-treatment. Initial loss of DA from axon terminals was dependent on a functional dopamine transporter (DAT) in NSDA neurons but DAT-independent in TIDA neurons. The active metabolite of MPTP, 1-methyl, 4-phenylpyradinium (MPP+), reached higher concentration and was eliminated slower in TIDA compared to NSDA neurons, which indicates that impaired toxicant bioactivation or distribution is an unlikely explanation for the observed resistance of TIDA neurons to MPTP exposure. Inhibition of protein synthesis prevented TIDA neuron recovery, suggesting that the ability to recover from injury was dependent on an induced, rather than a constitutive cellular mechanism. Further, there were no changes in total tyrosine hydroxylase (TH) expression following MPTP, indicating that up-regulation of the rate-limiting enzyme in DA synthesis does not account for TIDA neuronal recovery. Differential candidate gene expression analysis revealed a time-dependent increase in parkin and ubiquitin carboxyl-terminal hydrolase-L1 (UCH-L1) expression (mRNA and protein) in TIDA neurons during recovery from injury. Parkin expression was also found to increase with incremental doses of MPTP. The increase in parkin expression occurred specifically within TIDA neurons, suggesting that these neurons have an intrinsic ability to up-regulate parkin in response to MPTP-induced injury. These data suggest that TIDA neurons have a compensatory mechanism to deal with toxicant exposure and increased oxidative stress, and this unique TIDA neuron phenotype provides a platform for dissecting the mechanisms involved in the natural resistance of central DA neurons following toxic insult.
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PMID:Recovery of hypothalamic tuberoinfundibular dopamine neurons from acute toxicant exposure is dependent upon protein synthesis and associated with an increase in parkin and ubiquitin carboxy-terminal hydrolase-L1 expression. 2234 63


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