Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0752347 (Dementia with Lewy bodies)
 1,653 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Alpha-synuclein is a presynaptic protein that normally participates in the homeostasis of synaptic vesicles. Missense mutations in its gene cause the protein to participate actively in the development of heritable forms of Parkinson's disease. Moreover, its metabolism is perturbed in all cases of Parkinson's disease where alpha-synuclein accumulates in a filamentous form in the Lewy body nerve cell lesion. Lewy bodies also develop in other common neurodegenerative disorders, like dementia with Lewy bodies and Lewy body variant of Alzheimer's disease. In the present study, we have studied the detailed distribution of alpha-, beta- and gamma-synuclein in the rat CNS. Alpha-synuclein was not observed in perikarya, but was distributed with high intensity in nerve terminals in the caudate and putamen and ventral pallidum, where beta-synuclein was much weaker and less densely distributed in the caudate and putamen. Gamma-synuclein was not found in the caudate and putamen. Alpha-synuclein was robustly distributed in the substantia nigra pars reticulata, but was very weak or virtually absent from the perikarya of the neurons in the pars compacta. In contrast, beta-synuclein was very weak or absent from the substantia nigra. gamma-Synuclein was absent from the terminals of substantia nigra pars reticulata, but sparsely distributed gamma-synuclein-containing neurons were detected in the substantia nigra pars compacta. In the brainstem, alpha-synuclein as well as gamma-synuclein were present in the locus coeruleus with high intensity, while beta-synuclein was very weak. In addition, alpha-synuclein was intense in the vagus nucleus, but weak in the oculomotor, facial, hypoglossal, accessory and ambiguous nuclei, where beta-synuclein was very intensely present. Furthermore, gamma-synuclein was localized in the terminals and in cell bodies of the Edinger-Westphal nucleus, the red nucleus, locus coeruleus, and most cranial nerve-related nuclei. In the spinal cord, alpha- and gamma-synucleins were intensely present in laminae I and II and in the preganglionic sympathetic nuclei, whereas beta-synuclein was very weak. These results indicate that alpha-synuclein is abundant in central catecholaminergic regions. Beta-synuclein is more localized in the somatic cholinergic components, while it is particularly weak or absent from catecholaminergic neurons. Gamma-synuclein appears to be present in both cholinergic and catecholaminergic regions, but very weak in the forebrain.
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PMID:Differential localization of alpha-, beta- and gamma-synucleins in the rat CNS. 1212 2

We describe a Spanish family in which 3 of 4 siblings had dementia with Lewy bodies, 2 of them starting at age 26 years and the other at 29 years. The father has recently been diagnosed with Lewy body disease, with onset at 77 years. Neuropathological examination of the brain of the index patient disclosed unusual features characterized by diffuse Lewy body disease and generalized neurofibrillary tangle pathology but with no amyloid deposits in any region. Moreover, Lewy body pathology colocalized with neurofibrillary tangles in most affected neurons. Mutation screening that included all coding exons of presenilin 1 (PSEN1), presenilin 2 (PSEN2), alpha-synuclein (SNCA), beta-synuclein (SNCB), microtubule-associated protein tau (MAPT), leucine-rich repeat kinase 2 (LRRK2), glucocerebrosidase (GBA), and exons 16 and 17 of the amyloid precursor protein (APP) genes did not identify any mutation. Genome-wide single nucleotide polymorphism was performed in 4 family members and ruled out any pathogenic duplication or deletion in the entire genome. In summary, we report a unique family with pathologically confirmed early-onset dementia with Lewy bodies with widespread tau and alpha-synuclein deposition. The absence of mutations in genes known to cause Lewy body disease suggests that a novel locus or loci are implicated in this neurodegenerative disease.
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PMID:Early-onset familial lewy body dementia with extensive tauopathy: a clinical, genetic, and neuropathological study. 1910 44

Parkinson disease (PD) is the most important movement disorder and about 50% of patients develop dementia over the time. PD belongs to the group of Lewy body disorders. Alpha-synuclein (AS) is the main component of Lewy bodies and its aggregation is a key event in the pathogenesis of PD. Beta-synuclein (BS) inhibits AS aggregation in vitro and in vivo and has been shown to interact directly with AS regulating its functionality and preventing its oligomerization. Recently, we have described a molecular subgroup of DLB characterized by the drastic BS reduction in cortical areas. In this study we have analyzed the expression of two BS transcripts and the main AS transcript SNCA140, in frozen samples of three brain areas, temporal cortex, caudate nucleus and pons, from patients with PD and PDD in comparison with controls. Relative mRNA expression was determined by real-time PCR with SybrGreen, neuron-specific-enolase as housekeeping gene and the deltadeltaCt method. The most important difference in BS and AS mRNA expression between PD and PDD was found in the caudate nucleus, where BS mRNA was overexpressed in PD and AS mRNA diminished in PDD. Our findings provide new insights into the pathogenesis of dementia in PD, indicating that differential BS and AS expression in the caudate nucleus may represent one of the molecular mechanisms involved in these complex diseases.
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PMID:Alpha- and beta-synuclein expression in Parkinson disease with and without dementia. 2168 63

Dementia with Lewy bodies (DLB) is the second most prevalent neurodegenerative dementia, where an accumulation of aggregated fibrillar alpha-synuclein in neurons of limbic and forebrain regions of the brain leads to visual hallucination, cognitive impairment of a fluctuating nature and extrapyramidal motor disturbances. Beta-synuclein counteracts aggregation of alpha-synuclein in vitro and in animal models, however it is not clear whether this effect occurs in human Lewy body dementia (LBD) diseases. Here we examine expression of alpha-, beta-synuclein and autophagy markers in the frontal cortex (BA9) and occipital cortex (BA18-19) of patients with neuropathologically confirmed DLB/LBD and age-matched controls. We provide evidence for neuronal upregulation of beta-synuclein within the frontal cortex and its decrease in occipital cortex of DLB patients. While beta-synuclein-containing neurons were consistently devoid of oligomeric alpha-synuclein in the frontal cortex, we did not observe an overall correlation between total beta-synuclein and 5G4 levels (marker of oligomeric alpha-synuclein). The autophagy markers LC3-II and p62 were increased in the areas of beta-synuclein upregulation in DLB brains, and we show attenuation of autophagy flux when beta-synuclein is overexpressed in vitro. Altogether, this data suggests that beta-synuclein changes in DLB may exacerbate neuronal dysfunction caused by accumulation of alpha-synuclein by influencing protein degradation pathways; this should be taken into consideration when designing therapeutic strategies aimed to decrease alpha-synuclein burden in Lewy body diseases.
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PMID:Accumulation of beta-synuclein in cortical neurons is associated with autophagy attenuation in the brains of dementia with Lewy body patients. 2927 15