Parkin localizes to the Lewy bodies of Parkinson disease and dementia with Lewy bodies

Mutations in alpha-synuclein (alpha S) and parkin cause heritable forms of Parkinson disease (PD). We hypothesized that neuronal parkin, a known E3 ubiquitin ligase, facilitates the formation of Lewy bodies (LBs), a pathological hallmark of PD. Here, we report that affinity-purified parkin antibodies labeled classical LBs in substantia nigra sections from four related human disorders: sporadic PD, inherited alphaS-linked PD, dementia with LBs (DLB), and LB-positive, parkin-linked PD. Anti-parkin antibodies also detected LBs in entorhinal and cingulate cortices from DLB brain and alphaS inclusions in sympathetic gangliocytes from sporadic PD. Double labeling with confocal microscopy of DLB midbrain sections revealed that approximately 90% of anti-alpha S-reactive LBs were also detected by a parkin antibody to amino acids 342 to 353. Accordingly, parkin proteins, including the 53-kd mature isoform, were present in affinity-isolated LBs from DLB cortex. Fluorescence resonance energy transfer and immunoelectron microscopy showed that alphaS and parkin co-localized within brainstem and cortical LBs. Biochemically, parkin appeared most enriched in cytosolic and postsynaptic fractions of adult rat brain, but also in purified, alpha S-rich presynaptic elements that additionally contained parkin's E2-binding partner, UbcH7. We conclude that parkin and UbcH7 are present with alphaS in subcellular compartments of normal brain and that parkin frequently co-localizes with alpha S aggregates in the characteristic LB inclusions of PD and DLB. These results suggest that functional parkin proteins may be required during LB formation.     

Hippocampal and neocortical ubiquitin-immunoreactive inclusions in amyotrophic lateral sclerosis with dementia.

Amyotrophic lateral sclerosis (ALS) patients with dementia were found to have ubiquitin-immunoreactive (IR) inclusions in the dentate granule cells of the hippocampus. These inclusions were also present in some patients with minor cognitive changes but otherwise typical ALS. Ubiquitin-IR inclusions were also found in neurons of superficial layers of the frontal and temporal cortex and in the entorhinal cortex in patients with ALS and dementia. These ubiquitin-IR inclusions were non-argyrophilic, and were not labelled by antibodies which identify Alzheimer's neurofibrillary tangles and Pick bodies, nor were they typical of cortical Lewy bodies. Our findings indicate that ubiquitin-IR inclusions in small neurons of the hippocampus, entorhinal area and neocortex are a characteristic feature of degeneration of non-motor cortex in ALS, and are particularly associated with cognitive impairment and dementia of frontal lobe type.     

Aggregation of alpha-synuclein in Lewy bodies of sporadic Parkinson's disease and dementia with Lewy bodies.

Lewy bodies (LBs) are hallmark lesions of degenerating neurons in the brains of patients with Parkinson's disease (PD) and dementia with Lewy bodies (DLB). Recently, a point mutation in the gene encoding the presynaptic alpha-synuclein protein was identified in some autosomal-dominantly inherited familial PD pedigrees, and light microscopic studies demonstrated alpha-synuclein immunoreactivity in LBs of sporadic PD and DLB. To characterize alpha-synuclein in LBs, we raised monoclonal antibodies (MAbs) to LBs purified from DLB brains and obtained a MAb specific for alpha-synuclein that intensely labeled LBs. Light and electron microscopic immunocytochemical studies performed with this MAb as well as other antibodies to alpha-and beta-synuclein showed that alpha-synuclein, but not beta-synuclein, is a component of LBs in sporadic PD and DLB. Western blot analyses of highly purified LBs from DLB brains showed that full-length as well as partially truncated and insoluble aggregates of alpha-synuclein are deposited in LBs. Thus, these data strongly implicate alpha-synuclein in the formation of LBs and the selective degeneration of neurons in sporadic PD and DLB.     

Muscarinic receptors in basal ganglia in dementia with Lewy bodies,Parkinson's disease and Alzheimer's disease

Derivatives of the muscarinic antagonist 3-quinuclidinyl-4-iodobenzilate (QNB), particularly [123I]-(R,R)-I-QNB, are currently being assessed as in vivo ligands to monitor muscarinic receptors in Alzheimer's disease (AD) and dementia with Lewy bodies (DLB), relating changes to disease symptoms and to treatment response with cholinergic medication. To assist in the evaluation of in vivo binding, muscarinic receptor density in post-mortem human brain was measured by autoradiography with [125I]-(R,R)-I-QNB and [125I]-(R,S)-I-QNB and compared to M1 ([3H]pirenzepine) and M2 and M4 ([3H]AF-DX 384) receptor binding. Binding was calculated in tissue containing striatum, globus pallidus (GPe), claustrum, and cingulate and insula cortex, in cases of AD, DLB, Parkinson's disease (PD) and normal elderly controls. Pirenzepine, AF-DX 384 and (R,S)-I-QNB binding in the striatum correlated positively with increased Alzheimer-type pathology, and AF-DX 384 and (R,R)-I-QNB cortical binding correlated positively with increased Lewy body (LB) pathology; however, striatal pirenzepine binding correlated negatively with cortical LB pathology. M1 receptors were significantly reduced in striatum in DLB compared to AD, PD, and controls and there was a significant correlation between M1 and dopamine D2 receptor densities. [3H]AF-DX 384 binding was higher in the striatum and GPe in AD. Binding of [125I]-(R,R)-I-QNB, which may reflect increased muscarinic M4 receptors, was higher in cortex and claustrum in DLB and AD. [125I]-(R,S)-I-QNB binding was higher in the GPe in AD. Low M1 and D2 receptors in DLB imply altered regulation of the striatal projection neurons which express these receptors. Low density of striatal M1 receptors may relate to the extent of movement disorder in DLB, and to a reduced risk of parkinsonism with acetylcholinesterase inhibition.     

Alpha-synuclein accumulates in Lewy bodies in Parkinson's disease and dementia with Lewy bodies but not in Alzheimer's disease beta-amyloid plaque cores.

A growing body of evidence suggests that the non-Abeta component of Alzheimer's disease amyloid precursor protein (NACP) or alpha-synuclein contributes to the neurodegenerative processes in Alzheimer's disease (AD), Parkinson's disease (PD) and dementia with Lewy bodies (DLB). In the present study antisera to the N terminus and the NAC domain of the alpha-synuclein protein were employed to elucidate the expression pattern in brains of patients with AD, PD, DLB and control specimen. Alpha-synuclein exhibited an overall punctuate expression profile compatible with a synaptic function. Interestingly, while Lewy bodies were strongly immunoreactive, none of the alpha-synuclein antisera revealed staining in mature beta-amyloid plaques in AD. These observations suggest that alpha-synuclein does not contribute to late neurodegenerative processes in AD brains.     

Clinical correlates of pathology in the claustrum in Parkinson's disease and dementia with Lewy bodies

Dementia and visual hallucinations are common complications of Parkinson's disease (PD), yet their patho-anatomical bases are poorly defined. We studied α-synuclein (αSyn), tau and amyloid-β (Aβ) pathology in the claustrum of 20 PD cases without dementia, 12 PD cases with dementia (PDD) and 7 cases with dementia with Lewy bodies (DLB). αSyn positivity was observed in 75% of PD cases without dementia and in 100% of PDD and DLB cases. Aβ was observed in the claustrum in 25% of PD, 58% of PDD and 100% of DLB cases. Tau was negligible in all cases restricting further analysis. Compared to PD cases without dementia, PDD cases demonstrated a significantly greater αSyn burden in the claustrum (p = 0.0003). In addition, DLB cases showed a significantly increased αSyn deposition when compared to PDD (p = 0.02) and PD without dementia (p = 0.0002). A similar hierarchy, PD < PDD < DLB was seen in terms of Aβ burden in the claustrum. Comparison of αSyn and Aβ burden in those cases with and without visual hallucinations did not reveal any significant associations (p = 0.13 and 0.1, respectively). We demonstrate that pathology in the claustrum, a region of largely obscure physiological function, strongly relates to the presence of dementia in Parkinson's disease and DLB.     

Familial amyotrophic lateral sclerosis,dementia, and psychosis

Reports of amyotrophic lateral sclerosis (ALS) associated with dementia in families outside the Western Pacific have been rare. The authors present a neuropsychiatric survey of three generations of a family with adult-onset ALS with dementia and psychosis in each generation. Among the interesting findings were possible genetic links due to regional inbreeding and a consanguineous marriage     

Biomarkers of Parkinson's disease and Dementia with Lewy bodies

Parkinson's disease (PD) and Dementia with Lewy bodies (DLB) are progressive and disabling neurodegenerative disorders, in which signs and symptoms overlap with each other and with other neurodegenerative conditions. Currently, diagnosis, measurement of progression, and response to therapeutic intervention rely upon clinical observation. However, there remains a critical need for validated biomarkers in each of these areas. A definitive diagnostic test would improve clinical management and enrollment into clinical trials. An objective measure of progression is vitally important in identifying neuroprotective interventions. Biomarkers may also provide insight into pathogenesis, and might therefore suggest possible novel targets for therapeutic intervention. In addition, certain biomarkers might be of use in monitoring the biochemical and physiological effects of therapeutic interventions. Development of diagnostic biomarkers has focused until recently upon imaging techniques based upon measuring loss of dopamine neurons. Additionally, advances in understanding the genetic contribution to neurodegenerative disorders, in particular in PD, have identified multiple causative genes and risk factors that in some cases may help estimate PD risk. However, recent availability of increasingly sophisticated bioinformatics technology has rendered development of fluid biomarkers feasible, opening the possibility of generally accessible blood or cerebrospinal fluid (CSF) tests that could impact upon diagnosis, management, and research in PD, PDD, and DLB.     

Biomarkers of Parkinson's disease and Dementia with Lewy bodies

Parkinson's disease (PD) and Dementia with Lewy bodies (DLB) are progressive and disabling neurodegenerative disorders, in which signs and symptoms overlap with each other and with other neurodegenerative conditions. Currently, diagnosis, measurement of progression, and response to therapeutic intervention rely upon clinical observation. However, there remains a critical need for validated biomarkers in each of these areas. A definitive diagnostic test would improve clinical management and enrollment into clinical trials. An objective measure of progression is vitally important in identifying neuroprotective interventions. Biomarkers may also provide insight into pathogenesis, and might therefore suggest possible novel targets for therapeutic intervention. In addition, certain biomarkers might be of use in monitoring the biochemical and physiological effects of therapeutic interventions. Development of diagnostic biomarkers has focused until recently upon imaging techniques based upon measuring loss of dopamine neurons. Additionally, advances in understanding the genetic contribution to neurodegenerative disorders, in particular in PD, have identified multiple causative genes and risk factors that in some cases may help estimate PD risk. However, recent availability of increasingly sophisticated bioinformatics technology has rendered development of fluid biomarkers feasible, opening the possibility of generally accessible blood or cerebrospinal fluid (CSF) tests that could impact upon diagnosis, management, and research in PD, PDD, and DLB.     

Bunina bodies in dendrites of patients with amyotrophic lateral sclerosis

We studied the brains of two cases of amyotrophic lateral sclerosis with dementia. Bunina bodies were found in the motor neurons of cranial nerve nuclei (trigeminal, facial and hypoglossal nerves) as well as in the spinal motoneurons. They appeared mostly in the cytoplasm and occasionally in the neuronal processes. However, the present electron microscopic study disclosed clearly that Bunina bodies were present not only in the cell body but also in the dendrites. No Bunina bodies were observed in the axons. It is inferred that the Bunina bodies were degenerative products formed as a result of a protein metabolism disorder.     

Clinicopathologic and genetic features of multiple system atrophy with Lewy body disease

Background: Abnormal aggregates of α‐synuclein are pathologic hallmarks of multiple system atrophy (MSA) and Lewy body disease (LBD). LBD sometimes coexists with MSA, but the impact of co‐pathology, particularly diffuse LBD, on presentation of MSA has not been studied. We aimed to determine the frequency and clinicopathologic features of MSA with LBD (MSA+LBD). Methods: Using hematoxylin & eosin and α‐synuclein‐immunostained slides, we assessed the distribution and severity of LBD in 230 autopsy‐confirmed MSA patients collected from 1998 to 2018. Alzheimer‐type pathology was assessed to assign the likelihood of clinical presentations of dementia with Lewy body (DLB) using the consensus criteria for DLB. We reviewed medical records to characterize clinicopathologic features of MSA+LBD. Genetic risk factors for LBD, including APOE ε4 allele and mutations in GBA, SNCA, LRRK2, and VPS35, were analyzed. Results: LBD was observed in 11 MSA patients (5%); seven were brainstem type, three were transitional type, and one was diffuse type. The latter four had an intermediate or high likelihood of DLB. Three of the four had an antemortem diagnosis of Parkinson’s disease with dementia (PDD) or clinically probable DLB. Two patients had neuronal loss in the substantia nigra, but not in striatal or olivocerebellar systems with widespread glial cytoplasmic inclusions, consistent with minimal change MSA. In these cases, LBD was considered the primary pathology, and MSA was considered coincidental. APOE ε4 allele frequency was not different between MSA+LBD and MSA without LBD. Two of nine MSA+LBD patients had a risk variant of GBA (p.T408M and p.E365K). Conclusions: Although rare, MSA with transitional or diffuse LBD can develop clinical features of PDD or DLB. Minimal change MSA can be interpreted as a coincidental, but distinct, α‐synucleinopathy in a subset of patients with diffuse LBD.     

Nicotinic receptors in the putamen of patients with dementia with Lewy bodies and Parkinson's disease: relation to changes in alpha-synuclein expression

Caudal ventrolateral medulla (CVLM) plays an important role in the regulation of reflex cardiovascular activity. In the present study, the possible involvement of the CVLM in mediating the depressor response elicited by the greater splanchnic nerve (GSPL) afferent stimulation was explored in rats anesthetized with urethane and alpha-chloralose. Microinjection of lidocaine, and the glutamate receptor antagonists, kynurenic acid and 2-amino-7-phosphonolieptanoic acid, into the CVLM significantly blocked the depressor response induced by the GSPL afferent stimulation. Electrical stimulation of the GSPL inputs excited 48 of 75 CVLM neurons tested (64%). Sixteen out of 21 excited CVLM neurons tested received baroreceptor inputs. Coherence analysis revealed a strong cardiac-related rhythm in the discharges of 11 out of these 21 excited neurons. These results suggest the involvement of CVLM neurons and activation of glutamate receptors in the CVLM in mediating the depressor response induced by the GSPL afferent stimulation in rats.     

The two faces of L-DOPA: benefits and adverse side effects in the treatment of Encephalitis lethargica, Parkinson's disease, multiple sclerosis and amyotrophic lateral sclerosis

Parkinson's disease, encephalitis lethargica, multiple sclerosis and amyotrophic lateral sclerosis patients all display two distinct types of symptoms. Some of these are due directly to a deficiency of dopamine and are quickly reduced by laevodihydroxyphenylalanine (L-DOPA). The second set, however, are the result of neurological damage caused by metabolites of dopamine, which include dopachrome and other chrome indoles that are both hallucinogenic and neurotoxic. If this hypothesis is correct, three corollaries follow. Patients of all four disorders should display excessive oxidative stress, natural methyl acceptors should delay development and elevated antioxidant supplementation, given with L-DOPA, ought to prolong the "honeymoon" period in which the benefits of the drug out weigh its subsequent disadvantages. A literature review suggests that all three corollaries are probably correct.     

Polymorphism in the human DJ-1 gene is not associated with sporadic dementia with Lewy bodies or Parkinson's disease

Genetic analysis of early onset Parkinson's disease (PD) has indicated that the mutation DJ-1 gene is one cause of autosomal recessive PD. Its role in the development of late onset PD and other Lewy body associated disorders such as dementia with Lewy bodies (DLB) is however unknown. We have therefore determined the influence of a common polymorphism in the DJ-1 gene that shows strong linkage disequilibrium with other DJ-1 polymorphisms, in late onset PD and DLB. No alteration in the frequency of the intron 1 deletion allele was seen in PD or DLB, nor were DJ-1 genotypes altered by disease. Stratification of the cases according to the apolipoprotein E epsilon4 allele additionally failed to show any significant association. The DJ-1 gene does not appear to be a significant risk factor for late onset Lewy body disease in this population.     

Virus-like inclusions in the myocytes of the skeletal muscle in lateral amyotrophic sclerosis

Microscopic examination of musculus gastrocnemius biopsies was made in four cases of sporadic lateral amyotrophic sclerosis (LAS). The validity of the clinical diagnosis was confirmed by detected neurotrophic atrophy of the muscular fibers typical for LAS. Electron microscopic study revealed virus-like inclusions 200-450 nm in size in sarcoplasm of myocytes of all the patients. The inclusions consist of lined cells of hexagonal shape at the distance of 37-41 nm from each other. The inclusions resemble enteroviruses but are not identical to them both by size and structure of their elements. There were also specific ultrastructural changes of myocytes corresponding to viral infection. The above virus-like inclusions should be considered as specific structures formed as a result of metabolic shifts caused by productive action on the cell of infective or unknown factor.     

Nicotine binding in human striatum: elevation in schizophrenia and reductions in dementia with Lewy bodies, Parkinson's disease and Alzheimer's disease and in relation to neuroleptic medication

Striatal nicotinic acetylcholine receptors with high affinity for nicotinic agonists are involved with the release of a number of neurotransmitters, including dopamine. Previous findings as to whether these receptors are changed in Parkinson's disease and Alzheimer's disease are inconsistent and no previous investigations have focused on these receptors in dementia with Lewy bodies and schizophrenia, which are also associated with disorders of movement. The present autoradiographic study of striatal [3H]nicotine binding in Alzheimer's and Parkinson's diseases, dementia with Lewy bodies and schizophrenia was conducted with particular reference to the potentially confounding variables of tobacco use and neuroleptic medication. [3H]Nicotine binding in both dorsal and ventral caudate and putamen was significantly reduced in Parkinson's disease (43-67%, n=13), Alzheimer's disease (29-37%, n=13) and dementia with Lewy bodies (50-61%, n=20) compared to age-matched controls (n=42). Although tobacco use in the control group was associated with increased [3H]nicotine binding (21-38%), and neuroleptic treatment in dementia with Lewy bodies and Alzheimer's disease was associated with reduced [3H]nicotine binding (up to 29%), differences between neurodegenerative disease groups and controls persisted in subgroups of Alzheimer's disease cases (26-33%, n=6, in the ventral striatum) and dementia with Lewy body cases (30-49%, n=7, in both dorsal and ventral striatum) who had received no neuroleptic medication compared to controls who had not smoked (n=10). In contrast, striatal [3H]nicotine binding in a group of elderly (56-85 years) chronically medicated individuals with schizophrenia (n=6) was elevated compared with the entire control group (48-78%, n=42) and with a subgroup that had smoked (24-49%, n=8).The changes observed in [3H]nicotine binding are likely to reflect the presence of these receptors on multiple sites within the striatum, which may be differentially modulated in the different diseases. Further study is warranted to explore which nicotinic receptor subunits and which neuronal compartments are involved in the changes in [3H]nicotine binding reported, to aid development of potential nicotinic receptor therapy.     

TDP‐43 pathology in Alzheimer's disease,dementia with Lewy bodies and ageing

Intracellular inclusions consisting of TAR DNA binding protein‐43 (TDP‐43 pathology) are present in up to 57% of Alzheimer's disease (AD) cases and follow a distinct topographical pattern of progression described in the TDP‐43 in AD staging scheme. This scheme has not been applied to the assessment of TDP‐43 pathology in dementia with Lewy bodies (DLB) and aged controls. We investigated TDP‐43 pathology prevalence and severity in AD, DLB, mixed AD/DLB (Mx AD/DLB) and aged controls. One hundred and nineteen human post‐mortem brains were included, neuropathologically diagnosed as AD: 46, DLB: 15, Mx AD/DLB: 19 and aged controls: 39. Paraffin sections inclusive of the amygdala, hippocampus, striatum and neocortex were immunohistochemically stained with antibodies against phosphorylated TDP‐43 and staged according to the TDP‐43 in AD staging scheme. TDP‐43 pathology was present in all groups: AD: 73.9%, DLB: 33.3%, Mx AD/DLB: 52.6% and controls: 17.9%. Prevalence of TDP‐43 pathology was significantly higher in AD and Mx AD/DLB compared to controls. In controls, higher age at death was associated with prevalence of TDP‐43 pathology and higher TDP‐43 in AD stage, suggesting that this type of TDP‐43 pathology may partly be an age‐associated phenomenon. Significantly higher prevalence of TDP‐43 pathology in the AD group indicates that AD pathology possibly triggers and aggravates TDP‐43 pathology. The validity of the TDP‐43 in AD staging scheme is not limited to AD and should be applied to assess TDP‐43 pathology in post mortem brains of aged individuals to further elucidate the role of TDP‐43 pathology in age associated neurodegeneration.     

Degeneration process of Lewy bodies in the brains of patients with dementia with Lewy bodies using alpha-synuclein-immunohistochemistry

We investigated the degeneration process of Lewy bodies (LB) in the brains of dementia with Lewy bodies, using alpha-synuclein-immunohistochemistry. Intracellular LB, LB-related neurites and some extracellular LB were positively immunostained with anti-alpha-synuclein antibodies. Concentric LB-bearing neurons had no microglial involvement, while degenerated neurons with ill-defined LB displayed intense microglial involvement. The late stage of extracellular LB were immunoelectron-microscopically composed of loose aggregates of filamentous components with lost alpha-synuclein-immunoreactivity and penetrated astroglial processes. These findings suggest that microglias are involved during the stages from degenerated LB-bearing neurons to extracellular LB, while astroglias are involved during the stage of extracellular LB. Some intracellular LB were positive for anti-C3d and -C4d antibodies, suggesting that the classical complement pathway is activated in degenerated LB-bearing neurons, inducing microglial activation and neuronal death.