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Al-Sarraj, S., S. Maekawa, et al. (2002). "Ubiquitin-only
intraneuronal inclusion in the substantia nigra is a characteristic feature of
motor neurone disease with dementia." Neuropathol Appl Neurobiol 28(2):
120-8.
Two types of ubiquitinated inclusions have been described in motor neurone
disease (MND). (1) Skein or globular ubiquitinated inclusions in the motor
neurones (more frequently in the lower motor neurones). This is a characteristic
feature of all motor neurone disease categories. (2) Dot-shape or crescentric
ubiquitinated inclusions in the upper layers of cortex and dentate gyrus
described in cases of motor neurone disease with dementia (DMND). We
investigated the substantia nigra (SN) in MND cases; two cases of motor neurone
disease inclusion body (MND-IB) dementia, six cases of DMND, 14 cases of MND
(including one case from Guam and two cases of familial SOD1 mutation), four
cases of Parkinson's disease (PD), and 10 cases of age-matched normal controls.
SN and spinal cord sections were stained with ubiquitin (alpha-synuclein, tau,
PGM1, SMI-31 and SOD1 antibodies). The neuronal density in SN was quantified by
using a computer-based image analysis system. Four out of six DMND cases showed
rounded ubiquitin positive inclusions with irregular frayed edges, associated
with neuronal loss, reactive astrocytosis and a large number of activated
microglia cells. These inclusions are negative with antibodies to
(alpha-synuclein, tau, SMI-31 and SOD1). The SN in cases from MND-IB dementia
and MND showed occasional neuronal loss and no inclusions. The ubiquitin-only
inclusions in SN of DMND cases are similar (but not identical) to the
ubiquitinated inclusions described previously in the spinal cord of MND cases
and are distinct from Lewy bodies (LBs). The degeneration of SN is most likely a
primary neurodegenerative process of motor neurone disease type frequently
involving the DMND cases. MND disease is a spectrum and multisystem disorder
with DMND located at the extreme end of a spectrum affecting the CNS more widely
than just the motor system.
Alim, M. A., M. S. Hossain, et al. (2002). "Tubulin seeds alpha-synuclein fibril
formation." J Biol Chem 277(3): 2112-7.
Increasing evidence suggests that alpha-synuclein is a common pathogenic
molecule in several neurodegenerative diseases, particularly in Parkinson's
disease. To understand alpha-synuclein pathology, we investigated molecules that
interact with alpha-synuclein in human and rat brains and identified tubulin as
an alpha-synuclein binding/associated protein. Tubulin co-localized with
alpha-synuclein in Lewy bodies and other alpha-synuclein-positive pathological
structures. Tubulin initiated and promoted alpha-synuclein fibril formation
under physiological conditions in vitro. These findings suggest that an
interaction between tubulin and alpha-synuclein might accelerate alpha-synuclein
aggregation in diseased brains, leading to the formation of Lewy bodies.
Apaydin, H., J. E. Ahlskog, et al. (2002). "Parkinson disease neuropathology:
later-developing dementia and loss of the levodopa response." Arch Neurol
59(1): 102-12.
OBJECTIVE: To investigate the neuropathologic substrate for dementia occurring
late in Parkinson disease (PD). DESIGN: We identified 13 patients with a
clinical diagnosis of PD who experienced dementia at least 4 years after
parkinsonism onset (mean, 10.5 years) and subsequently underwent postmortem
examination. Despite levodopa therapy, 9 patients later became severely impaired
and nonambulatory, requiring total or near-total care; this included 4 patients
treated with 1200 mg/d or more of levodopa (with carbidopa), which was
consistent with loss of the levodopa response. These 13 patients were compared
with 9 patients clinically diagnosed as having PD, but without dementia, who had
undergone autopsies. RESULTS: Twelve of 13 PD patients with dementia had
findings of diffuse or transitional Lewy body disease as the primary pathologic
substrate for dementia; 1 had progressive supranuclear palsy. This pathology
also apparently accounted for the levodopa refractory state. Among the 12 PD
patients with dementia, mean and median Lewy body counts were increased nearly
10-fold in neocortex and limbic areas compared with PD patients without dementia
(P< or =.002). Alzheimer pathology was modest. Only one patient met the criteria
defined by the National Institute on Aging and the Reagan Institute Working
Group on the Diagnostic Criteria for the Neuropathologic Assessment of
Alzheimer's Disease for "intermediate probability of Alzheimer's disease." There
were, however, significant correlations between neocortical Lewy body counts and
senile plaques as well as neurofibrillary tangles. Senile plaque counts did not
significantly correlate with tangle counts in any of the analyzed nuclei.
Arteriolar disease may have contributed to the clinical picture in 2 patients.
CONCLUSIONS: Diffuse or transitional Lewy body disease is the primary pathologic
substrate for dementia developing later in PD. This same pathologic substrate
seemed to account for end-stage, levodopa refractory parkinsonism. The
occurrence of Alzheimer pathology was modest, but was highly correlated with
Lewy body pathology, suggesting common origins or one triggering the other.
Arsland, D. (2002). "[Dementia with Lewy bodies]." Tidsskr Nor Laegeforen
122(5): 525-9.
BACKGROUND: Some 10%-15% of patients with dementia are diagnosed as dementia
with Lewy bodies (DLB), a disorder characterised by the presence of Lewy bodies
in the brainstem and cortex. MATERIAL AND METHODS: Review of pathology, clinical
symptoms, pharmacological and nonpharmacological treatment, based on the
literature and on personal experience. RESULTS: Neurochemical findings are
marked cortical reduction of acetylcholine and nigrostriatal dopamine
deficiency. Key features of the clinical syndrome are dementia, fluctuating
consciousness, visual hallucinations and parkinsonism. There are pathological
and clinical overlaps between DLB and Alzheimer's disease on the one hand, and
between DLB and Parkinson's disease on the other; the relationship between these
diseases awaits further elucidation. Clinical consensus criteria for DLB have
been published and shown to have high sensitivity and specificity. Fluctuating
consciousness may be difficult to detect, but diagnostic instruments exist that
may help in the evaluation. Drug treatment of DLB is difficult. Cholinesterase
inhibitors have been shown to improve cognition and psychiatric symptoms.
Atypical antipsychotics may improve psychosis, but some patients develop severe
sensitivity reactions. The effect of antiparkinson agents is unknown.
Assal, F. and J. L. Cummings (2002). "Neuropsychiatric symptoms in the
dementias." Curr Opin Neurol 15(4): 445-50.
PURPOSE OF REVIEW: Neuropsychiatric, or non-cognitive symptoms are increasingly
recognized as manifestations of dementias. RECENT FINDINGS: In Alzheimer's
disease, recent advances have included the identification of behavioral
profiles, differentiation of apathy and depression, characterization of risk
factors for psychosis and its links to agitation and aggression, and an analysis
of depressive symptoms in the absence of major depression. Functional
neuroimaging data mainly supported the role of the anterior cingulate in apathy.
The orbitofrontal and anterior cingulate tangle burden were associated with
agitation, and increased orbitofrontal and mid-temporal muscarinic M2 receptors
with psychosis and hallucinations. Selected genetic polymorphisms of dopamine
and serotonin receptors or transporters were linked with aggression,
hallucinations or psychosis. When compared with other dementias, individuals
with frontotemporal dementia disclosed, as expected, different behaviors and
particularly aberrant social behavior. The frequency of delusions and visual
hallucinations was increased in Parkinson's disease, Parkinson's disease with
dementia, and dementia with Lewy bodies, suggesting common mechanisms such as
Lewy body pathology and cholinergic deficiency. The latter was supported by an
improvement of these symptoms by cholinesterase inhibitors. SUMMARY: Future
research directions include both clinical and basic neuroscience investigations.
The detection of early neuropsychiatric symptoms might be a marker for dementia,
and the possible existence of a mild neuropsychiatric impairment syndrome should
be explored. More longitudinal studies with pathological confirmation will
facilitate correlations with neuropsychiatric symptoms. Functional neuroimaging
and behavioral neurogenetics will permit in-vivo correlations and consequently
help patient management and care.
Auluck, P. K., H. Y. Chan, et al. (2002). "Chaperone suppression of
alpha-synuclein toxicity in a Drosophila model for Parkinson's disease."
Science 295(5556): 865-8.
Parkinson's disease is a movement disorder characterized by degeneration of
dopaminergic neurons in the substantia nigra pars compacta. Dopaminergic
neuronal loss also occurs in Drosophila melanogaster upon directed expression of
alpha-synuclein, a protein implicated in the pathogenesis of Parkinson's disease
and a major component of proteinaceous Lewy bodies. We report that directed
expression of the molecular chaperone Hsp70 prevented dopaminergic neuronal loss
associated with alpha-synuclein in Drosophila and that interference with
endogenous chaperone activity accelerated alpha-synuclein toxicity. Furthermore,
Lewy bodies in human postmortem tissue immunostained for molecular chaperones,
also suggesting that chaperones may play a role in Parkinson's disease
progression.
Barber, R., I. McKeith, et al. (2002). "Volumetric MRI study of the caudate
nucleus in patients with dementia with Lewy bodies, Alzheimer's disease, and
vascular dementia." J Neurol Neurosurg Psychiatry 72(3): 406-7.
OBJECTIVES: To determine whether parkinsonian symptoms in dementia with Lewy
bodies (DLB) are associated with greater atrophy of the caudate nucleus in
comparison with patients with Alzheimer's disease (AD) and vascular dementia (VaD).
METHODS: T1weighted MR scans were acquired in elderly patients with DLB, AD, VaD,
and healthy controls. Normalised volumetric measurements of the caudate nucleus
were obtained and parkinsonian symptoms rated using Hoehn and Yahr staging.
RESULTS: There were no significant differences in the volume of the caudate
nucleus between patients with dementia. However, the left caudate volume was
significantly reduced in AD and DLB compared with controls. Parkinsonian
symptoms did not correlate with caudate nucleus volume. CONCLUSIONS:
Parkinsonian symptoms in DLB may be more closely coupled to neurochemical rather
than structural changes in the caudate nucleus, and volumetric MRI analysis of
caudate nucleus does not discriminate between patients with DLB, AD, and VaD.
Bergman, J. and V. Lerner (2002). "Successful use of donepezil for the treatment
of psychotic symptoms in patients with Parkinson's disease." Clin
Neuropharmacol 25(2): 107-10.
The risk of psychosis among patients with Parkinson's disease (PD) is high, and
the management of these patients remains a substantial problem for physicians.
Atypical antipsychotics, despite their advantages over conventional
antipsychotics, can cause different side effects and deterioration of PD.
Several reports have suggested that donepezil can be helpful in the treatment of
psychotic conditions in patients with dementia with Lewy bodies and Alzheimer's
disease. This report presents the results of preliminary study of six patients
(four women, two men; age range, 60-75 years) with PD (range of duration, 3-7
years) and dementia complicated by psychosis. All patients were treated with
antiparkinsonian therapy, and donepezil was added to their regular treatment.
The severity of the psychotic symptoms was assessed using the Scale for the
Assessment of Positive Symptoms, and extrapyramidal symptoms were assessed using
the Simpson-Angus Scale. With the addition of donepezil (as much as 10 mg/day)
to their constant antiparkinsonian treatment, five patients had clinically
significant (more than 53%) improvement on the assessment scale, and one patient
had minimal (24%) improvement after 6 weeks of the treatment. None of the
patients had side effects or deterioration of parkinsonian symptoms. The results
suggest that donepezil may ameliorate psychotic symptoms in patients with PD,
but this will need to be tested further in controlled, double-blind trials.
Castellani, R. J., G. Perry, et al. (2002). "Hydroxynonenal adducts indicate a
role for lipid peroxidation in neocortical and brainstem Lewy bodies in humans."
Neurosci Lett 319(1): 25-8.
Multiple lines of evidence indicate that oxidative stress is a critical
pathogenic factor in Parkinson disease (PD) and diffuse Lewy body disease (DLBD).
Previously, we demonstrated increased levels of redox-active iron in Lewy
bodies, and that Lewy bodies accumulate advanced glycation end-products. To
further characterize the role of oxidative stress in diseases with Lewy body
formation, we examined immunocytochemically eight cases of PD and five cases of
DLBD for adducts of the lipid peroxidation adduct 4-hydroxy-2-nonenal, and for
N(epsilon)-(carboxymethyl)lysine (CML). Our findings demonstrate
immunolocalization of 4-hydroxynonenal and CML to Lewy bodies in PD and DLBD.
These findings not only support prior studies indicating that lipid peroxidation
is increased in patients with PD and DLBD but that oxidative damage may play a
critical role in Lewy body formation.
Choi, J. Y., Y. M. Sung, et al. (2002). "Rapid purification and analysis of
alpha-synuclein proteins: C-terminal truncation promotes the conversion of
alpha-synuclein into a protease-sensitive form in Escherichia coli."
Biotechnol Appl Biochem 36(Pt 1): 33-40.
Parkinson's disease (PD) is the most common neurodegenerative movement disorder
and is characterized by the loss of dopaminergic neurons and the formation of
eosinophilic intracytoplasmic inclusion bodies known as Lewy bodies. Although
alpha-synuclein is known to be a pivotal factor implicated in the pathogenesis
of PD, its function remains to be elucidated. We used the pGEX expression system
to develop a simple and rapid method for purifying alpha-synuclein proteins in
suitable forms for biochemical studies of their functions. The wild-type
alpha-synuclein protein was overexpressed in Escherichia coli and purified to
approx. 80% purity with relatively high yields. We also used this expression
system to investigate the expression pattern of the various domains of
alpha-synuclein. With the exception of the alpha-synuclein protein that was
truncated at amino acid residue 95, all domain constructs of alpha-synuclein
were purified at similar levels with relatively high yields. Unexpectedly,
removal of amino acid residues 96-140 in the C-terminal acidic region of
alpha-synuclein promotes its conversion to a protease-sensitive form during
expression and purification in E. coli. Our study suggests a method for
generating useful reagents to investigate the molecular mechanism by which
alpha-synuclein regulates the pathogenesis of PD.
Cohlberg, J. A., J. Li, et al. (2002). "Heparin and other glycosaminoglycans
stimulate the formation of amyloid fibrils from alpha-synuclein in vitro."
Biochemistry 41(5): 1502-11.
Parkinson's disease is the second most common neurodegenerative disease and
results from loss of dopaminergic neurons in the substantia nigra. The
aggregation and fibrillation of alpha-synuclein have been implicated as a
causative factor in the disease. Glycosaminoglycans (GAGs) are routinely found
associated with amyloid deposits in most amyloidosis diseases, and there is
evidence to support an active role of GAGs in amyloid fibril formation in some
cases. In contrast to the extracellular amyloid deposits, the alpha-synuclein
deposits in Lewy body diseases are intracellular, and thus it is less clear
whether GAGs may be involved. To determine whether the presence of GAGs does
affect the fibrillation of alpha-synuclein, the kinetics of fibril formation
were investigated in the presence of a number of GAGs and other charged
polymers. Certain GAGs (heparin, heparan sulfate) and other highly sulfated
polymers (dextran sulfate) were found to significantly stimulate the formation
of alpha-synuclein fibrils. Interestingly, the interaction of GAGs with
alpha-synuclein is quite specific, since some GAGs, e.g., keratan sulfate, had
negligible effect. Heparin not only increased the rate of fibrillation but also
apparently increased the yield of fibrils. The molar ratio of heparin to
alpha-synuclein and the incorporation of fluorescein-labeled heparin into the
fibrils demonstrate that the heparin is integrated into the fibrils and is not
just a catalyst for fibrillation. The apparent dissociation constant for heparin
in stimulating alpha-synuclein fibrillation was 0.19 microM, indicating a strong
affinity. Similar effects of heparin were observed with the A53T and A30P
mutants of alpha-synuclein. Since there is some evidence that Lewy bodies may
contain GAGs, these observations may be very relevant in the context of the
etiology of Parkinson's disease.
Cole, N. B. and D. D. Murphy (2002). "The cell biology of alpha-synuclein: a
sticky problem?" Neuromolecular Med 1(2): 95-109.
Parkinson's disease (PD) is the most common neurodegenerative motor disorder,
marked by chronic progressive loss of neurons in the substantia nigra, thereby
damaging purposeful control of movement. For decades, it was believed that PD
was caused solely by environmental causes. However, the discovery of genetic
factors involved in PD has revolutionized our attempts to understand the
disease's pathology. PD now appears to be more polygenetic than previously
thought and is most likely caused by a complex interaction of genetic risks and
environmental exposures. The first gene found to be mutated in PD encodes for
the presynaptic protein alpha-synuclein, which is also a major component of Lewy
bodies and Lewy neurites, the neuropathological hallmarks of the disease. While
these findings provide a classic example of how rare genetic mutations in
disease can point to important pathways in idiopathic disease pathologies, much
of the study of alpha-synuclein has focused on understanding how this protein
undergoes the transition from an unfolded monomer to amorphous aggregates or
Lewy body-like filaments rather than addressing what its fundamental function
might be. Since alterations in synuclein function may predispose to the disease
pathology of PD, regardless of the presence of genetic mutations, a more
thorough understanding of the cellular regulation and function of
alpha-synuclein may be of crucial importance to our understanding of this
degenerating disorder.
Cole, N. B., D. D. Murphy, et al. (2002). "Lipid droplet binding and
oligomerization properties of the Parkinson's disease protein alpha-synuclein."
J Biol Chem 277(8): 6344-52.
alpha-Synuclein is a major component of the fibrillary lesion known as Lewy
bodies and Lewy neurites that are the pathologic hallmarks of Parkinson's
disease (PD). In addition, point mutations in the alpha-synuclein gene imply
alpha-synuclein dysfunction in the pathology of inherited forms of PD.
alpha-Synuclein is a member of a family of proteins found primarily in the brain
and is concentrated within presynaptic terminals. Here, we address the
localization and membrane binding characteristics of wild type and PD mutants of
alpha-synuclein in cultured cells. In cells treated with high concentrations of
fatty acids, wild type alpha-synuclein accumulated on phospholipid monolayers
surrounding triglyceride-rich lipid droplets and was able to protect stored
triglycerides from hydrolysis. PD mutant synucleins showed variable
distributions on lipid droplets and were less effective in regulating
triglyceride turnover. Chemical cross-linking demonstrated that synuclein formed
small oligomers within cells, primarily dimers and trimers, that preferentially
associated with lipid droplets and cell membranes. Our results suggest that the
initial phases of synuclein aggregation may occur on the surfaces of membranes
and that pathological conditions that induce cross-linking of synuclein may
enhance the propensity for subsequent synuclein aggregation.
Corti, O. and A. Brice (2002). "[Parkin, alpha-synuclein and other molecular
aspects of Parkinson's disease]." J Soc Biol 196(1): 95-10.
Parkinson's disease is a neurodegenerative disorder characterized by the
progressive degeneration of the dopaminergic nigrostriatal pathway, and the
presence of Lewy bodies. Over the past few years, several genes involved in
inherited forms of the disease have been uncovered. In a small number of
families with autosomal dominant inheritance, mutations have been identified in
the genes encoding a-synuclein and ubiquitin carboxy-terminal hydrolase L1.
Mutations in the parkin gene are a common cause of autosomal recessive
parkinsonism with early onset, and also account for more than 15% of isolated
cases with onset before age 45. The function of Parkin, a ubiquitin ligase
involved in the degradation of protein substrates by the ubiquitin-proteasome
pathway, highlights that ubiquitin-mediated proteolysis may play an important
role in the pathophysiology of idiopathic Parkinson's disease.
Culvenor, J. G., R. L. Rietze, et al. (2002). "Oligodendrocytes from neural stem
cells express alpha-synuclein: increased numbers from presenilin 1 deficient
mice." Neuroreport 13(10): 1305-8.
alpha-Synuclein normally a synaptic vesicle-associated cytoplasmic protein is
the major component of filamentous inclusions of neurons in Parkinson's disease
and dementia with Lewy bodies. It is also the major component of glial
inclusions of multiple system atrophy. In characterizing cells derived from
embryonic neural stem cells we found all oligodendrocytes had strong cytoplasmic
expression of alpha-synuclein. Comparison of cells from presenilin 1
(PS1)-deficient mice with wild type revealed a 7-fold increase in
oligodendrocytes. Western blotting analysis indicated the cells contained
alpha-synuclein monomers and SDS-stable dimers and trimers. This cell system of
oligodendroglial alpha-synuclein expression is a useful system to study
alpha-synuclein metabolism in the cell type affected in multiple system atrophy.
Increased oligodendroglial cell numbers from PS1-deficient cells provides
further evidence for a role of PS1-dependent Notch signalling in cell fate
decisions.
Del Tredici, K., U. Rub, et al. (2002). "Where does parkinson disease pathology
begin in the brain?" J Neuropathol Exp Neurol 61(5): 413-26.
The substantia nigra is not the induction site in the brain of the
neurodegenerative process underlying Parkinson disease (PD). Instead, the
results of this semi-quantitative study of 30 autopsy cases with incidental Lewy
body pathology indicate that PD in the brain commences with the formation of the
very first immunoreactive Lewy neurites and Lewy bodies in non-catecholaminergic
neurons of the dorsal glossopharyngeus-vagus complex, in projection neurons of
the intermediate reticular zone, and in specific nerve cell types of the gain
setting system (coeruleus-subcoeruleus complex, caudal raphe nuclei,
gigantocellular reticular nucleus), olfactory bulb, olfactory tract, and/or
anterior olfactory nucleus in the absence of nigral involvement. The
topographical parcellation of the nuclear grays described here is based upon
known architectonic analyses of the human brainstem and takes into consideration
the pigmentation properties of a few highly susceptible nerve cell types
involved in PD. In this sample and in all 58 age- and gender-matched controls,
Lewy bodies and Lewy neurites do not occur in any of the known prosencephalic
predilection sites (i.e. hippocampal formation, temporal mesocortex,
proneocortical cingulate areas, amygdala, basal nucleus of Meynert, interstitial
nucleus of the diagonal band of Broca, hypothalamic tuberomamillary nucleus).
Ding, T. T., S. J. Lee, et al. (2002). "Annular alpha-Synuclein Protofibrils Are
Produced When Spherical Protofibrils Are Incubated in Solution or Bound to
Brain-Derived Membranes." Biochemistry 41(32): 10209-17.
The Parkinson's disease substantia nigra is characterized by the loss of
dopaminergic neurons and the presence of cytoplasmic fibrillar Lewy bodies in
surviving neurons. The major fibrillar protein of Lewy bodies is
alpha-synuclein. Two point mutations in the alpha-synuclein gene are associated
with autosomal-dominant Parkinson's disease (FPD). Studies of the in vitro
fibrillization behavior of the mutant proteins suggest that fibril precursors,
or alpha-synuclein protofibrils, rather than the fibrils, may be pathogenic.
Atomic force microscopy (AFM) revealed two distinct forms of protofibrillar
alpha-synuclein: rapidly formed spherical protofibrils and annular protofibrils,
which were produced on prolonged incubation of spheres. The spherical
protofibrils bound to brain-derived membrane fractions much more tightly than
did monomeric or fibrillar alpha-synuclein, and membrane-associated annular
protofibrils were observed. The structural features of alpha-synuclein annular
protofibrils are reminiscent of bacterial pore-forming toxins and are consistent
with their porelike activity in vitro. Thus, abnormal membrane permeabilization
may be a pathogenic mechanism in PD.
Duda, J. E., B. I. Giasson, et al. (2002). "Concurrence of alpha-synuclein and
tau brain pathology in the Contursi kindred." Acta Neuropathol (Berl)
104(1): 7-11.
Previous genetic analysis of the familial Parkinson's disease Contursi kindred
led to the identification of an Ala53Thr pathogenic mutation in the
alpha-synuclein gene. We have re-examined one of the original brains from this
kindred using new immunohistochemical reagents, thioflavin S staining and
immunoelectron microscopy. Surprisingly, we uncovered a dense burden of
alpha-synuclein neuritic pathology and rare Lewy bodies. Immunoelectron
microscopy demonstrated fibrillar alpha-synuclein-immunoreactive aggregates.
Unexpected tau neuritic and less frequent perikaryal inclusions were also
observed. Some inclusions were comprised of both proteins with almost complete
spatial disparity. We suggest that it is important to recognize that the
neurodegenerative process caused by the Ala53Thr mutation in alpha-synuclein is
not identical to that seen in typical idiopathic Parkinson's disease brains.
Elkon, H., J. Don, et al. (2002). "Mutant and wild-type alpha-synuclein interact
with mitochondrial cytochrome C oxidase." J Mol Neurosci 18(3):
229-38.
Alpha-synuclein, a presynaptic protein, was found to be the major component in
the Lewy bodies (LB) in both inherited and sporadic Parkinson's disease (PD).
Furthermore, rare mutations of alpha-synuclein cause autosomal-dominant PD.
However, it is unknown how alpha-synuclein is involved in the pathogenesis of
nigral degeneration in PD. In this study, we examine the protein-protein
interactions of wild-type and mutant (A53T) a-synuclein with adult human brain
cDNA expression library using the yeast two-hybrid technique. We found that both
normal and mutant alpha-synuclein specifically interact with the mitochondrial
complex IV enzyme, cytochrome C oxidase (COX). Wild-type and mutant
alpha-synuclein genes were further fused with c-Myc tag and translated in rabbit
reticulocyte lysate. Using anti-c-Myc antibody, we demonstrated that both
wild-type and mutant alpha-synuclein, coimmunoprecipitated with COX. We also
showed that potassium cyanide, a selective COX inhibitor, synergistically
enhanced the sensitivity of SH-SY5Y neuroblastoma cells to dopamine-induced cell
death. In conclusion, we found specific protein-protein interactions of
alpha-synuclein, a major LB protein, to COX, a key enzyme of the mithochondrial
respiratory system. This interaction suggests that alpha-synuclein aggregation
may contribute to enhance the mitochondrial dysfunction, which might be a key
factor in the pathogenesis of PD.
Fernandez, H. H., M. E. Trieschmann, et al. (2002). "Quetiapine for psychosis in
Parkinson's disease versus dementia with Lewy bodies." J Clin Psychiatry
63(6): 513-5.
BACKGROUND: Most clinicians perceive psychosis in dementia with Lewy bodies
(DLB) as more difficult to treat than Parkinson's disease, yet there are no
reports comparing the antipsychotic response between the 2 disorders. METHOD:
All charts of Parkinson's disease and DLB patients at our Movement Disorders
Center, Memorial Hospital of Rhode Island, Pawtucket, given quetiapine for
psychosis were reviewed. Demographic data, including type and severity of
psychosis, before and after Unified Parkinson's Disease Rating Scale
(UPDRS)-motor scores, motor worsening, and treatment response (recorded as
poor/none, partial, or total), were obtained. The chi-square test was used to
assess differences in efficacy and tolerability of quetiapine between
Parkinson's disease and DLB patients. RESULTS: Eighty-seven Parkinson's disease
and 11 DLB patients with psychosis were analyzed. No significant difference in
mean age, levodopa dose, quetiapine dose, duration of quetiapine use, or
baseline UPDRS-motor score was noted between Parkinson's disease and DLB
patients. Eighty percent (70/87) of Parkinson's disease patients and 90% (10/11)
of DLB patients had partial to complete resolution of psychosis using quetiapine
(p = .40). Motor worsening was noted at one point in 32% (28/87) of Parkinson's
disease and 27% (3/11) of DLB patients over the duration of quetiapine use (p =
.74). CONCLUSION: Long-term quetiapine use was generally well tolerated in this
geriatric Parkinson's disease and DLB population. Mild motor worsening occurred
in some patients. No significant difference in long-term efficacy and motor
worsening associated with quetiapine treatment was noted between the 2
disorders.
Fishman, P. S. and G. A. Oyler (2002). "Significance of the parkin gene and
protein in understanding Parkinson's disease." Curr Neurol Neurosci Rep
2(4): 296-302.
Mutations in the parkin gene cause autosomal recessive inherited juvenile
parkinsonism (ARJP) and account for the majority of cases of inherited
Parkinson's disease (PD) of young onset (<45 years of age). Patients with parkin
mutations commonly have atypical clinical features such as dystonia at onset,
hyper-reflexia, diurnal fluctuations, and sleep benefit; however, parkin
mutation patients with both typical PD symptoms and older age of onset have been
identified. Parkin is a ubiquitin protein ligase (E3), a component in the
pathway that attaches ubiquitin to specific proteins, designating them for
degradation by the proteasome. Several substrates for parkin have been
identified (CDCrel-1, o-glycosylated a-synuclein, parkin associated
endothelin-like cell receptor, and synphilin). The role of these substrates in
the pathogenesis of ARJP is under active study. Most patients with parkin
mutations lack Lewy bodies, suggesting that functional parkin is involved in the
formation of these highly ubiquitinated inclusions. Furthermore, the recognition
that parkin mutations can lead to a disorder clinically similar to sporadic PD,
but presumably lacking Lewy bodies, calls into question the necessity of Lewy
bodies for the diagnosis of PD and nigral cell death. Studies of parkin are
increasing the focus on the role of the ubiquitin-proteasome system in the
pathogenesis of both familial and sporadic PD.
Freo, U., G. Pizzolato, et al. (2002). "A short review of cognitive and
functional neuroimaging studies of cholinergic drugs: implications for
therapeutic potentials." J Neural Transm 109(5-6): 857-70.
In the last 20 years a cholinergic dysfunction has been the major working
hypothesis for the pharmacology of memory disorders. Cholinergic antagonists and
lesions impair and different classes of cholinomimetics (i.e. acetylcholine
precursors, cholinergic agonists and acetylcholinesterase inhibitors) enhance
attention and memory in experiment animals, healthy human subjects and Alzheimer
disease patients. In addition, acetylcholinesterase inhibitors improve different
cognitive (i.e. visuospatial and verbal) functions in a variety of unrelated
disorders such as dementia with Lewy bodies, Parkinson disease, multiple
sclerosis, schizoaffective disorders, iatrogenic memory loss, traumatic brain
injury, hyperactivity attention disorder and, as we recently reported, vascular
dementia and mild cognitive impairment. In animals, different cholinomimetics
dose-dependently increased regional cerebral metabolic rates for glucose
(rCMRglc) and regional blood flow (rCBF), two indices of neuronal function, more
markedly in subcortical regions (i.e. thalamus, hippocampus and visual system
nuclei). In both healthy human subjects and Alzheimer disease patients
acetylcholinesterase inhibitors increased rCMRglc and rCBF in subcortical and
cortical brain regions at rest but attenuated rCBF increases during cognitive
performances. Hence, acetylcholinesterase inhibitors may enhance cognition and
rCMRglc by acting primarily on subcortical regions that are involved in
attentional (i.e. thalamus) and memory (i.e. hippocampus) processes; such an
effect probably is not specific for Alzheimer disease and can be beneficial in
patients suffering from a wide array of neuropsychiatric disorders.
Fujiwara, H., M. Hasegawa, et al. (2002). "alpha-Synuclein is phosphorylated in
synucleinopathy lesions." Nat Cell Biol 4(2): 160-4.
The deposition of the abundant presynaptic brain protein alpha-synuclein as
fibrillary aggregates in neurons or glial cells is a hallmark lesion in a subset
of neurodegenerative disorders. These disorders include Parkinson's disease
(PD), dementia with Lewy bodies (DLB) and multiple system atrophy, collectively
referred to as synucleinopathies. Importantly, the identification of missense
mutations in the alpha-synuclein gene in some pedigrees of familial PD has
strongly implicated alpha-synuclein in the pathogenesis of PD and other
synucleinopathies. However, specific post-translational modifications that
underlie the aggregation of alpha-synuclein in affected brains have not, as yet,
been identified. Here, we show by mass spectrometry analysis and studies with an
antibody that specifically recognizes phospho-Ser 129 of alpha-synuclein, that
this residue is selectively and extensively phosphorylated in synucleinopathy
lesions. Furthermore, phosphorylation of alpha-synuclein at Ser 129 promoted
fibril formation in vitro. These results highlight the importance of
phosphorylation of filamentous proteins in the pathogenesis of neurodegenerative
disorders.
Golts, N., H. Snyder, et al. (2002). "Magnesium inhibits spontaneous and
iron-induced aggregation of alpha-synuclein." J Biol Chem 277(18):
16116-23.
Multiple studies implicate metals in the pathophysiology of neurodegenerative
diseases. Disturbances in brain iron metabolism are linked with
synucleinopathies. For example, in Parkinson's disease, iron levels are
increased and magnesium levels are reduced in the brains of patients. To
understand how changes in iron and magnesium might affect the pathophysiology of
Parkinson's disease, we investigated binding of iron to alpha-synuclein, which
accumulates in Lewy bodies. Using fluorescence of the four tyrosines in
alpha-synuclein as indicators of metal-related conformational changes in
alpha-synuclein, we show that iron and magnesium both interact with
alpha-synuclein. alpha-Synuclein exhibits fluorescence peaks at 310 and 375 nm.
Iron lowers both fluorescence peaks, while magnesium increases the fluorescence
peak only at 375 nm, which suggests that magnesium affects the conformation of
alpha-synuclein differently than iron. Consistent with this hypothesis, we also
observe that magnesium inhibits alpha-synuclein aggregation, measured by
immunoblot, cellulose acetate filtration, or thioflavine-T fluorescence. In each
of these studies, iron increases alpha-synuclein aggregation, while magnesium at
concentrations >0.75 mm inhibits the aggregation of alpha-synuclein induced
either spontaneously or by incubation with iron. These data suggest that the
conformation of alpha-synuclein can be modulated by metals, with iron promoting
aggregation and magnesium inhibiting aggregation.
Gomez-Santos, C., I. Ferrer, et al. (2002). "MPP+ increases alpha-synuclein
expression and ERK/MAP-kinase phosphorylation in human neuroblastoma SH-SY5Y
cells." Brain Res 935(1-2): 32-9.
Alpha-synuclein is a brain presynaptic protein that is linked to familiar early
onset Parkinson's disease and it is also a major component of Lewy bodies in
sporadic Parkinson's disease and other neurodegenerative disorders.
Alpha-synuclein expression increases in substantia nigra of both MPTP-treated
rodents and non-human primates, used as animal models of parkinsonism. Here we
describe an increase in alpha-synuclein expression in a human neuroblastoma cell
line, SH-SY5Y, caused by 5-100 microM MPP+, the active metabolite of MPTP, which
induces apoptosis in SH-SY5Y cells after a 4-day treatment. We also analysed the
activation of the MAPK family, which is involved in several cellular responses
to toxins and stressing conditions. Parallel to the increase in alpha-synuclein
expression we observed activation of MEK1,2 and ERK/MAPK but not of SAPK/JNK or
p38 kinase. The inhibition of the ERK/MAPK pathway with U0126, however, did not
affect the increase in alpha-synuclein. The highest increase in alpha-synuclein
(more than threefold) in 4-day cultures was found in adherent cells treated with
low concentrations of MPP+ (5 microM). Inhibition of ERK/MAPK reduced the damage
caused by MPP+. We suggest that alpha-synuclein increase and ERK/MAPK activation
have a prominent role in the cell mechanisms of rescue and damage, respectively,
after MPP+ -treatment.
Gu, G., P. E. Reyes, et al. (2002). "Mitochondrial DNA deletions/rearrangements
in parkinson disease and related neurodegenerative disorders." J Neuropathol
Exp Neurol 61(7): 634-9.
Inhibition of mitochondrial respiratory chain function may contribute to
dopaminergic neurodegeneration in the substantia nigra (SN) of patients with
Parkinson disease (PD). Since large-scale structural changes (e.g. deletions and
rearrangements in mitochondrial DNA [mtDNA]) have been associated with
mitochondrial dysfunction, we tested the hypothesis that increased total mtDNA
deletions/rearrangements are associated with neurodegeneration in PD. This study
employed a well-established technique, long-extension polymerase chain reaction
(LX-PCR), to detect the multiple mtDNA deletions/rearrangements in the SN of
patients with PD, multiple system atrophy (MSA), dementia with Lewy bodies
(DLB), Alzheimer disease (AD), and age-matched controls. We also compared the
total mtDNA deletions/rearrangements in different brain regions of PD patients.
The results demonstrated that both the number and variety of mtDNA
deletions/rearrangements were selectively increased in the SN of PD patients
compared to patients with other movement disorders as well as patients with AD
and age-matched controls. In addition, increased mtDNA deletions/rearrangements
were observed in other brain regions in PD patients, indicating that
mitochondrial dysfunction is not just limited to the SN of PD patients. These
data suggest that accumulation of total mtDNA deletions/rearrangements is a
relatively specific characteristic of PD and may be one of the contributing
factors leading to mitochondrial dysfunction and neurodegeneration in PD.
Harding, A. J., G. A. Broe, et al. (2002). "Visual hallucinations in Lewy body
disease relate to Lewy bodies in the temporal lobe." Brain 125(Pt
2): 391-403.
Consensus opinion characterizes dementia with Lewy bodies (DLB) as a progressive
dementing illness, with significant fluctuations in cognition, visual
hallucinations and/or parkinsonism. When parkinsonism is an early dominant
feature, consensus opinion recommends that dementia within the first year is
necessary for a diagnosis of DLB. If dementia occurs later, a diagnosis of
Parkinson's disease with dementia (PDD) is recommended. While many previous
studies have correlated the neuropathology in DLB with dementia and
parkinsonism, few have analysed the relationship between fluctuating cognition
and/or well-formed visual hallucinations and the underlying neuropathology in
DLB and PDD. The aim of the present study was to determine any relationship
between these less-studied core clinical features of DLB, and the distribution
and density of cortical Lewy bodies (LB). The brains of 63 cases with LB were
obtained over 6 years following population-based studies of dementia and
parkinsonian syndromes. Annual, internationally standardized, clinical
assessment batteries were reviewed to determine the presence and onset of the
core clinical features of DLB. The maximal density of LB, plaques and tangles in
the amygdala, parahippocampal, anterior cingulate, superior frontal, inferior
temporal, inferior parietal and visual cortices were determined. Current
clinicopathological diagnostic criteria were used to classify cases into DLB (n
= 29), PDD (n = 18) or parkinsonism without dementia (n = 16) groups. Predictive
statistics were used to ascertain whether fluctuating cognition or visual
hallucinations predicted the clinicopathological group. Analysis of variance and
regressions were used to identify any significant relationship(s) between the
presence and severity of neuropathological and clinical features. Cognitive
fluctuations and/or visual hallucinations were not good predictors of DLB in
pathologically proven patients, although the absence of these features early in
the disease course was highly predictive of PDD. Cases with DLB had higher LB
densities in the inferior temporal cortex than cases with PDD. There was no
association across groups between any neuropathological variable and the
presence or absence of fluctuating cognition. However, there was a striking
association between the distribution of temporal lobe LB and well-formed visual
hallucinations. Cases with well-formed visual hallucinations had high densities
of LB in the amygdala and parahippocampus, with early hallucinations relating to
higher densities in parahippocampal and inferior temporal cortices. These
temporal regions have previously been associated with visual hallucinations in
other disorders. Thus, our results suggest that the distribution of temporal
lobe LB is more related to the presence and duration of visual hallucinations in
cases with LB than to the presence, severity or duration of dementia.
Harding, A. J., B. Lakay, et al. (2002). "Selective hippocampal neuron loss in
dementia with Lewy bodies." Ann Neurol 51(1): 125-8.
Hippocampal volume and neuron number were measured using stereological
techniques in pathologically confirmed dementia with Lewy bodies (n = 8),
Parkinson's disease only (n = 4), and controls (n = 9). We, and others, have
previously shown considerable cell loss in the CA1 and subiculum subregions in
Alzheimer's disease. In contrast, these regions were spared in dementia with
Lewy bodies where a selective loss of lower presubiculum pyramidal neurons was
found. These findings suggest a selective loss of frontally projecting
hippocampal neurons in dementia with Lewy bodies versus those projecting to
temporal lobe regions in Alzheimer's disease.
Helfand, S. L. (2002). "Neurobiology. Chaperones take flight." Science
295(5556): 809-10.
Holdorff, B. (2002). "Friedrich Heinrich Lewy (1885-1950) and his work." J
Hist Neurosci 11(1): 19-28.
In 1912, Friedrich Heinrich Lewy first described the inclusion bodies named
after him and seen in paralysis agitans (p.a.). Tretiakoff had found (1919) that
the nucleus niger is most likely to be affected but in a subsequent large-scale
series of post-mortem examinations (1923). Lewy was able to confirm this for a
minority of cases only, with the exception of those that displayed
postencephalitic Parkinsonism (and an unknown number of atypical Parkinson
syndrome cases not identified until the 1960s). In a speculative paper (1932),
he saw similarities between inclusion bodies in p.a. and viral diseases like
lyssa and postulated a viral genesis of p.a. In a historical review of basal
ganglia diseases (1942), he did not mention the putative significance of the
inclusion bodies for the post-mortem diagnosis. It seems that their importance
was seen only after Lewy's death, long after Tretiakoff's initial naming of the
'corps de Lewy'. Lewy, however, had already described their diffuse and cortical
distribution (1923). An identification of diffuse Lewy body disease or dementia
followed much later. Lewy's career in many diverse branches of neurology and
internal medicine was strongly affected by World War I and the difficult
situation faced by Jews in Germany. Shortly after the Neurological Institute was
founded in Berlin in 1932 (as a clinic and research institute), he was forced,
in 1933, to emigrate. His exile in England and the United States mirrors the
fate of many German Jews and academics in the first half of the 20th century.
Iwatsubo, T. (2002). "[alpha-synuclein and Parkinson's disease]." Seikagaku
74(6): 477-82.
Jellinger, K. A. (2002). "Disturbance of the nigro-amygdaloid connections in
dementia with Lewy bodies." J Neurol Sci 193(2): 157-8.
Jha, N., M. J. Kumar, et al. (2002). "Glutathione decreases in dopaminergic PC12
cells interfere with the ubiquitin protein degradation pathway: relevance for
Parkinson's disease?" J Neurochem 80(4): 555-61.
Parkinson's disease (PD) is characterized by the presence of proteinaceous
neuronal inclusions called Lewy bodies in susceptible dopaminergic midbrain
neurons. Inhibition of the ubiquitin-proteasome protein degradation pathway may
contribute to protein build-up and subsequent cell death. Ubiquitin is normally
activated for transfer to substrate proteins by interaction with the E1
ubiquitin ligase enzyme via a thiol ester bond. Parkinson's disease is also
characterized by decreases in midbrain levels of total glutathione which could
impact on E1 enzyme activity via oxidation of the active site sulfhydryl. We
have demonstrated that increasing reductions in total glutathione in
dopaminergic PC12 cells results in corresponding decreases in ubiquitin-protein
conjugate levels suggesting that ubiquitination of proteins is inhibited in a
glutathione-dependent fashion. Decreased ubiquitinated protein levels appears to
be due to inhibition of E1 activity as demonstrated by reductions in endogenous
E1-ubiquitin conjugate levels as well as decreases in the production of de novo
E1-ubiquitin conjugates when glutathione is depleted. This is a reversible
process as E1 activity increases upon glutathione restoration. Our data suggests
that decreases in cellular glutathione in dopaminergic cells results in
decreased E1 activity and subsequent disruption of the ubiquitin pathway. This
may have implications for neuronal degeneration in PD.
Judkins, A. R., M. S. Forman, et al. (2002). "Co-occurrence of Parkinson's
disease with progressive supranuclear palsy." Acta Neuropathol (Berl)
103(5): 526-30.
Parkinson's disease (PD) and progressive supranuclear palsy (PSP) are distinct
neurodegenerative disorders. We describe an 81-year-old woman with 3 years of
progressive gait unsteadiness, frequent falls, and mild cognitive dysfunction,
all considered clinically to be an early fronto-temporal neurodegenerative
disorder. She died of an acute myocardial infarction. Examination of her brain
revealed alpha-synuclein- and tau-positive inclusions diagnostic of PD and PSP.
Immunoelectron microscopy and Western blot analysis confirmed combined PD/PSP.
This case provides strategies for the reliable molecular validation of
concomitant PD and PSP, and demonstrates the utility of these techniques in
patients with atypical clinical presentations.
Junn, E. and M. M. Mouradian (2002). "Human alpha-synuclein over-expression
increases intracellular reactive oxygen species levels and susceptibility to
dopamine." Neurosci Lett 320(3): 146-50.
alpha-Synuclein is a major component of Lewy bodies found in the brains of
patients with Parkinson's disease (PD). Two point mutations in alpha-synuclein
(A53T and A30P) are identified in few families with dominantly inherited PD. Yet
the mechanism by which this protein is involved in nigral cell death remains
poorly understood. Mounting evidence suggests the importance of oxidative stress
in the pathogenesis of PD. Here we investigated the effects of wild-type and two
mutant forms of alpha-synuclein on intracellular reactive oxygen species (ROS)
levels using clonal SH-SY5Y cells engineered to over-express these proteins. All
three cell lines, and particularly mutant alpha-synuclein-expressing cells, had
increased ROS levels relative to control LacZ-engineered cells. In addition,
cell viability was significantly curtailed following the exposure of all three
alpha-synuclein-engineered cells to dopamine, but more so with mutant
alpha-synuclein. These results suggest that over-expression of alpha-synuclein,
and especially its mutant forms, exaggerates the vulnerability of neurons to
dopamine-induced cell death through excess intracellular ROS generation. Thus,
these findings provide a link between mutations or over-expression of
alpha-synuclein and apoptosis of dopaminergic neurons by lowering the threshold
of these cells to oxidative damage.
Kahle, P. J., C. Haass, et al. (2002). "Structure/function of alpha-synuclein in
health and disease: rational development of animal models for Parkinson's and
related diseases." J Neurochem 82(3): 449-57.
Kawamoto, Y., I. Akiguchi, et al. (2002). "14-3-3 proteins in Lewy bodies in
Parkinson disease and diffuse Lewy body disease brains." J Neuropathol Exp
Neurol 61(3): 245-53.
Several components of Lewy bodies have been identified, but the precise
mechanism responsible for the formation of Lewy bodies remains undetermined. The
14-3-3 protein family is involved in numerous signal transduction pathways and
interacts with alpha-synuclein, which is a major constituent of Lewy bodies. To
elucidate the role of 14-3-3 proteins in neuro-degenerative disorders associated
with Lewy bodies, we performed immunohistochemical studies on 14-3-3 in brains
from 5 elderly control subjects and from 10 patients with Parkinson disease (PD)
or diffuse Lewy body disease (DLBD). In the normal controls, 14-3-3-like
immunoreactivity was mainly observed in the neuronal somata and processes in
various cortical and subcortical regions. In the PD and DLBD cases, a similar
immunostaining pattern was found and immunoreactivity was generally spared in
the surviving neurons from the severely affected regions. In addition, both
classical and cortical Lewy bodies were intensely immunolabeled and some
dystrophic neurites were also immunoreactive for 14-3-3. Our results suggest
that 14-3-3 proteins may be associated with Lewy body formation and may play an
important role in the pathogenesis of PD and DLBD.
Khotianov, N., R. Singh, et al. (2002). "Lewy body dementia: case report and
discussion." J Am Board Fam Pract 15(1): 50-4.
BACKGROUND: Lewy body dementia is a common but frequently underdiagnosed cause
of dementia often mistaken for the more familiar entity of Alzheimer disease.
Clinically the distinction is important, because it can have profound
implications for management. METHODS: The medical literature was searched using
the keywords "Lewy bodies," "Lewy body dementia," "Alzheimer dementia," and
"parkinsonian disorders." A case of Lewy body dementia is described. RESULTS: An
elderly man had long-standing diagnoses of Alzheimer disease and Parkinson
disease. After he was evaluated thoroughly, the diagnosis was revised to Lewy
body dementia, leading to changes in treatment that were associated with
dramatic improvement in the patient's mental status. Evidence from the
literature suggests that Lewy body dementia can be diagnosed in primary care
settings based on clinical criteria. The physician should be alert to this
diagnosis, and special attention should be paid to dementia patients who exhibit
parkinsonism, hallucinations, fluctuating cognition, or prominent
visuosperceptual deficits. CONCLUSIONS: The diagnosis of Lewy body dementia has
important implications. It is associated with a high incidence of neuroleptic
sensitivity, necessitating great caution in the use of these common
antipsychotic agents. Early studies indicate cholinesterase inhibitors can be
beneficial for treating the hallucinations and behavior disturbances that
afflict these patients and might also improve cognition.
Kim, K. S., S. Y. Choi, et al. (2002). "Aggregation of alpha-synuclein induced
by the Cu,Zn-superoxide dismutase and hydrogen peroxide system." Free Radic
Biol Med 32(6): 544-50.
Alpha-synuclein is a major component of the abnormal protein aggregation in Lewy
bodies of Parkinson's disease (PD) and senile plaques of Alzheimer's disease
(AD). Previous studies have shown that the aggregation of alpha-synuclein was
induced by copper (II) and H(2)O(2) system. Since copper ions could be released
from oxidatively damaged Cu,Zn-superoxide dismutase (SOD), we investigated the
role of Cu,Zn-SOD in the aggregation of alpha-synuclein. When alpha-synuclein
was incubated with both Cu,Zn-SOD and H(2)O(2), alpha-synuclein was induced to
be aggregated. This process was inhibited by radical scavengers and spin
trapping agents such as 5,5'-dimethyl 1-pyrolline N-oxide and
tert-butyl-alpha-phenylnitrone. Copper chelators, diethyldithiocarbamate and
penicillamine, also inhibited the Cu,Zn-SOD/H(2)O(2) system-induced
alpha-synuclein aggregation. These results suggest that the aggregation of
alpha-synuclein is mediated by the Cu,Zn-SOD/H(2)O(2) system via the generation
of hydroxyl radical by the free radical-generating function of the enzyme. The
Cu,Zn-SOD/H(2)O(2)-induced alpha-synuclein aggregates displayed strong
thioflavin-S reactivity, reminiscent of amyloid. These results suggest that the
Cu,Zn-SOD/H(2)O(2) system might be related to abnormal aggregation of
alpha-synuclein, which may be involved in the pathogenesis of PD and related
disorders.
Klein, R. L., M. A. King, et al. (2002). "Dopaminergic cell loss induced by
human A30P alpha-synuclein gene transfer to the rat substantia nigra." Hum
Gene Ther 13(5): 605-12.
Somatic cell gene transfer was used to express a mutant form of alpha-synuclein
(alpha-syn) that is associated with Parkinson's disease (PD) in the rat
substantia nigra (SN), a brain region that, in humans, degenerates during PD.
DNA encoding the A30P mutant of human alpha-syn linked to familial PD was
incorporated into an adeno-associated virus vector, which was injected into the
adult rat midbrain. The cytomegalovirus/chicken beta-actin promoter was used to
drive transgene expression. Over a 1-year time course, this treatment produced
three significant features relevant to PD: (1) accumulation of alpha-syn in SN
neuron perikarya, (2) Lewy-like dystrophic neurites in the SN and the striatum,
and (3) a 53% loss of SN dopamine neurons. However, motor dysfunction was not
found in either rotational or rotating rod testing. The lack of behavioral
deficits, despite the significant cell loss, may reflect pathogenesis similar to
that of PD, where greater than 50% losses occur before motor behavior is
affected.
Kurosinski, P., M. Guggisberg, et al. (2002). "Alzheimer's and Parkinson's
disease--overlapping or synergistic pathologies?" Trends Mol Med 8(1):
3-5.
Alzheimer's disease (AD) and Parkinson's disease (PD) are the two most common
neurodegenerative disorders in humans. They are characterized by insoluble
protein deposits; beta-amyloid plaques and tau-containing neurofibrillary
lesions in AD, and alpha-synuclein-containing Lewy bodies in PD. As a
significant percentage of patients have clinical and pathological features of
both diseases, the patho-cascades of the two diseases might overlap. For the
first time, new animal models that express multiple transgenes provide the tools
to dissect the pathogenic pathways and to differentiate between additive and
synergistic effects.
Le Couteur, D. G., M. Muller, et al. (2002). "Age-environment and
gene-environment interactions in the pathogenesis of Parkinson's disease."
Rev Environ Health 17(1): 51-64.
Parkinson's disease (PD) is a common neurodegenerative disease characterized by
dopaminergic cell death and deposition of Lewy bodies within the substantia
nigra of the midbrain. Although the major risk factors for PD are aging and
environmental factors, there is an important genetic component. An age-related
change in xenobiotic metabolism alters the metabolism of and net exposure to,
environmental neurotoxins. Genetic variability in xenobiotic metabolism may
similarly increase the susceptibility to PD by altering the metabolism of
neurotoxins. Genetic studies of rare familial cases of PD indicate a central
mechanistic role for the aggregation of alpha-synuclein, a protein found in Lewy
bodies. Environmental factors like pesticides and heavy metals can also
influence alpha-synuclein aggregation. Common final pathways for aging,
environmental, and genetic mechanisms can thus exist, involving both direct
neurotoxicity and alpha-synuclein aggregation.
Lee, M. K., W. Stirling, et al. (2002). "Human alpha-synuclein-harboring
familial Parkinson's disease-linked Ala-53 --> Thr mutation causes
neurodegenerative disease with alpha-synuclein aggregation in transgenic mice."
Proc Natl Acad Sci U S A 99(13): 8968-73.
Mutations in alpha-synuclein (alpha-Syn) cause Parkinson's disease (PD) in a
small number of pedigrees with familial PD. Moreover, alpha-Syn accumulates as a
major component of Lewy bodies and Lewy neurites, intraneuronal inclusions that
are neuropathological hallmarks of PD. To better understand the pathogenic
relationship between alterations in the biology of alpha-Syn and PD-associated
neurodegeneration, we generated multiple lines of transgenic mice expressing
high levels of either wild-type or familial PD-linked Ala-30 --> Pro (A30P) or
Ala-53 --> Thr (A53T) human alpha-Syns. The mice expressing the A53T human
alpha-Syn, but not wild-type or the A30P variants, develop adult-onset
neurodegenerative disease with a progressive motoric dysfunction leading to
death. Pathologically, affected mice exhibit neuronal abnormalities (in
perikarya and neurites) including pathological accumulations of alpha-Syn and
ubiquitin. Consistent with abnormal neuronal accumulation of alpha-Syn, brain
regions with pathology exhibit increases in detergent-insoluble alpha-Syn and
alpha-Syn aggregates. Our results demonstrate that the A53T mutant alpha-Syn
causes significantly greater in vivo neurotoxicity as compared with other
alpha-Syn variants. Further, alpha-Syn-dependent neurodegeneration is associated
with abnormal accumulation of detergent-insoluble alpha-Syn.
Lee, H. J., S. Y. Shin, et al. (2002). "Formation and removal of alpha-synuclein
aggregates in cells exposed to mitochondrial inhibitors." J Biol Chem
277(7): 5411-7.
Mitochondrial dysfunction has been associated with Parkinson's disease. However,
the role of mitochondrial defects in the formation of Lewy bodies, a
pathological hallmark of Parkinson's disease has not been addressed directly. In
this report, we investigated the effects of inhibitors of the mitochondrial
electron-transport chain on the aggregation of alpha-synuclein, a major protein
component of Lewy bodies. Treatment with rotenone, an inhibitor of complex I,
resulted in an increase of detergent-resistant alpha-synuclein aggregates and a
reduction in ATP level. Another inhibitor of the electron-transport chain,
oligomycin, also showed temporal correlation between the formation of aggregates
and ATP reduction. Microscopic analyses showed a progressive evolution of small
aggregates of alpha-synuclein to a large perinuclear inclusion body. The
inclusions were co-stained with ubiquitin, 20 S proteasome, gamma-tubulin, and
vimentin. The perinuclear inclusion bodies, but not the small cytoplasmic
aggregates, were thioflavin S-positive, suggesting the amyloid-like
conformation. Interestingly, the aggregates disappeared when the cells were
replenished with inhibitor-free medium. Disappearance of aggregates coincided
with the recovery of mitochondrial metabolism and was partially inhibited by
proteasome inhibitors. These results suggest that the formation of
alpha-synuclein inclusions could be initiated by an impaired mitochondrial
function and be reversed by restoring normal mitochondrial metabolism.
Leverenz, J. B. and I. G. McKeith (2002). "Dementia with Lewy bodies." Med
Clin North Am 86(3): 519-35.
DLB is a complex disorder with important associations with PD and AD. As
clinicians, it is important for us to identify these patients because of their
unique responses to medical interventions and to help patients and caregivers
more fully understand this disease process and its implications. Further
research is needed to improve our understanding of the pathophysiology of this
important dementing disorder, with the ultimate goal of improving clinical
management of this disease.
Li, J. Y., P. Henning Jensen, et al. (2002). "Differential localization of
alpha-, beta- and gamma-synucleins in the rat CNS." Neuroscience 113(2):
463-78.
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.
Li, H. T., H. N. Du, et al. (2002). "Structural transformation and aggregation
of human alpha-synuclein in trifluoroethanol: non-amyloid component sequence is
essential and beta-sheet formation is prerequisite to aggregation."
Biopolymers 64(4): 221-6.
Amyloid-like aggregation of alpha-synuclein and deposit in Lewy bodies are
thought to be the major cause of Parkinson's disease. Here we describe the
secondary structural transformation and aggregation of human alpha-synuclein and
its C-terminus truncated fragments in trifluoroethanol. Proteins containing the
NAC (non-amyloid component) segment undergo a three-state transition: from
native random coil to beta-sheet and to alpha-helical structure, while the NAC
deficient fragment and gamma-synuclein undergo a typical two-state coil-to-alpha
transition. The beta-sheet form is highly hydrophobic that strongly binds to
1-anilinonaphthalene-8-sulfonic acid (ANS) and is prone to self-aggregation. The
results suggest that the NAC sequence is essential to beta-sheet formation and
the aggregation originates from the beta-sheet intermediate, which may be
implicated in the pathogenesis of Parkinson's disease.
Lo Bianco, C., J. L. Ridet, et al. (2002). "alpha -Synucleinopathy and selective
dopaminergic neuron loss in a rat lentiviral-based model of Parkinson's
disease." Proc Natl Acad Sci U S A 99(16): 10813-8.
Parkinson's disease (PD) is characterized by the progressive loss of substantia
nigra dopaminergic neurons and the presence of cytoplasmic inclusions named Lewy
bodies. Two missense mutations of the alpha-synuclein (alpha-syn; A30P and A53T)
have been described in several families with an autosomal dominant form of PD.
alpha-Syn also constitutes one of the main components of Lewy bodies in sporadic
cases of PD. To develop an animal model of PD, lentiviral vectors expressing
different human or rat forms of alpha-syn were injected into the substantia
nigra of rats. In contrast to transgenic mice models, a selective loss of nigral
dopaminergic neurons associated with a dopaminergic denervation of the striatum
was observed in animals expressing either wild-type or mutant forms of human
alpha-syn. This neuronal degeneration correlates with the appearance of abundant
alpha-syn-positive inclusions and extensive neuritic pathology detected with
both alpha-syn and silver staining. Lentiviral-mediated expression of wild-type
or mutated forms of human alpha-syn recapitulates the essential
neuropathological features of PD. Rat alpha-syn similarly leads to protein
aggregation but without cell loss, suggesting that inclusions are not the
primary cause of cell degeneration in PD. Viral-mediated genetic models may
contribute to elucidate the mechanism of alpha-syn-induced cell death and allow
the screening of candidate therapeutic molecules.
Lopez, O. L., J. T. Becker, et al. (2002). "Research evaluation and prospective
diagnosis of dementia with Lewy bodies." Arch Neurol 59(1): 43-6.
OBJECTIVE: To evaluate the relative merits of recently developed criteria for
dementia with Lewy bodies (DLBs) in a longitudinal study of dementia. DESIGN:
The diagnosis of DLBs was used in combination with other clinical diagnosis.
Patients were classified primarily based on the NINCDS-ADRDA (National Institute
of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and
Related Disorders Association) clinical criteria for probable or possible
Alzheimer disease, or with other disease process that can cause dementia (eg,
Parkinson disease), and secondarily according to the consensus guidelines for
DLBs. This "double" clinical diagnosis was implemented to capture different
pathological entities. The neuropathological diagnosis of Lewy bodies was made
with monoclonal antibodies against alpha-synuclein. SETTING: Multidisciplinary
research clinic. RESULTS: Prospective application of the consensus guidelines
for DLBs from January 1, 1997, to September 29, 2000, identified 11 patients
having the diagnosis of probable DLBs and 35 having possible DLBs. The diagnosis
of probable or possible DLBs was associated with probable Alzheimer disease in
34 patients, with possible Alzheimer disease in 5 patients, with Parkinson
disease in 2 patients, and with other disease processes in 2 patients. Three
patients were diagnosed as having probable DLBs alone. An autopsy was performed
in 26 of the cases who were clinically examined during the study period.
Cortical Lewy bodies were identified in 13 cases; 4 had had premortem diagnosis
of DLBs (sensitivity, 30.7%; specificity, 100%). CONCLUSIONS: The prospective
validation of the clinical criteria for DLBs showed poor accuracy in this
series. We believe that current criteria for DLBs are useful when DLBs occur in
isolation, but have low sensitivity when Lewy bodies coexist with the
pathological abnormalities of Alzheimer disease.
Madsen, A. M., R. K. Lomholt, et al. (2002). "[Diagnosis and treatment of Lewy
body dementia]." Ugeskr Laeger 164(18): 2383-6.
Dementia with Lewy bodies (DLB) has recently gained recognition as a separate
disease. Lewy bodies are pathoanatomical inclusion bodies in the CNS. They are
well known as part of Parkinson's disease where they are present mainly in the
substantia nigra, and they are also found in large numbers in the neocortex. It
is still an unanswered question why Lewy bodies are formed, but their appearance
is connected with cellular degeneration of unknown aetiology. Neuropathological
investigations of dementia populations show that DLB accounts for 12-36%, which
places it as the second most frequent dementia disease after Alzheimer's disease
(AD) with a frequency close to that of vascular dementia. This article reviews
the development of the term DLB and describes the clinical characteristics,
including the neuropsychological symptom profile, which can contribute to the
diagnostic discrimination between DLB and AD. Furthermore, relevant treatment
possibilities are discussed.
McKeith, I. G. (2002). "Dementia with Lewy bodies." Br J Psychiatry
180: 144-7.
BACKGROUND: Dementia with Lewy bodies (DLB) is a common dementia subtype that
has only been recognised in the past decade and that remains widely
underdiagnosed. AIMS: To review the pathological and clinical features of DLB,
to consider methods of investigation and diagnosis, and to recommend safe and
effective management strategies. METHOD: A selective review was made of the key
literature. RESULTS: Using operationalised criteria, DLB can be clinically
diagnosed with an accuracy similar to that achieved for Alzheimer's disease or
Parkinson's disease. Underdetection is largely due to poor definition of the
criterion of cognitive fluctuation. Ancillary investigations, particularly
neuroimaging, can aid in differential diagnosis. Extreme caution in the use of
neuroleptic medication is advised. Cholinesterase inhibitors may be particularly
effective in DLB. CONCLUSIONS: Clinicians should be aware of DLB as part of a
spectrum of Lewy body disorders. Neuroleptic sensitivity reactions and good
response to cholinergic therapies are important aspects of management.
McLean, P. J. and B. T. Hyman (2002). "An alternatively spliced form of rodent
alpha-synuclein forms intracellular inclusions in vitro: role of the
carboxy-terminus in alpha-synuclein aggregation." Neurosci Lett 323(3):
219-23.
In the rat, the -synuclein gene is alternatively spliced and exists in three
forms, rat synuclein 1 (rSYN1), synuclein 2 (rSYN2) and synuclein 3. rSYN2 cDNA
encodes a 149 amino acid protein that is homologous to rSYN1 and human
-synuclein for the first 100 amino acids, but is divergent for the 49 amino acid
carboxy-terminal region. We demonstrate here that rSYN2 forms small aggregates
throughout the cytoplasm when overexpressed in human H4 cells, whereas rSYN1
expression is diffuse. Inhibition of the proteasome promotes the formation of
larger, cytoplasmic rSYN2 inclusions in transfected cells. Although a survey of
the available databases suggests that there is no human splice form equivalent
of rSYN2, thus arguing against a direct role in Lewy body formation and
Parkinson's disease, these data nonetheless suggest that modifications of the
carboxy-terminal region of -synuclein predispose it to inclusion formation.
McNaught, K. S., L. M. Bjorklund, et al. (2002). "Proteasome inhibition causes
nigral degeneration with inclusion bodies in rats." Neuroreport 13(11):
1437-1441.
Structural and functional defects in 26/20S proteasomes occur in the substantia
nigra pars compacta and may underlie protein accumulation, Lewy body formation
and dopaminergic neuronal death in Parkinson's disease. We therefore determined
the pathogenicity of proteasomal impairment following stereotaxic unilateral
infusion of lactacystin, a selective proteasome inhibitor, into the substantia
nigra pars compacta of rats. These animals became progressively bradykinetic,
adopted a stooped posture and displayed contralateral head tilting.
Administration of apomorphine to lactacystin-treated rats reversed behavioral
abnormalities and induced contralateral rotations. Lactacystin caused
dose-dependent degeneration of dopaminergic cell bodies and processes with the
cytoplasmic accumulation and aggregation of alpha-synuclein to form inclusion
bodies. These findings support the notion that failure of the
ubiquitin-proteasome system to degrade and clear unwanted proteins is an
important etiopathogenic factor in Parkinson's disease.
McNaught, K. S., R. Belizaire, et al. (2002). "Selective loss of 20S proteasome
alpha-subunits in the substantia nigra pars compacta in Parkinson's disease."
Neurosci Lett 326(3): 155-8.
The proteolytic activities of 26/20S proteasomes are impaired in the substantia
nigra pars compacta (SNc) in sporadic Parkinson's disease (PD). In the present
study, we examined the structural integrity of the proteasome by determining the
levels of the beta- and alpha-subunits which together normally constitute the
catalytic core of 26/20S proteasomes. Western blot analyzes and
immunohistochemical staining revealed a major and selective loss of
alpha-subunits in dopaminergic neurons of the SNc but not in other brain regions
in sporadic PD. This defect is known to cause the proteasome to become unstable
and prevents its assembly with resultant impairment of enzymatic activity. Thus,
structural and function defects in 26/20S proteasomes may underlie protein
accumulation, formation of proteinaceous Lewy bodies and dopaminergic neuronal
death in the SNc in sporadic PD.
McNaught, K. S., C. Mytilineou, et al. (2002). "Impairment of the
ubiquitin-proteasome system causes dopaminergic cell death and inclusion body
formation in ventral mesencephalic cultures." J Neurochem 81(2):
301-6.
Mutations in alpha-synuclein, parkin and ubiquitin C-terminal hydrolase L1, and
defects in 26/20S proteasomes, cause or are associated with the development of
familial and sporadic Parkinson's disease (PD). This suggests that failure of
the ubiquitin-proteasome system (UPS) to degrade abnormal proteins may underlie
nigral degeneration and Lewy body formation that occur in PD. To explore this
concept, we studied the effects of lactacystin-mediated inhibition of 26/20S
proteasomal function and ubiquitin aldehyde (UbA)-induced impairment of
ubiquitin C-terminal hydrolase (UCH) activity in fetal rat ventral mesencephalic
cultures. We demonstrate that both lactacystin and UbA caused
concentration-dependent and preferential degeneration of dopaminergic neurons.
Inhibition of 26/20S proteasomal function was accompanied by the accumulation of
alpha-synuclein and ubiquitin, and the formation of inclusions that were
immunoreactive for these proteins, in the cytoplasm of VM neurons. Inhibition of
UCH was associated with a loss of ubiquitin immunoreactivity in the cytoplasm of
VM neurons, but there was a marked and localized increase in alpha-synuclein
staining which may represent the formation of inclusions bodies in VM neurons.
These findings provide direct evidence that impaired protein clearance can
induce dopaminergic cell death and the formation of proteinaceous inclusion
bodies in VM neurons. This study supports the concept that defects in the UPS
may underlie nigral pathology in familial and sporadic forms of PD.
Miake, H., H. Mizusawa, et al. (2002). "Biochemical characterization of the core
structure of alpha-synuclein filaments." J Biol Chem 277(21):
19213-9.
Intracellular filamentous aggregates comprised of alpha-synuclein such as Lewy
bodies and glial cytoplasmic inclusions are the defining hallmarks of a subset
of neurodegenerative diseases including Parkinson's disease, dementia with Lewy
bodies, and multiple system atrophy. We have analyzed biochemical and structural
properties of alpha-synuclein filaments assembled in vitro or extracted from
brains of patients with multiple system atrophy and found that both types of
filaments are insoluble to detergents and partially resistant to proteinase K
digestion. Immunoelectron microscopy and immunoblot analysis showed that both
amino and carboxyl termini of alpha-synuclein in in vitro assembled filaments
were degraded by proteinase K treatment, whereas the central portion of
alpha-synuclein is resistant to proteinase K and retains filamentous structures.
Protein sequencing and mass spectrometric analyses of the proteinase
K-resistant, minimal fragment of 7 kDa revealed that amino acid residues 31-109
of alpha-synuclein constitute the core unit of the filaments. These observations
suggest that the central half of the alpha-synuclein polypeptide, containing
five tandem repeats as well as a part of the carboxyl-terminal acidic region,
forms the core structure of alpha-synuclein filaments, which is coated by the
amino- and carboxyl-terminal portions at the periphery.
Mori, H., M. Oda, et al. (2002). "Lewy bodies in progressive supranuclear
palsy." Acta Neuropathol (Berl) 104(3): 273-8.
Lewy bodies (LBs), whose major component is alpha-synuclein, are a pathological
hallmark of Parkinson's disease (PD) but have rarely been reported in
progressive supranuclear palsy (PSP). Whether LBs in PSP represent the aging
process or the coexistence of PD remains unclear. We found LBs in 5 of 16
patients with PSP. In 4 patients LBs were distributed widely throughout the
brain stem and cerebrum in a pattern similar to that in PD. In the remaining
patient one LB was found in the pontine reticular formation. Semiquantitative
analysis showed that neuronal loss in the locus coeruleus and the dorsal vagal
nucleus was more severe in patients with LBs than in patients without LBs.
Double-labeling immunohistochemical studies showed co-localization of
alpha-synuclein and tau in some neurons. Our study suggests that patients who
have PSP with LBs constitute a subset of patients with PSP in whom Lewy body
disease is also present.
Mouradian, M. M. (2002). "Recent advances in the genetics and pathogenesis of
Parkinson disease." Neurology 58(2): 179-85.
The identification of three genes and several additional loci associated with
inherited forms of levodopa-responsive PD has confirmed that this is not a
single disorder. Yet, analyses of the structure and function of these gene
products point to the critical role of protein aggregation in dopaminergic
neurons of the substantia nigra as the common mechanism leading to
neurodegeneration in all known forms of this disease. The three specific genes
identified to date--alpha-synuclein, Parkin, and ubiquitin C terminal hydrolase
L1--are either closely involved in the proper functioning of the
ubiquitin-proteasome pathway or are degraded by this protein-clearing machinery
of cells. Knowledge gained from genetically transmitted PD also has clear
implications for nonfamilial forms of the disease. Lewy bodies, even in sporadic
PD, contain these three gene products, particularly abundant amounts of
fibrillar alpha-synuclein. Increased aggregation of alpha-synuclein by oxidative
stress, as well as oxidant-induced proteasomal dysfunction, link genetic and
potential environmental factors in the onset and progression of the disease. The
biochemical and molecular cascades elucidated from genetic studies in PD can
provide novel targets for curative therapies.
Nicholl, D. J., J. R. Vaughan, et al. (2002). "Two large British kindreds with
familial Parkinson's disease: a clinico-pathological and genetic study."
Brain 125(Pt 1): 44-57.
We present the findings of a study of two large unrelated kindreds with
autosomal dominant Parkinson's disease. The affected members were assessed
clinically and with [(18)F]6-fluorodopa-PET and were indistinguishable from
patients with the sporadic form of Parkinson's disease. In one kindred, an
affected member was examined subsequently at autopsy and Lewy bodies were
present in a distribution typical of sporadic Parkinson's disease. These
kindreds are distinct from other Parkinsonian kindreds with identified genetic
loci (PARK1-4) and provide further evidence for genetic heterogeneity in
familial Parkinson's disease.
Nicoletti, G., G. Annesi, et al. (2002). "No evidence of association between the
alpha-2 macroglobulin gene and Parkinson's disease in a case-control sample."
Neurosci Lett 328(1): 65-7.
Alpha-2 macroglobulin (A2M) is a component of Lewy bodies, a hallmark of
Parkinson's disease (PD). In 159 PD patients and 190 normal controls, we studied
two A2M polymorphisms by the polymerase chain reaction-restriction fragment
length polymorphism method: a five-nucleotide deletion at the 5' splice site of
exon 18; and a valine to isoleucine exchange in amino acid position 1000 near
the thiolester active site. No significant differences in allelic and genotypic
distribution were found between cases and controls or between early and
late-onset PD patients. The present data suggest that these polymorphisms do not
represent a risk factor for PD and do not modulate the age at onset of PD.
Rajput, A. H., M. E. Fenton, et al. (2002). "Clinical-pathological study of
levodopa complications." Mov Disord 17(2): 289-96.
We sought to determine the continued benefit and the pattern of motor
complications of long-term levodopa treatment in Parkinson's disease. Patients
were evaluated between 1968 and 1996. Only those who had an adequate levodopa
trial and in whom autopsy revealed Lewy body Parkinson's disease were included.
Total levodopa and mean daily dose were calculated in each case. Dyskinesia,
wearing-off and on-off were collectively classified as motor adverse effects and
reported as cumulative incidence. Forty-two patients (male, 30; female, 12) with
mean 15.9 years of illness and 9.1 years follow-up received on average 500-mg
levodopa daily over 9.8 years. Seventeen of 21 patients assessed during the last
18 months of life reported some motor benefit. Adverse effects were seen in
71.4% of patients. The most common was dyskinesia, in 61.9%; wearing-off in
35.7%; and on-off in 16.7% of patients. The earliest adverse effect was
dyskinesia and the last to emerge was on-off. Isolated dyskinesia was seen in
35.7% and wearing-off in 7.1% of patients; 15.5% of patients developed
dyskinesia after 2.6 years and 31% after 6.4 years on levodopa. We concluded
that levodopa benefit declined and adverse effects increased with time.
Dyskinesia was the earliest and the most common isolated adverse effect.
Ransmayr, G. (2002). "[Dementia with Lewy bodies]." Wien Med Wochenschr
152(3-4): 81-4.
Dementia with Lewy bodies (DLB) is the second most frequent neuropathologically
diagnosed degenerative dementing illness. The clinical characteristics are
progressive dementia, Parkinson syndrome, fluctuations of cognitive functions,
vigilance and attention, visual hallucinations (usually detailed and well
described), depression, REM-sleep behavior disorder, adverse responses to
standard doses of neuroleptics, falls, syncopes, systematized delusions, and
non-visual hallucinations. Mean age at disease onset ranges between 60 and 68
years. Male persons are more frequently affected than female. Disease duration
is six to seven years. The differential diagnoses of DLB are dementia of the
Alzheimer-type, Parkinson's disease, subcortical arteriosclerotic
encephalopathy, progressive supranuclear palsy, multiple system atrophy, and, in
rare cases, Creutzfeldt-Jakob disease. The genetic background of the disease is
unclear. Magnetic resonance imaging and single photon emission tomography can
contribute to the diagnosis. The disease is treated with L-dopa, atypical
neuroleptics, acetylcholine esterase inhibitors, antihypotensive agents, and
peripheral anticholinergic and alpha-receptor-blocking medicaments to improve
neurogenic bladder dysfunction.
Ribeiro, C. S., K. Carneiro, et al. (2002). "Synphilin-1 is developmentally
localized to synaptic terminals, and its association with synaptic vesicles is
modulated by alpha -synuclein." J Biol Chem 277(26): 23927-33.
Alpha-synuclein is the major component of Lewy bodies in patients with
Parkinson's disease, and mutations in the alpha-synuclein gene are responsible
for some familial forms of the disease. alpha-Synuclein is enriched in the
presynapse, but its synaptic targets are unknown. Synphilin-1 associates in vivo
with alpha-synuclein promoting the formation of intracellular inclusions.
Additionally synphilin-1 has been found to be an intrinsic component of Lewy
bodies in patients with Parkinson's disease. To understand the role of
synphilin-1 in Parkinson's disease, we sought to define its localization and
function in the brain. We now report that, like alpha-synuclein, synphilin-1 was
enriched in neurons. In young rats, synphilin-1 was prominent in neuronal cell
bodies but gradually migrated to neuropil during development. Immunoelectron
microscopy of adult rat cerebral cortex demonstrated that synphilin-1 was highly
enriched in presynaptic nerve terminals. Synphilin-1 co-immunoprecipitated with
synaptic vesicles, indicating a strong association with these structures. In
vitro binding experiments demonstrated that the N terminus of synphilin-1
robustly associated with synaptic vesicles and that this association was
resistant to high salt washing but was abolished by inclusion of alpha-synuclein
in the incubation medium. Our data indicated that synphilin-1 is a synaptic
partner of alpha-synuclein, and it may mediate synaptic roles attributed to
alpha-synuclein.
Rosler, M. (2002). "The efficacy of cholinesterase inhibitors in treating the
behavioural symptoms of dementia." Int J Clin Pract Suppl(127): 20-36.
Multiple behavioural and psychological symptoms of dementia (BPSD) are commonly
associated with all dementia subtypes, and worsen during disease progression.
BPSD arise due to impairment of cholinergic function in the cortex, hippocampus
and related limbic systems. Recent studies have investigated the effect of
cholinesterase inhibitors on BPSD. The dual
acetylcholinesterase/butyrylcholinesterase (AChE/BuChE) inhibitor rivastigmine
was shown to have several potential advantages over the AChE-selective
inhibitors donepezil and galantamine for the treatment of BPSD. Rivastigmine
appears to be effective across the range of dementia severity from mild to
severe, and across the spectrum of dementia (Alzheimer's disease [AD], the AD
variant with Lewy bodies, Parkinson's disease dementia and vascular dementia
subtypes). It also appears to have a disease-modifying potential. Rivastigmine
improved a wider range of behavioural symptoms (apathy, anxiety/depression,
hallucinations and delusions) than donepezil and galantamine (which improved
apathy and depression/anxiety only). Unlike donepezil, rivastigmine reduced the
need for psychotropic medications to treat BPSD. Dual inhibition of AChE and
BuChE and brain-region selectivity through preferential inhibition of the G1
isoform of AChE may provide the underlying reasons for the apparently greater
and broader efficacy of rivastigmine over AChE-selective inhibitors for the
treatment of BPSD. However, randomised, controlled trials are required to
compare dual inhibitors, such as rivastigmine, and AChE-selective agents, to
confirm and quantify any differences in their effects on BPSD.
Rub, U., K. Del Tredici, et al. (2002). "Parkinson's disease: the thalamic
components of the limbic loop are severely impaired by alpha-synuclein
immunopositive inclusion body pathology." Neurobiol Aging 23(2):
245-54.
The Parkinson's disease (PD)-related inclusion body pathology comprises Lewy
bodies (LBs) as well as Lewy neurites (LNs). The distribution and severity of
this pathology were investigated in the thalamus of 12 autopsy cases with
clinically diagnosed and neuropathologically confirmed PD. The LBs and LNs were
visualized by immunoreactions against the protein alpha-synuclein. In the human
thalamus during PD, a specific and highly stereotypical distribution pattern of
LBs and LNs evolves. As in cortical and other subcortical regions, the
components of human thalamus assigned to the limbic loop bear the brunt of the
PD-related pathology. In contrast, the thalamic components integrated into the
striatal and cerebellar loops as well as the primary sensory nuclei of the
thalamus show at best a mildly developed pathology. Damage to the thalamic
components of the limbic loop nuclei may contribute not only to the cognitive,
emotional, and autonomic symptoms of PD but to the somatomotor and oculomotor
dysfunctions as well.
Sasaki, K., K. Doh-Ura, et al. (2002). "Clusterin/apolipoprotein J is associated
with cortical Lewy bodies: immunohistochemical study in cases with
alpha-synucleinopathies." Acta Neuropathol (Berl) 104(3): 225-30.
Clusterin/apolipoprotein J protein expression in cases with
"alpha-synucleinopathies", such as Parkinson's disease (PD), dementia with Lewy
bodies (DLB) and multiple system atrophy (MSA), was investigated using an
immunohistochemical method for the labeling of multiple antigens. About 50% of
the cortical Lewy bodies in the cases with DLB were immunoreactive for
clusterin, whereas brain-stem Lewy bodies in PD and DLB were rarely associated
with clusterin. Clusterin was also immunopositive in around 10% of the glial
cytoplasmic inclusions (GCIs) in the cases with MSA. Colocalization of clusterin
with alpha-synuclein in such bodies or inclusions was clearly correlated with
the immunostaining pattern of alpha-synuclein. Subcellular localization of
clusterin was almost completely overlapped with the homogeneous immunoreaction
of alpha-synuclein in the cortical Lewy bodies; however, clusterin
immunoreactivity was not detected in the halo or ring-like structures of the
brain-stem Lewy bodies. Furthermore, some Lewy bodies with intense
immunoreactivity for clusterin showed only a weak signal for alpha-synuclein.
These results suggest that clusterin may modify the formation of
alpha-synuclein-positive inclusion bodies such as Lewy bodies and GCIs, through
a previously proposed chaperone property of clusterin.
Satoh, J. I. and Y. Kuroda (2002). "A putative polymorphic Val44Ala variation in
the synphilin-1 gene is undetectable in Japanese sporadic Parkinson's disease
patients." Eur J Neurol 9(1): 15-8.
Recently, a novel protein-interaction partner of alpha-synuclein, designated
synphilin-1, is identified as a constituent of Lewy bodies (LB) in Parkinson's
disease (PD) brains. To investigate an involvement of genetic variations of
synphilin-1 in development of sporadic PD, a possible single nucleotide
polymorphism (SNP) of T131C corresponding to a valine (Val) to alanine (Ala)
substitution at codon 44 in exon 3 of the synphilin-1 gene was studied in a
Japanese population of 55 patients with sporadic PD and 61 patients with non-PD
by direct sequencing analysis. All 116 subjects showed a homozygosity of Val at
codon 44 in the synphilin-1 gene, suggesting that this SNP is unlikely to affect
genetic susceptibility to sporadic PD in the Japanese population.
Schlossmacher, M. G., M. P. Frosch, et al. (2002). "Parkin localizes to the Lewy
bodies of Parkinson disease and dementia with Lewy bodies." Am J Pathol
160(5): 1655-67.
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.
Shtilerman, M. D., T. T. Ding, et al. (2002). "Molecular crowding accelerates
fibrillization of alpha-synuclein: could an increase in the cytoplasmic protein
concentration induce Parkinson's disease?" Biochemistry 41(12):
3855-60.
Parkinson's disease (PD) is one of many neurodegenerative diseases that are
characterized by amyloid fibril formation. Alpha-synuclein is a primary
component of the fibrillar neuronal inclusions, known as Lewy bodies, that are
diagnostic of PD. In addition, the alpha-synuclein gene is linked to familial
PD. Fibril formation by alpha-synuclein proceeds via discrete beta-sheet-rich
oligomers, or protofibrils, that are consumed as fibrils grow. Both FPD
mutations accelerate formation of protofibrils, suggesting that these
intermediates, rather than the fibril product, trigger neuronal loss. In
idiopathic PD, other factors may be responsible for accelerating protofibril
formation by wild-type alpha-synuclein. One possible factor could be molecular
crowding in the neuronal cytoplasm. We demonstrate here that crowding using
inert polymers significantly reduced the lag time for protofibril formation and
the conversion of the protofibril to the fibril, but did not affect the
morphology of either species. Physiologically realistic changes in the degree of
in vitro crowding have significant kinetic consequences. Thus, nonspecific
changes in the total cytoplasmic protein concentration, induced by cell volume
changes and/or altered protein degradation, could promote formation of and
stabilize the alpha-synuclein protofibril.
Stefanova, N., M. Emgard, et al. (2002). "Ultrastructure of
alpha-synuclein-positive aggregations in U373 astrocytoma and rat primary glial
cells." Neurosci Lett 323(1): 37-40.
Abnormal alpha-synuclein-positive glial cytoplasmic inclusions are found in
Parkinson's disease, multiple system atrophy and dementia with Lewy bodies. We
have recently developed an in vitro model of alpha-synuclein-immunoreactive
aggregations in U373 astrocytoma cells. We have additionally overexpressed
wild-type and a C-terminally truncated form of alpha-synuclein in primary rat
glial cells. Astrocytes and oligodendrocytes were found to form
alpha-synuclein-positive aggregations in vitro perinuclearly or in the processes
of the cells. The morphological studies presented here demonstrate that the
aggregations we have observed in vitro are not limited by a membrane but have
unclear borders. They have an amorphous dense core that is intensely
alpha-synuclein-immunopositive and a predominantly filamentous halo around.
Mainly filamentous structures at the border area between the halo and the core
are alpha-synuclein-immunoreactive. We conclude that this in vitro model of
alpha-synuclein-positive glial aggregations mimics the morphology of the
abnormal glial inclusions described in neurodegenerative disorders and could be
a suitable model for studying their role in the pathogenesis of these diseases.
Szirmai, I. and T. Kovacs (2002). "[In Process Citation]." Ideggyogy Sz
55(7-8): 220-5.
The cognitive (executive) ability of patients with Parkinson's-disease (PD)
deteriorates gradually during the progression of the disease. Fluency of speech,
word finding, working memory, ability to plan the future and flexibility
decline. Cognitive disturbance was found to be proportional with the speech,
posture, gait and balance problems and can not be influenced by L-dopa
substitution. Apart the dorsal and ventral mesolimbic dopaminergic systems the
coerulo-cortical noradrenergic, serotoninergic and cholinergic systems are also
impaired in PD. Subcortical dementia in PD can also be explained by the
functional disability of dorsolateral and anterior cingular circuits. Attention
deficit can be explained by the dopamine depletion of cingular cortex. Cortical
Lewy bodies, neurofibrillary tangles, neurit plaques and additional vascular
pathology should also play a role in cognitive impairment of PD. In several
systemic degenerative diseases associating with Parkinson's syndrome (PS) i.e.
progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), multiple
system atrophy (MSA) dementia can be detected with various severity, therefore
the question arises concerning the correlation between cognitive disability and
PS. Parkinson syndrome can also develop in frontotemporal dementias (FTD),
Alzheimer's disease and cortical Lewy body disease (CLBD) but no correlation
exists between motor disability and severity of dementia. In CLBD dementia can
be the initial symptom in 18% of cases but PS can also preceeds the dementia. In
PSP profound depletion of other monoaminergic neurotransmitter system was also
reported. In FTDs associated with PS degeneration of substantia nigra, locus
coeruleus and basal nucleus of Meynert has been reported with increased number
of neurofibrillary tangles. In patients with vascular PS (VP) there is generally
no tremor and rigidity, but pseudobulbar palsy, dementia, gate disturbance,
incontinency appears; L-dopa treatment is generally ineffective. In VP no
cellular loss can be found within the substantia nigra, but leukoaraiosis,
lacunae in the white matter and basal ganglia are commonly demonstrated.
Tabner, B. J., S. Turnbull, et al. (2002). "Formation of hydrogen peroxide and
hydroxyl radicals from Abeta and alpha-synuclein as a possible mechanism of cell
death in Alzheimer's disease and Parkinson's disease(1,2)." Free Radic Biol
Med 32(11): 1076-83.
The formation of extracellular or intracellular deposits of amyloid-like protein
fibrils is a prominent pathological feature of many different neurodegenerative
diseases, including Alzheimer's disease (AD) and Parkinson's disease (PD). In
AD, the beta-amyloid peptide (Abeta) accumulates mainly extracellularly at the
center of senile plaques, whereas, in PD, the alpha-synuclein protein
accumulates within neurons inside the Lewy bodies and Lewy neurites. We have
shown recently that solutions of Abeta 1-40, Abeta 1-42, Abeta 25-35,
alpha-synuclein and non-Abeta component (NAC; residues 61-95 of alpha-synuclein)
all liberate hydroxyl radicals upon incubation in vitro followed by the addition
of small amounts of Fe(II). These hydroxyl radicals were readily detected by
means of electron spin resonance spectroscopy, employing
5,5-dimethyl-1-pyrroline N-oxide (DMPO) as a spin trapping agent. Hydroxyl
radical formation was inhibited by the inclusion of catalase or metal-chelators
during Abeta or alpha-synuclein incubation. Our results suggest that hydrogen
peroxide accumulates during the incubation of Abeta or alpha-synuclein, by a
metal-dependent mechanism, and that this is subsequently converted to hydroxyl
radicals, on addition of Fe (II), by Fenton's reaction. Consequently, one of the
fundamental molecular mechanisms underlying the pathogenesis of cell death in AD
and PD, and possibly other neurodegenerative or amyloid diseases, could be the
direct production of hydrogen peroxide during formation of the abnormal protein
aggregates.
Takahashi, T., H. Yamashita, et al. (2002). "Tyrosine 125 of alpha-synuclein
plays a critical role for dimerization following nitrative stress." Brain Res
938(1-2): 73-80.
alpha-Synuclein is a major component of Lewy bodies in Parkinson's disease,
dementia with Lewy bodies, and glial cytoplasmic inclusions in multiple system
atrophy. Increasing evidence suggests that the nitration of tyrosine residues in
alpha-synuclein induced by oxidative injury is involved in the formation of
inclusions characteristic to these synucleinopathies. Exposure of
alpha-synuclein to peroxynitrite induces nitration of tyrosine residues, thereby
forming alpha-synuclein oligomers. However, the contribution of tyrosine
residues to either the nitration or the oligomerization is currently unknown.
The present study used recombinant wild-type and mutant alpha-synuclein proteins
to investigate the role of each alpha-synuclein tyrosine residue in the in vitro
formation of alpha-synuclein oligomers under nitrative stress. Confocal
microscopic analysis revealed that wild-type alpha-synuclein protein was able to
accumulate and form an inclusion-like structure in the cytoplasm of living cells
upon introduction by streptolysin O. Authentic peroxynitrite induced nitration
of tyrosine residues in alpha-synuclein protein, as well as dimerization of
alpha-synuclein. The formation of both SDS- and heat-stable dimers suggests
cross-linking between nitrated tyrosine residues. Nonetheless, dimerization of
alpha-synuclein proteins lacking tyrosine 125 was significantly decreased
compared with alpha-synuclein proteins lacking tyrosine residues at positions
39, 133, or 136. Presumably, tyrosine 125 plays a critical role for
alpha-synuclein dimerization under nitrative stress.
Tamo, W., T. Imaizumi, et al. (2002). "Expression of alpha-synuclein, the
precursor of non-amyloid beta component of Alzheimer's disease amyloid, in human
cerebral blood vessels." Neurosci Lett 326(1): 5-8.
The non-amyloid beta component of Alzheimer's disease amyloid (NAC) is detected
in cerebral amyloid angiopathy; and the precursor of NAC is now known to be
identical to alpha-synuclein (alpha-S), a major component of Lewy bodies in
Parkinson's disease. We studied if cerebral vascular cells express alpha-S.
Immunohistochemical studies of human cerebral tissues from control and cerebral
amyloid angiopathy patients revealed the expression of alpha-S in vascular
endothelial and smooth muscle cells. Then we studied the expression of alpha-S
in vitro using cultures of vascular cells. Cultures of human umbilical vein
endothelial cells and umbilical artery smooth muscle cells were found to
constitutively express alpha-S messenger RNA and protein. alpha-S is normally
expressed in vascular cells and may play some physiological role in the vascular
wall.
Tsuchiya, K., K. Ikeda, et al. (2002). "Parkinson's disease mimicking senile
dementia of the Alzheimer type: a clinicopathological study of four autopsy
cases." Neuropathology 22(2): 77-84.
This report concerns four Japanese autopsy cases of Parkinson's disease (PD)
mimicking senile dementia of the Alzheimer type. Three patients with a clinical
diagnosis of senile dementia of the Alzheimer type developed memory disturbance
as the initial sign, and a patient with a clinical diagnosis of atypical senile
dementia presented with hallucination and delusion as the initial sign. Dementia
was evident in all four patients, and slight parkinsonism appeared in the middle
to late stages of the disease in two patients. Macroscopical examination of the
brain disclosed slight depigmentation of the substantia nigra and prominent
depigmentation of the locus ceruleus in all four cases. Histological examination
of the four patients showed neuronal loss with astrocytosis and the appearance
of Lewy bodies in the substantia nigra, locus ceruleus, and dorsal vagal
nucleus. The nucleus basalis of Meynert was involved in three cases, in which
this structure was examined. The total Lewy body scores of the four cases were 1
in three cases and 0 in the other, compatible with PD. Massive appearance of
senile plaques, consistent with Braak stage C, was found in one case, and the
slight appearance of senile plaques, consistent with Braak stage A, was evident
in two cases. One case had no evidence of senile plaques. In all four cases,
slight neurofibrillary changes were present in the limbic areas, compatible with
Braak stages II to III. Based on these clinicopathological findings and a review
of the literature, we concluded that PD simulating Alzheimer's disease without
overt parkinsonism rarely exists. Furthermore, we postulate that the clinical
features of PD are more widespread than previously believed.
Uversky, V. N. and A. L. Fink (2002). "Amino acid determinants of
alpha-synuclein aggregation: putting together pieces of the puzzle." FEBS
Lett 522(1-3): 9-13.
Parkinson's disease is the second most common neurodegenerative disease, and
results from loss of dopaminergic neurons in the substantia nigra. The
aggregation and fibrillation of alpha-synuclein in the form of intracellular
proteinaceous aggregates (Lewy bodies and Lewy neurites) have been implicated as
a causative factor in this disease, as well as in several other
neurodegenerative disorders, including dementia with Lewy bodies, Lewy body
variant of Alzheimer's disease, multiple system atrophy and Hallervorden-Spatz
disease. Thus, the aggregated forms of alpha-synuclein play a crucial role in
the pathogenesis of the synucleinopathies. However, the molecular mechanisms
underlying alpha-synuclein aggregation into specific filamentous inclusions
remained unknown until recently. Data on the aggregation and fibrillation
properties of human alpha-, beta- and gamma-synucleins, mouse alpha-synuclein
and familial Parkinson's disease mutants of human alpha-synuclein (A30P and
A53T) are analyzed in order to shed light on the amino acid determinants of
synuclein aggregation.
Uversky, V. N., J. Li, et al. (2002). "Biophysical properties of the synucleins
and their propensities to fibrillate: inhibition of alpha-synuclein assembly by
beta- and gamma-synucleins." J Biol Chem 277(14): 11970-8.
The pathological hallmark of Parkinson's disease is the presence of
intracellular inclusions, Lewy bodies, and Lewy neurites, in the dopaminergic
neurons of the substantia nigra and several other brain regions. Filamentous
alpha-synuclein is the major component of these deposits and its aggregation is
believed to play an important role in Parkinson's disease and several other
neurodegenerative diseases. Two homologous proteins, beta- and gamma-synucleins,
are also abundant in the brain. The synucleins are natively unfolded proteins.
beta-Synuclein, which lacks 11 central hydrophobic residues compared with its
homologs, exhibited the properties of a random coil, whereas alpha- and
gamma-synucleins were slightly more compact and structured. gamma-Synuclein,
unlike its homologs, formed a soluble oligomer at relatively low concentrations,
which appears to be an off-fibrillation pathway species. Here we show that,
although they have similar biophysical properties to alpha-synuclein, beta- And
gamma-synucleins inhibit alpha-synuclein fibril formation. Complete inhibition
of alpha-synuclein fibrillation was observed at 4:1 molar excess of beta- and
gamma-synucleins. No significant incorporation of beta-synuclein into the
fibrils was detected. The lack of fibrils formed by beta-synuclein is most
readily explained by the absence of a stretch of hydrophobic residues from the
middle region of the protein. A model for the inhibition is proposed.
Wakabayashi, K., S. Engelender, et al. (2002). "Immunocytochemical localization
of synphilin-1, an alpha-synuclein-associated protein, in neurodegenerative
disorders." Acta Neuropathol (Berl) 103(3): 209-14.
Alpha-synuclein is a major component of Lewy bodies (LB) in Parkinson's disease
(PD) and dementia with LB (DLB), as well as of glial cytoplasmic inclusions
(GCI) in multiple system atrophy (MSA). Recently, a novel protein called
synphilin-1 has been identified that associates with alpha-synuclein, and it has
been reported that co-transfection of both alpha-synuclein and synphilin-1 in
mammalian cells yielded eosinophilic cytoplasmic inclusions resembling LB.
Immunocytochemical and ultrastructural investigations have now been performed on
the brain of patients with various neurodegenerative disorders using
anti-synphilin-1 antibodies. These antibodies immunostained the neuropil in a
punctate pattern throughout the brain of control subjects. In PD, most LB
observed in the brain stem were positive for synphilin-1. These LB showed
intense staining in their central cores, but their peripheral portions were only
weakly stained or unstained. Pale bodies and Lewy neurites, which were positive
for alpha-synuclein, were synphilin-1 negative. In DLB, a small fraction of
cortical LB were immunolabeled by anti-synphilin-1. In MSA, numerous GCI were
positive for synphilin-1. Immunoelectron microscopy revealed that the reaction
product was localized within filamentous and circular structures in LB. Various
neuronal and glial inclusions in neurodegenerative disorders other than LB
disease and MSA were synphilin-1 negative. These findings suggest that abnormal
accumulation of synphilin-1 is specific for brain lesions in which
alpha-synuclein is a major component.
Walker, Z., D. C. Costa, et al. (2002). "Differentiation of dementia with Lewy
bodies from Alzheimer's disease using a dopaminergic presynaptic ligand." J
Neurol Neurosurg Psychiatry 73(2): 134-40.
BACKGROUND: Dementia with Lewy bodies (DLB) is one of the main differential
diagnoses of Alzheimer's disease (AD). Key pathological features of patients
with DLB are not only the presence of cerebral cortical neuronal loss, with Lewy
bodies in surviving neurones, but also loss of nigrostriatal dopaminergic
neurones, similar to that of Parkinson's disease (PD). In DLB there is 40-70%
loss of striatal dopamine. OBJECTIVE: To determine if detection of this
dopaminergic degeneration can help to distinguish DLB from AD during life.
METHODS: The integrity of the nigrostriatal metabolism in 27 patients with DLB,
17 with AD, 19 drug naive patients with PD, and 16 controls was assessed using a
dopaminergic presynaptic ligand, (123)I-labelled
2beta-carbomethoxy-3beta-(4-iodophenyl)-N-(3-fluoropropyl)nortropane (FP-CIT),
and single photon emission tomography (SPET). A SPET scan was carried out with a
single slice, brain dedicated tomograph (SME 810) 3.5 hours after intravenous
injection of 185 MBq FP-CIT. With occipital cortex used as a radioactivity
uptake reference, ratios for the caudate nucleus and the anterior and posterior
putamen of both hemispheres were calculated. All scans were also rated by a
simple visual method. RESULTS: Both DLB and PD patients had significantly lower
uptake of radioactivity than patients with AD (p<0.001) and controls (p<0.001)
in the caudate nucleus and the anterior and posterior putamen. CONCLUSION:
FP-CIT SPET provides a means of distinguishing DLB from AD during life.
Wolozin, B. and N. Golts (2002). "Iron and Parkinson's disease."
Neuroscientist 8(1): 22-32.
Multiple studies implicate iron in the pathophysiology of Parkinson's disease
(PD). In the brains of patients with PD, iron levels are elevated and the levels
of iron-binding proteins are abnormal. Iron has been suspected to contribute to
PD because Fe(II) is known to promote oxidative damage. Recent studies suggest
that an additional mechanism by which iron might contribute to PD is by inducing
aggregation of the alpha-synuclein, which is a protein that accumulates in Lewy
bodies in PD.
Wszolek, Z. K., K. Gwinn-Hardy, et al. (2002). "Neuropathology of two members of
a German-American kindred (Family C) with late onset parkinsonism." Acta
Neuropathol (Berl) 103(4): 344-50.
We present genealogical and longitudinal clinical observations and autopsy
findings of a previously reported kindred, Family C (German-American), with
late-onset autosomal dominant parkinsonism with evidence for linkage on
chromosome 2p13. The clinical phenotype includes the cardinal features of
idiopathic Parkinson's disease. In addition, postural tremor and dementia are
detected in some individuals. Two members of the kindred, one affected and one
unaffected have recently come to autopsy. The unaffected family member was an
82-year-old woman whose brain showed only mild age-related pathology and no
evidence of subclinical Lewy body disease. In contrast, the affected family
member was an 83-year-old man whose brain had neuronal loss, gliosis and Lewy
bodies in the substantia nigra and other monoaminergic brain stem nuclei, as
well as the basal forebrain and amygdala. Lewy bodies and Lewy neurites had a
distribution typical of cases of idiopathic Parkinson's disease. Thus, the
clinical and pathological findings in this family with autosomal dominant
parkinsonism are similar to those of sporadic Parkinson's disease.
Yokota, O., S. Terada, et al. (2002). "NACP/alpha-synuclein immunoreactivity in
diffuse neurofibrillary tangles with calcification (DNTC)." Acta Neuropathol
(Berl) 104(4): 333-41.
Diffuse neurofibrillary tangles with calcification (DNTC) is a rare
tangle-predominant dementia, as well as one of the tauopathies lacking Abeta
deposition. It is characterized by temporo-frontal lobar atrophy, Fahr-type
calcification and, histopathologically, numerous neurofibrillary tangles in the
limbic system and neocortex. Recently, accumulation of alpha-synuclein (alphaS),
the precursor of the non-beta amyloid component (NAC) of Alzheimer's disease,
has been shown in diverse neurodegenerative disorders, including Parkinson's
disease, dementia with Lewy bodies, Alzheimer's disease, multiple system atrophy
and parkinsonism-dementia complex of Guam. To clarify whether alphaS accumulates
in other neurodegenerative disorders, we investigated eight DNTC brains using
immunohistochemistry and demonstrated remarkable alphaS deposition in the
neurons and astrocytes in many anatomical regions. Abundant Lewy bodies were
observed in the amygdala (seven cases) and hippocampus (seven cases), and, to a
lesser degree, in the substantia nigra (six cases) and dorsal vagal nucleus
(five cases). In the hippocampus, many Lewy neurites were distributed in the
stratum oriens and stratum pyramidale in the CA2-3 and the subiculum.
Furthermore, numerous NAC-positive astrocytes were detected in the hippocampus
and temporal cortex. This investigation reveals that neurons and astrocytes are
extensively involved in remarkable alphaS pathology in the DNTC brain, and that
the alphaS pathology compounds the cardinal pathological features of tau
pathology. These findings suggest that (1) DNTC shares a common
pathophysiological background with Parkinson's disease, dementia with Lewy
bodies, and multiple system atrophy in which abnormal alphaS aggregation is
observed, and (2) there is an interaction between alphaS and tau pathology that
does not involve amyloid in DNTC.
Yokoyama, K., S. Ikebe, et al. (2002). "[A 68-year-old woman with dementia and
parkinsonism]." No To Shinkei 54(2): 175-84.
We report a 68-year-old woman who developed progressive dementia and
parkinsonism. She was well until 1990 when she was 58 years of age. She started
to show memory loss. Four years later, she developed difficulty in dressing and
behavioral problems such as eating rice with her hands, going out of her house
without purposes, and difficulty in finding the rest room in her house. She was
admitted to the neurology service of Hatsuishi Hospital on January 19, 1996,
when she was 64 years of the age. On admission, she was alert but markedly
demented. The score of Hansegawa Dementia Scale was 0/30. She was unable to make
any coherent conversation. She appeared to have dressing apraxia but did not
appear to have aphasia. Cranial nerves were intact. She walked in small steps
with stooped posture. She did not have motor weakness but she showed plastic
rigidity in all four limbs. No tremor or ataxia was noted. Deep tendon reflexes
were within normal limits but the plantar response was extensor bilaterally. She
continued to deteriorate after admission. In May of 1998, she started to fall.
In June of 1998, she had a generalized convulsion. In January of 1999, she
became unable to take foods orally and a gastrostomy was placed. She expired on
May 29, 1990. She was discussed in a neurological CPC and the chief discussant
arrived at the conclusion that the patient had Alzheimer's disease. The question
was whether her parkinsonism was a part of her Alzheimer's disease or she had an
additional disease to explain her parkinsonism. Post-mortem examination revealed
moderate to marked atrophy of the frontal and the temporal lobes as well as in
the limbic areas with dilatation of the lateral ventricles. Marked neuronal loss
was noted in the CA 1 to the subiculum region with gliosis. Neurofibrillary
tangles were seen in the remaining neurons. Neuropil threads were seen by
Gallyas-Braak staining. Similar changes were seen in the parahippocampal gyrus
and in the entorhinal cortex. Senile plaques were seen in the insular cortex and
in other cortical areas. Cortical type Lewy bodies were seen in the cingulate
cortex. The Meynert nucleus showed marked neuronal loss and gliosis. The
substantia nigra and the locus coeruleus showed moderate loss of pigmented
neurons. Lewy bodies were seen in these regions. The dorsal motor nucleus of the
vagal nerve was retained, however, one Lewy body was observed. Pathologic
diagnosis was Alzheimer's disease plus Parkinson's disease. It is an interesting
question whether or not her parkinsonism was due to nigral lesion or frontal
lesions. It is known that parkinsonism may complicate in advanced Alzheimer's
disease not necessarily due to nigral lesion. On the other hand, in incidental
Lewy body disease, the substantia nigra shows mild Parkinson's disease-like
change without clinical parkinsonism. This patient appeared to have been a true
complication of Alzheimer's disease and Parkinson's disease.
Zatloukal, K., C. Stumptner, et al. (2002). "p62 Is a common component of
cytoplasmic inclusions in protein aggregation diseases." Am J Pathol
160(1): 255-63.
Exposure of cells to stress, particularly oxidative stress, leads to misfolding
of proteins and, if they are not refolded or degraded, to cytoplasmic protein
aggregates. Protein aggregates are characteristic features of a variety of
chronic toxic and degenerative diseases, such as Mallory bodies (MBs) in
hepatocytes in alcoholic and non-alcoholic steatohepatitis, neurofibrillary
tangles in neurons in Alzheimer's, and Lewy bodies in Parkinson's disease. Using
2D gel electrophoresis and mass spectrometry, we identified p62 as a novel MB
component. p62 and cytokeratins (CKs) are major MB constituents; HSP 70, HSP 25,
and ubiquitinated CKs are also present. These proteins characterize MBs as a
prototype of disease-associated cytoplasmic inclusions generated by
stress-induced protein misfolding. As revealed by transfection of tissue culture
cells overexpressed p62 did not induce aggregation of regular CK filaments but
selectively bound to misfolded and ubiquitinated CKs. The general role of p62 in
the cellular response to misfolded proteins was substantiated by detection of
p62 in other cytoplasmic inclusions, such as neurofibrillary tangles, Lewy
bodies, Rosenthal fibers, intracytoplasmic hyaline bodies in hepatocellular
carcinoma, and alpha1-antitrypsin aggregates. The presence of p62 along with
other stress proteins and ubiquitin in cytoplasmic inclusions indicates
deposition as aggregates as a third line of defense against misfolded proteins
in addition to refolding and degradation.
Zhang, J., T. J. Montine, et al. (2002). "The mitochondrial common deletion in
Parkinson's disease and related movement disorders." Parkinsonism Relat
Disord 8(3): 165-70.
The mitochondrial 4977-bp common deletion has been reported in some studies to
occur exclusively or with increased frequency in the midbrain of patients with
Parkinson's disease (PD). Other studies could not confirm these results; rather,
it was suggested that the mitochondrial common deletion is associated with aging
in the midbrain and not PD. One possible explanation for these conflicting
results is the difficulty in quantifying mitochondrial DNA deletions or
mutations in the whole midbrain or substantia nigra (SN) while only a subset of
midbrain neurons degenerate in PD. In addition, none of the studies has
addressed the cell types with the common deletion within the midbrain. In this
study we used in situ hybridization to detect the common deletion in sections of
midbrain from patients with PD, multiple system atrophy-parkinsonian type
(MSA-P), progressive supranuclear palsy (PSP), dementia with Lewy bodies (DLB),
age-matched controls, and individuals of different ages. The results
demonstrated that the mitochondrial common deletion accumulated primarily in
neurons but not glia in both the SN and other midbrain regions. There was no
significant difference in the number or distribution of neurons with the common
deletion or the average of the mean densities (AMD) of staining with the common
deletion in nigral neurons among patients with PD, MSA-P, PSP, DLB, or
age-matched controls. In addition, there was no difference in the number or
distribution of neurons with the common deletion in nigral neurons between any
age group, although there was a tendency for the common deletion to increase in
the non-nigral neurons in older patients. These data indicate that accumu | |