A critical evaluation of current staging of α-synuclein pathology in Lewy body disorders

The two most frequent synucleinopathies, Parkinson disease (PD) or brainstem predominant type of Lewy body disease, and dementia with Lewy bodies (DLB), are neurodegenerative multisystem disorders with widespread occurrence of α-synuclein containing deposits in the central, peripheral, and autonomic systems. For both Lewy body-related disorders staging/classification systems based on semiquantitative assessment of the distribution and progression pattern of α-synuclein pathology are used that are considered to be linked to clinical dysfunctions. In PD a six-stage system is suggested to indicate a predictable sequence of lesions with ascending progression from medullary and olfactory nuclei to the cortex, the first two presymptomatic stages related to incidental Lewy body disease, stages 3 and 4 presenting with motor symptoms and the last two (cortical) stages frequently associated with cognitive impairment. DLB, according to consensus pathologic guidelines, by semiquantitative scoring of α-synuclein pathology (Lewy body density and distribution) in specific brain regions, is distinguished into three phenotypes (brainstem, transitory/limbic and diffuse cortical), also considering concomitant Alzheimer-related pathology. Recent retrospective clinico-pathologic studies, although largely confirming the staging system, particularly for younger onset PD with long duration, have shown that between 6.3 and 43% of cases did not follow the proposed caudo-rostral progression pattern of α-synuclein pathology. In 7 to 8.3% of clinically manifested PD cases with synuclein inclusions in midbrain and cortex corresponding to LB stages 4–5 the medullary nuclei were spared, whereas mild parkinsonian symptoms were already observed in stages 2 and 3. There is considerable clinical and pathologic overlap between PD (with or without dementia) and DLB, corresponding to Braak LB stages 5 and 6, both frequently associated with variable Alzheimer-type pathology. Dementia often does not correlate with progressed stages of Lewy body pathology, but is related to concomitant Alzheimer lesions or mixed pathologies. There is no relationship between Braak LB stages and clinical severity of PD. Therefore, the predictive validity of this concept is doubtful, since in large unselected autopsy series 30 to 55% of elderly subjects with widespread α-synuclein pathology (Braak stages 5–6) revealed no definite neuropsychiatric symptoms or were not classifiable, indicating compensatory mechanisms of the brain. The causes and molecular basis of rather frequent deviations from the proposed caudo-rostral progression of α-synuclein pathology in PD, its relation to the onset of classical parkinsonian symptoms, the causes for the lack of definite clinical symptoms despite widespread α-synuclein pathology in the nervous system, their relations to Alzheimer-type lesions, and the pathophysiologic impact of both pathologies remain to be further elucidated.     

Sensitive fluorescence polarization technique for rapid screening of alpha-synuclein oligomerization/fibrillization inhibitors

Parkinson's disease (PD) is characterized by the accumulation of fibrillar alpha-synuclein (alpha-Syn) inclusions known as Lewy bodies (LBs) and Lewy neurites. Mutations in the alpha-Syn gene or extra copies thereof cause familial PD or dementia with LBs (DLB) in rare kindreds, but abnormal accumulations of wildtype alpha-Syn also are implicated in the pathogenesis of sporadic PD, the most common movement disorder. Insights into mechanisms underlying alpha-Syn mediated neurodegeneration link alpha-Syn oligomerization and fibrillization to the onset and progression of PD. Thus, inhibiting alpha-Syn oligomer or fibril formation is a compelling target for discovering disease modifying therapies for PD, DLB, and related synucleinopathies. Although amyloid dyes recognize alpha-Syn fibrils, efficient detection of soluble oligomers remains a challenge. Here, we report a novel fluorescence polarization (FP) technique for examining alpha-Syn assembly by monitoring changes in its relative molecular mass during progression of normal alpha-Syn from highly soluble monomers to higher order multimers and thence insoluble amyloid fibrils. We report that FP is more sensitive than conventional amyloid dye methods for the quantification of mature fibrils, and that FP is capable of detecting oligomeric alpha-Syn, allowing for rapid automated screening of potential inhibitors of alpha-Syn oligomerization and fibrillization. Furthermore, FP can be combined with an amyloid dye in a single assay that simultaneously provides two independent biophysical readouts for monitoring alpha-Syn fibrillization. Thus, this FP method holds potential to accelerate discovery of disease modifying therapies for LB PD, DLB, and related neurodegenerative synucleinopathies.     

Interaction between parkin and alpha-synuclein

A dramatic paradigm shift in understanding Parkinson's disease (PD) has emerged with implications for Alzheimer's disease (AD) because: (1) Mutations in the alpha-synuclein (AS) gene cause familial PD, (2) Antibodies to AS detect Lewy bodies (LBs) and dystrophic Lewy neurites in PD, dementia with LBs (DLB), sporadic AD and the LB variant of AD (LBVAD), (3) Insoluble AS filaments are recovered from DLB brains and purified LBs, (4) Recombinant AS assembles into LB-like filaments and residues 71–82 are essential for filament assembly, (5) AS transgenic mice and flies develop a PD-like phenotype, (6) Cortical LBs detected with antibodies to AS correlate with dementia in PD, DLB and LBVAD, (7) Antibodies to AS detect LBs in 50% of familial AD, sporadic AD and Down's syndrome brains, (8) AS forms glial cytoplasmic inclusions (GCIs) in multiple system atrophy, (9) Epitopes throughout AS in LBs and GCIs, (10) Filamentous AS aggregates in LBs, GCIs and related lesions contain nitrated tyrosines, (11) Cells transfected with AS and treated with nitric oxide generators develop LB-like AS inclusions, (12) Bigenic mice overexpressing mutant human APP and AS show an augmentation in AS inclusions. Thus, neurodegenerative diseases characterized by AS pathologies are synucleinopathies, and the filamentous AS lesions in these disorders may result in part from oxidative/nitrative damage to AS. Abnormal interactions of brain proteins may underlie synucleinopathies and other neurodegenerative disorders. Acknowledgements:
Supported by NIA/NIH and Alzheimer's Association.     

Fatal attractions: abnormal protein aggregation and neuron death in Parkinson's disease and Lewy body dementia

The abnormal aggregation of proteins into fibrillar lesions is a neuropathological hallmark of several sporadic and hereditary neurodegenerative diseases. For example, Lewy bodies (LBs) are intracytoplasmic filamentous inclusions that accumulate primarily in subcortical neurons of patients with Parkinson's disease (PD), or predominantly in neocortical neurons in a subtype of Alzheimer's disease (AD) known as the LB variant of AD (LBVAD) and in dementia with LBs (DLB). Aggregated neurofilament subunits and alpha-synuclein are major protein components of LBs, and these inclusions may contribute mechanistically to the degeneration of neurons in PD, DLB and LBVAD. Here we review recent studies of the protein building blocks of LBs, as well as the role LBs play in the onset and progression of PD, DLB and LBVAD. Increased understanding of the protein composition and pathological significance of LBs may provide insight into mechanisms of neuron dysfunction and death in other neurodegenerative disorders characterized by brain lesions containing massive deposits of proteinacious fibrils.     

Age- and disease-dependent increase of the mitophagy marker phospho-ubiquitin in normal aging and Lewy body disease

Although exact causes of Parkinson disease (PD) remain enigmatic, mitochondrial dysfunction is increasingly appreciated as a key determinant of dopaminergic neuron susceptibility in both familial and sporadic PD. Two genes associated with recessive, early-onset PD encode the ubiquitin (Ub) kinase PINK1 and the E3 Ub ligase PRKN/PARK2/Parkin, which together orchestrate a protective mitochondrial quality control (mitoQC) pathway. Upon stress, both enzymes cooperatively identify and decorate damaged mitochondria with phosphorylated poly-Ub (p-S65-Ub) chains. This specific label is subsequently recognized by autophagy receptors that further facilitate mitochondrial degradation in lysosomes (mitophagy). Here, we analyzed human post-mortem brain specimens and identified distinct pools of p-S65-Ub-positive structures that partially colocalized with markers of mitochondria, autophagy, lysosomes and/or granulovacuolar degeneration bodies. We further quantified levels and distribution of the ‘mitophagy tag’ in 2 large cohorts of brain samples from normal aging and Lewy body disease (LBD) cases using unbiased digital pathology. Somatic p-S65-Ub structures independently increased with age and disease in distinct brain regions and enhanced levels in LBD brain were age- and Braak tangle stage-dependent. Additionally, we observed significant correlations of p-S65-Ub with LBs and neurofibrillary tangle levels in disease. The degree of co-existing p-S65-Ub signals and pathological PD hallmarks increased in the pre-mature stage, but decreased in the late stage of LB or tangle aggregation. Altogether, our study provides further evidence for a potential pathogenic overlap among different forms of PD and suggests that p-S65-Ub can serve as a biomarker for mitochondrial damage in aging and disease.

Abbreviations: BLBD: brainstem predominant Lewy body disease; CCCP: carbonyl cyanide m-chlorophenyl hydrazone; DLB: dementia with Lewy bodies; DLBD: diffuse neocortical Lewy body disease; EOPD: early-onset Parkinson disease; GVB: granulovacuolar degeneration body; LB: Lewy body; LBD: Lewy body disease; mitoQC: mitochondrial quality control; nbM: nucleus basalis of Meynert; PD: Parkinson disease; PDD: Parkinson disease with dementia; p-S65-Ub: PINK1-phosphorylated serine 65 ubiquitin; SN: substantia nigra; TLBD: transitional Lewy body disease; Ub: ubiquitin     

Tracking extranigral degeneration in animal models of Parkinson's disease: quest for effective therapeutic strategies

Sporadic Parkinson's disease (PD) is now interpreted as a complex nervous system disorder in which the projection neurons are predominantly damaged. Such an interpretation is based on mapping of Lewy body and Lewy neurite pathology. Symptoms of the human disease are much widespread, which span from pre-clinical non-motor symptoms and clinical motor symptoms to cognitive discrepancies often seen in advanced stages. Existing symptomatic treatments further complicate with overt drug-irresponsive symptoms. PD is better understood by assimilation of extranigral degenerative pathways with nigrostriatal degenerative mechanisms. The term 'extranigral' appeared first in the 1990s to more rigorously define the nigral pathology by process of elimination. However, as clinicians progressively identified PD symptoms unresponsive to the gold standard drug l-DOPA, definitions of PD symptoms were redefined. Non-motor symptoms prodromal to motor symptoms just as pre-clinical to clinical, and conjointly emerged the concept of nigral versus extranigral degeneration in PD. While nigrostriatal degeneration is responsible for the neurobiological substrates of extrapyramydal motor features, extranigral degeneration corroborates a vast majority of other changes in discrete central, peripheral, and enteric nervous system nuclei, which together account for global symptoms of the human disease. As an extranigral site, spinal cord degeneration has also been implicated in PD progression. Interconnected to the upper CNS structures with descending and ascending pathways, spinal neurons participate in movement and sensory circuits, controlling movement and reflexes. Several clinical and in vivo studies have demonstrated signs of parkinsonism-related degenerative processes in spinal cord, which led to recent consideration of spinal cord as an area of potential therapeutic target. In a nutshell, this review explores how the existing animal models can actually reflect the human disease in order to facilitate PD research. Evolution of extranigral degeneration studies has been succinctly revisited, followed by a survey on animal models in light of recent findings in clinical PD. Together, it may help to develop effective therapeutic strategies for PD.     

Cognitive impairment in Parkinson's disease and dementia with lewy bodies: a spectrum of disease

Parkinson's disease (PD) is classically thought of as a movement disorder characterized by tremor, rigidity and postural instability. Nevertheless, there is growing recognition of prominent cognitive impairment in PD and related disorders, which is responsible for substantial disability in these patients. This review will focus on cognitive impairment associated with Lewy body pathology, including PD with dementia (PDD) and dementia with Lewy bodies (DLB). We will review the epidemiology, clinical evaluation, underlying mechanisms and treatment of cognitive impairment in these patients. Despite differences between PDD and DLB, there is clinical, neuropathological and radiological overlap between these disorders, supporting the view that they represent a spectrum of disease. These observations suggest that common targets for diagnosis and treatment of these disorders can be identified.     

Symposium 3: Function and Pathogenesis in Parkinson’s Disease. Synuclein: the third amyloid in Alzheimer's disease

A dramatic paradigm shift in understanding Parkinson's disease (PD) has emerged with implications for Alzheimer's disease (AD) because: (1) Mutations in the alpha‐synuclein (AS) gene cause familial PD, (2) Antibodies to AS detect Lewy bodies (LBs) and dystrophic Lewy neurites in PD, dementia with LBs (DLB), sporadic AD and the LB variant of AD (LBVAD), (3) Insoluble AS filaments are recovered from DLB brains and purified LBs, (4) Recombinant AS assembles into LB‐like filaments and residues 71–82 are essential for filament assembly, (5) AS transgenic mice and flies develop a PD‐like phenotype, (6) Cortical LBs detected with antibodies to AS correlate with dementia in PD, DLB and LBVAD, (7) Antibodies to AS detect LBs in 50% of familial AD, sporadic AD and Down's syndrome brains, (8) AS forms glial cytoplasmic inclusions (GCIs) in multiple system atrophy, (9) Epitopes throughout AS in LBs and GCIs, (10) Filamentous AS aggregates in LBs, GCIs and related lesions contain nitrated tyrosines, (11) Cells transfected with AS and treated with nitric oxide generators develop LB‐like AS inclusions, (12) Bigenic mice overexpressing mutant human APP and AS show an augmentation in AS inclusions. Thus, neurodegenerative diseases characterized by AS pathologies are synucleinopathies, and the filamentous AS lesions in these disorders may result in part from oxidative/nitrative damage to AS. Abnormal interactions of brain proteins may underlie synucleinopathies and other neurodegenerative disorders. Acknowledgements: Supported by NIA/NIH and Alzheimer's Association.     

Autres applications de la MIBG : « applications de la scintigraphie de l’innervation myocardique à la 123-I-MIBG en neurologie »

Myocardial 123-I-metaiodobenzylguanidine (MIBG) imaging enables the assessment of postganglionic sympathetic cardiac innervation. Recently myocardial 123-I-MIBG scintigraphy has been found to be useful to distinguishing Parkinsońs disease (PD) from other akinetic rigid syndromes. The absence of published guidelines for cardiac 123-I-MIBG imaging makes standardization of procedures among individual users of this technique even more important. Cardiac MIBG study showed markedly decreased uptake in PD, dementia with Lewy bodies (DLB) and pure autonomic failure, which is a common feature of Lewy body disease. The cardiac MIBG uptake is severely impaired even in the early disease stage. Atypical parkinsonian syndromes, including Multiple System Atrophy, Progressive Supranuclear Palsy, and other, show modest reduction of cardiac MIBG uptake. The MIBG study can be used for differentiating patients with extrapyramidal signs and dementia, and might provide useful diagnostic information to discriminate DLB and Alzheime?s disease.     

Olfactory dysfunction in Parkinson's disease

Prior to the onset of the cardinal motor features of idiopathic Parkinson's disease (PD), other manifestations of neurodegeneration such as olfactory dysfunction are often apparent. Characterizing these potential biomarkers of preclinical PD is particularly important in identifying individuals who will go on to develop disabling symptoms, and thus be good candidates for new neuroprotective strategies. As shown by the Braak neuropathologic staging of PD, the olfactory system is among the first neuronal populations to display Lewy body pathology. Clinically, loss of smell can be easily tested in the office using several validated techniques and is often helpful to the physician in distinguishing idiopathic PD from other forms of parkinsonism. Recent findings have indicated that a decline in olfaction may be observed in selected at-risk patients, which has significant implications for identifying potential study populations. Ongoing studies of olfactory dysfunction may also reveal potential for use as a medication-independent biomarker of disease progression in addition to use as a biomarker for the diagnosis of PD.     

Selective detection, quantification, and subcellular location of alpha-synuclein aggregates with a protein aggregate filtration assay

Parkinson's disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy are caused by alpha-synuclein aggregates. At present, there is no good biochemical method defining alpha-synuclein aggregates formed in vivo versus oligomers as a means to investigate alpha-synuclein aggregation and its mechanisms of neurodegeneration. A simple method, therefore, for the selective and sensitive detection of alpha-synuclein aggregates suited for screening purposes would be useful. Since in contrast to prions a proper detection of alpha-synuclein aggregates by Western blot analysis is difficult, we developed a protein aggregate filtration (PAF) assay. It takes advantage of the inherent insolubility of aggregated alpha-synuclein using microfiltration to separate it from soluble isoforms. For the first time, this assay even makes quantitative comparisons possible. We describe how the PAF assay can be applied to human brain tissue and animal and cell culture models, as well as used as a screening method for the subcellular location of alpha-synuclein aggregates. Since it detects the pathological isoform instead of surrogate markers, the PAF assay may have also potential in diagnosis of PD and DLB.     

Mechanisms of Parkinson's disease linked to pathological alpha-synuclein: new targets for drug discovery

Classic Parkinson's disease (PD) is characterized by fibrillar alpha-synuclein inclusions known as Lewy bodies in the substantia nigra, which are associated with nigrostriatal degeneration. However, alpha-synuclein pathologies accumulate throughout the CNS in areas that also undergo progressive neurodegeneration, leading to dementia and other behavioral impairments in addition to parkinsonism. Although mutations in the alpha-synuclein gene only cause Lewy body PD in rare families, and although there are multiple other, albeit rare, genetic causes of familial parkinsonism, sporadic Lewy body PD is the most common movement disorder, and insights into mechanisms underlying alpha-synuclein-mediated neurodegeneration provide novel targets for the discovery of disease-modifying therapies for PD and related neurodegenerative alpha-synucleinopathies.     

Colonic Biopsies to Assess the Neuropathology of Parkinson's Disease and Its Relationship with Symptoms

Background

The presence of Lewy bodies and Lewy neurites (LN) has been demonstrated in the enteric nervous system (ENS) of Parkinson''s disease (PD) patients. The aims of the present research were to use routine colonoscopy biopsies (1) to analyze, in depth, enteric pathology throughout the colonic submucosal plexus (SMP), and (2) to correlate the pathological burden with neurological and gastrointestinal (GI) symptoms.

Methodology/Principal Findings

A total of 10 control and 29 PD patients divided into 3 groups according to disease duration were included. PD and GI symptoms were assessed using the Unified Parkinson''s Disease Rating Scale part III and the Rome III questionnaire, respectively. Four biopsies were taken from the ascending and descending colon during the course of a total colonoscopy. Immunohistochemical analysis was performed using antibodies against phosphorylated alpha-synuclein, neurofilaments NF 220 kDa (NF) and tyrosine hydroxylase (TH). The density of LN, labeled by anti-phosphorylated alpha-synuclein antibodies, was evaluated using a quantitative rating score. Lewy pathology was apparent in the colonic biopsies from 21 patients and in none of the controls. A decreased number of NF-immunoreactive neurons per ganglion was observed in the SMP of PD patients compared to controls. The amount of LN in the ENS was inversely correlated with neuronal count and positively correlated with levodopa-unresponsive features and constipation.

Conclusion/Significance

Analysis of the ENS by routine colonoscopy biopsies is a useful tool for pre-mortem neuropathological diagnosis of PD, and also provides insight into the progression of motor and non-motor symptoms.     

Induction of neuronal cell death by Rab5A-dependent endocytosis of alpha-synuclein

The presynaptic alpha-synuclein is a prime suspect for contributing to Lewy pathology and clinical aspects of diseases, including Parkinson's disease, dementia with Lewy bodies, and a Lewy body variant of Alzheimer's disease. Here we examined the pathogenic mechanism of neuronal cell death induced by alpha-synuclein. The exogenous addition of alpha-synuclein caused a marked decrease of cell viability in primary and immortalized neuronal cells. The neuronal cell death appeared to be correlated with the Rab5A-specific endocytosis of alpha-synuclein that subsequently caused the formation of Lewy body-like intracytoplasmic inclusions. This was further supported by the fact that the expression of GTPase-deficient Rab5A resulted in a significant decrease of its cytotoxicity as a result of incomplete endocytosis of alpha-synuclein.     

Inhibiting aggregation of alpha-synuclein with human single chain antibody fragments

The alpha-synuclein protein has been strongly correlated with Parkinson's disease (PD) and is a major component of the hallmark Lewy body aggregates associated with PD. Two different mutations in the alpha-synuclein gene as well as increased gene dosage of wild-type alpha-synuclein all associate with early onset cases of PD; and transgenic animal models overexpressing alpha-synuclein develop PD symptoms. Alpha-synuclein, a natively unfolded protein, can adopt a number of different folded conformations including a beta-sheet form that facilitates formation of numerous aggregated morphologies, including long fibrils, spherical and linear protofibrils, and smaller aggregates or oligomers. The roles of the various morphologies of alpha-synuclein in the progression of PD are not known, and different species have been shown to be toxic. Here we show that single chain antibody fragments (scFv's) isolated from na?ve phage display antibody libraries can be used to control the aggregation of alpha-synuclein. We isolated an scFv with nanomolar affinity for monomeric alpha-synuclein (K(D) = 2.5 x 10(-8) M). When co-incubated with monomeric alpha-synuclein, the scFv decreased not only the rate of aggregation of alpha-synuclein, but also inhibited the formation of oligomeric and protofibrillar structures. The scFv binds the carboxyl terminal region of alpha-synuclein, suggesting that perturbation of this region can influence folding and aggregation of alpha-synuclein in vitro along with the previously identified hydrophobic core region of alpha-synuclein (residues 61-95, particularly residues 71-82). Since the scFv has been isolated from an antibody library based on human gene sequences, such scFv's can have potential therapeutic value in controlling aggregation of alpha-synuclein in vivo when expressed intracellularly as intrabodies in dopaminergic neurons.     

alpha-synuclein fibrillogenesis is nucleation-dependent. Implications for the pathogenesis of Parkinson's disease.

Parkinson's disease (PD) is a neurodegenerative disorder that is pathologically characterized by the presence of intracytoplasmic Lewy bodies, the major components of which are filaments consisting of alpha-synuclein. Two recently identified point mutations in alpha-synuclein are the only known genetic causes of PD. alpha-Synuclein fibrils similar to the Lewy body filaments can be formed in vitro, and we have shown recently that both PD-linked mutations accelerate their formation. This study addresses the mechanism of alpha-synuclein aggregation: we show that (i) it is a nucleation-dependent process that can be seeded by aggregated alpha-synuclein functioning as nuclei, (ii) this fibril growth follows first-order kinetics with respect to alpha-synuclein concentration, and (iii) mutant alpha-synuclein can seed the aggregation of wild type alpha-synuclein, which leads us to predict that the Lewy bodies of familial PD patients with alpha-synuclein mutations will contain both, the mutant and the wild type protein. Finally (iv), we show that wild type and mutant forms of alpha-synuclein do not differ in their critical concentrations. These results suggest that differences in aggregation kinetics of alpha-synucleins cannot be explained by differences in solubility but are due to different nucleation rates. Consequently, alpha-synuclein nucleation may be the rate-limiting step for the formation of Lewy body alpha-synuclein fibrils in Parkinson's disease.     

Cytosolic proteins regulate alpha-synuclein dissociation from presynaptic membranes

Intracellular accumulation of insoluble alpha-synuclein in Lewy bodies is a key neuropathological trait of Parkinson disease (PD). Neither the normal function of alpha-synuclein nor the biochemical mechanisms that cause its deposition are understood, although both are likely influenced by the interaction of alpha-synuclein with vesicular membranes, either for a physiological role in vesicular trafficking or as a pathological seeding mechanism that exacerbates the propensity of alpha-synuclein to self-assemble into fibrils. In addition to the alpha-helical form that is peripherally-attached to vesicles, a substantial portion of alpha-synuclein is freely diffusible in the cytoplasm. The mechanisms controlling alpha-synuclein exchange between these compartments are unknown and the possibility that chronic dysregulation of membrane-bound and soluble alpha-synuclein pools may contribute to Lewy body pathology led us to search for cellular factors that can regulate alpha-synuclein membrane interactions. Here we reveal that dissociation of membrane-bound alpha-synuclein is dependent on brain-specific cytosolic proteins and insensitive to calcium or metabolic energy. Two PD-linked mutations (A30P and A53T) significantly increase the cytosol-dependent alpha-synuclein off-rate but have no effect on cytosol-independent dissociation. These results reveal a novel mechanism by which cytosolic brain proteins modulate alpha-synuclein interactions with intracellular membranes. Importantly, our finding that alpha-synuclein dissociation is up-regulated by both familial PD mutations implicates cytosolic cofactors in disease pathogenesis and as molecular targets to influence alpha-synuclein aggregation.     

Small heat shock proteins protect against alpha-synuclein-induced toxicity and aggregation

Protein misfolding and inclusion formation are common events in neurodegenerative diseases, such as Parkinson's disease (PD), Alzheimer's disease (AD) or Huntington's disease (HD). Alpha-synuclein (aSyn) is the main protein component of inclusions called Lewy bodies (LB) which are pathognomic of PD, Dementia with Lewy bodies (DLB), and other diseases collectively known as LB diseases. Heat shock proteins (HSPs) are one class of the cellular quality control system that mediate protein folding, remodeling, and even disaggregation. Here, we investigated the role of the small heat shock proteins Hsp27 and alphaB-crystallin, in LB diseases. We demonstrate, via quantitative PCR, that Hsp27 messenger RNA levels are approximately 2-3-fold higher in DLB cases compared to control. We also show a corresponding increase in Hsp27 protein levels. Furthermore, we found that Hsp27 reduces aSyn-induced toxicity by approximately 80% in a culture model while alphaB-crystallin reduces toxicity by approximately 20%. In addition, intracellular inclusions were immunopositive for endogenous Hsp27, and overexpression of this protein reduced aSyn aggregation in a cell culture model.