Parkinson’s disease (PD) is an irreversible neurodegenerative disorder clinically manifesting in uncontrolled motor symptoms. There are two primary hallmark features of Parkinson’s disease—an irreversible loss of dopaminergic neurons of the substantia nigra pars compacta and formation of intracellular insoluble aggregates called Lewy bodies mostly composed of alpha-synuclein. Using a clinical improvements-first approach, we identified several clinical trials involving consumption of a specific diet or nutritional supplementation that improved motor and nonmotor functions. Here, we aimed to investigate if and how pyrroloquinoline quinone (PQQ) compound disrupts preformed alpha-synuclein deposits using SH-SY5Y cells, widely used Parkinson’s disease cellular model. SH-SY5Y neuroblastoma cells, incubated in presence of potassium chloride (KCl) to induce alpha-synuclein protein aggregation, were treated with PQQ for up to 48 hr. Resulting aggregates were examined and quantified using confocal microscopy. Overall, nutritional compound PQQ reduced the average number and overall size of intracellular cytoplasmic alpha-synuclein aggregates in a PD cellular model.

α-Synuclein is a small neuronal protein that reversibly associates with lipid membranes. The membrane interactions are believed to be central to the healthy function of this protein involved in synaptic plasticity and neurotransmitter release. α-Synuclein has been speculated to induce vesicle fusion as well as fission, processes which are analogous to each other but proceed in different directions and involve different driving forces. In the current work, we analyse α-synuclein-induced small unilamellar vesicle deformation from a thermodynamics point of view. We show that the structures interpreted in the literature as fusion intermediates are in fact a stable deformed state and neither fusion nor vesicle clustering occurs. We speculate on the driving force for the observed deformation and put forward a hypothesis that α-synuclein self-assembly on the lipid membrane precedes and induces membrane remodelling.

Previous studies of amyloid diseases reported that the aggregating proteins share a similar conserved peptide sequence which can form the cross-β-sheet-containing nanostructures like nanofilaments. The template-assisted self-assembly (TASA) of peptides on inorganic substrates with different hydrophilicity could be an alternative approach to shed light on the fibrillization mechanism of proteins/peptides in vivo. To figure out the effect of interfaces on amyloid aggregation, we herein employed in situ atomic force microscopy (AFM) to investigate the self-assembling of a Parkinson disease-related core peptide sequence (TGV-9) on a hydrophobic liquid–solid interface via real-time observation of the dynamic fibrillization process. The results show that TGV-9 forms one-dimensional nanostructures on the surface of highly ordered pyrolytic graphite (HOPG) with three preferred growth orientations, which are consistent with the atomic lattice of HOPG, indicating an epitaxial growth or TASA. Conversely, the nanostructures formed in bulk solution can be free-standing nanofilaments, and the fibrillization mechanism is different from that on HOPG. These results could not only deepen the understanding of the protein/peptide aggregation mechanism but also benefit for the early diagnosis and clinic treatment of related diseases.

Dementia with Lewy bodies (DLB) is the second most common neuropathologically diagnosed cause of degenerating dementia after Alzheimer's disease. We report the first autopsy-confirmed case in sub-Saharan Africa in a Nigerian patient. The case presented highlights the varied clinical presentation of DLB, and is intended to raise awareness about another possible cause of dementia in Nigerian subjects.

Parkinson's disease (PD) is a common neurodegenerative disorder of the brain and typically presents with a disorder of movement. The core pathological event underlying the condition is the loss of the dopaminergic nigrostriatal pathway with the formation of α-synuclein-positive Lewy bodies. As a result, drugs that target the degenerating dopaminergic network within the brain work well, at least in the early stages of the disease. Unfortunately, with time, these therapies fail and produce their own unique side-effect profile and this, coupled with the more-diffuse pathological and clinical findings in advancing disease, has led to the search for more-effective therapies. In this review, we discuss the emerging new therapies in PD in terms of neuroprotective agents, drugs designed to control symptoms more effectively, and finally curative cell therapies.

In this review, we discuss examples that show how glial-cell pathology is increasingly recognized in several neurodegenerative diseases. We also discuss the more provocative idea that some of the disorders that are currently considered to be neurodegenerative diseases might, in fact, be due to primary abnormalities in glia. Although the mechanism of glial pathology (i.e. modulating glutamate excitotoxicity) might be better established for amyotrophic lateral sclerosis (ALS), a role for neuronal–glial interactions in the pathogenesis of most neurodegenerative diseases is plausible. This burgeoning area of neuroscience will receive much attention in the future and it is expected that further understanding of basic neuronal–glial interactions will have a significant impact on the understanding of the fundamental nature of human neurodegenerative disorders.

α-Synuclein, a major constituent of Lewy bodies (LBs) in Parkinson's disease (PD), has been implicated to play a critical role in synaptic events, such as neuronal plasticity during development, learning, and degeneration under pathological conditions, although the physiological function of α-synuclein has not yet been established. We here present biochemical evidence that recombinant α-synuclein has a chaperone-like function against thermal and chemical stress in vitro. In our experiments, α-synuclein protected glutathione S-transferase (GST) and aldolase from heat-induced precipitation, and α-lactalbumin and bovine serum albumin from dithiothreitol (DTT)-induced precipitation like other molecular chaperones. Moreover, preheating of α-synuclein, which is believed to reorganize the molecular surface of α-synuclein, increased the chaperone-like activity. Interestingly, in organic solvents, which promotes the formation of secondary structure, α-synuclein aggregated more easily than in its native condition, which eventually might abrogate the chaperone-like function of the protein. In addition, α-synuclein was also rapidly and significantly precipitated by heat in the presence of Zn2+ in vitro, whereas it was not affected by the presence of Ca2+ or Mg2+. Circular dichroism spectra confirmed that α-synuclein underwent conformational change in the presence of Zn2+. Taken together, our data suggest that α-synuclein could act as a molecular chaperone, and that the conformational change of the α-synuclein could explain the aggregation kinetics of α-synuclein, which may be related to the abolishment of the chaperonic-like activity.