Previous studies revealed that pesticides interact with α-synuclein and accelerate the rate of fibrillation. These results are consistent with the prevailing hypothesis that the direct interaction of α-synuclein with pesticides is one of many suspected factors leading to α-synuclein fibrillation and ultimately to Parkinson’s disease. In this study, the biophysical properties and fibrillation kinetics of α-synuclein in the presence of rotenone were investigated and, more specifically, the effects of rotenone on the early-stage misfolded forms of α-synuclein were considered. The thioflavine T (ThT) fluorescence assay studies provide evidence that early-phase misfolded α-synuclein forms are affected by rotenone and that the fibrillation process is accelerated. Further characterization by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) shows that rotenone increases the amount of ordered secondary structure in this intrinsically disordered protein. Morphological characterization by transmission electron microscopy (TEM) and atomic force microscopy (AFM) provide visualization of the differences in the aggregated α-synuclein species developing during the early kinetics of the fibrillation process in the absence and presence of rotenone. We believe that these data provide useful information for a better understanding of the molecular basis of rotenone-induced misfolding and aggregation of α-synuclein.
Epidemiological, population-based case-control, and experimental studies at the molecular, cellular, and organism levels revealed that exposure to various environmental agents, including a number of structurally different agrochemicals, may contribute to the pathogenesis of Parkinson's disease (PD) and several other neurodegenerative disorders. The role of genetic predisposition in PD has also been increasingly acknowledged, driven by the identification of a number of disease-related genes [e.g., α-synuclein, parkin, DJ-1, ubiquitin C-terminal hydrolase isozyme L1 (UCH-L1), and nuclear receptor-related factor 1]. Therefore, the etiology of this multifactorial disease is likely to involve both genetic and environmental factors. Various neurotoxicants, including agrochemicals, have been shown to elevate the levels of α-synuclein expression in neurons and to promote aggregation of this protein in vivo. Many agrochemicals physically interact with α-synuclein and accelerate the fibrillation and aggregation rates of this protein in vitro. This review analyzes some of the aspects linking α-synuclein to PD, provides brief structural and functional descriptions of this important protein, and represents some data connecting exposure to agrochemicals with α-synuclein aggregation and PD pathogenesis.
A combination of spectroscopic techniques including atomic force microscopy (AFM) and transmission electron microscopy (TEM), was used to analyze the effect of chemically distinct agrochemicals (pesticides, herbicides, and fungicides) on the in vitro misfolding and aggregation of a presynaptic intrinsically disordered protein α-synuclein. Despite their differences in chemical properties, almost all the compounds screened affected the α-synuclein fibrillation in a concentration-dependent manner. The morphology of the aggregated α-synuclein was characterized by AFM and TEM techniques. In addition to typical fibrils abundantly found at the equilibrium phase, this analysis revealed the existence of a noticeable nonfibrillar fraction where α-synuclein was present as protofilaments, small oligomers, and large oligomeric species. The aggregated α-synuclein samples were separated into soluble and insoluble fractions by ultracentrifugation and subjected to structural and morphological characterization. Attenuated total reflectance Fourier transform infrared spectroscopic analysis showed that the insoluble α-synuclein fractions possessed a high content of ordered β-structure, whereas the β-structure content of the supernatant pool populated by oligomeric species was noticeably lower. This study provides evidence that chemically distinct agrochemicals can directly interact with α-synuclein to induce structural changes and affect the fibrillation process of this important protein.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.