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Natural Alkaloid Compounds as Inhibitors for Alpha-Synuclein Seeded Fibril Formation and Toxicity. Molecules 2021; 26:molecules26123736. [PMID: 34205249 PMCID: PMC8234408 DOI: 10.3390/molecules26123736] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 06/12/2021] [Accepted: 06/15/2021] [Indexed: 01/26/2023] Open
Abstract
The accumulation and aggregation of α-synuclein (α-syn) is the main pathologic event in Parkinson’s disease (PD), dementia with Lewy bodies, and multiple system atrophy. α-Syn-seeded fibril formation and its induced toxicity occupy a major role in PD pathogenesis. Thus, assessing compounds that inhibit this seeding process is considered a key towards the therapeutics of synucleinopathies. Using biophysical and biochemical techniques and seeding-dependent cell viability assays, we screened a total of nine natural compounds of alkaloid origin extracted from Chinese medicinal herbs. Of these compounds, synephrine, trigonelline, cytisine, harmine, koumine, peimisine, and hupehenine exhibited in vitro inhibition of α-syn-seeded fibril formation. Furthermore, using cell viability assays, six of these compounds inhibited α-syn-seeding-dependent toxicity. These six potent inhibitors of amyloid fibril formation and toxicity caused by the seeding process represent a promising therapeutic strategy for the treatment of PD and other synucleinopathies.
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Meade RM, Morris KJ, Watt KJC, Williams RJ, Mason JM. The Library Derived 4554W Peptide Inhibits Primary Nucleation of α-Synuclein. J Mol Biol 2020; 432:166706. [PMID: 33186583 DOI: 10.1016/j.jmb.2020.11.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 11/02/2020] [Accepted: 11/05/2020] [Indexed: 11/28/2022]
Abstract
Aggregation of α-Synuclein (αS) is widely regarded as a key factor in neuronal cell death, leading to a wide range of synucleinopathies, including Parkinson's Disease. Development of therapeutics has therefore focused on inhibiting aggregation of αS into toxic forms. One such inhibitor, based on the preNAC region αS45-54 (4554W), was identified using an intracellular peptide library screen, and subsequently shown to both inhibit formation of αS aggregates while simultaneously lowering toxicity. Subsequent efforts have sought to determine the mode of 4554W action. In particular, and consistent with the fact that both target and peptide are co-produced during library screening, we find that the peptide inhibits primary nucleation of αS, but does not modulate downstream elongation or secondary nucleation events. These findings hold significant promise towards mechanistic understanding and development of molecules that can module the first steps in αS aggregation towards novel treatments for Parkinson's disease and related synucleinopathies.
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Affiliation(s)
- Richard M Meade
- Depart of Biology and Biochemistry, University of Bath, Claverton Down, BA2 7AY, United Kingdom
| | - Kimberley J Morris
- Depart of Biology and Biochemistry, University of Bath, Claverton Down, BA2 7AY, United Kingdom
| | - Kathryn J C Watt
- Depart of Biology and Biochemistry, University of Bath, Claverton Down, BA2 7AY, United Kingdom
| | - Robert J Williams
- Depart of Biology and Biochemistry, University of Bath, Claverton Down, BA2 7AY, United Kingdom
| | - Jody M Mason
- Depart of Biology and Biochemistry, University of Bath, Claverton Down, BA2 7AY, United Kingdom.
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Torpey JH, Meade RM, Mistry R, Mason JM, Madine J. Insights Into Peptide Inhibition of Alpha-Synuclein Aggregation. Front Neurosci 2020; 14:561462. [PMID: 33177976 PMCID: PMC7594713 DOI: 10.3389/fnins.2020.561462] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 09/21/2020] [Indexed: 12/22/2022] Open
Abstract
α-Synuclein (aSyn) aggregation is an attractive target for therapeutic development for a range of neurodegenerative conditions, collectively termed synucleinopathies. Here, we probe the mechanism of action of a peptide 4554W, (KDGIVNGVKA), previously identified through intracellular library screening, to prevent aSyn aggregation and associated toxicity. We utilize NMR to probe association and identify that 4554W associates with a "partially aggregated" form of aSyn, with enhanced association occurring over time. We also report the ability of 4554W to undergo modification through deamidation of the central asparagine residue, occurring on the same timescale as aSyn aggregation in vitro, with peptide modification enhancing its association with aSyn. Additionally, we report that 4554W can act to reduce fibril formation of five Parkinson's disease associated aSyn mutants. Inhibitory peptide binding to partially aggregated forms of aSyn, as identified here, is particularly attractive from a therapeutic perspective, as it would eliminate the need to administer the therapy at pre-aggregation stages, which are difficult to diagnose. Taken together the data suggest that 4554W could be a suitable candidate for future therapeutic development against wild-type, and most mutant aSyn aggregation.
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Affiliation(s)
- James H Torpey
- Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Richard M Meade
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Ravina Mistry
- Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Jody M Mason
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Jillian Madine
- Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
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Zhou H, Shao M, Guo B, Li C, Lu Y, Yang X, ShengnanLi, Li H, Zhu Q, Zhong H, Wang Y, Zhang Z, Lu J, Lee SMY. Tetramethylpyrazine Analogue T-006 Promotes the Clearance of Alpha-synuclein by Enhancing Proteasome Activity in Parkinson's Disease Models. Neurotherapeutics 2019; 16:1225-1236. [PMID: 31313223 PMCID: PMC6985330 DOI: 10.1007/s13311-019-00759-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative disorder worldwide and is characterized in part by the degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNc). The main pathological hallmark of PD is the intraneuronal accumulation of misfolded α-synuclein (α-syn) aggregates. Mutations in the SNCA gene (encoding α-syn) and variations in its copy number are associated with some forms of familial PD. In the present study, T-006, a new tetramethylpyrazine (TMP) derivative with recently reported anti-Alzheimer activity, is shown to significantly promote α-syn degradation in a cellular PD model. Moreover, we illustrate that T-006 inhibits the accumulation of both Triton-soluble and -insoluble forms of α-syn and protects against α-syn-induced neurotoxicity in A53T-α-syn transgenic mice. The mechanism of action of T-006 was verified by evaluation of a potential protein degradation pathway. We found that T-006 promotes α-syn degradation in a proteasome-dependent and autophagy-independent manner. We further confirmed that T-006 enhances proteasome activity by upregulating 20S proteasome subunit β5i (LMP7) protein expression. A functional study revealed that T-006 activates the PKA/Akt/mTOR/p70S6K pathway to trigger LMP7 expression and enhance chymotrypsin-like proteasomal activity. These findings indicate that T-006 is a potent proteasome activator and a potential therapeutic agent for the prevention and treatment of PD and related diseases.
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Affiliation(s)
- Hefeng Zhou
- Department of Bioengineering, Zhuhai Campus of Zunyi Medical University, Zhuhai, China
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Min Shao
- Department of Bioengineering, Zhuhai Campus of Zunyi Medical University, Zhuhai, China
| | - Baojian Guo
- Institute of New Drug Research, College of Pharmacy, Jinan University, Guangzhou, China
| | - Chuwen Li
- Key Laboratory of Molecular Target & Clinical Pharmacology, School of Pharmaceutical Sciences, Guangzhou Medical University, Guangzhou, China
| | - Yucong Lu
- Department of Bioengineering, Zhuhai Campus of Zunyi Medical University, Zhuhai, China
| | - Xuanjun Yang
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Macau, China
- Department of Biology, South University of Science and Technology, Shenzhen, China
| | - ShengnanLi
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Haitao Li
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Qi Zhu
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Hanbing Zhong
- Department of Biology, South University of Science and Technology, Shenzhen, China
| | - Yuqiang Wang
- Institute of New Drug Research, College of Pharmacy, Jinan University, Guangzhou, China
| | - Zaijun Zhang
- Institute of New Drug Research, College of Pharmacy, Jinan University, Guangzhou, China
| | - Jiahong Lu
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Macau, China.
| | - Simon Ming-Yuen Lee
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Macau, China.
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Computational insights into the role of α-strand/sheet in aggregation of α-synuclein. Sci Rep 2019; 9:59. [PMID: 30635607 PMCID: PMC6329781 DOI: 10.1038/s41598-018-37276-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 12/05/2018] [Indexed: 01/03/2023] Open
Abstract
The α-synuclein is a major component of amyloid fibrils found in Lewy bodies, the characteristic intracellular proteinaceous deposits which are pathological hallmarks of neurodegenerative diseases such as Parkinson’s disease (PD) and dementia. It is an intrinsically disordered protein that may undergo dramatic structural changes to form amyloid fibrils. Aggregation process from α-synuclein monomers to amyloid fibrils through oligomeric intermediates is considered as the disease-causative toxic mechanism. However, mechanism underlying aggregation is not well-known despite several attempts. To characterize the mechanism, we have explored the effects of pH and temperature on the structural properties of wild-type and mutant α-synuclein using molecular dynamics (MD) simulation technique. MD studies suggested that amyloid fibrils can grow by monomer. Conformational transformation of the natively unfolded protein into partially folded intermediate could be accountable for aggregation and fibrillation. An intermediate α-strand was observed in the hydrophobic non-amyloid-β component (NAC) region of α-synuclein that could proceed to α-sheet and initiate early assembly events. Water network around the intermediate was analyzed to determine its influence on the α-strand structure. Findings of this study provide novel insights into possible mechanism of α-synuclein aggregation and promising neuroprotective strategy that could aid alleviate PD and its symptoms.
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Advances at the intersection of chemical biology and medicinal chemistry. Future Med Chem 2016; 7:2089-90. [PMID: 26571116 DOI: 10.4155/fmc.15.151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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