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Fornstedt Wallin B. Oxidation of dopamine and related catechols in dopaminergic brain regions in Parkinson's disease and during ageing in non-Parkinsonian subjects. J Neural Transm (Vienna) 2024; 131:213-228. [PMID: 38238531 DOI: 10.1007/s00702-023-02718-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 10/28/2023] [Indexed: 02/18/2024]
Abstract
The present study was performed to examine if catechol oxidation is higher in brains from patients with Parkinson's disease compared to age-matched controls, and if catechol oxidation increases with age. Brain tissue from Parkinson patients and age-matched controls was examined for oxidation of dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC) and 3,4-dihydroxyphenylalanine (DOPA) to corresponding quinones, by measurement of 5-S-cysteinyl-dopamine, 5-S-cysteinyl-DOPAC and 5-S-cysteinyl-DOPA. The cysteinyl catechols are assumed to be biomarkers for DA, DOPAC and DOPA autoxidation and part of the biosynthetic pathway of neuromelanin. The concentrations of the 5-S-cysteinyl catechols were lower, whereas the 5-S-cysteinyl-DA/DA and 5-S-cysteinyl-DOPAC/DOPAC ratios tended to be higher in the Parkinson group compared to controls, which was interpreted as a higher degree of oxidation. High 5-S-cysteinyl-DA/DA ratios were found in the substantia nigra of a sub-population of the Parkinson group. Based on 5-S-cysteinyl-DA/DA ratios, dopamine oxidation was found to increase statistically significantly with age in the caudate nucleus, and non-significantly in the substantia nigra. In conclusion, the occurrence of 5-S-cysteinyl-DA, 5-S-cysteinyl-DOPAC and 5-S-cysteinyl-DOPA was demonstrated in dopaminergic brain areas of humans, a tendency for higher oxidation of DA in the Parkinson group compared to controls was observed as well as a statistically significant increase in DA oxidation with age. Possibly, autoxidation of DA and other catechols are involved in both normal and pathological ageing of the brain. This study confirms one earlier but small study, as well as complements one study on non-PD cases and one study on both PD cases and controls on NM bound or integrated markers or catechols.
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Affiliation(s)
- Bodil Fornstedt Wallin
- Department of Pharmacology, University of Göteborg (at the time of the study), Göteborg, Sweden.
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Berg SZ, Berg J. Melanin: a unifying theory of disease as exemplified by Parkinson's, Alzheimer's, and Lewy body dementia. Front Immunol 2023; 14:1228530. [PMID: 37841274 PMCID: PMC10570809 DOI: 10.3389/fimmu.2023.1228530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 09/13/2023] [Indexed: 10/17/2023] Open
Abstract
Melanin, a ubiquitous dark pigment, plays important roles in the immune system, including scavenging reactive oxygen species formed in response to ultraviolet radiation absorption, absorbing metals, thermal regulation, drug uptake, innate immune system functions, redox, and energy transduction. Many tissue types, including brain, heart, arteries, ovaries, and others, contain melanin. Almost all cells contain precursors to melanin. A growing number of diseases in which there is a loss of melanin and/or neuromelanin are increasingly thought to have infectious etiologies, for example, Alzheimer's disease (AD), Parkinson's disease (PD), Lewy Body Dementia (LBD), and vitiligo. AD, PD, LBD, and vitiligo have been linked with herpesvirus, which enters melanosomes and causes apoptosis, and with gut dysbiosis and inflammation. Herpesvirus is also linked with gut dysbiosis and inflammation. We theorize that under normal healthy states, melanin retains some of the energy it absorbs from electromagnetic radiation, which is then used to fuel cells, and energy from ATP is used to compliment that energy supply. We further theorize that loss of melanin reduces the energy supply of cells, which in the case of AD, PD, and LBD results in an inability to sustain immune system defenses and remove the plaques associated with the disease, which appear to be part of the immune system's attempt to eradicate the pathogens seen in these neurodegenerative diseases. In addition, in an attempt to explain why removing these plaques does not result in improvements in cognition and mood and why cognitions and moods in these individuals have ebbs and flows, we postulate that it is not the plaques that cause the cognitive symptoms but, rather, inflammation in the brain resulting from the immune system's response to pathogens. Our theory that energy retained in melanin fuels cells in an inverse relationship with ATP is supported by studies showing alterations in ATP production in relationship to melanin levels in melanomas, vitiligo, and healthy cells. Therefore, alteration of melanin levels may be at the core of many diseases. We propose regulating melanin levels may offer new avenues for treatment development.
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Affiliation(s)
- Stacie Z. Berg
- Department of Translational Biology, William Edwards LLC, Baltimore, MD, United States
| | - Jonathan Berg
- Department of Translational Biology, William Edwards LLC, Baltimore, MD, United States
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Wüllner U, Borghammer P, Choe CU, Csoti I, Falkenburger B, Gasser T, Lingor P, Riederer P. The heterogeneity of Parkinson's disease. J Neural Transm (Vienna) 2023; 130:827-838. [PMID: 37169935 PMCID: PMC10174621 DOI: 10.1007/s00702-023-02635-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 04/12/2023] [Indexed: 05/13/2023]
Abstract
The heterogeneity of Parkinson's disease (PD), i.e. the various clinical phenotypes, pathological findings, genetic predispositions and probably also the various implicated pathophysiological pathways pose a major challenge for future research projects and therapeutic trail design. We outline several pathophysiological concepts, pathways and mechanisms, including the presumed roles of α-synuclein misfolding and aggregation, Lewy bodies, oxidative stress, iron and melanin, deficient autophagy processes, insulin and incretin signaling, T-cell autoimmunity, the gut-brain axis and the evidence that microbial (viral) agents may induce molecular hallmarks of neurodegeneration. The hypothesis is discussed, whether PD might indeed be triggered by exogenous (infectious) agents in susceptible individuals upon entry via the olfactory bulb (brain first) or the gut (body-first), which would support the idea that disease mechanisms may change over time. The unresolved heterogeneity of PD may have contributed to the failure of past clinical trials, which attempted to slow the course of PD. We thus conclude that PD patients need personalized therapeutic approaches tailored to specific phenomenological and etiologic subtypes of disease.
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Affiliation(s)
- Ullrich Wüllner
- Department of Neurology, University Clinic Bonn and German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany
| | - Per Borghammer
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark
| | - Chi-un Choe
- Department of Neurology, Klinikum Itzehoe, Robert-Koch-Straße 2, 25524 Itzehoe, Germany
| | - Ilona Csoti
- Fachklinik Für Parkinson, Gertrudis Klinik Biskirchen, Karl-Ferdinand-Broll-Straße 2-4, 35638 Leun-Biskirchen, Germany
| | - Björn Falkenburger
- Department of Neurology, University Hospital Dresden, Fetscherstrasse 74, 01307 Dresden, Germany
| | - Thomas Gasser
- Department of Neurology, Hertie-Institute for Clinical Brain Research, University of Tübingen and German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Paul Lingor
- Department of Neurology, School of Medicine, Klinikum Rechts Der Isar, Technical University of Munich, Munich, Germany
- Department of Neurology and German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Peter Riederer
- University Hospital Wuerzburg, Clinic and Policlinic for Psychiatry, Psychosomatics and Psychotherapy, Margarete-Höppel-Platz 1, 97080 Würzburg, Germany
- Department of Psychiatry, University of Southern Denmark Odense, J.B. Winslows Vey 18, 5000 Odense, Denmark
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Mitra R, Premraj L, Khoo TK. Neuromelanin: Its role in the pathogenesis of idiopathic Parkinson's disease and potential as a therapeutic target. Parkinsonism Relat Disord 2023:105448. [PMID: 37236833 DOI: 10.1016/j.parkreldis.2023.105448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 05/10/2023] [Accepted: 05/18/2023] [Indexed: 05/28/2023]
Abstract
Parkinson's disease is an increasingly prevalent condition that involves the marked loss of dopaminergic neurons in the substantia nigra pars compacta. These neurons pigmented with neuromelanin along with other regions of the brain are almost exclusively victims of neurodegeneration in the disease. The link between neuromelanin and Parkinson's disease has been widely studied for decades. While many studies have outlined the pigment's neuroprotective function as a potent free radical scavenger, antioxidant, and ion-chelator, it has also been observed to play a role in cell death due to mitochondrial dysfunction and oxidative stress, especially in the parkinsonian disease state. This is due to the damaging effects of neuromelanin precursors, neuromelanin-related ion dysregulation and intra- and extraneuronal neuromelanin accumulation. Current and emerging therapeutic endeavours guided by these pathological processes may include antioxidant therapy, proteostasis enhancement, ion chelation and neuromelanin-targeted immunotherapy to prevent the accumulation, formation and effects of neuromelanin and oxidative neuromelanin precursors. Some of these therapeutic strategies are already in nascent stages, while others have produced mixed results in clinical trials. This review aims to provide an update on how neuromelanin and neuromelanin-related substances may be linked to the pathogenesis of Parkinson's disease and how future therapeutic strategies may be able to hamper or prevent neuromelanin-related pathological processes and ultimately modify disease progression in Parkinson's.
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Affiliation(s)
- Ritoban Mitra
- College of Medicine and Public Health, Flinders University, South Australia, Australia.
| | - Lavienraj Premraj
- School of Medicine & Dentistry, Griffith University, Queensland, Australia
| | - Tien K Khoo
- School of Medicine & Dentistry, Griffith University, Queensland, Australia; Graduate School of Medicine, University of Wollongong, New South Wales, Australia
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Nagatsu T, Nakashima A, Watanabe H, Ito S, Wakamatsu K, Zucca FA, Zecca L, Youdim M, Wulf M, Riederer P, Dijkstra JM. The role of tyrosine hydroxylase as a key player in neuromelanin synthesis and the association of neuromelanin with Parkinson's disease. J Neural Transm (Vienna) 2023; 130:611-625. [PMID: 36939908 PMCID: PMC10121510 DOI: 10.1007/s00702-023-02617-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 02/28/2023] [Indexed: 03/21/2023]
Abstract
The dark pigment neuromelanin (NM) is abundant in cell bodies of dopamine (DA) neurons in the substantia nigra (SN) and norepinephrine (NE) neurons in the locus coeruleus (LC) in the human brain. During the progression of Parkinson's disease (PD), together with the degeneration of the respective catecholamine (CA) neurons, the NM levels in the SN and LC markedly decrease. However, questions remain among others on how NM is associated with PD and how it is synthesized. The biosynthesis pathway of NM in the human brain has been controversial because the presence of tyrosinase in CA neurons in the SN and LC has been elusive. We propose the following NM synthesis pathway in these CA neurons: (1) Tyrosine is converted by tyrosine hydroxylase (TH) to L-3,4-dihydroxyphenylalanine (L-DOPA), which is converted by aromatic L-amino acid decarboxylase to DA, which in LC neurons is converted by dopamine β-hydroxylase to NE; (2) DA or NE is autoxidized to dopamine quinone (DAQ) or norepinephrine quinone (NEQ); and (3) DAQ or NEQ is converted to eumelanic NM (euNM) and pheomelanic NM (pheoNM) in the absence and presence of cysteine, respectively. This process involves proteins as cysteine source and iron. We also discuss whether the NM amounts per neuromelanin-positive (NM+) CA neuron are higher in PD brain, whether NM quantitatively correlates with neurodegeneration, and whether an active lifestyle may reduce NM formation.
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Affiliation(s)
- Toshiharu Nagatsu
- Center for Research Promotion and Support, Fujita Health University, Toyoake, Aichi, Japan.
| | - Akira Nakashima
- Department of Physiological Chemistry, School of Medicine, Fujita Health University, Toyoake, Aichi, Japan
| | - Hirohisa Watanabe
- Department of Neurology, School of Medicine, Fujita Health University, Toyoake, Aichi, Japan
| | - Shosuke Ito
- Institute for Melanin Chemistry, Fujita Health University, Toyoake, Aichi, Japan
| | - Kazumasa Wakamatsu
- Institute for Melanin Chemistry, Fujita Health University, Toyoake, Aichi, Japan
| | - Fabio A Zucca
- Institute of Biomedical Technologies, National Research Council of Italy, Segrate (Milan), Italy
| | - Luigi Zecca
- Institute of Biomedical Technologies, National Research Council of Italy, Segrate (Milan), Italy
| | - Moussa Youdim
- Technion-Rappaport Family Faculty of Medicine, Haifa, Israel
- Department of Biology, Yonsey World Central University, Seoul, South Korea
| | - Maximilian Wulf
- Medical Proteome-Analysis, Center for Protein Diagnostics (PRODI), Ruhr-University Bochum, Bochum, Germany
- Medizinisches Proteom‑Center, Medical Faculty, Ruhr-University Bochum, Bochum, Germany
| | - Peter Riederer
- Clinic and Polyclinic of Psychiatry, Psychosomatics and Psychotherapy, University Hospital, Würzburg, Germany
- Department and Research Unit of Psychiatry, Syddansk University, Odense, Denmark
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