scholarly journals Dopamine Oxidation and Autophagy

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Patricia Muñoz ◽  
Sandro Huenchuguala ◽  
Irmgard Paris ◽  
Juan Segura-Aguilar

The molecular mechanisms involved in the neurodegenerative process of Parkinson's disease remain unclear. Currently, there is a general agreement that mitochondrial dysfunction,α-synuclein aggregation, oxidative stress, neuroinflammation, and impaired protein degradation are involved in the neurodegeneration of dopaminergic neurons containing neuromelanin in Parkinson's disease. Aminochrome has been proposed to play an essential role in the degeneration of dopaminergic neurons containing neuromelanin by inducing mitochondrial dysfunction, oxidative stress, the formation of neurotoxicα-synuclein protofibrils, and impaired protein degradation. Here, we discuss the relationship between the oxidation of dopamine to aminochrome, the precursor of neuromelanin, autophagy dysfunction in dopaminergic neurons containing neuromelanin, and the role of dopamine oxidation to aminochrome in autophagy dysfunction in dopaminergic neurons. Aminochrome induces the following: (i) the formation ofα-synuclein protofibrils that inactivate chaperone-mediated autophagy; (ii) the formation of adducts withα- andβ-tubulin, which induce the aggregation of the microtubules required for the fusion of autophagy vacuoles and lysosomes.

2021 ◽  
Author(s):  
Moataz Dowaidar

Parkinson's disease progresses by a number of regionally specific cellular and molecular mechanisms. Furthermore, these pathways interact and have an influence on one another in both normal and pathological conditions. Neuroinflammation caused by activated microglia and astrocytes can contribute to the progression of pathogenic damage to substantia nigra (SN) neurons. Similarly, oxidative stress may be caused by a variety of stressors, such as contaminants in the environment or age-related mitochondrial dysfunction, leading to the production of reactive oxygen species (ROS). Dopamine auto-oxidation is a significant generator of ROS in dopaminergic neurons, resulting in neuronal oxidative stress. The high energy demands of dopaminergic neurons may result in mitochondrial dysfunction and oxidative damage as they age. Because mitophagy clears dysfunctional mitochondria from SN neurons, mutation-related abnormalities in autophagy of defective proteins might allow damaging proteins to accumulate in the cell. Because the effects of aging on these molecular pathways and cellular activities are unknown, further study into these molecular pathways and their connections in normal and sick states will be essential for developing disease-specific therapies.


2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Daniela M. Arduíno ◽  
A. Raquel Esteves ◽  
Sandra M. Cardoso

Understanding the molecular basis of Parkinson's disease (PD) has proven to be a major challenge in the field of neurodegenerative diseases. Although several hypotheses have been proposed to explain the molecular mechanisms underlying the pathogenesis of PD, a growing body of evidence has highlighted the role of mitochondrial dysfunction and the disruption of the mechanisms of mitochondrial dynamics in PD and other parkinsonian disorders. In this paper, we comment on the recent advances in how changes in the mitochondrial function and mitochondrial dynamics (fusion/fission, transport, and clearance) contribute to neurodegeneration, specifically focusing on PD. We also evaluate the current controversies in those issues and discuss the role of fusion/fission dynamics in the mitochondrial lifecycle and maintenance. We propose that cellular demise and neurodegeneration in PD are due to the interplay between mitochondrial dysfunction, mitochondrial trafficking disruption, and impaired autophagic clearance.


Author(s):  
Linlin Zhang ◽  
Aurelio Reyes ◽  
Xiangdong Wang

Abstract: The discovery of charged molecules being able to cross the mitochondrial membrane has prompted many scholars to exploit this idea to find a way of preventing or slowing down aging. In this paper, we will focus on mitochondriatargeted antioxidants, which are cationic derivatives of plastoquinone, and in particular on the mitochondria-targeted antioxidant therapy of neurodegenerative diseases. It is well known that the accumulation of amyloid-β peptide (Aβ) in mitochondria and its related mitochondrial dysfunction are critical signatures of Alzheimer’ s disease (AD). In another neurodegenerative disease, Parkinson’s disease (PD), the loss of dopaminergic neurons in the substantia nigra and the production of Lewy bodies are among their pathological features. Pathogenesis of Parkinson’s disease and Alzheimer’s disease has been frequently linked to mitochondrial dysfunction and oxidative stress. Recent studies show that MitoQ, a mitochondria-targeted antioxidant, may possess therapeutic potential for Aβ-related and oxidative stress-associated neurodegenerative diseases, especially AD. Although MitoQ has been developed to the stage of clinical trials in PD, its true clinical effect still need further verification. This review aims to discuss the role of mitochondrial pathology in neurodegenerative diseases, as well as the recent development of mitochondrial targeted antioxidants as a potential treatment for these diseases by removing excess oxygen free radicals and inhibiting lipid peroxidation in order to improve mitochondrial function.  


Biomolecules ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1421 ◽  
Author(s):  
Hayate Javed ◽  
M. F. Nagoor Meeran ◽  
Sheikh Azimullah ◽  
Lujain Bader Eddin ◽  
Vivek Dhar Dwivedi ◽  
...  

Rotenone (ROT), a plant-derived pesticide is a well-known environmental neurotoxin associated with causation of Parkinson’s disease (PD). ROT impairs mitochondrial dysfunction being mitochondrial complex-I (MC-1) inhibitor and perturbs antioxidant-oxidant balance that contributes to the onset and development of neuroinflammation and neurodegeneration in PD. Due to the scarcity of agents to prevent the disease or to cure or halt the progression of symptoms of PD, the focus is on exploring agents from naturally occurring dietary phytochemicals. Among numerous phytochemicals, α-Bisabolol (BSB), natural monocyclic sesquiterpene alcohol found in many ornamental flowers and edible plants garnered attention due to its potent pharmacological properties and therapeutic potential. Therefore, the present study investigated the neuroprotective effects of BSB in a rat model of ROT-induced dopaminergic neurodegeneration, a pathogenic feature of PD and underlying mechanism targeting oxidative stress, inflammation and apoptosis. BSB treatment significantly prevented ROT-induced loss of dopaminergic neurons and fibers in the substantia nigra and striatum respectively. BSB treatment also attenuated ROT-induced oxidative stress evidenced by inhibition of MDA formation and GSH depletion as well as improvement in antioxidant enzymes, SOD and catalase. BSB treatment also attenuated ROT-induced activation of the glial cells as well as the induction and release of proinflammatory cytokines (IL-1β, IL-6 and TNF-α) and inflammatory mediators (iNOS and COX-2) in the striatum. In addition to countering oxidative stress and inflammation, BSB also attenuated apoptosis of dopaminergic neurons by attenuating downregulation of anti-apoptotic protein Bcl-2 and upregulation of pro-apoptotic proteins Bax, cleaved caspases-3 and 9. Further, BSB was observed to attenuate mitochondrial dysfunction by inhibiting mitochondrial lipid peroxidation, cytochrome-C release and reinstates the levels/activity of ATP and MC-I. The findings of the study demonstrate that BSB treatment salvaged dopaminergic neurons, attenuated microglia and astrocyte activation, induction of inflammatory mediators, proinflammatory cytokines and reduced the expression of pro-apoptotic markers. The in vitro study on ABTS radical revealed the antioxidant potential of BSB. The results of the present study are clearly suggestive of the neuroprotective effects of BSB through antioxidant, anti-inflammatory and anti-apoptotic properties in ROT-induced model of PD.


2011 ◽  
Vol 2011 ◽  
pp. 1-14 ◽  
Author(s):  
Shin Hisahara ◽  
Shun Shimohama

Parkinson's disease (PD) is a common progressive neurodegenerative disorder. The major pathological hallmarks of PD are the selective loss of nigrostriatal dopaminergic neurons and the presence of intraneuronal aggregates termed Lewy bodies (LBs), but the pathophysiological mechanisms are not fully understood. Epidemiologically, environmental neurotoxins such as pesticides are promising candidates for causative factors of PD. Oxidative stress and mitochondrial dysfunction induced by these toxins could contribute to the progression of PD. While most cases of PD are sporadic, specific mutations in genes that cause familial forms of PD have led to provide new insights into its pathogenesis. This paper focuses on animal models of both toxin-induced and genetically determined PD that have provided significant insight for understanding this disease. We also discuss the validity, benefits, and limitations of representative models.


Biomedicines ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1467
Author(s):  
Mariano Catanesi ◽  
Laura Brandolini ◽  
Michele d’Angelo ◽  
Maria Grazia Tupone ◽  
Elisabetta Benedetti ◽  
...  

The mucolytic agent S-carboxymethylcysteine is widely used as an expectorant for the treatment of numerous respiratory disorders. The metabolic fate of S-carboxymethyl-L-cysteine is complex. Several clinical studies have demonstrated that the metabolism of this agent differs within the same individual, with sulfur oxygenated metabolites generated upon night-time administration. It has been indicated that this drug behaves like a free radical scavenger and that, in this regard, the sulfide is the active species with sulphoxide metabolites (already oxidized) being inactive. Consequently, a night-time consumption of the drug should be more effective upon daytime administration. Still, this diurnal variation in biotransformation (deactivation) is dependent on the genetic polymorphism on which relies the patient population capacities of S-carboxymethyl-L-cysteine sulphoxidation. It has been reported that those cohorts who are efficient sulfur oxidizers will generate inactive oxygenated metabolites. In contrast, those who have a relative deficiency in this mechanism will be subjected to the active sulfide for a more extended period. In this regard, it is noteworthy that 38–39% of Parkinson’s disease patients belong to the poor sulphoxide cohort, being exposed to higher levels of active sulfide, the active antioxidant metabolite of S-carboxymethyl-L-cysteine. Parkinson’s disease is a neurodegenerative disorder that affects predominately dopaminergic neurons. It has been demonstrated that oxidative stress and mitochondrial dysfunction play a crucial role in the degeneration of dopaminergic neurons. Based on this evidence, in this study, we evaluated the effects of S-carboxymethyl cysteine in an in vitro model of Parkinson’s disease in protecting against oxidative stress injury. The data obtained suggested that an S-carboxymethylcysteine-enriched diet could be beneficial during aging to protect neurons from oxidative imbalance and mitochondrial dysfunction, thus preventing the progression of neurodegenerative processes.


2018 ◽  
Vol 6 (1) ◽  
Author(s):  
Linlin Zhang ◽  
Aurelio Reyes ◽  
Xiangdong Wang

The discovery of charged molecules being able to cross the mitochondrial membrane has prompted many scholars to exploit this idea to find a way of preventing or slowing down aging. In this paper, we will focus on mitochondria-targeted antioxidants, which are cationic derivatives of plastoquinone, and in particular on the mitochondria-targeted antioxidant therapy of neurodegenerative diseases. It is well known that the accumulation of amyloid-β peptide (Aβ) in mitochondria and its related mitochondrial dysfunction are critical signatures of Alzheimer’s disease (AD). In another neurodegenerative disease, Parkinson’s disease (PD), the loss of dopaminergic neurons in the substantia nigra and the production of Lewy bodies are among their pathological features. Pathogenesis of Parkinson’s disease and Alzheimer’s disease has been frequently linked to mitochondrial dysfunction and oxidative stress. Recent studies show that MitoQ, a mitochondria-targeted antioxidant, may possess therapeutic potential for Aβ-related and oxidative stress-associated neurodegenerative diseases, especially AD. Although MitoQ has been developed to the stage of clinical trials in PD, its true clinical effect still need further verification. This review aims to discuss the role of mitochondrial pathology in neurodegenerative diseases, as well as the recent development of mitochondrial targeted antioxidants as a potential treatment for these diseases by removing excess oxygen free radicals and inhibiting lipid peroxidation in order to improve mitochondrial function.


2019 ◽  
Vol 26 (20) ◽  
pp. 3719-3753 ◽  
Author(s):  
Natasa Kustrimovic ◽  
Franca Marino ◽  
Marco Cosentino

:Parkinson’s disease (PD) is the second most common neurodegenerative disorder among elderly population, characterized by the progressive degeneration of dopaminergic neurons in the midbrain. To date, exact cause remains unknown and the mechanism of neurons death uncertain. It is typically considered as a disease of central nervous system (CNS). Nevertheless, numerous evidence has been accumulated in several past years testifying undoubtedly about the principal role of neuroinflammation in progression of PD. Neuroinflammation is mainly associated with presence of activated microglia in brain and elevated levels of cytokine levels in CNS. Nevertheless, active participation of immune system as well has been noted, such as, elevated levels of cytokine levels in blood, the presence of auto antibodies, and the infiltration of T cell in CNS. Moreover, infiltration and reactivation of those T cells could exacerbate neuroinflammation to greater neurotoxic levels. Hence, peripheral inflammation is able to prime microglia into pro-inflammatory phenotype, which can trigger stronger response in CNS further perpetuating the on-going neurodegenerative process.:In the present review, the interplay between neuroinflammation and the peripheral immune response in the pathobiology of PD will be discussed. First of all, an overview of regulation of microglial activation and neuroinflammation is summarized and discussed. Afterwards, we try to collectively analyze changes that occurs in peripheral immune system of PD patients, suggesting that these peripheral immune challenges can exacerbate the process of neuroinflammation and hence the symptoms of the disease. In the end, we summarize some of proposed immunotherapies for treatment of PD.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Chun Chen ◽  
David McDonald ◽  
Alasdair Blain ◽  
Ashwin Sachdeva ◽  
Laura Bone ◽  
...  

AbstractHere we report the application of a mass spectrometry-based technology, imaging mass cytometry, to perform in-depth proteomic profiling of mitochondrial complexes in single neurons, using metal-conjugated antibodies to label post-mortem human midbrain sections. Mitochondrial dysfunction, particularly deficiency in complex I has previously been associated with the degeneration of dopaminergic neurons in Parkinson’s disease. To further our understanding of the nature of this dysfunction, and to identify Parkinson’s disease specific changes, we validated a panel of antibodies targeting subunits of all five mitochondrial oxidative phosphorylation complexes in dopaminergic neurons from Parkinson’s disease, mitochondrial disease, and control cases. Detailed analysis of the expression profile of these proteins, highlighted heterogeneity between individuals. There is a widespread decrease in expression of all complexes in Parkinson’s neurons, although more severe in mitochondrial disease neurons, however, the combination of affected complexes varies between the two groups. We also provide evidence of a potential neuronal response to mitochondrial dysfunction through a compensatory increase in mitochondrial mass. This study highlights the use of imaging mass cytometry in the assessment and analysis of expression of oxidative phosphorylation proteins, revealing the complexity of deficiencies of these proteins within individual neurons which may contribute to and drive neurodegeneration in Parkinson’s disease.


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