Mitochondrial Metabolism Modulation: A New Therapeutic Approach for Parkinsons Disease (original) (raw)

Mitochondrial Biology and Parkinson's Disease

Cold Spring Harbor Perspectives in Medicine, 2011

Mitochondria are highly dynamic organelles with complex structural features which play several important cellular functions, such as the production of energy by oxidative phosphorylation, the regulation of calcium homeostasis, or the control of programmed cell death (PCD). Given its essential role in neuronal viability, alterations in mitochondrial biology can lead to neuron dysfunction and cell death. Defects in mitochondrial respiration have long been implicated in the etiology and pathogenesis of Parkinson's disease (PD). However, the role of mitochondria in PD extends well beyond defective respiration and also involves perturbations in mitochondrial dynamics, leading to alterations in mitochondrial morphology, intracellular trafficking, or quality control. Whether a primary or secondary event, mitochondrial dysfunction holds promise as a potential therapeutic target to halt the progression of dopaminergic neurodegeneration in PD.

Mitochondrial dysfunction in the limelight of Parkinson's disease pathogenesis

2009

Parkinson's disease (PD) is a progressive neurodegenerative movement disorder with unknown etiology. It is marked by widespread neurodegeneration in the brain with profound loss of A9 midbrain dopaminergic neurons in substantia nigra pars compacta. Several theories of biochemical abnormalities have been linked to pathogenesis of PD of which mitochondrial dysfunction due to an impairment of mitochondrial complex I and subsequent oxidative stress seems to take the center stage in experimental models of PD and in postmortem tissues of sporadic forms of illness. Recent identification of specific gene mutations and their influence on mitochondrial functions has further reinforced the relevance of mitochondrial abnormalities in disease pathogenesis. In both sporadic and familial forms of PD abnormal mitochondrial paradigms associated with disease include impaired functioning of the mitochondrial electron transport chain, aging associated damage to mitochondrial DNA, impaired calcium buffering, and anomalies in mitochondrial morphology and dynamics. Here we provide an overview of specific mitochondrial functions affected in sporadic and familial PD that play a role in disease pathogenesis. We propose to utilize these gained insights to further streamline and focus the research to better understand mitochondria's role in disease development and exploit potential mitochondrial targets for therapeutic interventions in PD pathogenesis.

Genetic findings in Parkinson’s disease and translation into treatment: a leading role for mitochondria?

Genes, Brain and Behavior, 2008

Parkinson's disease (PD) is a progressive neurodegenerative movement disorder and in most patients its aetiology remains unknown. Molecular genetic studies in familial forms of the disease identified key proteins involved in PD pathogenesis, and support a major role for mitochondrial dysfunction, which is also of significant importance to the common sporadic forms of PD. While current treatments temporarily alleviate symptoms, they do not halt disease progression. Drugs that target the underlying pathways to PD pathogenesis, including mitochondrial dysfunction, therefore hold great promise for neuroprotection in PD. Here we summarize how the proteins identified through genetic research (a-synuclein, parkin, PINK1, DJ-1, LRRK2 and HTRA2) fit into and add to our current understanding of the role of mitochondrial dysfunction in PD. We highlight how these genetic findings provided us with suitable animal models and critically review how the gained insights will contribute to better therapies for PD.

Mitochondrial alterations in Parkinson’s disease: new clues

Journal of Neurochemistry, 2008

Mitochondrial dysfunction has long been associated with Parkinson's disease (PD). In particular, complex I impairment and subsequent oxidative stress have been widely demonstrated in experimental models of PD and in post-mortem PD samples. A recent wave of new studies is providing novel clues to the potential involvement of mitochondria in PD. In particular, (i) mitochondria-dependent programmed cell death pathways have been shown to be critical to PD-related dopaminergic neurodegeneration, (ii) many disease-causing proteins associated with familial forms of PD have been demonstrated to interact either directly or indirectly with mitochondria, (iii) aging-related mitochondrial changes, such as alterations in mitochondrial DNA, are increasingly being associated with PD, and (iv) anomalies in mitochondrial dynamics and intra-neuronal distribution are emerging as critical participants in the pathogenesis of PD. These new findings are revitalizing the field and reinforcing the potential role of mitochondria in the pathogenesis of PD. Whether a primary or secondary event, or part of a multifactorial pathogenic process, mitochondrial dysfunction remains at the forefront of PD research and holds the promise as a potential molecular target for the development of new therapeutic strategies for this devastating, currently incurable, disease.

Sirtuin 3 rescues neurons through the stabilisation of mitochondrial biogenetics in the virally-expressing mutant α-synuclein rat model of parkinsonism

Neurobiology of disease, 2017

Parkinson's disease (PD) is a neurodegenerative movement disorder, which affects approximately 1-2% of the population over 60years of age. Current treatments for PD are symptomatic, and the pathology of the disease continues to progresses over time until palliative care is required. Mitochondria are key players in the pathology of PD. Genetic and post mortem studies have shown a large number of mitochondrial abnormalities in the substantia nigra pars compacta (SNc) of the parkinsonian brain. Furthermore, physiologically, mitochondria of nigral neurons are constantly under unusually high levels of metabolic stress because of the excitatory properties and architecture of these neurons. The protein deacetylase, Sirtuin 3 (SIRT3) reduces the impact subcellular stresses on mitochondria, by stabilising the electron transport chain (ETC), and reducing oxidative stress. We hypothesised that viral overexpression of myc-tagged SIRT3 (SIRT3-myc) would slow the progression of PD pathology, ...

Mitochondrial matters in Parkinson disease: introduction

Journal of Bioenergetics and Biomembranes, 2009

Individuals with Parkinson disease (PD) are encountered frequently and have progressively severe neurologic changes. The central nervous system changes involve dopaminergic neurons in the basal ganglia and substantia nigra. Although usually sporadic, rare forms of PD are familial and the responsible genes have been identified. These genes affect mitochondrial function and can be studied in animals. Brains of affected animals reveal consequences of reactive oxygen species (ROS)-quinones, dopamine oxidation products, tyrosine nitration, lipid peroxidation and amino-aldehyde adducts. The three genes are important for maintaining physical and functional mitochondrial integrity. The cumulative effects of mitochondrial dysfunction, particularly those mediated by ROS, ultimately lead to at least some of the clinical and pathologic changes of PD.

The Parkinson's disease-related genes act in mitochondrial homeostasis

Neuroscience & Biobehavioral Reviews, 2012

Neurons are metabolically active cells with high energy demands. Thus, neurons are particularly reliant on mitochondrial function, especially on the homeostasis properties of mitochondria. This is reflected by the observation that mitochondrial abnormalities have been well recognized to contribute to neurodegenerative diseases, like Parkinson's disease (PD). Mitochondria are highly complex and dynamic organelles continuously undergoing different alterations. The dynamic property of mitochondria is named as mitochondrial homeostasis. Imbalance of mitochondrial homeostasis is associated with neurodegenerative disease, such as Parkinson's diseases. Recently, the related genes of PD-familial, such as alpha-synuclein, Parkin, PINK1, DJ-1 and LRRK2, are observed to be associated with mitochondria, and capable of modulating normal mitochondrial integrity and functions under certain conditions. Therefore, in this review, we will focus on the action of PD-related genes in mitochondrial homeostasis.

Mitochondrial homeostasis molecules: regulation by a trio of recessive Parkinson's disease genes

Experimental neurobiology, 2014

Mitochondria are small organelles that produce the majority of cellular energy as ATP. Mitochondrial dysfunction has been implicated in the pathogenesis of Parkinson's disease (PD), and rare familial forms of PD provide valuable insight into the pathogenic mechanism underlying mitochondrial impairment, even though the majority of PD cases are sporadic. The regulation of mitochondria is crucial for the maintenance of energy-demanding neuronal functions in the brain. Mitochondrial biogenesis and mitophagic degradation are the major regulatory pathways that preserve optimal mitochondrial content, structure and function. In this mini-review, we provide an overview of the mitochondrial quality control mechanisms, emphasizing regulatory molecules in mitophagy and biogenesis that specifically interact with the protein products of three major recessive familial PD genes, PINK1, Parkin and DJ-1.

Loss of the Parkinson's disease-linked gene DJ-1 perturbs mitochondrial dynamics

Human Molecular Genetics, 2010

Growing evidence highlights a role for mitochondrial dysfunction and oxidative stress as underlying contributors to Parkinson's disease (PD) pathogenesis. DJ-1 (PARK7) is a recently identified recessive familial PD gene. Its loss leads to increased susceptibility of neurons to oxidative stress and death. However, its mechanism of action is not fully understood. Presently, we report that DJ-1 deficiency in cell lines, cultured neurons, mouse brain and lymphoblast cells derived from DJ-1 patients display aberrant mitochondrial morphology. We also show that these DJ-1-dependent mitochondrial defects contribute to oxidative stress-induced sensitivity to cell death since reversal of this fragmented mitochondrial phenotype abrogates neuronal cell death. Reactive oxygen species (ROS) appear to play a critical role in the observed defects, as ROS scavengers rescue the phenotype and mitochondria isolated from DJ-1 deficient animals produce more ROS compared with control. Importantly, the aberrant mitochondrial phenotype can be rescued by the expression of Pink1 and Parkin, two PD-linked genes involved in regulating mitochondrial dynamics and quality control. Finally, we show that DJ-1 deficiency leads to altered autophagy in murine and human cells. Our findings define a mechanism by which the DJ-1-dependent mitochondrial defects contribute to the increased sensitivity to oxidative stress-induced cell death that has been previously reported.