Role of mitochondria in the etiology and pathogenesis of Parkinson's disease (original) (raw)

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.

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.

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 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.

Mitochondrial dysfunction in parkinson's disease

Annals of Neurology, 1998

The review highlights mitochondrial structural and functional abnormalities in Parkinson's dis ease and experimental animal models of this pathology. Special attention is paid to the inactivation of mito chondrial enzymes, mutations in mitochondrial and nuclear DNA, and genomic and proteomic studies of mitochondrial proteins in Parkinson's disease and experimental parkinsonism in animals.

Mitochondrial Complex I Deficiency in Parkinson's Disease

Journal of Neurochemistry, 1990

The structure and function of mitochondria1 respiratory-chain enzyme proteins were studied postmortem in the substantia nigra of nine patients with Parkinson's disease and nine matched controls. Total protein and mitochondrial mass were similar in the two groups. NADH-ubiquinone reductase (Complex I) and NADH cytochrome c reductase activities were significantly reduced, whereas succinate cytochrome c reductase activity was normal.

The Centrality of Mitochondria in the Pathogenesis and Treatment of Parkinson's Disease

CNS Neuroscience & Therapeutics, 2014

Parkinson's disease (PD) is an incurable neurodegenerative disorder leading to progressive motor impairment and for which there is no cure. From the first postmortem account describing a lack of mitochondrial complex I in the substantia nigra of PD sufferers, the direct association between mitochondrial dysfunction and death of dopaminergic neurons has ever since been consistently corroborated. In this review, we outline common pathways shared by both sporadic and familial PD that remarkably and consistently converge at the level of mitochondrial integrity. Furthermore, such knowledge has incontrovertibly established mitochondria as a valid therapeutic target in neurodegeneration. We discuss several mitochondria-directed therapies that promote the preservation, rescue, or restoration of dopaminergic neurons and which have been identified in the laboratory and in preclinical studies. Some of these have progressed to clinical trials, albeit the identification of an unequivocal disease-modifying neurotherapeutic is still elusive. The challenge is therefore to improve further, not least by more research on the molecular mechanisms and pathophysiological consequences of mitochondrial dysfunction in PD.

Oxidative stress as a cause of nigral cell death in Parkinson's disease and incidental lewy body disease

Annals of Neurology, 1992

We examine the evidence for free radical involvement and oxidative stress in the pathological process underlying Parkinson's disease, from postmortem brain tissue. The concept of free radical involvement is supported by enhanced basal lipid peroxidation in substantia nigra in patients with Parkinson's disease, demonstrated by increased levels of malondialdehyde and lipid hydroperoxides. The activity of many of the protective mechanisms against oxidative stress does not seem to be significantly altered in the nigra in Parkinson's disease. Thus, activities of catalase and glutathione peroxidase are more or less unchanged, as are concentrations of vitamin C and vitamin E. The activity of mitochondrial superoxide dismutase and the levels of the antioxidant ion zinc are, however, increased, which may reflect oxidative stress in substantia nigra. Levels of reduced glutathione are decreased in nigra in Parkinson's disease; this decrease does not occur in other brain areas or in other neurodegenerative illnesses affecting this brain region (i.e., multiple system atrophy, progressive supranuclear palsy). Altered glutathione metabolism may prevent inactivation of hydrogen peroxide and enhance formation of toxic hydroxyl radicals. In brain material from patients with incidental Lewy body disease (ptesymptomatic Parkinson's disease), there is no evidence for alterations in iron metabolism and no significant change in mitochondrial complex I function. The levels of reduced glutathione in substantia nigra, however, are reduced to the same extent as in advanced Parkinson's disease. These data suggest that changes in glutathione function are an early component of the pathological process of Parkinson's disease. The data presented suggest (1) there is oxidative stress in the substantia nigra at the time of death in advanced Parkinson's disease that manifests in terms of increased lipid peroxidation, superoxide dismutase activity, and zinc levels; (2) there is a major impairment of the glutathione pathway in Parkinson's disease; and (3) alterations in reduced glutathione levels may occur very early in the illness.