Mitochondrial impairment in patients with Parkinson disease with the G2019S mutation in LRRK2.
Summary of "Mitochondrial impairment in patients with Parkinson disease with the G2019S mutation in LRRK2."
OBJECTIVE:
The LRRK2(G2019S) mutation is the most common identifiable cause for Parkinson disease (PD), but the underlying mechanisms leading to neuronal cell death remain largely unclear. Impaired mitochondrial function and morphology have been described in different in vivo and in vitro model systems of early-onset PD (EOPD) as well as in EOPD patient tissue. The aim of our study was to assess mitochondrial function and morphology in LRRK2(G2019S) mutant patient tissue to determine whether impaired mitochondrial function and morphology are shared features in early-onset and late-onset PD.
METHODS:
Skin biopsies were taken from 5 patients with PD with the LRRK2(G2019S) mutation. Assessment of mitochondrial membrane potential and intracellular ATP levels as well as substrate-linked mitochondrial ATP production assays were all carried out on 3 independent cell preparations per patient. Results were compared to 5 age-matched controls. Mitochondrial elongation and interconnectivity was assessed using previously published methods.
RESULTS:
Both mitochondrial membrane potential and total intracellular ATP levels were decreased in the G2019S mutation carriers. Subsequently undertaken mitochondrial ATP production assays suggested that the observed reduction is at least partially due to impaired mitochondrial function. Mitochondrial elongation and interconnectivity were increased in the LRRK2(G2019S) patient cohort.
CONCLUSION:
Our results provide evidence for impaired mitochondrial function and morphology in LRRK2(G2019S) mutant patient tissue. Further studies are required to determine whether the impaired mitochondrial function is due to increased LRRK2 kinase activity or other mechanisms such as LRRK2 haploinsufficiency.
Affiliation
Academic Neurology Unit, Medical School, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK o.bandmann@sheffield.ac.uk.
Journal Details
This article was published in the following journal.
Name: Neurology
ISSN: 1526-632X
Pages: 2017-20
Links
- PubMed Source: http://www.ncbi.nlm.nih.gov/pubmed/21115957
- DOI: http://dx.doi.org/10.1212/WNL.0b013e3181ff9685
Medical and Biotech [MESH] Definitions
Selegiline
A selective, irreversible inhibitor of Type B monoamine oxidase. It is used in newly diagnosed patients with Parkinson's disease. It may slow progression of the clinical disease and delay the requirement for levodopa therapy. It also may be given with levodopa upon onset of disability. (From AMA Drug Evaluations Annual, 1994, p385) The compound without isomeric designation is Deprenyl.
Mptp Poisoning
A condition caused by the neurotoxin MPTP which causes selective destruction of nigrostriatal dopaminergic neurons. Clinical features include irreversible parkinsonian signs including rigidity and bradykinesia (PARKINSON DISEASE, SECONDARY). MPTP toxicity is also used as an animal model for the study of PARKINSON DISEASE. (Adams et al., Principles of Neurology, 6th ed, p1072; Neurology 1986 Feb;36(2):250-8)
Parkinsonian Disorders
A group of disorders which feature impaired motor control characterized by bradykinesia, MUSCLE RIGIDITY; TREMOR; and postural instability. Parkinsonian diseases are generally divided into primary parkinsonism (see PARKINSON DISEASE), secondary parkinsonism (see PARKINSON DISEASE, SECONDARY) and inherited forms. These conditions are associated with dysfunction of dopaminergic or closely related motor integration neuronal pathways in the BASAL GANGLIA.
Parkinson Disease, Postencephalitic
Parkinsonism following encephalitis, historically seen as a sequella of encephalitis lethargica (Von Economo Encephalitis). The early age of onset, the rapid progression of symptoms followed by stabilization, and the presence of a variety of other neurological disorders (e.g., sociopathic behavior; TICS; MUSCLE SPASMS; oculogyric crises; hyperphagia; and bizarre movements) distinguish this condition from primary PARKINSON DISEASE. Pathologic features include neuronal loss and gliosis concentrated in the MESENCEPHALON; SUBTHALAMUS; and HYPOTHALAMUS. (From Adams et al., Principles of Neurology, 6th ed, p754)
Parkinson Disease, Secondary
Conditions which feature clinical manifestations resembling primary Parkinson disease that are caused by a known or suspected condition. Examples include parkinsonism caused by vascular injury, drugs, trauma, toxin exposure, neoplasms, infections and degenerative or hereditary conditions. Clinical features may include bradykinesia, rigidity, parkinsonian gait, and masked facies. In general, tremor is less prominent in secondary parkinsonism than in the primary form. (From Joynt, Clinical Neurology, 1998, Ch38, pp39-42)
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