Accumulation of mitochondrial DNA deletions within dopaminergic neurons triggers neuroprotective mechanisms

Celine Perier, Andreas Bender, Elena García-Arumí, Ma Jesus Melià, Jordi Bové, Christoph Laub, Thomas Klopstock, Matthias Elstner, Ross B Mounsey, Peter Teismann, Tomas Prolla, Antoni L Andreu, Miquel Vila

Research output: Contribution to journalArticle

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Abstract

Acquired alterations in mitochondrial DNA are believed to play a pathogenic role in Parkinson's disease. In particular, accumulation of mitochondrial DNA deletions has been observed in substantia nigra pars compacta dopaminergic neurons from patients with Parkinson's disease and aged individuals. Also, mutations in mitochondrial DNA polymerase gamma result in multiple mitochondrial DNA deletions that can be associated with levodopa-responsive parkinsonism and severe substantia nigra pars compacta dopaminergic neurodegeneration. However, whether mitochondrial DNA deletions play a causative role in the demise of dopaminergic neurons remains unknown. Here we assessed the potential pathogenic effects of mitochondrial DNA deletions on the dopaminergic nigrostriatal system by using mutant mice possessing a proofreading-deficient form of mitochondrial DNA polymerase gamma (POLGD257A), which results in a time-dependent accumulation of mitochondrial DNA deletions in several tissues, including the brain. In these animals, we assessed the occurrence of mitochondrial DNA deletions within individual substantia nigra pars compacta dopaminergic neurons, by laser capture microdissection and quantitative real-time polymerase chain reaction, and determined the potential deleterious effects of such mitochondrial DNA alterations on mitochondrial function and dopaminergic neuronal integrity, by cytochrome c oxidase histochemistry and quantitative morphology. Nigral dopaminergic neurons from POLGD257A mice accumulate mitochondrial DNA deletions to a similar extent (∼40-60%) as patients with Parkinson's disease and aged individuals. Despite such high levels of mitochondrial DNA deletions, the majority of substantia nigra pars compacta dopaminergic neurons from these animals did not exhibit mitochondrial dysfunction or degeneration. Only a few individual substantia nigra pars compacta neurons appeared as cytochrome c oxidase-negative, which exhibited higher levels of mitochondrial DNA deletions than cytochrome c oxidase-positive cells (60.38±3.92% versus 45.18±2.83%). Survival of dopaminergic neurons in POLGD257A mice was associated with increased mitochondrial DNA copy number, enhanced mitochondrial cristae network, improved mitochondrial respiration, decreased exacerbation of mitochondria-derived reactive oxygen species, greater striatal dopamine levels and resistance to parkinsonian mitochondrial neurotoxins. These results indicate that primary accumulation of mitochondrial DNA deletions within substantia nigra pars compacta dopaminergic neurons, at an extent similar to that observed in patients with Parkinson's disease, do not kill dopaminergic neurons but trigger neuroprotective compensatory mechanisms at a mitochondrial level that may account for the high pathogenic threshold of mitochondrial DNA deletions in these cells.

Original languageEnglish
Pages (from-to)2369-78
Number of pages10
JournalBrain
Volume136
Issue numberPt 8
DOIs
Publication statusPublished - Aug 2013

Fingerprint

Dopaminergic Neurons
Mitochondrial DNA
Parkinson Disease
Electron Transport Complex IV
Laser Capture Microdissection
Corpus Striatum
Neurotoxins
Parkinsonian Disorders
Levodopa
Substantia Nigra

Keywords

  • Animals
  • Cell Death
  • Corpus Striatum
  • DNA, Mitochondrial
  • DNA-Directed DNA Polymerase
  • Dopaminergic Neurons
  • Mice
  • Mice, Transgenic
  • Mitochondria
  • Parkinson Disease
  • Substantia Nigra
  • neurodegeneration

Cite this

Perier, C., Bender, A., García-Arumí, E., Melià, M. J., Bové, J., Laub, C., ... Vila, M. (2013). Accumulation of mitochondrial DNA deletions within dopaminergic neurons triggers neuroprotective mechanisms. Brain, 136(Pt 8), 2369-78. https://doi.org/10.1093/brain/awt196

Accumulation of mitochondrial DNA deletions within dopaminergic neurons triggers neuroprotective mechanisms. / Perier, Celine; Bender, Andreas; García-Arumí, Elena; Melià, Ma Jesus; Bové, Jordi; Laub, Christoph; Klopstock, Thomas; Elstner, Matthias; Mounsey, Ross B; Teismann, Peter; Prolla, Tomas; Andreu, Antoni L; Vila, Miquel.

In: Brain, Vol. 136, No. Pt 8, 08.2013, p. 2369-78.

Research output: Contribution to journalArticle

Perier, C, Bender, A, García-Arumí, E, Melià, MJ, Bové, J, Laub, C, Klopstock, T, Elstner, M, Mounsey, RB, Teismann, P, Prolla, T, Andreu, AL & Vila, M 2013, 'Accumulation of mitochondrial DNA deletions within dopaminergic neurons triggers neuroprotective mechanisms', Brain, vol. 136, no. Pt 8, pp. 2369-78. https://doi.org/10.1093/brain/awt196
Perier C, Bender A, García-Arumí E, Melià MJ, Bové J, Laub C et al. Accumulation of mitochondrial DNA deletions within dopaminergic neurons triggers neuroprotective mechanisms. Brain. 2013 Aug;136(Pt 8):2369-78. https://doi.org/10.1093/brain/awt196
Perier, Celine ; Bender, Andreas ; García-Arumí, Elena ; Melià, Ma Jesus ; Bové, Jordi ; Laub, Christoph ; Klopstock, Thomas ; Elstner, Matthias ; Mounsey, Ross B ; Teismann, Peter ; Prolla, Tomas ; Andreu, Antoni L ; Vila, Miquel. / Accumulation of mitochondrial DNA deletions within dopaminergic neurons triggers neuroprotective mechanisms. In: Brain. 2013 ; Vol. 136, No. Pt 8. pp. 2369-78.
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title = "Accumulation of mitochondrial DNA deletions within dopaminergic neurons triggers neuroprotective mechanisms",
abstract = "Acquired alterations in mitochondrial DNA are believed to play a pathogenic role in Parkinson's disease. In particular, accumulation of mitochondrial DNA deletions has been observed in substantia nigra pars compacta dopaminergic neurons from patients with Parkinson's disease and aged individuals. Also, mutations in mitochondrial DNA polymerase gamma result in multiple mitochondrial DNA deletions that can be associated with levodopa-responsive parkinsonism and severe substantia nigra pars compacta dopaminergic neurodegeneration. However, whether mitochondrial DNA deletions play a causative role in the demise of dopaminergic neurons remains unknown. Here we assessed the potential pathogenic effects of mitochondrial DNA deletions on the dopaminergic nigrostriatal system by using mutant mice possessing a proofreading-deficient form of mitochondrial DNA polymerase gamma (POLGD257A), which results in a time-dependent accumulation of mitochondrial DNA deletions in several tissues, including the brain. In these animals, we assessed the occurrence of mitochondrial DNA deletions within individual substantia nigra pars compacta dopaminergic neurons, by laser capture microdissection and quantitative real-time polymerase chain reaction, and determined the potential deleterious effects of such mitochondrial DNA alterations on mitochondrial function and dopaminergic neuronal integrity, by cytochrome c oxidase histochemistry and quantitative morphology. Nigral dopaminergic neurons from POLGD257A mice accumulate mitochondrial DNA deletions to a similar extent (∼40-60{\%}) as patients with Parkinson's disease and aged individuals. Despite such high levels of mitochondrial DNA deletions, the majority of substantia nigra pars compacta dopaminergic neurons from these animals did not exhibit mitochondrial dysfunction or degeneration. Only a few individual substantia nigra pars compacta neurons appeared as cytochrome c oxidase-negative, which exhibited higher levels of mitochondrial DNA deletions than cytochrome c oxidase-positive cells (60.38±3.92{\%} versus 45.18±2.83{\%}). Survival of dopaminergic neurons in POLGD257A mice was associated with increased mitochondrial DNA copy number, enhanced mitochondrial cristae network, improved mitochondrial respiration, decreased exacerbation of mitochondria-derived reactive oxygen species, greater striatal dopamine levels and resistance to parkinsonian mitochondrial neurotoxins. These results indicate that primary accumulation of mitochondrial DNA deletions within substantia nigra pars compacta dopaminergic neurons, at an extent similar to that observed in patients with Parkinson's disease, do not kill dopaminergic neurons but trigger neuroprotective compensatory mechanisms at a mitochondrial level that may account for the high pathogenic threshold of mitochondrial DNA deletions in these cells.",
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T1 - Accumulation of mitochondrial DNA deletions within dopaminergic neurons triggers neuroprotective mechanisms

AU - Perier, Celine

AU - Bender, Andreas

AU - García-Arumí, Elena

AU - Melià, Ma Jesus

AU - Bové, Jordi

AU - Laub, Christoph

AU - Klopstock, Thomas

AU - Elstner, Matthias

AU - Mounsey, Ross B

AU - Teismann, Peter

AU - Prolla, Tomas

AU - Andreu, Antoni L

AU - Vila, Miquel

N1 - Acknowledgements We thank Annabelle Parent and Esther Perez for their technical assistance and Dr. Kim Tieu for his insightful comments.

PY - 2013/8

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N2 - Acquired alterations in mitochondrial DNA are believed to play a pathogenic role in Parkinson's disease. In particular, accumulation of mitochondrial DNA deletions has been observed in substantia nigra pars compacta dopaminergic neurons from patients with Parkinson's disease and aged individuals. Also, mutations in mitochondrial DNA polymerase gamma result in multiple mitochondrial DNA deletions that can be associated with levodopa-responsive parkinsonism and severe substantia nigra pars compacta dopaminergic neurodegeneration. However, whether mitochondrial DNA deletions play a causative role in the demise of dopaminergic neurons remains unknown. Here we assessed the potential pathogenic effects of mitochondrial DNA deletions on the dopaminergic nigrostriatal system by using mutant mice possessing a proofreading-deficient form of mitochondrial DNA polymerase gamma (POLGD257A), which results in a time-dependent accumulation of mitochondrial DNA deletions in several tissues, including the brain. In these animals, we assessed the occurrence of mitochondrial DNA deletions within individual substantia nigra pars compacta dopaminergic neurons, by laser capture microdissection and quantitative real-time polymerase chain reaction, and determined the potential deleterious effects of such mitochondrial DNA alterations on mitochondrial function and dopaminergic neuronal integrity, by cytochrome c oxidase histochemistry and quantitative morphology. Nigral dopaminergic neurons from POLGD257A mice accumulate mitochondrial DNA deletions to a similar extent (∼40-60%) as patients with Parkinson's disease and aged individuals. Despite such high levels of mitochondrial DNA deletions, the majority of substantia nigra pars compacta dopaminergic neurons from these animals did not exhibit mitochondrial dysfunction or degeneration. Only a few individual substantia nigra pars compacta neurons appeared as cytochrome c oxidase-negative, which exhibited higher levels of mitochondrial DNA deletions than cytochrome c oxidase-positive cells (60.38±3.92% versus 45.18±2.83%). Survival of dopaminergic neurons in POLGD257A mice was associated with increased mitochondrial DNA copy number, enhanced mitochondrial cristae network, improved mitochondrial respiration, decreased exacerbation of mitochondria-derived reactive oxygen species, greater striatal dopamine levels and resistance to parkinsonian mitochondrial neurotoxins. These results indicate that primary accumulation of mitochondrial DNA deletions within substantia nigra pars compacta dopaminergic neurons, at an extent similar to that observed in patients with Parkinson's disease, do not kill dopaminergic neurons but trigger neuroprotective compensatory mechanisms at a mitochondrial level that may account for the high pathogenic threshold of mitochondrial DNA deletions in these cells.

AB - Acquired alterations in mitochondrial DNA are believed to play a pathogenic role in Parkinson's disease. In particular, accumulation of mitochondrial DNA deletions has been observed in substantia nigra pars compacta dopaminergic neurons from patients with Parkinson's disease and aged individuals. Also, mutations in mitochondrial DNA polymerase gamma result in multiple mitochondrial DNA deletions that can be associated with levodopa-responsive parkinsonism and severe substantia nigra pars compacta dopaminergic neurodegeneration. However, whether mitochondrial DNA deletions play a causative role in the demise of dopaminergic neurons remains unknown. Here we assessed the potential pathogenic effects of mitochondrial DNA deletions on the dopaminergic nigrostriatal system by using mutant mice possessing a proofreading-deficient form of mitochondrial DNA polymerase gamma (POLGD257A), which results in a time-dependent accumulation of mitochondrial DNA deletions in several tissues, including the brain. In these animals, we assessed the occurrence of mitochondrial DNA deletions within individual substantia nigra pars compacta dopaminergic neurons, by laser capture microdissection and quantitative real-time polymerase chain reaction, and determined the potential deleterious effects of such mitochondrial DNA alterations on mitochondrial function and dopaminergic neuronal integrity, by cytochrome c oxidase histochemistry and quantitative morphology. Nigral dopaminergic neurons from POLGD257A mice accumulate mitochondrial DNA deletions to a similar extent (∼40-60%) as patients with Parkinson's disease and aged individuals. Despite such high levels of mitochondrial DNA deletions, the majority of substantia nigra pars compacta dopaminergic neurons from these animals did not exhibit mitochondrial dysfunction or degeneration. Only a few individual substantia nigra pars compacta neurons appeared as cytochrome c oxidase-negative, which exhibited higher levels of mitochondrial DNA deletions than cytochrome c oxidase-positive cells (60.38±3.92% versus 45.18±2.83%). Survival of dopaminergic neurons in POLGD257A mice was associated with increased mitochondrial DNA copy number, enhanced mitochondrial cristae network, improved mitochondrial respiration, decreased exacerbation of mitochondria-derived reactive oxygen species, greater striatal dopamine levels and resistance to parkinsonian mitochondrial neurotoxins. These results indicate that primary accumulation of mitochondrial DNA deletions within substantia nigra pars compacta dopaminergic neurons, at an extent similar to that observed in patients with Parkinson's disease, do not kill dopaminergic neurons but trigger neuroprotective compensatory mechanisms at a mitochondrial level that may account for the high pathogenic threshold of mitochondrial DNA deletions in these cells.

KW - Animals

KW - Cell Death

KW - Corpus Striatum

KW - DNA, Mitochondrial

KW - DNA-Directed DNA Polymerase

KW - Dopaminergic Neurons

KW - Mice

KW - Mice, Transgenic

KW - Mitochondria

KW - Parkinson Disease

KW - Substantia Nigra

KW - neurodegeneration

U2 - 10.1093/brain/awt196

DO - 10.1093/brain/awt196

M3 - Article

VL - 136

SP - 2369

EP - 2378

JO - Brain

JF - Brain

SN - 0006-8950

IS - Pt 8

ER -