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Microtubule depolymerization potentiates alpha-synuclein oligomerization.

Esteves AR, Arduíno DM, Swerdlow RH, Oliveira CR, Cardoso SM - Front Aging Neurosci (2010)

Bottom Line: Compared to a control cybrid cell line, the PD line showed reduced ATP levels, an increased free/polymerized tubulin ratio, and alpha-synuclein oligomer accumulation.Taxol (which stabilizes microtubules) normalized the PD tubulin ratio and reduced alpha-synuclein oligomerization.In our model, mitochondrial dysfunction triggers an increased free tubulin, which destabilizes the microtubular network and promotes alpha-synuclein oligomerization.

View Article: PubMed Central - PubMed

Affiliation: Centro de Neurociências e Biologia Celular, Universidade de Coimbra Portugal.

ABSTRACT
Parkinson's disease (PD) is associated with perturbed mitochondria function and alpha-synuclein fibrillization. We evaluated potential mechanistic links between mitochondrial dysfunction and alpha-synuclein aggregation. We studied a PD cytoplasmic hybrid (cybrid) cell line in which platelet mitochondria from a PD subject were transferred to NT2 neuronal cells previously depleted of endogenous mitochondrial DNA. Compared to a control cybrid cell line, the PD line showed reduced ATP levels, an increased free/polymerized tubulin ratio, and alpha-synuclein oligomer accumulation. Taxol (which stabilizes microtubules) normalized the PD tubulin ratio and reduced alpha-synuclein oligomerization. A nexus exists between mitochondrial function, cytoskeleton homeostasis, and alpha-synuclein oligomerization. In our model, mitochondrial dysfunction triggers an increased free tubulin, which destabilizes the microtubular network and promotes alpha-synuclein oligomerization.

No MeSH data available.


Related in: MedlinePlus

Tubulin alterations in the PD cybrid lines. (A) Tubulin immunocytochemistry reveals disruption of the microtubule network in the PD cybrid lines. (B) SDS-PAGE analysis shows that in the PD cybrids the free/polymerized tubulin ratio is elevated. (C) After correcting for GADPH content the PD cybrids free/polymerized tubulin ratio was elevated as compared to the control cybrid cell line. **P < 0.01, significantly different as compared to the CT cybrid lines. Bars, 10 μm.
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Figure 2: Tubulin alterations in the PD cybrid lines. (A) Tubulin immunocytochemistry reveals disruption of the microtubule network in the PD cybrid lines. (B) SDS-PAGE analysis shows that in the PD cybrids the free/polymerized tubulin ratio is elevated. (C) After correcting for GADPH content the PD cybrids free/polymerized tubulin ratio was elevated as compared to the control cybrid cell line. **P < 0.01, significantly different as compared to the CT cybrid lines. Bars, 10 μm.

Mentions: MT assembly requires ATP, therefore the reduction of PD cybrids ATP may interfere with the efficacy of the polymerization/depolymerization process of tubulin. For that reason we immunocytochemically evaluated MT network integrity. MT networks were less well defined in the PD cybrid cells (Figure 2A), and the free/polymerized tubulin ratio was also elevated (Figures 2B,C). In the CT cybrid cells approximately one-third of the tubulin was in the free form, and in the PD cybrid approximately one-half of the tubulin was in the free form (Table 1). Because of the viscosity of the polymerized tubulin all samples were corrected with GAPDH antibody in order to eliminate loading errors (Figures 2B,C).


Microtubule depolymerization potentiates alpha-synuclein oligomerization.

Esteves AR, Arduíno DM, Swerdlow RH, Oliveira CR, Cardoso SM - Front Aging Neurosci (2010)

Tubulin alterations in the PD cybrid lines. (A) Tubulin immunocytochemistry reveals disruption of the microtubule network in the PD cybrid lines. (B) SDS-PAGE analysis shows that in the PD cybrids the free/polymerized tubulin ratio is elevated. (C) After correcting for GADPH content the PD cybrids free/polymerized tubulin ratio was elevated as compared to the control cybrid cell line. **P < 0.01, significantly different as compared to the CT cybrid lines. Bars, 10 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2874407&req=5

Figure 2: Tubulin alterations in the PD cybrid lines. (A) Tubulin immunocytochemistry reveals disruption of the microtubule network in the PD cybrid lines. (B) SDS-PAGE analysis shows that in the PD cybrids the free/polymerized tubulin ratio is elevated. (C) After correcting for GADPH content the PD cybrids free/polymerized tubulin ratio was elevated as compared to the control cybrid cell line. **P < 0.01, significantly different as compared to the CT cybrid lines. Bars, 10 μm.
Mentions: MT assembly requires ATP, therefore the reduction of PD cybrids ATP may interfere with the efficacy of the polymerization/depolymerization process of tubulin. For that reason we immunocytochemically evaluated MT network integrity. MT networks were less well defined in the PD cybrid cells (Figure 2A), and the free/polymerized tubulin ratio was also elevated (Figures 2B,C). In the CT cybrid cells approximately one-third of the tubulin was in the free form, and in the PD cybrid approximately one-half of the tubulin was in the free form (Table 1). Because of the viscosity of the polymerized tubulin all samples were corrected with GAPDH antibody in order to eliminate loading errors (Figures 2B,C).

Bottom Line: Compared to a control cybrid cell line, the PD line showed reduced ATP levels, an increased free/polymerized tubulin ratio, and alpha-synuclein oligomer accumulation.Taxol (which stabilizes microtubules) normalized the PD tubulin ratio and reduced alpha-synuclein oligomerization.In our model, mitochondrial dysfunction triggers an increased free tubulin, which destabilizes the microtubular network and promotes alpha-synuclein oligomerization.

View Article: PubMed Central - PubMed

Affiliation: Centro de Neurociências e Biologia Celular, Universidade de Coimbra Portugal.

ABSTRACT
Parkinson's disease (PD) is associated with perturbed mitochondria function and alpha-synuclein fibrillization. We evaluated potential mechanistic links between mitochondrial dysfunction and alpha-synuclein aggregation. We studied a PD cytoplasmic hybrid (cybrid) cell line in which platelet mitochondria from a PD subject were transferred to NT2 neuronal cells previously depleted of endogenous mitochondrial DNA. Compared to a control cybrid cell line, the PD line showed reduced ATP levels, an increased free/polymerized tubulin ratio, and alpha-synuclein oligomer accumulation. Taxol (which stabilizes microtubules) normalized the PD tubulin ratio and reduced alpha-synuclein oligomerization. A nexus exists between mitochondrial function, cytoskeleton homeostasis, and alpha-synuclein oligomerization. In our model, mitochondrial dysfunction triggers an increased free tubulin, which destabilizes the microtubular network and promotes alpha-synuclein oligomerization.

No MeSH data available.


Related in: MedlinePlus