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Protein-protein interaction networks identify targets which rescue the MPP+ cellular model of Parkinson's disease.

Keane H, Ryan BJ, Jackson B, Whitmore A, Wade-Martins R - Sci Rep (2015)

Bottom Line: Neurodegenerative diseases are complex multifactorial disorders characterised by the interplay of many dysregulated physiological processes.We also found that modulation of two distinct proteins in the protein-protein interaction network was necessary and sufficient to mitigate neurotoxicity.Together, these findings validate our network science approach to multi-target identification in complex neurological diseases.

View Article: PubMed Central - PubMed

Affiliation: Oxford Parkinson's Disease Centre, Anatomy and Genetics, University of Oxford, OX1 3QX.

ABSTRACT
Neurodegenerative diseases are complex multifactorial disorders characterised by the interplay of many dysregulated physiological processes. As an exemplar, Parkinson's disease (PD) involves multiple perturbed cellular functions, including mitochondrial dysfunction and autophagic dysregulation in preferentially-sensitive dopamine neurons, a selective pathophysiology recapitulated in vitro using the neurotoxin MPP(+). Here we explore a network science approach for the selection of therapeutic protein targets in the cellular MPP(+) model. We hypothesised that analysis of protein-protein interaction networks modelling MPP(+) toxicity could identify proteins critical for mediating MPP(+) toxicity. Analysis of protein-protein interaction networks constructed to model the interplay of mitochondrial dysfunction and autophagic dysregulation (key aspects of MPP(+) toxicity) enabled us to identify four proteins predicted to be key for MPP(+) toxicity (P62, GABARAP, GBRL1 and GBRL2). Combined, but not individual, knockdown of these proteins increased cellular susceptibility to MPP(+) toxicity. Conversely, combined, but not individual, over-expression of the network targets provided rescue of MPP(+) toxicity associated with the formation of autophagosome-like structures. We also found that modulation of two distinct proteins in the protein-protein interaction network was necessary and sufficient to mitigate neurotoxicity. Together, these findings validate our network science approach to multi-target identification in complex neurological diseases.

No MeSH data available.


Related in: MedlinePlus

A minimal overexpression set contains P62 and members of the GABARAP subfamily.All pairwise and triple combinations of the overexpression set were tested for rescue of MPP+ toxicity. Cells were transfected with appropriate expression constructs, treated with MPP+ (100 μM) and neutral red uptake measured 36 h post-MPP+ treatment. Bars represent mean ± SEM (n = 3), one way ANOVA with Dunnett multiple comparison test to MPP+ control, *P ≤ 0.05, **P ≤ 0.01.
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f5: A minimal overexpression set contains P62 and members of the GABARAP subfamily.All pairwise and triple combinations of the overexpression set were tested for rescue of MPP+ toxicity. Cells were transfected with appropriate expression constructs, treated with MPP+ (100 μM) and neutral red uptake measured 36 h post-MPP+ treatment. Bars represent mean ± SEM (n = 3), one way ANOVA with Dunnett multiple comparison test to MPP+ control, *P ≤ 0.05, **P ≤ 0.01.

Mentions: Finally, we investigated potential redundancy in our selected network targets to understand if overexpression of all target proteins is needed for the observed neuro-protective effect. Each possible pairwise and triple combination of network targets was overexpressed and vulnerability to MPP+ assessed. We determined P62 was essential for cellular rescue and that there was considerable redundancy in the GABARAP subfamily proteins, with any combination of two GABARAP subfamily members, or GBRL1 alone, sufficient for neuroprotection (Fig. 5). It has previously been demonstrated that a combined knockdown of all GABARAP subfamily members is required to elicit an autophagic phenotype35. These data demonstrate that interventions are required at multiple distinct positions in the protein-protein interaction network to achieve a phenotypic outcome, suggesting that, in common with networks underpinning normal function, this pathological network is resilient, exhibiting considerable redundancy, and that non-trivial techniques are required to identify vulnerabilities.


Protein-protein interaction networks identify targets which rescue the MPP+ cellular model of Parkinson's disease.

Keane H, Ryan BJ, Jackson B, Whitmore A, Wade-Martins R - Sci Rep (2015)

A minimal overexpression set contains P62 and members of the GABARAP subfamily.All pairwise and triple combinations of the overexpression set were tested for rescue of MPP+ toxicity. Cells were transfected with appropriate expression constructs, treated with MPP+ (100 μM) and neutral red uptake measured 36 h post-MPP+ treatment. Bars represent mean ± SEM (n = 3), one way ANOVA with Dunnett multiple comparison test to MPP+ control, *P ≤ 0.05, **P ≤ 0.01.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4660280&req=5

f5: A minimal overexpression set contains P62 and members of the GABARAP subfamily.All pairwise and triple combinations of the overexpression set were tested for rescue of MPP+ toxicity. Cells were transfected with appropriate expression constructs, treated with MPP+ (100 μM) and neutral red uptake measured 36 h post-MPP+ treatment. Bars represent mean ± SEM (n = 3), one way ANOVA with Dunnett multiple comparison test to MPP+ control, *P ≤ 0.05, **P ≤ 0.01.
Mentions: Finally, we investigated potential redundancy in our selected network targets to understand if overexpression of all target proteins is needed for the observed neuro-protective effect. Each possible pairwise and triple combination of network targets was overexpressed and vulnerability to MPP+ assessed. We determined P62 was essential for cellular rescue and that there was considerable redundancy in the GABARAP subfamily proteins, with any combination of two GABARAP subfamily members, or GBRL1 alone, sufficient for neuroprotection (Fig. 5). It has previously been demonstrated that a combined knockdown of all GABARAP subfamily members is required to elicit an autophagic phenotype35. These data demonstrate that interventions are required at multiple distinct positions in the protein-protein interaction network to achieve a phenotypic outcome, suggesting that, in common with networks underpinning normal function, this pathological network is resilient, exhibiting considerable redundancy, and that non-trivial techniques are required to identify vulnerabilities.

Bottom Line: Neurodegenerative diseases are complex multifactorial disorders characterised by the interplay of many dysregulated physiological processes.We also found that modulation of two distinct proteins in the protein-protein interaction network was necessary and sufficient to mitigate neurotoxicity.Together, these findings validate our network science approach to multi-target identification in complex neurological diseases.

View Article: PubMed Central - PubMed

Affiliation: Oxford Parkinson's Disease Centre, Anatomy and Genetics, University of Oxford, OX1 3QX.

ABSTRACT
Neurodegenerative diseases are complex multifactorial disorders characterised by the interplay of many dysregulated physiological processes. As an exemplar, Parkinson's disease (PD) involves multiple perturbed cellular functions, including mitochondrial dysfunction and autophagic dysregulation in preferentially-sensitive dopamine neurons, a selective pathophysiology recapitulated in vitro using the neurotoxin MPP(+). Here we explore a network science approach for the selection of therapeutic protein targets in the cellular MPP(+) model. We hypothesised that analysis of protein-protein interaction networks modelling MPP(+) toxicity could identify proteins critical for mediating MPP(+) toxicity. Analysis of protein-protein interaction networks constructed to model the interplay of mitochondrial dysfunction and autophagic dysregulation (key aspects of MPP(+) toxicity) enabled us to identify four proteins predicted to be key for MPP(+) toxicity (P62, GABARAP, GBRL1 and GBRL2). Combined, but not individual, knockdown of these proteins increased cellular susceptibility to MPP(+) toxicity. Conversely, combined, but not individual, over-expression of the network targets provided rescue of MPP(+) toxicity associated with the formation of autophagosome-like structures. We also found that modulation of two distinct proteins in the protein-protein interaction network was necessary and sufficient to mitigate neurotoxicity. Together, these findings validate our network science approach to multi-target identification in complex neurological diseases.

No MeSH data available.


Related in: MedlinePlus