Limits...
Proteome analysis reveals roles of L-DOPA in response to oxidative stress in neurons.

Jami MS, Pal R, Hoedt E, Neubert TA, Larsen JP, Møller SG - BMC Neurosci (2014)

Bottom Line: We observed that oxidative stress affects metabolic pathways as well as cytoskeletal integrity and that neuronal cells respond to oxidative conditions by enhancing numerous survival pathways.Oxidative stress changes neuronal metabolic routes and affects cytoskeletal integrity.Further, L-DOPA appears to reverse some H2O2-mediated effects evident at both the proteome and cellular level.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Sciences, St John's University, New York, NY, USA. mollers@stjohns.edu.

ABSTRACT

Background: Parkinson's disease (PD) is the second most common neurodegenerative movement disorder, caused by preferential dopaminergic neuronal cell death in the substantia nigra, a process also influenced by oxidative stress. L-3,4-dihydroxyphenylalanine (L-DOPA) represents the main treatment route for motor symptoms associated with PD however, its exact mode of action remains unclear. A spectrum of conflicting data suggests that L-DOPA may damage dopaminergic neurons due to oxidative stress whilst other data suggest that L-DOPA itself may induce low levels of oxidative stress, which in turn stimulates endogenous antioxidant mechanisms and neuroprotection.

Results: In this study we performed a two-dimensional gel electrophoresis (2DE)-based proteomic study to gain further insight into the mechanism by which L-DOPA can influence the toxic effects of H2O2 in neuronal cells. We observed that oxidative stress affects metabolic pathways as well as cytoskeletal integrity and that neuronal cells respond to oxidative conditions by enhancing numerous survival pathways. Our study underlines the complex nature of L-DOPA in PD and sheds light on the interplay between oxidative stress and L-DOPA.

Conclusions: Oxidative stress changes neuronal metabolic routes and affects cytoskeletal integrity. Further, L-DOPA appears to reverse some H2O2-mediated effects evident at both the proteome and cellular level.

Show MeSH

Related in: MedlinePlus

Quantitative ROS measurements in response to H2O2, L-DOPA and H2O2/L-DOPA treatments. Quantification of ROS production in SH-SY5Y cells in response to eight hours of 2 mM H2O2, 200 μM L-DOPA and 2 mM H2O2/200 μM L-DOPA treatments as determined by DCF fluorescence intensity. Each data point is the average of 12 replicate samples and presented as means ± SD. Standard deviations are indicated by error bars. ***p < 0.001.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4125692&req=5

Fig5: Quantitative ROS measurements in response to H2O2, L-DOPA and H2O2/L-DOPA treatments. Quantification of ROS production in SH-SY5Y cells in response to eight hours of 2 mM H2O2, 200 μM L-DOPA and 2 mM H2O2/200 μM L-DOPA treatments as determined by DCF fluorescence intensity. Each data point is the average of 12 replicate samples and presented as means ± SD. Standard deviations are indicated by error bars. ***p < 0.001.

Mentions: An interesting phenomenon that was observed in our treatments is the ability of L-DOPA to reverse the effects of H2O2 on cellular morphology and cell viability (Figure 1). This reversal was also observed in terms of ROS where L-DOPA exposure reduced ROS levels, in the presence of H2O2, down to levels observed in control cells (Figure 5). Indeed, all the H2O2-induced protein alterations, affecting the cytoskeleton, were restored to baseline by supplementing the H2O2-containing media with L-DOPA (spots 3, 4, 5, 11, 12 and 13) (Figures 3B, Table 2). Furthermore, the induction of mitochondrial enzymes under oxidative stress condition (fumarate hydratase (spot 1), nucleoside-diphosphate kinase (spot 6) and 3-Hydroxyacyl CoA dehydrogenase (spot 2) was abolished in response to L-DOPA exposure (Table 2).Figure 5


Proteome analysis reveals roles of L-DOPA in response to oxidative stress in neurons.

Jami MS, Pal R, Hoedt E, Neubert TA, Larsen JP, Møller SG - BMC Neurosci (2014)

Quantitative ROS measurements in response to H2O2, L-DOPA and H2O2/L-DOPA treatments. Quantification of ROS production in SH-SY5Y cells in response to eight hours of 2 mM H2O2, 200 μM L-DOPA and 2 mM H2O2/200 μM L-DOPA treatments as determined by DCF fluorescence intensity. Each data point is the average of 12 replicate samples and presented as means ± SD. Standard deviations are indicated by error bars. ***p < 0.001.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4125692&req=5

Fig5: Quantitative ROS measurements in response to H2O2, L-DOPA and H2O2/L-DOPA treatments. Quantification of ROS production in SH-SY5Y cells in response to eight hours of 2 mM H2O2, 200 μM L-DOPA and 2 mM H2O2/200 μM L-DOPA treatments as determined by DCF fluorescence intensity. Each data point is the average of 12 replicate samples and presented as means ± SD. Standard deviations are indicated by error bars. ***p < 0.001.
Mentions: An interesting phenomenon that was observed in our treatments is the ability of L-DOPA to reverse the effects of H2O2 on cellular morphology and cell viability (Figure 1). This reversal was also observed in terms of ROS where L-DOPA exposure reduced ROS levels, in the presence of H2O2, down to levels observed in control cells (Figure 5). Indeed, all the H2O2-induced protein alterations, affecting the cytoskeleton, were restored to baseline by supplementing the H2O2-containing media with L-DOPA (spots 3, 4, 5, 11, 12 and 13) (Figures 3B, Table 2). Furthermore, the induction of mitochondrial enzymes under oxidative stress condition (fumarate hydratase (spot 1), nucleoside-diphosphate kinase (spot 6) and 3-Hydroxyacyl CoA dehydrogenase (spot 2) was abolished in response to L-DOPA exposure (Table 2).Figure 5

Bottom Line: We observed that oxidative stress affects metabolic pathways as well as cytoskeletal integrity and that neuronal cells respond to oxidative conditions by enhancing numerous survival pathways.Oxidative stress changes neuronal metabolic routes and affects cytoskeletal integrity.Further, L-DOPA appears to reverse some H2O2-mediated effects evident at both the proteome and cellular level.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Sciences, St John's University, New York, NY, USA. mollers@stjohns.edu.

ABSTRACT

Background: Parkinson's disease (PD) is the second most common neurodegenerative movement disorder, caused by preferential dopaminergic neuronal cell death in the substantia nigra, a process also influenced by oxidative stress. L-3,4-dihydroxyphenylalanine (L-DOPA) represents the main treatment route for motor symptoms associated with PD however, its exact mode of action remains unclear. A spectrum of conflicting data suggests that L-DOPA may damage dopaminergic neurons due to oxidative stress whilst other data suggest that L-DOPA itself may induce low levels of oxidative stress, which in turn stimulates endogenous antioxidant mechanisms and neuroprotection.

Results: In this study we performed a two-dimensional gel electrophoresis (2DE)-based proteomic study to gain further insight into the mechanism by which L-DOPA can influence the toxic effects of H2O2 in neuronal cells. We observed that oxidative stress affects metabolic pathways as well as cytoskeletal integrity and that neuronal cells respond to oxidative conditions by enhancing numerous survival pathways. Our study underlines the complex nature of L-DOPA in PD and sheds light on the interplay between oxidative stress and L-DOPA.

Conclusions: Oxidative stress changes neuronal metabolic routes and affects cytoskeletal integrity. Further, L-DOPA appears to reverse some H2O2-mediated effects evident at both the proteome and cellular level.

Show MeSH
Related in: MedlinePlus