Limits...
Loss of PLA2G6 leads to elevated mitochondrial lipid peroxidation and mitochondrial dysfunction.

Kinghorn KJ, Castillo-Quan JI, Bartolome F, Angelova PR, Li L, Pope S, Cochemé HM, Khan S, Asghari S, Bhatia KP, Hardy J, Abramov AY, Partridge L - Brain (2015)

Bottom Line: Furthermore, we demonstrate that loss of iPLA2-VIA function leads to a number of mitochondrial abnormalities, including mitochondrial respiratory chain dysfunction, reduced ATP synthesis and abnormal mitochondrial morphology.Moreover, we show that loss of iPLA2-VIA is strongly associated with increased lipid peroxidation levels.Similar abnormalities were seen including elevated mitochondrial lipid peroxidation and mitochondrial membrane defects, as well as raised levels of cytoplasmic and mitochondrial reactive oxygen species.

View Article: PubMed Central - PubMed

Affiliation: 1 Institute of Healthy Ageing and Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK 2 Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK k.kinghorn@ucl.ac.uk.

Show MeSH

Related in: MedlinePlus

Elevated lipid peroxidation is a possible therapeutic target in PLA2G6-associated disease. (A) Lipid peroxidation levels in intact human fibroblasts taken from two patients with PLA2G6 mutations (mutant 1 fibroblasts were taken from a patient with a p.R747W PLA2G6 mutation and mutant 2 fibroblasts were from a patient with a PLA2G6 mutation and infantile neuroaxonal dystrophy) are increased compared with fibroblasts from healthy controls. In addition, pretreatment with D-PUFAs (D4-linoleic acid) for 24 h significantly rescues the elevated lipid peroxidation rates in the human PLA2G6 mutant fibroblasts (***P < 0.0001; n.s = non-significant). (B) The mitochondrial membrane potential of human mutant PLA2G6 fibroblasts is considerably reduced compared with control fibroblasts and is significantly recovered below control levels following 24 h pre-treatment with D4-linoleic acid (***P < 0.0001). (C) Lipid peroxidation levels are also increased in permeabilized mutant p.R747W PLA2G6 fibroblasts compared with controls in the absence (***P < 0.05 for control 1 and control 2) and presence of rotenone (***P < 0.05 for controls 1 and 2), suggesting that it is generated from a mitochondrial source. (D) Treatment of iPLA2-VIA−/− flies with 10 μM D2-linoleic acid partially rescues the climbing deficits in an age-dependent manner compared with untreated controls (n = 45 flies per group, three repeats per group; one-way ANOVA with Bonferroni correction ***P < 0.003). There is a trend for 100 μM D2-linoleic acid to rescue the climbing deficits of iPLA2-VIA−/− flies but this is not statistically significant. (E) Schematic diagram showing how loss of normal PLA2G6 activity might lead to mitochondrial dysfunction. A mutation in PLA2G6 results in loss of PLA2G6 activity. In turn this results in elevated lipid peroxidation of mitochondria, with the resultant decrease in mitochondrial membrane potential, decrease in ATP synthesis and mitochondrial reactive oxygen species production. The mitochondria eventually degenerate and become swollen in appearance. All of these abnormalities result in mitochondrial dysfunction and subsequent cellular dysfunction with consequent neuronal death. NBIA = neurodegeneration with brain iron accumulation; ROS = reactive oxygen species.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4559908&req=5

awv132-F7: Elevated lipid peroxidation is a possible therapeutic target in PLA2G6-associated disease. (A) Lipid peroxidation levels in intact human fibroblasts taken from two patients with PLA2G6 mutations (mutant 1 fibroblasts were taken from a patient with a p.R747W PLA2G6 mutation and mutant 2 fibroblasts were from a patient with a PLA2G6 mutation and infantile neuroaxonal dystrophy) are increased compared with fibroblasts from healthy controls. In addition, pretreatment with D-PUFAs (D4-linoleic acid) for 24 h significantly rescues the elevated lipid peroxidation rates in the human PLA2G6 mutant fibroblasts (***P < 0.0001; n.s = non-significant). (B) The mitochondrial membrane potential of human mutant PLA2G6 fibroblasts is considerably reduced compared with control fibroblasts and is significantly recovered below control levels following 24 h pre-treatment with D4-linoleic acid (***P < 0.0001). (C) Lipid peroxidation levels are also increased in permeabilized mutant p.R747W PLA2G6 fibroblasts compared with controls in the absence (***P < 0.05 for control 1 and control 2) and presence of rotenone (***P < 0.05 for controls 1 and 2), suggesting that it is generated from a mitochondrial source. (D) Treatment of iPLA2-VIA−/− flies with 10 μM D2-linoleic acid partially rescues the climbing deficits in an age-dependent manner compared with untreated controls (n = 45 flies per group, three repeats per group; one-way ANOVA with Bonferroni correction ***P < 0.003). There is a trend for 100 μM D2-linoleic acid to rescue the climbing deficits of iPLA2-VIA−/− flies but this is not statistically significant. (E) Schematic diagram showing how loss of normal PLA2G6 activity might lead to mitochondrial dysfunction. A mutation in PLA2G6 results in loss of PLA2G6 activity. In turn this results in elevated lipid peroxidation of mitochondria, with the resultant decrease in mitochondrial membrane potential, decrease in ATP synthesis and mitochondrial reactive oxygen species production. The mitochondria eventually degenerate and become swollen in appearance. All of these abnormalities result in mitochondrial dysfunction and subsequent cellular dysfunction with consequent neuronal death. NBIA = neurodegeneration with brain iron accumulation; ROS = reactive oxygen species.

Mentions: Following the demonstration that there is an increase in lipid peroxidation in the brains of flies lacking iPLA2-VIA compared with controls, we also assessed lipid peroxidation in two human PLA2G6 fibroblast lines; one taken from a patient with dystonia-parkinsonism with a p.R747W mutation (Paisan-Ruiz et al., 2009) and the other from a child with infantile neuroaxonal dystrophy. We assessed lipid peroxidation levels using the fluorescent ratiometric oxidation-sensitive C11 BODIPY581/591 dye. This demonstrated that PLA2G6 mutant fibroblasts had an increased level of lipid peroxidation compared to controls (Fig. 7A), suggesting therefore that lipid peroxides may be a potential therapeutic target.Figure 7


Loss of PLA2G6 leads to elevated mitochondrial lipid peroxidation and mitochondrial dysfunction.

Kinghorn KJ, Castillo-Quan JI, Bartolome F, Angelova PR, Li L, Pope S, Cochemé HM, Khan S, Asghari S, Bhatia KP, Hardy J, Abramov AY, Partridge L - Brain (2015)

Elevated lipid peroxidation is a possible therapeutic target in PLA2G6-associated disease. (A) Lipid peroxidation levels in intact human fibroblasts taken from two patients with PLA2G6 mutations (mutant 1 fibroblasts were taken from a patient with a p.R747W PLA2G6 mutation and mutant 2 fibroblasts were from a patient with a PLA2G6 mutation and infantile neuroaxonal dystrophy) are increased compared with fibroblasts from healthy controls. In addition, pretreatment with D-PUFAs (D4-linoleic acid) for 24 h significantly rescues the elevated lipid peroxidation rates in the human PLA2G6 mutant fibroblasts (***P < 0.0001; n.s = non-significant). (B) The mitochondrial membrane potential of human mutant PLA2G6 fibroblasts is considerably reduced compared with control fibroblasts and is significantly recovered below control levels following 24 h pre-treatment with D4-linoleic acid (***P < 0.0001). (C) Lipid peroxidation levels are also increased in permeabilized mutant p.R747W PLA2G6 fibroblasts compared with controls in the absence (***P < 0.05 for control 1 and control 2) and presence of rotenone (***P < 0.05 for controls 1 and 2), suggesting that it is generated from a mitochondrial source. (D) Treatment of iPLA2-VIA−/− flies with 10 μM D2-linoleic acid partially rescues the climbing deficits in an age-dependent manner compared with untreated controls (n = 45 flies per group, three repeats per group; one-way ANOVA with Bonferroni correction ***P < 0.003). There is a trend for 100 μM D2-linoleic acid to rescue the climbing deficits of iPLA2-VIA−/− flies but this is not statistically significant. (E) Schematic diagram showing how loss of normal PLA2G6 activity might lead to mitochondrial dysfunction. A mutation in PLA2G6 results in loss of PLA2G6 activity. In turn this results in elevated lipid peroxidation of mitochondria, with the resultant decrease in mitochondrial membrane potential, decrease in ATP synthesis and mitochondrial reactive oxygen species production. The mitochondria eventually degenerate and become swollen in appearance. All of these abnormalities result in mitochondrial dysfunction and subsequent cellular dysfunction with consequent neuronal death. NBIA = neurodegeneration with brain iron accumulation; ROS = reactive oxygen species.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4559908&req=5

awv132-F7: Elevated lipid peroxidation is a possible therapeutic target in PLA2G6-associated disease. (A) Lipid peroxidation levels in intact human fibroblasts taken from two patients with PLA2G6 mutations (mutant 1 fibroblasts were taken from a patient with a p.R747W PLA2G6 mutation and mutant 2 fibroblasts were from a patient with a PLA2G6 mutation and infantile neuroaxonal dystrophy) are increased compared with fibroblasts from healthy controls. In addition, pretreatment with D-PUFAs (D4-linoleic acid) for 24 h significantly rescues the elevated lipid peroxidation rates in the human PLA2G6 mutant fibroblasts (***P < 0.0001; n.s = non-significant). (B) The mitochondrial membrane potential of human mutant PLA2G6 fibroblasts is considerably reduced compared with control fibroblasts and is significantly recovered below control levels following 24 h pre-treatment with D4-linoleic acid (***P < 0.0001). (C) Lipid peroxidation levels are also increased in permeabilized mutant p.R747W PLA2G6 fibroblasts compared with controls in the absence (***P < 0.05 for control 1 and control 2) and presence of rotenone (***P < 0.05 for controls 1 and 2), suggesting that it is generated from a mitochondrial source. (D) Treatment of iPLA2-VIA−/− flies with 10 μM D2-linoleic acid partially rescues the climbing deficits in an age-dependent manner compared with untreated controls (n = 45 flies per group, three repeats per group; one-way ANOVA with Bonferroni correction ***P < 0.003). There is a trend for 100 μM D2-linoleic acid to rescue the climbing deficits of iPLA2-VIA−/− flies but this is not statistically significant. (E) Schematic diagram showing how loss of normal PLA2G6 activity might lead to mitochondrial dysfunction. A mutation in PLA2G6 results in loss of PLA2G6 activity. In turn this results in elevated lipid peroxidation of mitochondria, with the resultant decrease in mitochondrial membrane potential, decrease in ATP synthesis and mitochondrial reactive oxygen species production. The mitochondria eventually degenerate and become swollen in appearance. All of these abnormalities result in mitochondrial dysfunction and subsequent cellular dysfunction with consequent neuronal death. NBIA = neurodegeneration with brain iron accumulation; ROS = reactive oxygen species.
Mentions: Following the demonstration that there is an increase in lipid peroxidation in the brains of flies lacking iPLA2-VIA compared with controls, we also assessed lipid peroxidation in two human PLA2G6 fibroblast lines; one taken from a patient with dystonia-parkinsonism with a p.R747W mutation (Paisan-Ruiz et al., 2009) and the other from a child with infantile neuroaxonal dystrophy. We assessed lipid peroxidation levels using the fluorescent ratiometric oxidation-sensitive C11 BODIPY581/591 dye. This demonstrated that PLA2G6 mutant fibroblasts had an increased level of lipid peroxidation compared to controls (Fig. 7A), suggesting therefore that lipid peroxides may be a potential therapeutic target.Figure 7

Bottom Line: Furthermore, we demonstrate that loss of iPLA2-VIA function leads to a number of mitochondrial abnormalities, including mitochondrial respiratory chain dysfunction, reduced ATP synthesis and abnormal mitochondrial morphology.Moreover, we show that loss of iPLA2-VIA is strongly associated with increased lipid peroxidation levels.Similar abnormalities were seen including elevated mitochondrial lipid peroxidation and mitochondrial membrane defects, as well as raised levels of cytoplasmic and mitochondrial reactive oxygen species.

View Article: PubMed Central - PubMed

Affiliation: 1 Institute of Healthy Ageing and Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK 2 Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK k.kinghorn@ucl.ac.uk.

Show MeSH
Related in: MedlinePlus