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A novel role for 12/15-lipoxygenase in regulating autophagy.

Morgan AH, Hammond VJ, Sakoh-Nakatogawa M, Ohsumi Y, Thomas CP, Blanchet F, Piguet V, Kiselyov K, O'Donnell VB - Redox Biol (2014)

Bottom Line: Herein, we show that cells deficient in 12/15-LOX contain defective mitochondria and numerous cytoplasmic vacuoles containing electron dense material, indicating defects in autophagy or membrane processing, However, both LC3 expression and lipidation were normal both basally and on chloroquine treatment.A LOX-derived oxidized phospholipid, 12-hydroxyeicosatetraenoic acid-phosphatidylethanolamine (12-HETE-PE) was found to be a preferred substrate for yeast Atg8 lipidation, versus native PE, while both native and oxidized PE were effective substrates for LC3 lipidation.Thus, we show that oxidized phospholipids generated by 12/15-LOX can act as substrates for key proteins required for effective autophagy and that cells deficient in this enzyme show evidence of autophagic dysfunction.

View Article: PubMed Central - PubMed

Affiliation: Institute of Infection and Immunity, School of Medicine, Cardiff University, Cardiff CF14 4XN, UK.

No MeSH data available.


Lipidomic profiling reveals altered phospholipid and cholesteryl esters in 12/15-LOX deficiency. Lipids were extracted from macrophages, and analyzed as described in Section “Materials and methods” (n=8, mean±S.E.). *Student's t-test, p<0.05. The overall differences between WT and 12/15-LOX data sets is significant following analysis by one-way ANOVA with a Tukey' post-hoc test, p<0.05 (except for cholesteryl esters).
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f0015: Lipidomic profiling reveals altered phospholipid and cholesteryl esters in 12/15-LOX deficiency. Lipids were extracted from macrophages, and analyzed as described in Section “Materials and methods” (n=8, mean±S.E.). *Student's t-test, p<0.05. The overall differences between WT and 12/15-LOX data sets is significant following analysis by one-way ANOVA with a Tukey' post-hoc test, p<0.05 (except for cholesteryl esters).

Mentions: Next, the ability of HETE-PE to act as a substrate for the mammalian LC3 was tested using recombinant proteins. In these experiments, it was initially seen that 55 mol% SAPE and HETE-PE were similarly conjugated over 30 min (Fig. 2B, left panel). Thus, we also tested a lower substrate concentration (10 mol% PE) and shorter time course, in case the enzyme system was already saturated, but no differences were found between the lipids (Fig. 2B, right panel). DOPE conjugation to LC3 is shown as comparison (Fig. 3B). The results demonstrate that oxidized PE is an effective substrate for LC3 lipidation, although in this case, it is equally effective as the unoxidized parent lipid.


A novel role for 12/15-lipoxygenase in regulating autophagy.

Morgan AH, Hammond VJ, Sakoh-Nakatogawa M, Ohsumi Y, Thomas CP, Blanchet F, Piguet V, Kiselyov K, O'Donnell VB - Redox Biol (2014)

Lipidomic profiling reveals altered phospholipid and cholesteryl esters in 12/15-LOX deficiency. Lipids were extracted from macrophages, and analyzed as described in Section “Materials and methods” (n=8, mean±S.E.). *Student's t-test, p<0.05. The overall differences between WT and 12/15-LOX data sets is significant following analysis by one-way ANOVA with a Tukey' post-hoc test, p<0.05 (except for cholesteryl esters).
© Copyright Policy - CC BY
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4309860&req=5

f0015: Lipidomic profiling reveals altered phospholipid and cholesteryl esters in 12/15-LOX deficiency. Lipids were extracted from macrophages, and analyzed as described in Section “Materials and methods” (n=8, mean±S.E.). *Student's t-test, p<0.05. The overall differences between WT and 12/15-LOX data sets is significant following analysis by one-way ANOVA with a Tukey' post-hoc test, p<0.05 (except for cholesteryl esters).
Mentions: Next, the ability of HETE-PE to act as a substrate for the mammalian LC3 was tested using recombinant proteins. In these experiments, it was initially seen that 55 mol% SAPE and HETE-PE were similarly conjugated over 30 min (Fig. 2B, left panel). Thus, we also tested a lower substrate concentration (10 mol% PE) and shorter time course, in case the enzyme system was already saturated, but no differences were found between the lipids (Fig. 2B, right panel). DOPE conjugation to LC3 is shown as comparison (Fig. 3B). The results demonstrate that oxidized PE is an effective substrate for LC3 lipidation, although in this case, it is equally effective as the unoxidized parent lipid.

Bottom Line: Herein, we show that cells deficient in 12/15-LOX contain defective mitochondria and numerous cytoplasmic vacuoles containing electron dense material, indicating defects in autophagy or membrane processing, However, both LC3 expression and lipidation were normal both basally and on chloroquine treatment.A LOX-derived oxidized phospholipid, 12-hydroxyeicosatetraenoic acid-phosphatidylethanolamine (12-HETE-PE) was found to be a preferred substrate for yeast Atg8 lipidation, versus native PE, while both native and oxidized PE were effective substrates for LC3 lipidation.Thus, we show that oxidized phospholipids generated by 12/15-LOX can act as substrates for key proteins required for effective autophagy and that cells deficient in this enzyme show evidence of autophagic dysfunction.

View Article: PubMed Central - PubMed

Affiliation: Institute of Infection and Immunity, School of Medicine, Cardiff University, Cardiff CF14 4XN, UK.

No MeSH data available.