Activation of PPARγ by 12/15-lipoxygenase during cerebral ischemia-reperfusion injury.
Peroxisome proliferator-activated receptor γ (PPARγ) expression and activity are increased in brain ischemic injury and its agonists have shown potential for brain injury protection. The influence of 12/15-lipoxygenase (12/15-LOX) on the activity of PPARγ in oxygen-glucose deprivation (OGD) and ischemia-reperfusion (I/R) was investigated. A middle cerebral artery occlusion/reperfusion model with Sprague Dawley (SD) rats was established. For I/R intervention, the rats were treated with the 12/15-LOX-derived product 12-hydroxyeicosatetraenoic acid (12-HETE) for 30 min before cerebral artery occlusion. Primary cortical neurons from SD rats were used to establish an OGD cell model. 12-HETE or a 12/15-LOX antisense oligonucleotide (asON-12/15-LOX) was added to OGD-treated neurons. Western blots, immunofluorescence and enzyme-linked immunosorbent assays detected protein. Reverse transcription-polymerase chain reaction analyzed the expression of the PPARγ target genes. PPARγ-DNA binding activity was determined by peroxisome proliferator responsive element luciferase reporter vectors. 12/15-LOX total protein increased significantly with I/R, and expression of 12-HETE was also upregulated. 12-HETE treatment increased PPARγ protein expression and inhibited inducible nitric oxide synthase protein expression, which was upregulated with I/R. PPARγ nuclear protein and 12/15-LOX total protein expression in OGD-treated neurons increased significantly. 12-HETE treatment increased the expression of PPARγ nuclear protein, upregulated the mRNA levels of PPARγ target genes (lipoprotein lipase and acyl-CoA oxidase) and enhanced PPARγ-DNA binding activity. asON-12/15-LOX treatment inhibited 12/15-LOX and PPARγ protein expression and lipoprotein lipase mRNA. Cerebral I/R injury in rats and OGD treatment in neurons promoted 12/15-LOX expression, and 12-HETE activated PPARγ. Therefore, PPARγ can be activated by the 12/15-LOX pathway during cerebral I/R injury.
Department of Neurology, Tianjin Neurology Institute, Tianjin Medical University General Hospital, Tianjin, P.R. China.
Jing
J
Han
Tianjin Neurology Institute, Tianjin Medical University General Hospital, Tianjin, P.R. China.
Li
L
Sun
Department of Neurology, Tianjin Neurology Institute, Tianjin Medical University General Hospital, Tianjin, P.R. China.
Yanwei
Y
Xu
Tianjin Neurology Institute, Tianjin Medical University General Hospital, Tianjin, P.R. China.
Hao
H
Liang
Department of Neurology, Tianjin Neurology Institute, Tianjin Medical University General Hospital, Tianjin, P.R. China.
Yan
Y
Cheng
D000818:Animals; D001092:Arachidonate 12-Lipoxygenase / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D001093:Arachidonate 15-Lipoxygenase / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D002540:Cerebral Cortex / Q000098:blood supply / Q000378:metabolism* / Q000473:pathology*; D004195:Disease Models, Animal; D004789:Enzyme Activation; D015870:Gene Expression; D005947:Glucose / Q000378:metabolism; D020244:Infarction, Middle Cerebral Artery / Q000150:complications; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000235:genetics / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D047495:PPAR gamma / Q000378:metabolism*; D011485:Protein Binding; D021381:Protein Transport; D051381:Rats; D015427:Reperfusion Injury / Q000209:etiology / Q000378:metabolism*
C475064:12-15-lipoxygenase; D047495:PPAR gamma; D001092:Arachidonate 12-Lipoxygenase; D001093:Arachidonate 15-Lipoxygenase; D052247:Nitric Oxide Synthase Type II; D005947:Glucose; D010100:Oxygen