12-hydroxy-5-8-10-14-eicosatetraenoic-acid and Hyperplasia

We showed recently that IL-4 causes mitochondrial dysfunction in allergic asthma. IL-4 is also known to induce 12/15-lipoxygenase (12/15-LOX), a potent candidate molecule in asthma. Because vitamin E (Vit-E) reduces IL-4 and inhibits 12/15-LOX in vitro, here we tested the hypothesis that Vit-E may be effective in restoring key mitochondrial dysfunctions, thus alleviating asthma features in an experimental allergic murine model. Ovalbumin (OVA)-sensitized and challenged male BALB/c mice showed the characteristic features of asthma such as airway hyperresponsiveness (AHR), airway inflammation, and airway remodeling. In addition, these mice showed increase in the expression and metabolites of 12/15-LOX, reduction in the activity and expression of the third subunit of mitochondrial cytochrome-c oxidase, and increased cytochrome c in lung cytosol, which indicate that OVA sensitization and challenge causes mitochondrial dysfunction. Vit-E was administered orally to these mice, and 12/15-LOX expression, key mitochondrial functions, ultrastructural changes of mitochondria in bronchial epithelia, and asthmatic parameters were determined. Vit-E treatment reduced AHR, Th2 response including IL-4, IL-5, IL-13, and OVA-specific IgE, eotaxin, transforming growth factor-beta1, airway inflammation, expression and metabolites of 12/15-LOX in lung cytosol, lipid peroxidation, and nitric oxide metabolites in the lung, restored the activity and expression of the third subunit of cytochrome-c oxidase in lung mitochondria and bronchial epithelia, respectively, reduced the appearance of cytochrome c in lung cytosol, and also restored mitochondrial ultrastructural changes of bronchial epithelia. In summary, these findings show that Vit-E reduces key mitochondrial dysfunctions and alleviates asthmatic features.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Airway Remodeling; Animals; Anti-Asthmatic Agents; Arachidonate 12-Lipoxygenase; Arachidonate 15-Lipoxygenase; Asthma; Bronchial Hyperreactivity; Bronchial Provocation Tests; Cytochromes c; Disease Models, Animal; Electron Transport Complex IV; Goblet Cells; Hyperplasia; Hypersensitivity; Immunoglobulin E; Interleukin-13; Interleukin-4; Interleukin-5; Linoleic Acids; Lung; Male; Mice; Mice, Inbred BALB C; Mitochondria; Ovalbumin; Oxidative Stress; Pulmonary Fibrosis; Transforming Growth Factor beta1; Vitamin E

The efficacy of OPC-29030, a newly developed inhibitor of 12(S)-hydroxyeicosatetraenoic acid (12-HETE) production, was evaluated on intimal hyperplasia of experimental autologous vein grafts in a distal poor-runoff model and a hyperlipidemic model in rabbits. First, rabbits were divided into two groups, the distal poor-runoff group (PR group) and the hyperlipidemic group (HL group). After 4 weeks preparing the PR model and the HL model, the femoral vein was implanted into the ipsilateral femoral artery. Then they were subdivided into two groups, depending on the diet provided; diet group with 0.1% OPC-29030 (OPC-29030 group) and normal diet group (control group). At 4 weeks, the grafts were harvested, and intimal hyperplasia of the graft was measured with an ocular cytometer. Intimal cell proliferation was determined by bromodeoxyuridine (BrdU) incorporation at 2 weeks after surgery. In addition, the effect of OPC-29030 on the proliferation or migration of rat aortic smooth muscle cells in culture was investigated. In the in vivo study in the PR group, the intimal hyperplasia and the plasma 12-HETE levels in the OPC-29030 group were significantly inhibited, compared with those of the control group. However, in the HL group, the intimal hyperplasia in both the OPC-29030 and control groups showed a remarkable degree of intimal hyperplasia. There was no significant difference between those two groups. Furthermore, there was no significant difference in the plasma 12-HETE levels in the HL group irrespective of the presence of OPC-29030. The BrdU labeling index at 2 weeks after grafting was significantly lower in the OPC-29030 group compared with that in the control group in the PR group. In the in vitro study, OPC-29030 did not inhibit smooth muscle cell proliferation; however, OPC-29030 inhibited the migration. These results demonstrate the efficacy of OPC-29030 in reducing the degree of intimal hyperplasia under PR conditions, but not under hyperlipidemic conditions. The mechanism of reducing the intimal hyperplasia may be that OPC-29030 inhibited 12-HETE production, which did not inhibit proliferation while inhibiting migration of the smooth muscle cell. These results suggested the possible involvement of 12-HETE with the intimal hyperplasia under PR conditions.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; 6-Ketoprostaglandin F1 alpha; Animals; Cells, Cultured; Cholesterol; Femoral Vein; Graft Survival; Hypercholesterolemia; Hyperplasia; Imidazoles; Male; Muscle, Smooth, Vascular; Platelet Aggregation Inhibitors; Quinolones; Rabbits; Rats; Sulfur Compounds; Thromboxane B2; Tunica Intima

Aspirin is frequently used after vascular reconstruction to pharmacologically prevent graft occlusion and to suppress the development of myointimal hyperplasia in vascular surgery, but its efficacy is controversial. The purpose of this study was to examine the direct effects of aspirin on platelet-derived growth factor (PDGF)-induced vascular smooth muscle cell (SMC) proliferation.. Human aortic SMCs were grown to confluence in 96 well plates. 3 x 10(-5) mol/L aspirin was added 24 hours previously and PDGF 10 ng/ml at the beginning of each experiment. Cell proliferation at 48 hours was determined using tritiated thymidine uptake. Supernatant 12-L-hydroxy 5,8,10,14-eicosatetraenoic acid (12-HETE) and prostaglandin E2 (PGE2) were measured by competitive enzyme immunoassay.. Aspirin did not change vascular SMC proliferation rates relative to controls (4665 +/- 181 counts per minute [CPM] vs 4749 +/- 155 CPM). However, aspirin pretreatment of PDGF-stimulated vascular SMCs increased proliferation (9408 +/- 237 CPM vs 7283 +/- 283 CPM; p < 0.001). 5,8,10,14-eicosatriynoic acid, a 12-lipoxygenase inhibitor, decreased basal (2037 +/- 181 CPM vs 2306 +/- 158 CPM; p < 0.05) and PDGF-stimulated vascular SMC proliferation (4909 +/- 1089 CPM vs 4310 +/- 1022 CPM; p < 0.001). Aspirin increased supernatant 12-HETE levels and decreased PGE2 levels in both basal and PDGF-stimulated cell cultures.. Aspirin enhances PDGF-stimulated vascular SMC proliferation. The effects of aspirin on vascular SMC proliferation may be mediated by changes in vascular SMC arachidonic acid metabolism.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Aorta; Arachidonate 12-Lipoxygenase; Arachidonic Acids; Aspirin; Cell Division; Cells, Cultured; Cyclooxygenase Inhibitors; Dinoprostone; Drug Synergism; Graft Occlusion, Vascular; Humans; Hyperplasia; Multivariate Analysis; Muscle, Smooth, Vascular; Platelet Aggregation Inhibitors; Platelet-Derived Growth Factor; Regression Analysis; Thymidine; Tritium; Tunica Intima; Vascular Surgical Procedures