Loss of peroxisome proliferator-activated receptor (PPAR)- function in the vascular endothelium enhances atherosclerosis and NF-B target gene expression in high-fat diet-fed apolipoprotein E-deficient mice. aorta compared with the aorta from nontransgenic mice, suggesting that PPAR–mediated protection involves antioxidant effects. IL-1 increased ROS and decreased the phospho-endothelial nitric oxide synthase (Ser1177)-to-endothelial nitric oxide synthase ratio in the nontransgenic aorta. These effects were completely abolished in the aorta with endothelial overexpression of WT PPAR- FK-506 supplier but were worsened in the aorta with E-V290M even in the absence of IL-1. We conclude FK-506 supplier that PPAR- protects against IL-1-mediated endothelial dysfunction through a reduction of oxidative stress responses but not by blunting IL-1-mediated NF-B activity. values were 0.05. RESULTS IL-1 induces NF-B activity and vascular dysfunction. To examine whether IL-1 activates NF-B, isolated aortas from C57BL/6J mice were treated with IL-1 (0.1C100 pg/ml) in vitro, and NF-B activity was examined. IL-1, starting at 5 pg/ml, increased p65 phosphorylation without affecting total expression of p65 and reduced the levels of IB- (Fig. 1and and = 6). All data are means SE. # 0.05 and * 0.01 vs. no treatment. Aortas isolated from C57BL/6J mice were incubated with IL-1 in vitro to determine if IL-1 can induce endothelial dysfunction. IL-1 dose dependently impaired vasodilation to ACh (Fig. 2). IL-1 treatment caused a much smaller decrease in endothelium-independent vasodilation induced by SNP, suggesting possible additional impairment of easy muscle mass function (Fig. 2). KCl and PGF2-induced contraction were not altered by IL-1 at any concentrations (1C500 pg/ml, = 5C6, data not shown). These data show that IL-1 treatment of the aorta ex lover vivo causes endothelial dysfunction. Open in a separate windows Fig. 2. Effect of IL-1 on vascular relaxation. Isometric tension experiments were performed using thoracic aortic rings from C57BL/6J mice treated ex vivo with or without low (1C20 pg/ml; = 5C6. # 0.05 and * 0.01 vs. control. PPAR- in ECs protects against IL-1-induced vascular dysfunction. Next, we investigated whether PPAR- activation can protect against IL-1-induced EC dysfunction. Rosiglitazone, a potent PPAR- agonist, did not FK-506 supplier impact relaxation to ACh or SNP in vehicle-treated aortas from C57BL/6J mice (Fig. 3and = 6C8, 0.05). Consistent with the results from the rosiglitazone experiment, overexpression of WT PPAR- in the endothelium significantly improved ACh-induced relaxation in IL-1 (500 pg/ml)-treated aortas (Fig. 3= 6C8). = 6). = 6). All data are means SE. * 0.01, IL-1 vs. Rosi + IL-1 (= 6, 0.05). In contrast, FK-506 supplier high-dose IL-1 (500 pg/ml) caused an almost total ablation of ACh-induced vasodilation in NT aortas, and this maximal level of dysfunction could not be worsened in aortas from E-V290M mice (maximum relaxation by ACh: ?5.17 9.96% in NT mice and 3.90 6.25% in E-V290M mice, = 3). There were no differences in SNP-induced relaxation (Fig. 4) and KCl-induced contraction (data not shown) between NT and E-V290M mice. These data support the hypothesis that endothelial PPAR- functions to protect against IL-1-induced endothelial dysfunction in the aorta. Open in a separate windows Fig. 4. Vasomotor function with PPAR- interference. Concentration-dependent relaxation to ACh (1 nMC30 M) or SNP (0.1 nMC30 M) in aortas from NT or transgenic mice expressing dominant unfavorable PPAR- Rabbit Polyclonal to KAP1 specifically in the endothelium (E-V290M) is shown. Aortic rings were treated with IL-1 (20 pg/ml) or control for 24 h (= 6). All data are means SE. * 0.01, NT + IL-1 vs. E-V290M + IL-1. NF-B activity does not impact EC dysfunction by IL-1. We showed that IL-1 induces NF-B activity in the aorta (Fig. 1). To determine if IL-1-induced endothelial dysfunction requires activation of NF-B, we used a NF-B p65 inhibitory peptide at a concentration that blunted IL-1 (20 pg/ml)-induced luciferase activity in aortas from NF-B-LUC mice (Fig. 5and = 6, data not shown), suggesting that the protective actions of endothelial PPAR- are not dependent on altering NF-B activity. Consistent with this, endothelium-specific overexpression of WT PPAR- in E-WT mice did not blunt the.