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TNF-[alpha] is a proinflammatory cytokine and is an important mediator of maternal endothelial dysfunction leading to preeclampsia. In this study, we tested whether IL-10 protects against TNF-[alpha]-induced endothelial dysfunction in murine aorta. In in vitro experiments, aortic rings of C57BL/6 female mice were incubated in Dulbecco's modified Eagle's medium in the presence of either vehicle (distilled [H.sub.2]O), TNF-[alpha] (4 nmol/1), or recombinant mouse IL-10 (300 ng/ml) or in the presence of both TNF-[alpha] and IL-10 for 22 h at 37[degrees]C. In in vivo experiments C57BL6/IL-10 knockout female mice were treated with saline or TNF-[alpha] (220 ng x [kg.sup.-1] x [day.sup.-1]) for 14 days. Aortic rings were isolated from in vitro and in vivo experiments and mounted in a wire myograph (Danish Myotech) and stretched to a tension of 5 mN. Endothelium-dependent relaxation was assessed by constructing cumulative concentration-response curves to acetylcholine (ACh, 0.001-10 [micro]mol/l) during phenylephrine (10 [micro]mol/l)-induced contraction. As a result, overnight exposure of aortic rings to TNF-[alpha] resulted in significant blunted maximal relaxing responses ([E.sub.max]) to ACh compared with untreated rings (22 [+ or -] 4 vs. 82 [+ or -] 3%, respectively). IL-10 knockout mice treated with TNF-[alpha] showed significant impairment in ACh responses ([E.sub.max]) compared with C57BL/6 mice treated with TNF-[alpha] (51 [+ or -] 3 vs. 72 [+ or -] 3%, respectively). Western blot analysis showed that endothelial nitric oxide synthase (eNOS) expression was reduced by TNF-[alpha] in in vitro and in vivo experiments, whereas IL-10 restored the eNOS expression. In conclusion, the anti-inflammatory cytokine IL-10 prevents impairment in endothelium-dependent vasorelaxation caused by TNF-[alpha] by protecting eNOS expression. tumor necrosis factor-[alpha]; nuclear factor-[kappa]B doi: 10.1152/ajpheart.00763.2009.

Interleukin-10 (IL-10) is an anti-inflammatory cytokine with protective actions on the vasculature. On the other hand, endothelin (ET)-I has potent vasoconstrictor, mitogenic, and proinflammatory activities, which have been implicated in the pathophysiology of a number of cardiovascular diseases. We hypothesized that, in a condition where ET-1 expression is upregulated, i.e., on infusion of TNF-[alpha], IL-10 confers vascular protection from ET-1-induced injury. Aortic rings and first-order mesenteric arteries from male C57BL/6 (WT) and IL-10-knockout (IL-10 -/- ) mice were treated with human recombinant TNF-[alpha] (220 ng x [kg.sup.-1] x [day.sup.-l]) or vehicle (saline) for 14 days. TNF-[alpha] infusion significantly increased blood pressure in IL-[10.sup.-/-], but not WT, mice. TNF-[alpha] augmented vascular ET-1 mRNA expression in arteries from WT and IL-[10.sup.-/-] mice. ET type A (ETA) receptor expression was increased in arteries from IL-[10.sup.-/-] mice, and TNF-[alpha] infusion did not change vascular ETA receptor expression in control or IL-[10.sup.-/-] mice. Aorta and mesenteric arteries from TNF[alpha]-infused IL-[10.sup.-/-] mice displayed increased contractile responses to ET-1, but not the ET type B receptor agonist IRL-1620. The ETA receptor antagonist atrasentan completely abolished responses to ET-1 in aorta and mesenteric vessels, whereas the ERK1/2 inhibitor PD98059 abrogated increased contractions to ET-1 in arteries from TNF-[alpha]-infused IL-[10.sup.-/-] mice. Infusion of TNF-[alpha], as well as knockdown of IL-10 (IL-[10.sup.-/-]), induced an increase in total and phosphorylated ERK1/2. These data demonstrate that [L-10 counteracts ETAmediated vascular responses to ET-1, as well as activation of the ERK1/2 pathway. tumor necrosis factor-[alpha]; vascular reactivity; blood pressure

Abstract: Endothelin-1 (ET-1) is implicated in the development of endothelial dysfunction through the generation of reactive oxygen species by NADPH oxidase activation. Interleukin-10 (IL-10) is an antiinflammatory cytokine that stimulates [...]

ANG II stimulates the production of reactive oxygen species and activates proinflammatory cytokines leading to endothelial dysfunction. We hypothesized that the anti-inflammatory cytokine IL-10 counteracts the impairment in endothelium-dependent ACh relaxation caused by ANG II. Aortic rings of C57BL/6 mice were incubated in DMEM in the presence of vehicle (deionized H20), ANG II (100 nmol/l), recombinant mouse IL-10 (300 ng/ml), or both ANG II and IL-10 for 22 h at 37 [degrees]C. After incubation, rings were mounted in a wire myograph to assess endothelium-dependent vasorelaxation to cumulative concentrations of ACh. Overnight exposure of aortic tings to ANG II resulted in blunted ACh-induced vasorelaxation compared with that shown in untreated rings (maximal response = 44 [+ or -] 3% vs. 64 [+ or -] 3%, respectively; P < 0.05). IL-10 treatment significantly restored this impairment in relaxation (63 [+ or -] 2%). In addition, the NADPH oxidase inhibitor apocynin restored the impairment in relaxation (maximal response = 76 [+ or -] 3%). Western blotting showed increased gp[91.sup.phox] expression (a subunit of NADPH oxidase) in response to ANG II. Vessels treated with a combination of ANG II and IL-10 showed decreased expression of gp[91.sup.phox]. Immunohistochemical analysis showed increased gp[91.sup.phox] expression in ANG II-treated vessels compared with those treated with combined ANG II and IL-10. We found that the anti-inflammatory cytokine IL-10 prevents impairment in endothelium-dependent vasorelaxation in response to long-term incubation with ANG II via decreasing NADPH oxidase expression. NADPH oxidase doi: 10.1152/ajpheart.00456.2006

BackgroundBAY 41-2272 (5-cyclopropyl-2-[1-(2-fluoro-benzyl)-1H-pyrazolo[3,4-b]pyridin-3-yl]-pyrimidin-4-ylamine) relaxes mesenteric arteries (MA) in a synergistic fashion with nitric oxide (NO). We hypothesized that the relaxation to BAY 41-2272 is decreased in spontaneously hypertensive rats (SHR) because of the reduced NO bioavailability in this strain and that relaxation would be improved by inhibiting the oxidative stress. We aimed to evaluate the influence of oxidative stress in BAY 41-2272-induced vasorelaxation in isolated MA from SHR.MethodsMA function was evaluated by concentration-response curves to BAY 41-2272. We measured protein expression of endothelial NO synthase (eNOS), soluble guanylyl cyclase (sGC) and human-antigen R (HuR) (sGC mRNA-stabilizing protein), sGC activity and plasma levels of superoxide dismutase (SOD), and total antioxidant status (TAS).ResultsCyclic guanosine monophosphate (cGMP)-dependent and -independent relaxation induced by BAY 41-2272 (0.0001–1 µmol/l) was impaired in SHR compared with Wistar-Kyoto (WKY). We observed reduced expression of eNOS, sGC and HuR, and decreased sGC activity in SHR. Plasma levels of SOD and TAS were also diminished in SHR. Incubation with SOD or indomethacin increased relaxation to BAY 41-2272 in SHR. Furthermore, acetylcholine (ACh)-induced relaxation was increased in the presence of BAY 41-2272 or SOD, apocynin, or indomethacin.ConclusionAugmented oxidative stress in SHR impaired cGMP-dependent and -independent relaxation induced by BAY 41-2272, by decreasing NO bioavailability and sGC expression and by increasing contractile activity. Inhibiton of oxidative stress improved the relaxation of BAY 41-2272 in SHR. BAY 41-2272 might be an alternative therapeutic tool for hypertension if administrated with antioxidant compounds.American Journal of Hypertension 2009; doi:10.1038/ajh.2009.18American Journal of Hypertension (2009); 22, 5, 493–499. doi:10.1038/ajh.2009.18 [ABSTRACT FROM AUTHOR]