Objective-Resveratrol (3,5,4Ј-trihydroxystilbene), a polyphenol found in red wine, is known to activate sirtuin1 (SIRT1), a longevity gene. Previous studies have demonstrated that resveratrol extends the life span of diverse species through activation of SIRT1. It was also reported that inhibition of angiotensin II function by angiotensin II type I receptor (AT1R) antagonist prolonged rat life span. We, therefore, hypothesized that resveratrol may inhibit the renin-angiontein system and examined whether resveratrol affects AT1R expression in vascular smooth muscle cells (VSMCs). Methods and Results-Northern and Western blot analysis revealed that resveratrol significantly decreased the expression of AT1R at mRNA and protein levels in a dose-and time-dependent manner. Overexpression of SIRT1 reduced AT1R expression whereas nicotinamide, an inhibitor of SIRT1, increased AT1R expression and reversed the resveratrolinduced AT1R downregulation. AT1R gene promoter activity was decreased by resveratrol, but resveratrol did not affect the AT1R mRNA stability. Deletion analysis showed that the most proximal region of AT1R gene promoter containing Sp1 site is responsible for downregulation. Administration of resveratrol suppressed AT1R expression in the mouse aorta and blunted angiotensin II-induced hypertension. Conclusion-Resveratrol suppressed AT1R expression through SIRT1 activation both in vivo and in vitro. The inhibition of the renin-angiotensin system may contribute, at least in part, to the resveratrol-induced longevity and antiatherogenic effect of resveratrol.

Our data provides a novel insight into an effect of telmisartan: telmisartan inhibits AT1R gene expression through PPARgamma activation. The dual inhibition of angiotensin II function by telmisartan - AT1R blockade and downregulation - would contribute to more complete inhibition of the renin-angiotensin system.

Objective-Prolyl hydroxylase domain-containing proteins (PHDs) play pivotal roles in oxygen-sensing system through the regulation of ␣-subunit of hypoxia-inducible factor (HIF), a key transcription factor governing a large set of gene expression to adapt hypoxia. Although tissue hypoxia plays an essential role in maintaining inflammation, the role of PHDs in the inflammatory responses has not been clearly determined. Here, we investigated the role of PHDs in lipopolysaccharide (LPS)-induced tumor necrosis factor ␣ (TNF-␣) induction in macrophages. Methods and Results-Northern blot analysis and ELISA revealed that LPS-induced TNF-␣ upregulation was strongly suppressed by PHD inhibitors, dimethyloxallyl glycine (DMOG), and TM6008 in RAW264.7 macrophages. DMOG suppressed LPS-induced TNF-␣ upregulation in HIF-1␣-depleted cells and HIF-1␣ overexpression failed to suppress the induction of TNF-␣. DMOG rather suppressed LPS-induced NF-B transcriptional activity. Downregulation of Phd1 or Phd2 mRNA by RNA interference partially attenuated LPS-induced TNF-␣ induction. DMOG also inhibited LPS-induced TNF-␣ production in peritoneal macrophages as well as human macrophages. Conclusions-PHD inhibition by DMOG or RNA interference inhibited LPS-induced TNF-␣ upregulation in macrophages possibly through NF-B inhibition, which is independent of HIF-1␣ accumulation. This study suggests that PHDs are positive regulators of LPS-induced inflammatory process, and therefore inhibition of PHD may be a novel strategy for the treatment of inflammatory diseases. Key Words: tumor necrosis factor -alpha Ⅲ prolyl hydroxylase domain-containing protein Ⅲ hypoxia-inducible factor Ⅲ inflammation Ⅲ hypoxia I nflammation is a fundamental process for the protection of our body against outside pathogen. Tissues with inflammation are characterized by several features including the accumulation of inflammatory cells such as macrophages, lymphocytes, and neutrophils, limited blood supply attributable to impaired local microcirculation, and abnormal angiogenesis. 1 Inflammatory cells are metabolically active and consume a large amount of oxygen and nutrient. These cells are, therefore, eventually exposed to hypoxic and nutrient-deprived condition. 2 Thus, the inflammatory cells need to adapt these hypoxic conditions to perpetuate inflammatory reaction. 3 The reduced oxygen concentration is directly sensed by an innate oxygen-sensing system. 4 -6 The hypoxia-inducible factor (HIF) is a key transcription factor that mediates cellular adaptive responses to hypoxia. 7 HIF is a heterodimer consisting of an oxygen-labile ␣-subunit and a stable ␤-subunit. The stability of the ␣-subunit of HIF-1 and HIF-2 (HIF-1␣ and HIF-2␣) is regulated through the hydroxylation at the 4-position of specific proline residues in HIF-1␣ and HIF-2␣ by prolyl hydroxylase domain-containing proteins (PHDs). 8,9 Because PHD activity depends on the availability of molecular oxygen, PHDs are able to serve as a sensor for oxygen concentration. Under normal oxygen concentration, HIF-␣ i...

Abstract-Telmisartan, an angiotensin II type 1 receptor antagonist, was reported to be a partial agonist of peroxisome proliferator-activated receptor-␥. Although peroxisome proliferator-activated receptor-␥ activators have been shown to have an anti-inflammatory effect, such as inhibition of cytokine production, it has not been determined whether telmisartan has such effects. We examined whether telmisartan inhibits expression of interleukin-6 (IL-6), a proinflammatory cytokine, in vascular smooth muscle cells. Telmisartan, but not valsartan, attenuated IL-6 mRNA expression induced by tumor necrosis factor-␣ (TNF-␣). Telmisartan decreased TNF-␣-induced IL-6 mRNA and protein expression in a dose-dependent manner. Because suppression of IL-6 mRNA expression was prevented by pretreatment with GW9662, a specific peroxisome proliferator-activated receptor-␥ antagonist, peroxisome proliferatoractivated receptor-␥ may be involved in the process. Telmisartan suppressed IL-6 gene promoter activity induced by TNF-␣. Deletion analysis suggested that the DNA segment between Ϫ150 bp and Ϫ27 bp of the IL-6 gene promoter that contains nuclear factor B and CCAAT/enhancer-binding protein-␤ sites was responsible for telmisartan suppression. Telmisartan attenuated TNF-␣-induced nuclear factor B-and CCAAT/enhancer-binding protein-␤-dependent gene transcription and DNA binding. Telmisartan also attenuated serum IL-6 level in TNF-␣-infused mice and IL-6 production from rat aorta stimulated with TNF-␣ ex vivo. These data suggest that telmisartan may attenuate inflammatory process induced by TNF-␣ in addition to the blockade of angiotensin II type 1 receptor. Because both TNF-␣ and angiotensin II play important roles in atherogenesis through enhancement of vascular inflammation, telmisartan may be beneficial for treatment of not only hypertension but also vascular inflammatory change. (Hypertension. 2009;53: 798-804.)

Recent studies have shown that resveratrol (3,5,4¢-trihydroxystilbene), a polyphenolic compound found in grapes and red wine, has various beneficial effects on cardiovascular diseases and prolongs the life span of mice fed a high-fat diet. We hypothesized that resveratrol may attenuate vascular inflammatory response induced by angiotensin (Ang) II. We examined the effect of resveratrol on Ang II-induced interleukin (IL)-6 expression in vascular smooth muscle cells (VSMCs). Resveratrol significantly attenuated Ang II-induced IL-6 mRNA expression and IL-6 protein in the supernatant of VSMC in a dose-dependent manner. Resveratrol suppressed the IL-6 gene promoter activity. Resveratrol inhibited the Ang II-induced cAMP-response element-binding protein and nuclear factor-kappa B activity, which are critical for Ang II-induced IL-6 gene activation. An increase in the serum concentration of IL-6 induced by Ang II infusion was attenuated by an oral administration of resveratrol. Resveratrol also inhibited Ang II-induced hypertension and perivascular fibrosis of the heart. Although hydralazine reduced blood pressure level equal to resveratrol, it did not reduce the Ang II-induced IL-6 production and perivascular fibrosis. These data suggest that the inhibition of Ang II-induced vascular inflammation and high blood pressure by resveratrol may contribute, at least in part, to the anti-atherogenic effects of resveratrol.

The MDM2 antagonist nutlin-3 inhibits VSMC proliferation, migration, and NF-κB activation, and also attenuates neointimal hyperplasia after vascular injury in mice, which is associated with suppression of vascular cell proliferation and an inflammatory response. Targeting MDM2 might be a potential therapeutic strategy for the treatment of vascular proliferative diseases.

Abstract-Atherosclerosis is considered to be a combined disorder of lipid metabolism and chronic inflammation. Recent studies have reported that liver X receptors (LXRs) are involved in lipid metabolism and inflammation and that LXR agonists inhibit atherogenesis. In contrast, angiotensin II is well known to accelerate atherogenesis through activation of the angiotensin II type 1 receptor (AT1R). To better understand the mechanism of LXR on the prevention of atherogenesis, we examined whether activation of LXR affects AT1R expression in vascular smooth muscle cells. T0901317, a synthetic LXR ligand, decreased AT1R mRNA and protein expression with a peak reduction at 6 hours and 12 hours of incubation, respectively. A well-established ligand of LXR, 22-(R)-hydroxycholesterol, also suppressed AT1R expression. The downregulation of AT1R by T0901317 required de novo protein synthesis. AT1R gene promoter activity measured by luciferase assay revealed that the DNA segment between Ϫ61 bp and ϩ25 bp was sufficient for downregulation. Luciferase construct with a mutation in Sp1 binding site located in this segment lost its response to T0901317. T0901317 decreased Sp1 serine phosphorylation. Although preincubation of vascular smooth muscle cells with T0901317 for 30 minutes had no effect on angiotensin II-induced extracellular signal-regulated kinase phosphorylation, phosphorylation of extracellular signal-regulated kinase by angiotensin II was markedly suppressed after 6 hours of preincubation. These results indicate that the suppression of AT1R may be one of the important mechanisms by which LXR ligands exert antiatherogenic effects. T he liver X receptors (LXRs) are member of the nuclear hormone receptor superfamily. 1 Their endogenous ligands are oxidized cholesterol derivatives, such as oxysterols 1 and glucose. 2 LXRs regulate the expression of genes involved in lipid and glucose metabolism. In lipid metabolism, LXRs are known to regulate genes involved in "reverse cholesterol transport," which includes cholesterol efflux, transport, and excretion. ATP binding cassette A1 is involved in cholesterol efflux, and ABCG5 and ABCG8 are involved in cholesterol transport. 3,4 Expression of these ABC proteins is increased by LXR agonists. In mice, LXR agonists were reported to promote biliary and fecal excretion of cholesterol. 5 It was reported recently that glucose directly activated LXRs 2 and regulated the transcription of genes such as GLUT4. 6 In addition, LXR agonists were reported to negatively regulate the expression of inflammatory cytokines 7 and prevent the formation of atherosclerotic lesions in atherosclerosis-prone mice. 8,9 The effects of angiotensin II (Ang II) are mediated by Ang II receptors, and so far 2 isoforms, type 1 receptor (AT1R) and type 2 receptor, have been identified. 10 AT1R mediates most of the traditional effects of Ang II, such as vasoconstriction and cell proliferation. It is well known that Ang II enhances atherogenesis, 11,12 and an AT1R antagonist attenuated atherogenesis in animal mode...

The present study revealed novel anti-oxidative and anti-atherosclerotic effects of pharmacological stimulation of cholinergic system by donepezil. Donepezil may be used as a novel therapeutics for the atherosclerotic cardiovascular diseases.