Endothelium-selective activation of AMP-activated protein kinase prevents diabetes mellitus-induced impairment in vascular function and reendothelialization via induction of heme oxygenase-1 in mice.

Background: Endothelial damage and dysfunction are crucial mediators that link diabetes mellitus with atherosclerotic cardiovascular disease. AMP-activated kinase (AMPK) has been implicated in regulation of both energy metabolism and vascular homeostasis. The present study investigated whether endothelium-selective activation of AMPK prevents diabetes mellitus-induced endothelial damage and vascular dysfunction by improving reendothelialization in mice.

Toll-like receptor-4 mediates obesity-induced non-alcoholic steatohepatitis through activation of X-box binding protein-1 in mice.

Background: Non-alcoholic fatty liver disease is an obesity-related chronic liver disorder ranging from simple steatosis to non-alcoholic steatohepatitis (NASH), which may progress to liver fibrosis and cirrhosis.

Objective: Tto investigate the role of Toll-like receptor (TLR) 4 in mediating the transition from steatosis to inflammation.

Methods: ApoE(-/-)/TLR4(mut) mice and ApoE(-/-)/TLR4 wild-type mice (ApoE(-/-)/TLR4-WT) were generated by cross-breeding an ApoE-deficient (ApoE(-/-)) strain with TLR4-mutant (TLR4(mut)) mice, which were fed with high-fat, high-cholesterol (HFHC) diet to induce obesity.

Lipopolysaccharide and hypoxia-induced HIF-1 activation in human gingival fibroblasts.

Background: We previously reported that chronic periodontal inflammation causes the accumulation of the transcriptional activator hypoxia-inducible factor-1α (HIF-1α) in human gingival fibroblasts (HGFs) in vivo. Here, evidence is provided that bacterial lipopolysaccharides (LPS) and cellular hypoxia, both associated with periodontitis, can individually, or in combination, lead to the accumulation and activation of HIF-1 in HGF in vitro.

Methods: Primary gingival fibroblasts were cultured from human gingival biopsies.

Transforming growth factor-beta1 elicits Nrf2-mediated antioxidant responses in aortic smooth muscle cells.

The anti-inflammatory properties of transforming growth factor-beta(1) (TGF-beta(1)) account for its protection against atherosclerotic plaque rupture. This study investigates whether activation of the Nrf2 (nuclear factor erythroid 2 [NF-E2]-related factor 2) transcription pathway is involved in TGF-beta(1) mediated induction of the antioxidant enzyme heme oxygenase-1 (HO-1) in smooth muscle cells (SMC). Human aortic smooth muscle cells (HAoSMC) or wild-type and Nrf2-deficient mouse (MAoSMC) aortic SMC were treated with TGF-beta(1) (2.

Activation of endothelial nitric oxide synthase by dietary isoflavones: role of NO in Nrf2-mediated antioxidant gene expression.

The endothelium plays a key role in the maintenance of vascular homeostasis, and increased oxidative stress in vascular disease leads to reduced nitric oxide bioavailability and impaired endothelium-dependent relaxation of resistance vessels. Although epidemiological evidence suggests that diets containing high amounts of natural antioxidants afford protection against coronary heart disease (CHD), antioxidant supplementation trials have largely reported only marginal health benefits. There is controversy concerning the cardiovascular benefits of prolonged estrogen/progestin or soy isoflavone therapy for postmenopausal women and patients with an increased risk of CHD.

Cardiovascular targets for estrogens and phytoestrogens: transcriptional regulation of nitric oxide synthase and antioxidant defense genes.

The benefits of dietary antioxidants against cardiovascular disease have been examined in numerous clinical trials and animal models, yet there is limited evidence linking consumption of soy isoflavones with enhanced expression of antioxidant defense genes in the vasculature. Epidemiological evidence that populations consuming soy products, rich in isoflavones genistein and daidzein, have a lower incidence of cardiovascular disease has led to the suggestion that isoflavones may be beneficial for cardiovascular health. However, population-based studies cannot prove causality and may be confounded by other dietary influences.

Induction of heme oxygenase 1 by moderately oxidized low-density lipoproteins in human vascular smooth muscle cells: role of mitogen-activated protein kinases and Nrf2.

Oxidized low-density lipoproteins (LDL) play a central role in atherogenesis and induce expression of the antioxidant stress protein heme oxygenase 1 (HO-1). In the present study we investigated induction of HO-1 and adaptive increases in reduced glutathione (GSH) in human aortic smooth muscle cells (SMC) in response to moderately oxidized LDL (moxLDL, 100 microg protein/ml, 24 h), a species containing high levels of lipid hydroperoxides. Expression and activity of HO-1 and GSH levels were elevated to a greater extent by moxLDL than highly oxidized LDL but unaffected by native or acetylated LDL.