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This article describes the development of the Claudication Symptom Instrument (CSI) and its measurement properties for evaluating the symptom experience of patients diagnosed with intermittent claudication (IC). We conducted semistructured qualitative interviews with IC patients for item development and cognitive interviews in which patient comprehension of items was tested. We evaluated measurement properties using data collected and analyzed in the context of an observational comparative effectiveness study of IC treatments. Items measuring five symptom important to patients were developed and cognitively tested: Pain, Numbness, Heaviness, Cramping, and Tingling. Item means (higher means worse) ranged from 1.1 (Tingling) to 2.3 (Pain) (range: 0 'none' to 4 'extreme'). Rasch analysis yielded support for an overall score (χ²=26.5, df=20, p=0.15). The total CSI score differed by clinician-rated severity of mild versus moderate (p<0.05), but not moderate versus severe. Re-administration of the CSI 5-10 days after baseline yielded an intra-class correlation coefficient of 0.86. Changes in CSI total score and VASCUQOL total score between baseline and 6 months post-treatment were correlated at -0.52 (p<0.05). The CSI preliminarily meets accepted measurement standards for content validity, internal consistency and test-retest reliability, construct validity, and sensitivity for detecting change. Because of its high test-retest reliability, it may also be useful in clinical care with individual patients. It takes approximately 3 minutes to complete. [ABSTRACT FROM AUTHOR]

Endothelial nitric oxide (NO) signaling plays a physiological role in limiting obesity-associated insulin resistance and inflammation. This study was undertaken to investigate whether this NO effect involves polarization of macro-phages toward an anti-inflammatory M2 phenotype. Mice with transgenic endothelial NO synthase overexpression were protected against high-fat diet (HFD)-induced hepatic inflammation and insulin resistance, and this effect was associated with reduced proinflammatory M1 and increased anti-inflammatory M2 activation of Kupffer cells. In cell culture studies, exposure of macrophages to endothelial NO similarly reduced inflammatory (M1) and increased anti-inflammatory (M2) gene expression. Similar effects were induced by macrophage overexpression of vasodilator-stimulated phosphoprotein (VASP), a key downstream mediator of intracellular NO signaling. Conversely, VASP deficiency induced proinflammatory M1 macrophage activation, and the transplantation of bone marrow from VASP-deficient donor mice into normal recipients caused hepatic inflammation and insulin resistance resembling that induced in normal mice by consumption of an HFD. These data suggest that proinflammatory macrophage M1 activation and macrophage-mediated inflammation are tonically inhibited by NO → VASP signal transduction, and that reduced NO → VASP signaling is involved in the effect of HFD feeding to induce M1 activation of Kupffer cells and associated hepatic inflammation. Our data implicate endothelial NO → VASP signaling as a physiological determinant of macrophage polarization and show that signaling via this pathway is required to prevent hepatic inflammation and insulin resistance. [ABSTRACT FROM AUTHOR]

Among the pleotropic effects of endothelial nitric oxide (NO) is protection against vascular inflammation during high-fat diet (HFD) feeding. The current work investigated the role of the enzyme vasodilatory- stimulated phosphoprotein (VASP) as a downstream mediator of the anti-inflammatory effect of NO signaling in vascular tissue. Relative to mice fed a low-fat diet (LFD), levels of VASP Ser239 phosphorylation, a marker of VASP activation, were dramatically reduced in aortic tissue of mice with obesity induced by consuming a HFD. As reported previously, the effect of the HFD was associated with increased aortic inflammation, as measured by increased N F - K B - dependent gene expression, and reduced vascular insulin sensitivity (including insulin-stimulated phosphorylation of eNOS and Akt). These effects of the HFD were recapitulated by VASP knockout, implying a physiological role for VASP to constrain inflammatory signaling and thereby maintain vascular insulin sensitivity. Conversely, overexpression of VASP in endothelial cells blocked inflammation and insulin resistance induced by palmitate. The finding that transplantation of bone marrow from VASP-deficient donors into normal recipients does not recapitulate the vascular effects of whole body VASP deficiency suggests that the protective effects of this enzyme are not mediated in immune or other bone marrow-derived cells. These studies implicate VASP as a downstream mediator of the NO/cGMP pathway that is both necessary and sufficient to protect against vascular inflammation and insulin resistance. As such, this work identifies VASP as a potential therapeutic target in the treatment of obesity-related vascular dysfunction. [ABSTRACT FROM AUTHOR]

Activation of AMP-activated protein kinase (AMPK) signaling reduces hepatic steatosis and hepatic insulin resistance; however, its regulatory mechanisms are not fully understood. hi this study, we sought to determine whether vasodilator-stimulated phosphoprotein (VASP) signaling improves lipid metabolism in the liver and, if so, whether VASP's effects are mediated by AMPK. We show that disruption of VASP results in significant hepatic steatosis as a result of significant impairment of fatty acid oxidation, VLDL-triglyceride (TG) secretion, and AMPK signaling. Overexpression of VASP in hepatocytes increased AMPK phosphorylation and fatty acid oxidation and reduced hepatocyte TG accumulation; however, these responses were suppressed in the presence of an AMPK inhibitor. Restoration of AMPK phosphorylation by administration of 5-aminoimidazole-4-carboxamide riboside in Vasp-/- mice reduced hepatic steatosis and normalized fatty acid oxidation and VLDL-TG secretion. Activation of VASP by the phosphodiesterase-5 inhibitor, sildenafil, in db/db mice reduced hepatic steatosis and increased phosphorylated (p-)AMPK and p-acetyl CoA carboxylase. In Vasp-/- mice, however, sildendafil treatment did not increase p-AMPK or reduce hepatic TG content. These studies identify a role of VASP to enhance hepatic fatty acid oxidation by activating AMPK and to promote VLDL-TG secretion from the liver. [ABSTRACT FROM AUTHOR]

Syndecans are receptors for soluble ligands, including heparin-binding growth factors, and matrix proteins. However, intracellular targets of syndecan- 1 (Sdc-1)-mediated signaling are not fully understood. A yeast two-hybrid protein interaction screening of a mouse embryo library identified the ubiquitin and SUMO-1 E3 ligase, Topors, as a novel ligand of the Sdc-1 cytoplasmic domain (S1CD), a finding confirmed by ligand blotting and co-precipitation with Sdc-1 from cell lysates. Deletion mutagenesis identified an 18-amino acid sequence of Topors required for the interaction with the S1CD. By immunohistochemistry, Topors and Sdc-1 co-localized near the cell periphery in normal murine mammary gland (NMuMG) cells in vitro and in mouse embryonic epithelia in vivo. Finally, siRNA-mediated knockdown of Topors demonstrated that Topors is a growth promoter for murine arterial smooth muscle cells and is required for the inhibitory effect of Sdc-1 on cell growth and platelet-derived growth factor-B induction. These data suggest a novel mechanism for the inhibitory effects of Sdc-1 on cell growth that involves the interaction between the cytoplasmic domain of Sdc-1 and the SUMO-1 E3 ligase, Topors. [ABSTRACT FROM AUTHOR]

OBJECTIVE--Proinflammatory activation of Kupffer cells is implicated in the effect of high-fat feeding to cause liver insulin resistance. We sought to determine whether reduced endothelial nitric oxide (NO) signaling contributes to the effect of high-fat feeding to increase hepatic inflammatory signaling and if so, whether this effect 1) involves activation of Kupffer cells and 2) is ameliorated by increased NO signaling. RESEARCH DESIGN AND METHODS--Effect of NO/cGMP signaling on hepatic inflammation and on isolated Kupffer cells was examined in C57BL/6 mice, eNos-/- mice, and Vasp-/- mice fed a low-fat or high-fat diet. RESULTS--We show that high-fat feeding induces proinflammatory activation of Kupffer cells in wild-type mice coincident with reduced liver endothelial nitric oxide synthase activity and NO content while, conversely, enhancement of signaling downstream of endogenous NO by phosphodiesterase-5 inhibition protects against high fat--induced inflammation in Kupffer cells. Furthermore, proinflammatory activation of Kupffer cells is evident in eNos-/- mice even on a low-fat diet. Targeted deletion of vasodilator-stimulated phosphoprotein (VASP), a key downstream target of endothelially derived NO, similarly predisposes to hepatic and Kupffer cell inflammation and abrogates the protective effect of NO signaling in both macrophages and hepatocytes studied in a cell culture model. CONCLUSIONS--These results collectively imply a physiological role for endothelial NO to limit obesity-associated inflammation and insulin resistance in hepatocytes and support a model in which Kupffer cell activation during high-fat feeding is dependent on reduced NO signaling. Our findings also identify the NO/VASP pathway as a novel potential target for the treatment of obesity-associated liver insulin resistance. [ABSTRACT FROM AUTHOR]

Nitric oxide triggers cGMP-dependent kinase-mediated phosphorylation of the actin regulator vasodilator-stimulated phosphoprotein (VASP) at residue serine239. The function of this phosphorylation for smooth muscle cell (SMC) adhesion, spreading, matrix contraction, and invasion is not well understood. We reconstituted VASP deficient SMC with wild-type VASP (wt-VASP) or VASP mutants that mimic “locked” serine239 phosphorylation (S239D-VASP) or “blocked” serine239 phosphorylation (S239A-VASP). Collagen gel contraction was reduced in S239D-VASP compared to S239A-VASP and wt-VASP expressing cells and nitric oxide (NO) stimulation decreased gel contraction of wt-VASP reconstituted SMC. Invasion of collagen was enhanced in S239D-VASP and NO-stimulated wild-type SMCs compared to S239A-VASP expressing cells. Expression of S239D-VASP impaired SMC attachment to collagen, reduced the number of membrane protrusions, and caused cell rounding compared to expression of S239A-VASP. Treatment of wt-VASP reconstituted SMCs with NO exerted similar effects as expression of S239D-VASP. As unstimulated cells were spreading on collagen S239A-VASP and wt-VASP localized to actin fibers whereas S239D-VASP was enriched in the cytosol. NO interferes with SMC invasion and contraction of collagen matrices. This requires phosphorylation of VASP on serine239, which reduces VASP binding to actin fibers. These findings support the conclusion that VASP phosphorylation at serine239 regulates cytoskeleton remodeling. J. Cell. Physiol. 222:230–237, 2010. © 2009 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Abstract: Objective: Constrictive remodeling accounts for lumen loss in postangioplasty restenosis. Matrix metalloproteinase-9 (MMP-9) has been shown to prevent constrictive remodeling in vivo. To investigate potential mechanisms for this observation, we investigated the role of MMP-9 in smooth muscle cell (SMC)-mediated collagen gel contraction, an in vitro model of constrictive remodeling. Methods: Fischer rat SMCs were stably transfected with a construct-expressing rat-MMP-9 under the control of a tetracycline (Tet)-off promoter. SMCs were seeded in type I collagen gels (2.4 mg/ml) in the presence or not of tetracycline (1 μg/ml), and gel contraction was defined as the percentage of retraction of the collagen gel. The depletion of MMP-9 was obtained by using siRNA targeting MMP-9 mRNA or a blocking antibody. Results: Gel contraction was significantly reduced at all times when MMP-9 was overexpressed (Tet−) as compared with the control condition (Tet+). However, MMP-9 depletion of control (Tet+) SMCs (using siRNA or antibody) also inhibited gel contraction. To resolve the apparent discrepancy and determine if MMP-9 exerts a dose-dependent biphasic effect on gel contraction, conditioned medium and purified rat-MMP-9 were prepared. Gel contraction was significantly increased by addition of 0.8 ng/ml of MMP-9, while high concentrations of MMP-9 (≥100 ng/ml) inhibited contraction. The addition of BB94 and TIMP-1 did not alter the inhibitory or stimulatory effect of MMP-9. Conclusions: Our data suggest that MMP-9, independent of its proteolytic function, has a biphasic effect on SMC-mediated collagen gel contraction. Understanding the different roles of MMP-9 should allow the development of better therapeutic strategies for restenotic vascular disease. [Copyright &y& Elsevier]

Surgical bypass of peripheral arterial occlusive disease with autologous vein grafts provides an effective means of restoring blood flow to the lower extremity, and has been a standard therapy for patients with disabling claudication or critical limb ischemia CCLI). However, failure rates may run as high as 50% within 5 years. These graft failures occur as a result of neointimal hyperplasia, a ubiquitous biologic response of blood vessel walls to injury, which is characterized by the migration and proliferation of smooth muscle cells (SMC), The E2F family of transcription factors regulates the expression of genes controlling SMC proliferation. Edifoligide (E2F Decoy) is a novel therapy that inhibits E2F function, thus attenuating neointimal hyperplasia. Its use in conjunction with a patented drug delivery pressurization chamber is under investigation. Using this system, edifoligide is administered to vein grafts in a single, ex vivo treatment following vein harvest and before implantation, resulting in minimal systemic drug exposure and exigent patient compliance. This Phase 3, randomized, double-blind, multi center clinical trial is designed to evaluate the safety and efficacy of edifoligide in a population of approximately 1400 patients with CU undergoing infra inguinal bypass for peripheral arterial disease (PAD). The primary outcome measure will be the time to occurrence of non-technical graft failure resulting in either graft revision or major amputation at 12 months after enrollment A governing Clinical Events Classification committee (CEC) will adjudicate each graft failure to determine its etiology. The PREVENT 111 trial is the largest multi center trial ever performed in patients receiving autologous vein bypass grafts for CLI. This landmark study will determine if edifoligide is safe and effective at preventing vein graft failure in patients undergoing lower extremity bypass, but it also provides a unique opportunity to observe current treatment practices in vascular surgery. [ABSTRACT FROM AUTHOR]

AIM: The aim of the study was to determine whether a single intravenous infusion of 25 mg/kg CDP860, a humanized di-Fab′ fragment against PDGF-β receptor, leads to a reduction of in-stent restenosis. METHODS: In this phase II, double-blind, placebo-controlled, multicentre study 145 patients presenting with stable or unstable angina were randomized to a single infusion of placebo or active drug (CDP860) before undergoing stenting. Quantitative angiography and 3D intravascular ultrasound (IVUS) were obtained at baseline and follow-up. Primary endpoint was the IVUS assessment of percentage in-stent volume obstruction. RESULTS: At six-month follow-up, the placebo group and CDP860 group did not differ significantly regarding minimal luminal diameter (1.75 ± 0.68 versus 1.82 ±­0.66 mm), restenosis rate (16.2 versus 14.1%), minimal lumen area (4.71 ± 1.85 versus 4.41 ± 1.77 mm 2 ), in-stent neointimal volume (30 ± 23 versus 31 ± 31 mm 3 ) and in-stent obstruction volume (23.8 ± 14.4 versus 22.1 ± 15.3%). Major adverse cardiac events at 210 days were similar in both groups: death 1.5 versus 1.4%, myocardial infarction 5.9 versus 8.1% and target vessel revascularization 16.4 versus 17.6%. CONCLUSION: A single intravenous administration of monoclonal antibody against PDGF-β receptor failed to reduce the amount of neointimal hyperplasia after stent implantation. (Int J Cardiovasc Intervent 2003; 5: 214-222) [ABSTRACT FROM AUTHOR]