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Background: ApoA-IV is associated with HDL in plasma but a large portion circulates lipid free. It has been shown to possess anti-inflammatory and anti-atherosclerotic effects. Methods and Results: We isolated HDL from plasma of type 2 diabetic patients and healthy controls, and found that apoA-IV of HDL from diabetic patients was significantly glycated by using Western blot and mass spectrometry. The glycation levels of apoA-IV were higher in diabetic patients than in controls, and were associated with the severity of coronary artery disease. Immunohistochemically, glycation sites co-localized with apoA-IV in atherosclerotic plaques from diabetic patients. In cell and animal studies, in vitro glycated apoA-IV protein promoted inflammatory reactions in human aortic endothelial cells and atherogenesis in apoE-KO mice as compared with control, whereas apoA-IV exhibited anti-inflammatory and anti-atherogenic effects. The pro-inflammatory action of glycated apoA-IV was mediated by receptor for glycation end products in endothelial cells. In microarray analysis and verification in endothelial cells, glycated apoA-IV but not apoA-IV, enhanced the expression of nuclear receptor NR4A3 greatly. Glycated apoA-IV-induced inflammatory reaction and atherogenic effect was significantly attenuated in endothelial cell with siRNA-NR4A3, native endothelial cells and macrophages from NR4A3-KO mice and in NR4A3-KO mice. Co-localization of NR4A3 with CD31 was observed in atherosclerotic plaque from diabetic patients. Moreover, glycated apoA-IV but not apoA-IV induced trans-activation of NR4A3 to the promoter of adhesion molecules (VCAM-1, ICAM-1 and E-selectin). ESI-Q-TOF-MS identified several glycation sites including K78, K189 and K328 in apoA-IV from diabetic patients, but not in controls. Mutated apoA-IV proteins (m-apoA-IV-K78A/K189A/K328A) were made. In vitro glycated m-apoA-IV displayed significantly attenuated activation of NR4A3 in endothelial cells and atherogenesis in apoE-KO mice, as compared with glycated apoA-IV. Conclusion: Glycation of apoA-IV is associated with the severity of coronary artery disease in diabetic patients and glycated apoA-IV protein promotes atherogenesis through nuclear receptor NR4A3 mediation.

Background: C1q/TNF-related protein (CTRP) 1 was initially identified as a paralog of adiponectin based on the similarity in C1q domain of these two proteins. However, vascular functions of CTRP1 remain largely undetermined. Here, we sought to investigate whether CTRP1 influences the pathogenesis of atherosclerosis. Methods and Results: We analyzed CTRP1 levels in sera of coronary artery disease (CAD) patients (n=451) and non-CAD controls (n=686), in coronary endarterectomy specimens (n=26) and non-atherosclerotic internal mammary arteries (n=32), and in peripheral blood mononuclear cells (PBMCs) from severe CAD patients (n=58) and non-CAD controls (n=25). CTRP1 levels were higher in sera, endarterectomy specimens and PBMCs from CAD patients compared with controls, and were related to CAD severity. Immunohistochemistry of human femoral arteries exhibited VE-cadherin loci-associated increased CTRP1 expression in atherosclerotic plaques. In cultured endothelial cells, CTRP1 stimulation resulted in reduced nitric oxide (NO) bioavailability and promotion of inflammatory reactions (increased production of inflammatory cytokines and induction of adhesion molecules). Intravital microscopy exhibited impaired endothelium-dependent arteriole dilation and enhanced leukocyte-endothelium interactions after injection of recombinant CTRP1, whereas improved arteriole dilation and decreased leukocyte-endothelium interactions were observed in CTRP1 knockout mice. Furthermore, we found that arginase 1 was significantly increased by CTRP1 in a dose-dependent fashion, thereby leading to eNOS-uncoupling and reactive oxygen species generation. Inhibition of arginase activity by synthetic chemicals markedly improved CTRP1-dependent endothelial dysfunction. Finally, intraperitoneal injection of recombinant CTRP1 promoted atherogenesis in apoE-/- mice. In contrast, proatherogenic effects were significantly attenuated in CTRP1-/-/apoE-/- double knockout mice. Conclusions: Our findings have demonstrated that CTRP1 is a pro-atherogenic adipokine, likely by modulating arginase 1 expression and enzyme activity. CTPP1 may represent a crucial therapeutic target in atherosclerosis.

In a placebo-controlled, randomized, cross-over, double-blind study of 12 patients with stable exertional angina, we measured at rest and during bicycle exercise the effects of 20 mg of nifedipine administered sublingually on hemodynamics and systemic and regional oxygen extraction and metabolism. Nifedipine decreased systemic vascular resistance by 38% at rest (p less than .001) and by 28% during exercise (p less than .001). Cardiac output increased from 4.6 +/- 0.6 to 6.0 +/- 0.9 liters/min (p less than .001) at rest after nifedipine and from 10.6 +/- 3.7 to 11.8 +/- 3.4 liters/min (p less than .005) during exercise. After nifedipine, the arterial-mixed venous O2 content difference decreased from 4.7 +/- 0.6 to 3.5 +/- 0.5 ml/100 ml (p less than .001) at rest and from 10.5 +/- 1.7 to 8.8 +/- 1.6 ml/100 ml (p less than .001) during exercise. After nifedipine the arterial-iliac venous O2 content difference also decreased at rest, from 5.9 +/- 1.5 to 4.8 +/- 1.7 ml/100 ml (p = .06) but increased during exercise from 13.1 +/- 1.5 to 14.0 +/- 1.8 ml/100 ml (p less than .05). Oxygen consumption was not significantly altered at rest or during exercise. Nifedipine decreased mixed venous carbon dioxide tension (PCO2) during exercise from 53 +/- 3.5 to 50 +/- 4.0 mm Hg (p less than .05) but increased iliac venous PCO2 slightly from 61 +/- 4.6 to 63 +/- 5.2 mm Hg (p less than .01). Exercise pH was not significantly altered, but arterial lactate increased more after nifedipine (2.65 +/- 1.95 mmol/liter placebo, 3.54 +/- 2.74 mmol/liter nifedipine; p less than .05). Thus nifedipine produces similar changes in O2 extraction in mixed venous and iliac venous blood at rest but directionally opposite changes during exercise. The data support the hypothesis that nifedipine does not alter the distribution of cardiac output to the legs at rest, but during dynamic leg exercise reduces the redistribution of cardiac output to the legs. This probably results from the shunting of blood flow away from exercising muscles by the generalized vasodilatation of nifedipine.

We studied the relationship between myocardial contractile state and left ventricular functional response to exercise in 14 asymptomatic patients with isolated moderate-to-severe aortic regurgitation and six control subjects. The slope of the systolic blood pressure-left ventricular end-systolic volume (pressure-volume) relationship determined by radionuclide ventriculography during angiotensin infusion was used as an indirect measure of myocardial contractility and was compared with left ventricular ejection fraction at rest and during both isometric handgrip and dynamic bicycle exercise. The slope of the pressure-volume relationship was significantly lower in patients with aortic regurgitation than in the control subjects (1.75 +/- 0.57 vs 2.78 +/- 0.42, p less than 0.01). The slope correlated exponentially with resting ejection fraction and was linearly related to changes in left ventricular ejection fraction during both handgrip and bicycle exercise. In patients with aortic regurgitation, resting ejection fraction may overestimate myocardial function. The slope of the pressure-volume relationship measured during afterload stress and left ventricular ejection fraction response to exercise intervention more reliably reflect the degree of left ventricular dysfunction.