Oxidative stress plays a fundamental role in abdominal aortic aneurysm (AAA) formation. Activated polymorphonuclear leukocytes (or neutrophils) are associated with AAA and express myeloperoxidase (MPO), which promotes inflammation, matrix degradation, and other pathological features of AAA, including enhanced oxidative stress through generation of reactive oxygen species. Both plasma and aortic MPO levels are elevated in patients with AAA, but the role of MPO in AAA pathogenesis has, heretofore, never been investigated. Here, we show that MPO gene deletion attenuates AAA formation in two animal models: ANG II infusion in apolipoprotein E-deficient mice and elastase perfusion in C57BL/6 mice. Oral administration of taurine [1% or 4% (wt/vol) in drinking water], an amino acid known to react rapidly with MPO-generated oxidants like hypochlorous acid, also prevented AAA formation in the ANG II and elastase models as well as the CaCl application model of AAA formation while reducing aortic peroxidase activity and aortic protein-bound dityrosine levels, an oxidative cross link formed by MPO. Both MPO gene deletion and taurine supplementation blunted aortic macrophage accumulation, elastin fragmentation, and matrix metalloproteinase activation, key features of AAA pathogenesis. Moreover, MPO gene deletion and taurine administration significantly attenuated the induction of serum amyloid A, which promotes ANG II-induced AAAs. These data implicate MPO in AAA pathogenesis and suggest that studies exploring whether taurine can serve as a potential therapeutic for the prevention or treatment of AAA in patients merit consideration. Neutrophils are abundant in abdominal aortic aneurysm (AAA), and myeloperoxidase (MPO), prominently expressed in neutrophils, is associated with AAA in humans. This study demonstrates that MPO gene deletion or supplementation with the natural product taurine, which can scavenge MPO-generated oxidants, can prevent AAA formation, suggesting an attractive potential therapeutic strategy for AAA.

BackgroundRecruitment of macrophage precursors to the adventitia plays a key role in the pathogenesis of abdominal aortic aneurysms (AAAs), but molecular mechanisms remain undefined. The innate immune signaling molecule CD14 was reported to be upregulated in adventitial macrophages in a murine model of AAA and in monocytes cocultured with aortic adventitial fibroblasts (AoAf) in vitro, concurrent with increased interleukin‐6 (IL‐6) expression. We hypothesized that CD14 plays a crucial role in adventitial macrophage precursor recruitment early during AAA formation.Methods and ResultsCD14−/− mice were resistant to AAA formation induced by 2 different AAA induction models: aortic elastase infusion and systemic angiotensin II (AngII) infusion. CD14 gene deletion led to reduced aortic macrophage infiltration and diminished elastin degradation. Adventitial monocyte binding to AngII‐infused aorta in vitro was dependent on CD14, and incubation of human acute monocytic leukemia cell line‐1 (THP‐1) monocytes with IL‐6 or conditioned medium from perivascular adipose tissue (PVAT) upregulated CD14 expression. Conditioned medium from AoAf and PVAT induced CD14‐dependent monocyte chemotaxis, which was potentiated by IL‐6. CD14 expression in aorta and plasma CD14 levels were increased in AAA patients compared with controls.ConclusionsThese findings link CD14 innate immune signaling via a novel IL‐6 amplification loop to adventitial macrophage precursor recruitment in the pathogenesis of AAA.

Human cytomegalovirus (CMV) is a possible co-factor in atherogenesis and vascular occlusion, but its ability to actively infect medium and large blood vessels is unclear. A vascular explant model was adapted to investigate CMV infection in human coronary artery, internal mammary artery (IMA), and saphenous vein (SV). Vascular explants were inoculated with CMV Towne or low-passage clinical isolate and examined in situ for CMV cytopathic effect and immediate-early and early antigens, as indicators of active infection. At 5 to 7 days after inoculation, we found that CMV Towne actively infected eight of eight different atherosclerotic blood vessel explants (coronary artery, n = 4; SV and IMA grafts, n = 4), whereas it only infected 2 of 14 nonatherosclerotic blood vessel explants (SV, n = 10; IMA, n = 4) (P = 0.001). The CMV clinical isolate actively infected none of six sets of nonatherosclerotic SV explants at 5 to 7 days after inoculation. The active CMV infections involved adventitial and, less frequently, intimal cells. A small subset of infected cells in atherosclerotic tissue expresses the endothelial cell marker CD31. Smooth muscle cells residing in both atherosclerotic and nonatherosclerotic blood vessels were free of active CMV infections even after all vascular tissue layers were exposed to the virus. In contrast, active CMV Towne infection was evident at 2 days after inoculation in smooth muscle cells and endothelial cells previously isolated from the SV tissues. We conclude that active CMV infection is enhanced in atherosclerotic blood vessels compared to atherosclerosis-free vascular equivalents, and this viral activity is restricted to subpopulations of intimal and adventitial cells.

While furosemide improved the hyperdynamic circulation in pregnancy, it did not lower blood pressure or cause clinically significant vasoconstriction.

Introduction: Recent studies have suggested a higher recurrence rate of hepatocellular carcinoma (HCC) in patients with a history of HCC and hepatitis C virus (HCV)-associated cirrhosis treated with direct-acting antiviral (DAA) agents. Material and methods: We conducted a prospective analysis of 24 patients with HCV-associated cirrhosis and treated HCC who received ombitasvir/paritaprevir/ritonavirþdasabuvirþribavirin for 12 weeks. Prior therapies for HCC included resection (9/24 patients), radiofrequency ablation (RFA) (7/24) and trans-arterial chemoembolization (TACE) (8/24). All patients were eligible for treatment if they had no HCC recurrence 6 months after their last procedure. A control group was defined. All patients were followed every 6 months, with dynamic computed tomography and/or magnetic resonance imaging. Results: The sustained virological response rate per protocol was 21/24 (87.5%). The study group included 14 (59%) males, median age 64 years (51-77), 50% with associated non-alcoholic steatohepatitis and 24% with Child-Pugh A6 points. HCC recurrence rate/100 patient-years was lower in the DAA-HCC group versus control: 5.5 versus 24.6% patient-years for the resectionþRFA group (p ¼ 0.044), respectively, and 18.6 versus 72.7% patient-years for TACE group (p ¼ 0.002). Survival without recurrence was higher in the resectionþRFA group (45 compared to 18 months (p < 0.001)) and also in the TACE group (44 compared to 11.5 months (p ¼ 0.002)). Conclusions: DAA therapy significantly reduced the recurrence rate of HCC and improved survival without recurrence in patients with treated HCV-associated HCC.