Aortic Inflammation Research Articles

1436Overexpression of Cytotoxic T-Lymphocyte Associated Antigen-4 suppresses aortic immunoinflammatory responses and prevents angiotensin II-induced abdominal aortic aneurysm formation in mice

Abstract Aims Vascular inflammation via T-cell-mediated immune responses has been shown to be critically involved in the pathogenesis of abdominal aortic aneurysm (AAA). T-cell coinhibitory molecule cytotoxic T-lymphocyte–associated antigen-4 (CTLA-4) is known to act as a potent negative regulator of immune responses. However, the role of this molecule in the development of AAA remains completely unknown. In the present study, we determined the effects of CTLA-4 overexpression on experimental AAA. Methods and results We continuously infused 12-week-old CTLA-4 transgenic (CTLA-4-Tg)/apolipoprotein E–deficient (Apoe−/−) mice (n=35) or control Apoe−/− mice (n=40) fed a high-cholesterol diet with angiotensin II by implanting osmotic mini-pumps and evaluated the development of AAA. Ninety percent of angiotensin II-infused mice developed AAA, with 50% mortality because of aneurysm rupture. Overexpression of CTLA-4 significantly reduced the incidence (66%), mortality (26%), and diameter (18%) of AAA (incidence: P=0.0104; mortality: P=0.031; diameter: P=0.011). These protective effects were associated with a decreased number of effector CD4+ T cells and the downregulated expression of costimulatory molecules CD80 and CD86, ligands for CTLA-4, on CD11c+ dendritic cells in lymphoid tissues. In addition, by performing in situ zymography of the abdominal aortic aneurysm lesions, we observed a trend toward a decrease in MMP activity in the aneurysmal lesion following overexpression of CTLA-4. Finally, CTLA-4-Tg/Apoe−/− mice had reduced macrophage and CD4+ T cell accumulation and MMP activity in the aneurysmal lesion, leading to attenuated aortic inflammation, preserved vessel integrity, and decreased susceptibility to AAA and aortic rupture. Conclusion Our findings suggest that CTLA-4 protects against AAA by suppressing immunoinflammatory responses and could be an attractive therapeutic target for AAA.

2105 Below the Belt: Unsual Site of Aortitis in Crohn's Remission

INTRODUCTION: Aortitis is inflammation of the vessel wall that results in luminal narrowing or vessel strictures. It can involve any part of the aorta. In patients with Crohn’s, the reported sites of aortic inflammation are aortic valve leaflets and aortic root, which can result in aortic insufficiency and aneurysmal dilation. CASE DESCRIPTION/METHODS: A 61-year-old female with stable Crohn’s disease presented with epigastric pain, non-bilious non-bloody emesis, and diarrhea. She discontinued Mesalamine 8 years ago. Laboratory studies revealed leukocytosis (12K) and erythrocyte sedimentation rate of 12. Computed Tomography showed fat deposition in the terminal ileum and cecum, mesenteric edema with new wall thickening and fat stranding of the abdominal aorta (AA) and left common iliac artery (CIA). CT angiography (CTA) revealed a 6 mm soft tissue ring around the infra-renal AA with moderate stenosis and extension into the left CIA, compatible with aortitis. Aortic biopsy was not performed given no signs of systemic vasculitis or giant cell arteritis. Infectious etiology was suspected; blood cultures, urinalysis, stool PCR, Clostridium-difficile, HIV, Syphilis, Hepatitis, QuantiFERON, Histoplasmosis, Blastomycosis, Yersinia-Enterocolitica PCR, Cryptococcal antigen, serologies for Lyme disease, Rickettsia, Coxiella, Brucella, Bartonella, and Chlamydia were all negative. Transthoracic echocardiogram showed no evidence of endocarditis. Rheumatologic workup was negative (ANA, RF, ANCAs, CRP, IgG subclasses). Systemic antibiotics were started given concern for infection but the patient did not clinically improve. Given lack of improvement on antibiotics, methylprednisolone was initiated. Repeat CTA showed persistent inflammation. Adalimumab was started with significant symptomatic improvement. At 6 month follow up the patient was asymptomatic and repeat CTA showed no evidence of inflammation. DISCUSSION: We present a rare case of infra-renal aortitis in a patient with stable Crohn’s disease. There is only one reported case of abdominal aortitis in a patient with Crohn’s, but that patient had severe fulminant disease. Our patient with Crohn’s in remission had nonspecific gastrointestinal symptoms (epigastric pain, emesis, diarrhea), and was found to have infra-renal aortitis. Aortitis carries a high risk of aortic rupture and thrombosis of small vessels. Early recognition is crucial, as immunosuppressive agents can be used to reduce the risk of life threatening clinical complications.

P1937Deficiency of PI 3-kinase isoform p110alpha in smooth muscle cells impairs vascular integrity and promotes aortic aneurysm formation

Abstract Background The pathobiology of aortic aneurysms is characterized by vascular inflammation, extracellular matrix degeneration, and particularly by loss and dedifferentiation of vascular smooth muscle cells (SMCs). In SMCs, the PI 3-kinase isoform p110α mediates receptor tyrosine kinase dependent proliferation, chemotaxis, and survival. Smooth muscle specific p110α deficient mice (SM-p110α−/− mice) display reduced medial wall thickness, substantially reduced neointima formation and media hypertrophy after balloon injury of the carotid artery. Objective We hypothesized that loss of p110α signaling impairs vascular integrity and promotes development and progression of abdominal aortic aneurysms (AAA). We aimed to elucidate the impact of p110α deficiency on vascular integrity, SMC phenotypic modulation, vascular inflammation, and AAA formation. Methods and results Ultra-structural characterization of aortic wall morphology in abdominal aortas from SM-p110α−/− mice by transmission electron microscopy (TEM) revealed disarranged structure of tunica media as indicated by disorganized elastic fibers, detached SMCs, and elastic fiber breaks. Western blots showed reduced elastin and fibrillin expression in SMCs from p110α−/− mice. Media thickness was significantly reduced in abdominal aortas from SM-p110α−/− mice compared to wild type (WT) controls (29.0±3.1 vs. 42.5±4.1 μm). Lack of p110α decreased expression of differentiation markers SM-α-actin and SM-MHC. p110α deficiency significantly diminished responsiveness of aortic rings to vasodilator acetylcholine. These data indicate loss of differentiation and impaired contractility of p110α−/− SMCs. We subjected SM-p110α−/− mice and WT littermate controls to the porcine pancreatic elastase (PPE) model of AAA. PPE was infused into the infrarenal aorta, respectively, to induce AAA formation. Ultrasonic examination of abdominal aortas demonstrated an enlarged aortic diameter in PPE challenged mice. AAA formation was significantly (p<0.01) enhanced in SM-p110α−/− (0.46±0.12 mm, n=8) compared to SM-p110α+/+ mice (0.18±0.03 mm, n=4). These data indicate a protective function of p110α in AAA formation. Immunocytochemistry of the aortic medial compartment from PPE-perfused SM-p110α−/− mice revealed significantly increased MOMA-2+ monocyte/macrophage content indicating augmented aortic inflammation during AAA formation compared to WT controls. Furthermore, SMCs from SM-p110α−/− mice expressed reduced amounts of anti-inflammatory angiopoietin1 compared to p110α+/+ SMCs. Moreover, frequent apoptotic/necrotic SMCs were found in the aortic media of SM-p110α−/− mice by TEM, potentially contributing to vascular inflammation in a critical fashion. Conclusion These data indicate that p110α signaling critically contributes to vascular integrity via maintaining SMC plasticity, elastic fiber homeostasis, and anti-inflammatory processes. Consequently, lack of proper p110α signaling promotes progression of AAA formation.

Abstract 124: NaCl Treatment Prior To Chronic Angiotensin Ii Infusion Exaggerates Vascular Inflammation And The Development of Abdominal Aortic Aneurysms By Affecting Immune Cell Response

Chronic high salt (NaCl) intake is a major risk factor for cardiovascular diseases. Recent studies showed that excessive chronic NaCl intake affects immune response and thereby contributes to the pathogenesis of vascular injury. However, it remains unclear whether NaCl intake initially primes immune cell response by promoting memory T cells and sensitize the development of vascular injury in response to a subsequent stimulus. Therefore, we investigate whether 14 days of NaCl treatment (1% NaCl) followed by a 7 day washout period affects the incidence and outcome of abdominal aortic aneurysms (AAA) in apolipoprotein E deficient (ApoE-KO) mice infused chronically with angiotensin II (Ang II) (1000ng/kg/min) via osmotic minipumps for 10 days. Assessment of AAA was done by magnetic resonance imaging (MRI). To visualize vascular inflammation in vivo , perfluorocarbon nano-emulsions (PFC) injected intravenously before and 2, 4, 7 and 10 days after chronic Ang II infusion were detected by combining 1H/19F MRI using a 19 F RARE sequence. After 10 days of Ang II infusion, aortas with perivascular fat were dissected. Aortic inflammation and immune cells infiltration were analyzed by flow cytometery, immunohistology and realtime PCR. The survival rate of ApoE-KO mice pretreated with NaCl was significant lower and the AAA incidence rate was significant higher compared to non-NaCl treated apoE-KO mice. The amount of 19 F signal detected in areas of AAA was significantly increased in apoE-KO mice pretreated with NaCl. Histological analysis confirmed these results. At day 10, proinflammatory cytokines like TNF-alpha, iNOS and TGF-ß as well as numbers of neutrophils, monocytes as well as effector memory CD4 and CD8 T cells were significantly higher in aortas of NaCl pretreated apoE-KO mice compared to non-NaCl treated mice. In conclusion, these results suggest a significant role of NaCl in priming immune cell phenotype and thereby mediating vascular inflammation and damage in Ang II infused apoE-KO mice.

Abstract P1108: Serum Immunoglobulins are Not Necessary for Experimental Hypertension

The role of B cells and serum immunoglobulins (Ig) in hypertension is unclear. Elevated serum IgG has been observed in some hypertensive patients and in animal models of hypertension. Mice with a severe B cell deficiency due to lack of B cell activating factor receptor (BAFF-R) and mice lacking the cytokine interleukin 21 (IL21) - which is a potent inducer of B cell Ig class switching and high affinity Ig production - are protected from Ang II-induced hypertension and exhibit reduced serum IgG levels. Thus, we sought to determine whether hypertensive IgGs play a causative role in hypertension and end-organ dysfunction. First, we purified serum IgG from normotensive and hypertensive wild type (WT) mice and adoptively transferred equal amounts of IgG by intraperitoneal injection into normotensive recipient mice followed by infusion of a sub-pressor dose of angiotensin II (Ang II) for 2 weeks. Flow cytometric analysis of aortas revealed a modest increase in F4/80+ macrophages (p=0.04) and CD8+ T cells (p=0.02) in mice that received hypertensive IgG. However, there was no difference in endothelial dependent relaxation, renal inflammation, albuminuria, and blood pressure (BP) between the two groups. As an alternative method to investigate the role of class-switched high affinity Igs, we studied mice with genetic deletion of activation-induced deaminase (AID) which is an enzyme necessary for somatic hypermutation (to generate high affinity Igs) and isotype class switching. AID -/- mice exhibit undetectable IgG and higher levels of IgM in serum compared to WT mice. Ang II infusion for 4 weeks revealed no difference in BP, aortic inflammation, renal inflammation, and albuminuria. We also studied mice with deficiency of the IgM heavy chain (uMT). These mice exhibit undetectable levels of all immunoglobulins and are severely deficient in mature B cells. uMT-/- mice are also not protected from hypertension induced by Ang II infusion or deoxycorticosterone acetate (DOCA-salt) treatment. Together, these results demonstrate that while elevated serum immunoglobulins seen in hypertensive animals and humans may represent a biomarker of aberrant immune activation, they are likely not playing a causal role in hypertension pathophysiology.

Aortic Oxidative Stress, Inflammation and DNA Damage Following Pulmonary Exposure to Cerium Oxide Nanoparticles in a Rat Model of Vascular Injury.

Pulmonary exposure to cerium oxide nanoparticles (CeO2 NPs) can occur either at the workplace, or due to their release in the environment. Inhaled CeO2 NPs are known to cross the alveolar–capillary barrier and reach various parts of the body, including the vasculature. The anticancer drug cisplatin (CP) causes vascular damage. However, the effects CeO2 NPs on vascular homeostasis in a rat model of CP-induced vascular injury remain unclear. Here, we assessed the impact and underlying mechanism of pulmonary exposure to CeO2 NPs on aorta in rats given a single intraperitoneal injection of cisplatin (CP, 6 mg/kg) to induce vascular damage. Six days later, the rats were intratracheally instilled with either CeO2 NPs (1 mg/kg) or saline (control), and various variables were studied 24 h thereafter in the aortic tissue. The concentration of reduced glutathione and the activity of catalase were significantly increased in the CP + CeO2 NPs group compared with both the CP + saline and the CeO2 NPs groups. The activity of superoxide dismutase was significantly decreased in the CP + CeO2 NPs group compared with both the CP + saline and CeO2 NPs groups. The expression of nuclear factor erythroid-derived 2-like 2 (Nrf2) by the nuclei of smooth muscles and endocardial cells assessed by immunohistochemistry was significantly augmented in CeO2 NPs versus saline, in CP + saline versus saline, and in CP + CeO2 NPs versus CeO2 NPs. Moreover, the concentrations of total nitric oxide, lipid peroxidation and 8-hydroxy-2-deoxyguanosine were significantly elevated in the CP + CeO2 NPs group compared with both the CP + saline and the CeO2 NPs groups. Similarly, compared with both the CP + saline and CeO2 NPs groups, the combination of CP and CeO2 NPs significantly elevated the concentrations of interleukin-6 and tumour necrosis factor-α. Additionally, aortic DNA damage assessed by Comet assay was significantly increased in CeO2 NPs compared with saline, and in CP + saline versus saline, and all these effects were significantly aggravated by the combination of CP and CeO2 NPs. We conclude that pulmonary exposure to CeO2 NPs aggravates vascular toxicity in animal model of vascular injury through mechanisms involving oxidative stress, Nrf2 expression, inflammation and DNA damage.

Activation of Bone Marrow–Derived Cells and Resident Aortic Cells During Aortic Injury

BackgroundThe process of aortic injury, repair, and remodeling during aortic aneurysm and dissection is poorly understood. We examined the activation of bone marrow (BM)-derived and resident aortic cells in response to aortic injury in a mouse model of sporadic aortic aneurysm and dissection. Materials and methodsWild-type C57BL/6 mice were transplanted with green fluorescent protein (GFP)+ BM cells. For 4 wk, these mice were either unchallenged with chow diet and saline infusion or challenged with high-fat diet and angiotensin II infusion. We then examined the aortic recruitment of GFP+ BM-derived cells, growth factor production, and the differentiation potential of GFP+ BM-derived and GFP− resident aortic cells. ResultsAortic challenge induced recruitment of GFP+ BM cells and activation of GFP− resident aortic cells, both of which produced growth factors. Although BM cells and resident aortic cells equally contributed to the fibroblast populations, we did not detect the differentiation of BM cells into smooth muscle cells. Interestingly, aortic macrophages were both of BM-derived (45%) and of non−BM-derived (55%) origin. We also observed a significant increase in stem cell antigen-1 (Sca-1)+ stem/progenitor cells and neural/glial antigen 2 (NG2+) cells in the aortic wall of challenged mice. Although some of the Sca-1+ cells and NG2+ cells were BM derived, most of these cells were resident aortic cells. Sca-1+ cells produced growth factors and differentiated into fibroblasts and NG2+ cells. ConclusionsBM-derived and resident aortic cells are activated in response to aortic injury and contribute to aortic inflammation, repair, and remodeling by producing growth factors and differentiating into fibroblasts and inflammatory cells.

A Phase IV, Randomized, Double-Blind, Placebo-Controlled Crossover Study of the Effects of Ustekinumab on Vascular Inflammation in Psoriasis (the VIP-U Trial)

Psoriasis is a T helper type 17 autoimmune disease associated with an increased risk cardiovascular events and mortality. Ustekinumab, an antibody to p40, blocks cytokines IL-12 and IL-23, and is a highly effective and safe treatment for psoriasis. We conducted a randomized double-blinded placebo-controlled trial to determine the effect of ustekinumab on aortic vascular inflammation (AVI) measured by imaging, and key biomarkers of inflammation, lipid, and glucose metabolism in the blood of patients with moderate-to-severe psoriasis. A total of 43 patients were randomized, and at week 12, ustekinumab-treated patients had a -18.65% (95% confidence interval= -29.45% to -7.85%) reduction in AVI, a reduction in inflammatory biomarkers, and an increase in apolipoprotein B lipoproteins compared with placebo. At week 12, placebo patients were crossed over such that all patients received ustekinumab for 52 weeks. At the end of 52 weeks of ustekinumab treatment, there was no change in AVI compared with baseline, inflammatory markers were reduced, and there were increases in selected measures of lipids and leptin. These results show that blockade of IL-12 and/or IL-23 may transiently reduce AVI, with more durable reduction in inflammatory cytokines associated with cardiovascular disease.

Endothelial Mineralocorticoid Receptors Contribute to Vascular Inflammation in Atherosclerosis in a Sex-Specific Manner.

MR (mineralocorticoid receptor) activation is associated with cardiovascular ischemia in humans. This study explores the role of the MR in atherosclerotic mice of both sexes and identifies a sex-specific role for endothelial cell (EC)-MR in vascular inflammation. Approach and Results: In the AAV-PCSK9 (adeno-associated virus-proprotein convertase subtilisin/kexin type 9) mouse atherosclerosis model, MR inhibition attenuated vascular inflammation in males but not females. Further studies comparing male and female littermates with intact MR or EC-MR deletion revealed that although EC-MR deletion did not affect plaque size in either sex, it reduced aortic arch inflammation specifically in male mice as measured by flow cytometry. Moreover, MR-intact females had larger plaques but were protected from vascular inflammation compared with males. Intravital microscopy of the mesenteric vasculature demonstrated that EC-MR deletion attenuated TNFα (tumor necrosis factor α)-induced leukocyte slow rolling and adhesion in males, while females exhibited fewer leukocyte-endothelial interactions with no additional effect of EC-MR deletion. These effects corresponded with decreased TNFα-induced expression of the endothelial adhesion molecules ICAM-1 (intercellular adhesion molecule-1) and E-selectin in males with EC-MR deletion compared with MR-intact males and females of both genotypes. These observations were also consistent with MR and estrogen regulation of ICAM-1 transcription and E-selectin expression in primary cultured mouse ECs and human umbilical vein ECs. In male mice, EC-MR deletion attenuates leukocyte-endothelial interactions, plaque inflammation, and expression of E-selectin and ICAM-1, providing a potential mechanism by which the MR promotes vascular inflammation. In females, plaque inflammation and leukocyte-endothelial interactions are decreased relative to males and EC-MR deletion is not protective.

The Protective Effect of Crataegus aronia Against High-Fat Diet-Induced Vascular Inflammation in Rats Entails Inhibition of the NLRP-3 Inflammasome Pathway.

This study investigated whether the whole-plant aqueous extract of Crataegus aronia (C. aronia) could protect against or alleviate high-fat diet (HFD)-induced aortic vascular inflammation in rats by inhibiting the NLRP-3 inflammasome pathway and examined some mechanisms of action with respect to its antioxidant and hypolipidemic effects. Adult male Wistar rats were divided into five groups (n = 6/each): standard diet (10% fat) fed to control rats, control + C. aronia (200mg/kg), HFD (40% fat), HFD + C. aronia, and HFD post-treated with C. aronia. The HFD was fed for 8weeks and C. aronia was administered orally for 4weeks. In addition, isolated macrophages from control rats were pre-incubated with two doses of C. aronia (25 and 50μg/mL) with or without lipopolysaccharide (LPS) stimulation. Only in HFD-fed rats, co- and post-C. aronia therapy lowered circulatory levels of LDL-C and ox-LDL-c and aortic protein levels of LOX-1 and CD36. C. aronia also inhibited the nuclear accumulation of NF-κB and lowered protein levels of NLRP-3, caspase-1, and mature IL-1β. In vitro, in the absence of ox-LDL-c, C. aronia led to reduced nuclear levels of NF-κB, ROS generation, and protein NLRP-3 levels, in both LPS-stimulated and unstimulated macrophages, in a dose-dependent manner. However, protein levels of LOX-1 were not affected by C. aronia in unstimulated cells. In conclusion, C. aronia inhibits the NLRP-3 inflammasome pathway, induced by HFD feeding in the aorta of rats, mainly by its hypolipidemic effect and in vitro, in LPS-stimulated macrophages, by its antioxidant effect.

CTLA-4 Protects against Angiotensin II-Induced Abdominal Aortic Aneurysm Formation in Mice

Vascular inflammation via T-cell-mediated immune responses has been shown to be critically involved in the pathogenesis of abdominal aortic aneurysm (AAA). T-cell coinhibitory molecule cytotoxic T-lymphocyte–associated antigen-4 (CTLA-4) is known to act as a potent negative regulator of immune responses. However, the role of this molecule in the development of AAA remains completely unknown. We determined the effects of CTLA-4 overexpression on experimental AAA. We continuously infused CTLA-4 transgenic (CTLA-4-Tg)/apolipoprotein E–deficient (Apoe−/−) mice or control Apoe−/− mice fed a high-cholesterol diet with angiotensin II by implanting osmotic mini-pumps and evaluated the development of AAA. Ninety percent of angiotensin II-infused mice developed AAA, with 50% mortality because of aneurysm rupture. Overexpression of CTLA-4 significantly reduced the incidence (66%), mortality (26%), and diameter of AAA. These protective effects were associated with a decreased number of effector CD4+ T cells and the downregulated expression of costimulatory molecules CD80 and CD86, ligands for CTLA-4, on CD11c+ dendritic cells in lymphoid tissues. CTLA-4-Tg/Apoe−/− mice had reduced accumulation of macrophages and CD4+ T cells, leading to attenuated aortic inflammation, preserved vessel integrity, and decreased susceptibility to AAA and aortic rupture. Our findings suggest T-cell coinhibitory molecule CTLA-4 as a novel therapeutic target for AAA.

Polydatin attenuates atherosclerosis in apolipoprotein E-deficient mice: Role of reverse cholesterol transport

BackgroundPolydatin has been recently shown to possess extensive cardiovascular pharmacological activities. However, its protective effect against atherosclerosis in vivo remains poorly understood. The aim of the present study was to evaluate the potential effects of polydatin on high fat diet (HFD)-induced atherosclerosis using ApoE−/− mice, and explore the underlying mechanisms involved, especially focusing on reverse cholesterol transport (RCT) regulation. Methodsafter 12 weeks treatment, serum samples, mouse aorta, liver, peritoneal macrophages were collected to determine lipid profiles, atherosclerotic lesions, hepatic steatosis, foam cell formation and expression of related molecules. RAW264.7 macrophages were used to study cholesterol efflux. ResultsPolydatin improved serum lipid profiles, attenuated atherosclerosis and hepatic steatosis. Furthermore, polydatin may facilitate RCT by stimulating cholesterol efflux through ATP-binding cassette transporters (ABC) A1, ABCG1 and scavenger receptor class B type I (SR-BI) in macrophages, increasing serum levels of high density lipoprotein and apolipoprotein A-I, promoting of SR-BI-mediated cholesterol uptake of liver, increasing secretion of cholesterol into bile by ABCG5/ABCG8 and improving cholesterol metabolism by CYP7A1 pathway. Polydatin also regulated the protein expressions of hepatic fatty acid synthase and peroxisome proliferator-activated receptor-α. Additionally, polydatin reduced hepatic and aortic reactive oxygen species generation, normalized activities of antioxidant enzymes and increased protein expressions of NADPH-oxidase (NOX) 2 and NOX4 in liver. Polydatin also prevented hepatic and aortic inflammation as evidenced by the reduced macrophage infiltration and mRNA expressions of tumor necrosis factor-α and interleukin-6 in both aorta and liver. ConclusionThese findings indicated that polydatin can inhibit atherosclerosis through enhancement of overall RCT. In addition, anti-oxidative and anti-inflammatory effect of polydatin may also contribute to its inhibitory effects on atherosclerosis.

LncRNA H19 promotes vascular inflammation and abdominal aortic aneurysm formation by functioning as a competing endogenous RNA

Abdominal aortic aneurysm (AAA) is accepted as a chronic vascular inflammatory disease. However, how the inflammatory response is regulated during AAA formation is not fully understood. This study was undertaken to determine whether the long noncoding RNA (lncRNA) H19 (H19) promotes AAA formation by enhancing aortic inflammation. qRT-PCR detected the upregulation of H19 in human and mouse AAA tissue samples. Co-staining for H19 and the macrophage marker MAC-2 showed that H19 was located in vascular smooth muscle cells (VSMCs) and infiltrating aortic macrophages. In vivo overexpression of H19 increased vascular inflammation and induced AAA formation, which was supported by exacerbated aortic morphology, maximum aortic diameter values, elastin degradation, expression of interleukin-6 (IL-6) and macrophage chemoattractant protein-1 (MCP-1), and macrophage infiltration. H19 suppression resulted in the opposite effects. A rescue experiment indicated that IL-6 neutralization significantly mitigated the aortic inflammation and AAA formation evoked by H19 overexpression. Luciferase reporter assays and ex vivo experiments using VSMCs and macrophages confirmed that H19 induced aneurysm formation in part via endogenous competition with the let-7a microRNA to induce the transcription of its target gene, IL-6. This mechanism was further validated by in vivo experiments using a mutant H19 that could not effectively bind let-7a. Collectively, our study revealed a pathogenic H19/let-7a/IL-6 inflammatory pathway in AAA formation, which offers a new potential therapeutic strategy for AAA.

Essential oil from Fructus Alpinia zerumbet (fruit of Alpinia zerumbet (Pers.) Burtt.et Smith) protected against aortic endothelial cell injury and inflammation in vitro and in vivo

Ethnopharmacological relevanceFructus Alpinia zerumbet (FAZ), a dry and ripe fruit of Alpinia zerumbet (Pers.) Burtt. et Smith, is widely used as a spice to treat cardiovascular diseases in clinic as a miao folk medicine in Guizhou Province of China. Essential oil extracted from FAZ (EOFAZ) is the key bioactive ingredients. Aim of the studyThis study aimed to examine the effects and mechanisms of EOFAZ on lipopolysaccharide (LPS)-induced endothelial cell injury, inflammation and apoptosis in vitro and in vivo. Materials and methodsFor the in vitro study, LPS-treated human aortic endothelial cells were used to perform PCR, western blot analysis and immunofluorescence. For the in vivo study, male mouse were divided into four groups, vehicle control group and LPS group received 0.5% Tween-80 in saline; and two EOFAZ groups receive different dose of EOFAZ (90 mg kg −1·day−1, 180 mg kg −1·day−1) respectively. Each group was fed for 7 days by intragastrical administration at daily base. Then, except vehicle control group received saline, mice in other three groups were administered with LPS (1 mg kg −1, dissolved in saline) by intraperitoneal injection. 24 h later, Aorta tissue was collected and frozen immediately in liquid N2, stored at −80 °C for western blot analysis. ResultsWe found that EOFAZ completely prevented LPS-induced HAEC activation and inflammation in vitro and in vivo, as assessed by expression of endothelial adhesion molecules, ICAM-1 and VCAM-1. Similarly, EOFAZ significantly blunted LPS-induced endothelial injury, as tested by MTT assay, LDH release and caspase-3 activation. We further demonstrated that TLR4-dependent NF-κB signaling may be involved in the process. ConclusionEOFAZ protected against LPS-induced endothelial cell injury and inflammation likely via inhibition of TLR4-dependent NF-κB signaling.

Abstract P041: Adipose Inflammation as Assessed by Adipose FDG Uptake is Associated With Aortic Vascular Inflammation in Psoriasis

Background: Psoriasis, a chronic inflammatory disease, is associated with accelerated vascular inflammation (VI) by FDG PET/CT and increased cardiometabolic dysfunction, including adipose tissue dysregulation. Both visceral and subcutaneous adipose volume are associated with sub-clinical aortic VI as well as future cardiovascular events, however, the relationship of adipose inflammation (assessed as adipose FDG uptake) with sub-clinical aortic VI has never been characterized in psoriasis. Methods: 104 consecutive biologic naïve psoriasis patients underwent FDG PET/CT scans to measure VI and adipose FDG uptake, represented as target-to-background ratio (TBR) and standardized uptake value (SUV) respectively. After identification of anatomical location (vertebral level T10), a single 3D-volume region of interest with a fixed volume (4.0 cm 3 ) was placed in the subcutaneous adipose to measure FDG uptake as standardized uptake value (SUV) using a dedicated software (OsiriX MD, Geneva, Switzerland). Results: The cohort was middle-aged, predominantly male, low CV risk by Framingham risk score and mild-moderate psoriasis. Adipose FDG uptake significantly associated with skin disease severity as well as aortic VI even beyond traditional risk factors (β=0.33, p=0.001 and β=0.24, p=0.014 respectively). Additionally, adipose FDG uptake mediated the association between psoriasis skin disease severity and aortic VI accounting for 23% of the total effect (Figure). Conclusions: Our study demonstrated that adipose inflammation is positively associated with psoriasis severity as well as aortic VI. Moreover, adipose inflammation also mediated the relationship between skin disease severity and aortic VI, suggesting that it may contribute to the potential link between psoriasis and CV disease. However, larger studies are needed to confirm our findings.

Inflammation in thoracic aortic aneurysms.

Mutations in extracellular matrix and smooth muscle cell contractile proteins predispose to thoracic aortic aneurysms in Marfan syndrome (MFS) and related disorders. These genetic alterations lead to acompromised extracellular matrix-smooth muscle cell contractile unit. The abnormal aortic tissue responds with defective mechanosensing under hemodynamic stress. Aberrant mechanosensing is associated with transforming growth factor-beta (TGF-β) hyperactivity, enhanced angiotensin-II (Ang-II) signaling, and perturbation of other cellular signaling pathways. The downstream consequences include enhanced proteolytic activity, expression of inflammatory cytokines and chemokines, infiltration of inflammatory cells in the aortic wall, vascular smooth muscle cell apoptosis, and medial degeneration. Mouse models highlight aortic inflammation as acontributing factor in the development of aortic aneurysms. Anti-inflammatory drugs and antioxidants can reduce aortic oxidative stress that prevents aggravation of aortic disease in MFS mice. Targeting TGF-β and Ang-II downstream signaling pathways such as ERK1/2, mTOR, PI3/Akt, P38/MAPK, and Rho kinase signaling attenuates disease pathogenesis. Aortic extracellular matrix degradation and medial degeneration were reduced upon inhibition of inflammatory cytokines and matrix metalloproteinases, but the latter lack specificity. Treating inflammation associated with aortic aneurysms in MFS and related disorders could prove to be beneficial in limiting disease pathogenesis.

Role of aortic stiffness and inflammation in the etiology of young-onset hypertension

Background/aimYoung-onset hypertension is a form of condition diagnosed in patients aged below 40. Cytokines such as interleukin (IL)-6 and also MCP-1 may play a role in the development of arterial hypertension. Aortic stiffness can be detected by measuring pulse wave velocity (PWV). We aimed to explore the relationship between inflammation and aortic stiffness and investigate their roles in the etiology of young-onset hypertension. Materials and methodsWe enrolled 16 patients diagnosed with young-onset hypertension and 16 volunteers without hypertension. The plasma levels of MCP-1 and IL-6 were determined using an enzyme-linked immunosorbent assay and quantitative enzyme-linked immunoassay, respectively. Carotid-femoral PWV was measured using an arteriograph device. ResultsCompared with those in normotensive controls, the plasma levels of IL-6 and MCP-1 and the PWV values were significantly higher in patients with young-onset hypertension (P < 0.001). PWV values were also positively correlated with the levels of MCP-1 and IL-6. However, no statistically significant difference was noted in intima-media thickness ​​between the two groups (P = 0.224).Conclusion In this study, increased PWVs and the levels of inflammation markers were associated with aortic stiffness and inflammation in patients with young-onset hypertension, suggesting they have a role in the etiology of hypertension.

Th1-type immune responses to Porphyromonas gingivalis antigens exacerbate angiotensin II-dependent hypertension and vascular dysfunction.

Background and PurposeEmerging evidence indicates that hypertension is mediated by immune mechanisms. We hypothesized that exposure to Porphyromonas gingivalis antigens, commonly encountered in periodontal disease, can enhance immune activation in hypertension and exacerbate the elevation in BP, vascular inflammation and vascular dysfunction.Experimental ApproachTh1 immune responses were elicited through immunizations using P. gingivalis lysate antigens (10 μg) conjugated with aluminium oxide (50 μg) and IL‐12 (1 μg). The hypertension and vascular endothelial dysfunction evoked by subpressor doses of angiotensin II (0.25 mg·kg−1·day−1) were studied, and vascular inflammation was quantified by flow cytometry and real‐time PCR.Key ResultsSystemic T‐cell activation, a characteristic of hypertension, was exacerbated by P. gingivalis antigen stimulation. This translated into increased aortic vascular inflammation with enhanced leukocyte, in particular, T‐cell and macrophage infiltration. The expression of the Th1 cytokines, IFN‐γ and TNF‐α, and the transcription factor, TBX21, was increased in aortas of P. gingivalis/IL‐12/aluminium oxide‐immunized mice, while IL‐4 and TGF‐β were unchanged. These immune changes in mice with induced T‐helper‐type 1 immune responses were associated with an enhanced elevation of BP and endothelial dysfunction compared with control mice in response to 2 week infusion of a subpressor dose of angiotensin II.Conclusions and ImplicationsThese results support the concept that Th1 immune responses induced by bacterial antigens such as P. gingivalis can increase sensitivity to subpressor pro‐hypertensive insults such as low‐dose angiotensin II, thus providing a mechanistic link between chronic infection, such as periodontitis, and hypertension.Linked ArticlesThis article is part of a themed section on Immune Targets in Hypertension. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.12/issuetoc

Cyclophilin D deficiency protects against the development of mitochondrial ROS and cellular inflammation in aorta

IntroductionInflammation and oxidative stress are closely correlated in the pathology of cardiovascular disease. Mitochondrial cyclophilin D (CypD), the important modulator for mPTP opening, is increasingly recognized as a key regulator of cellular ROS generation. Besides, its association with cell inflammation is also being discovered. However, the effects of CypD in modulating vascular inflammatory response is unknown. We sought to investigate whether CypD deficiency attenutes vascular inflammation under physical conditions. Methods and resultsWe adopted CypD KO mouse and their littermate controls to observe the effects of CypD deficiency on aortic mitochondrial functions and vascular inflammation. As we found in our study, we confirmed that under physical conditions, CypD deficiency enhanced mouse whole body metabolic status, increased aortic mitochondrial complex III activity and decreased mitochondrial ROS generation. Functionally, CypD deficiency also attenuated inflammatory molecules expression, including VCAM-1, IL-6 and TNF-α in mouse aorta. ConclusionsOur results review that mitochondrial CypD is involved in the regulation of inflammation in aorta and provide insights that blocking mitochondrial CypD enhances vascular resistance to inflammatory injuries.

Aortic calcifications and inflammation are associated with in-hospital complications in acute coronary syndrome

Purpose/Background/ObjectivesAortic calcifications and inflammation are independent predictors of adverse cardiovascular events. We sought to investigate the association of aortic calcifications and inflammation with in-hospital morbidity and mortality of patients with acute coronary syndrome (ACS).MethodsTwo hundred patients (mean age 66 ± 15 years, 150 males) admitted to our Hospital with ACS from 2016-2017 were included in the study. The extent of aortic arch calcification (AAC) on a postero-anterior plain chest X-ray was divided into four grades (0 to 3). Grades 0 to 1 and grades 2 to 3 were categorized as lower and higher AAC grade respectively. High-sensitivity C-reactive protein (hsCRP) was also assessed. In-hospital complications that included reinfarction, arrhythmias, heart failure, stroke, mechanical complications, renal failure, surgery and death were assessed in all patients.ResultsThe majority of patients (n = 132, 66%) presented with non-ST elevation ACS, whereas 68 patients as ST-elevation myocardial infarction (STEMI) (n = 68, 34%). Seventy-seven (38.5%) patients presented with one or more in-hospital complications (6 of them died). Higher AAC grade was visible in 44 patients (22%). Patients with higher AAC had increased risk (Odds ratio [OR] = 2.29, 95% Confidence intervals [CI] 1.03 to 5.12, p = 0.043) for in hospital complications after adjusting for age, gender, STEMI/NSTE-ACS diagnosis (OR = 4.10, 95% CI 2.08 to 8.05 for STEMI diagnosis, p < 0.001) and hsCRP (OR = 1.80, 95% CI 1.10 to 2.93, p = 0.02).ConclusionsOur study shows that simple tools can be used to assess the inhospital risk of ACS patients. It also highlights the prognostic role of arterial stiffness and low-grade inflammation in ACS.