Case report: Coronary atherosclerosis in a patient with long-standing very low LDL-C without lipid-lowering therapy

Background

ApoB-containing lipoproteins including low-density lipoprotein cholesterol (LDL-C) are necessary for the development of atherosclerosis, and lifelong exposure to low serum levels of LDL-C have been associated with a substantial reduction of cardiovascular risk. Although plaque regression has been observed in patients with serum LDL-C less than 70-80 mg/dl on lipid-lowering therapy, an LDL-C level under which atherosclerosis cannot develop has not been established.

Case presentation

In this case we describe a 60-year-old man with well-controlled diabetes mellitus and hypertension who presented to the hospital after an acute stroke likely due to an atrial myxoma discovered on imaging. A coronary computed tomography angiography scan performed in preparation for the planned surgical myxoma resection revealed an anomalous origin of the right coronary artery as well as evidence of nonobstructive coronary atherosclerosis in the right coronary and non-anomalous left coronary system. Despite not having ever been on any lipid-lowering therapy, this patient was found to have low LDL-C levels (<40 mg/dl) during this admission and on routine laboratory data collected over the prior 16 years. His family history strongly suggested heterozygous familial hypobetalipoproteinemia as a possible diagnosis.

Conclusions

This case illustrates that even long-standing, very low levels of LDL-C may be insufficient to completely prevent atherosclerosis and emphasizes the importance of primordial prevention of all cardiovascular risk factors.

17R/S-Benzo-RvD1, a synthetic resolvin D1 analogue, attenuates neointimal hyperplasia in a rat model of acute vascular injury

BACKGROUND

Persistent inflammation following vascular injury drives neointimal hyperplasia (NIH). Specialized lipid mediators (SPM) mediate resolution which attenuates inflammation and downstream NIH. We investigated the effects of a synthetic analogue of resolvin D1 (RvD1) on vascular cells and in a model of rat carotid angioplasty.

METHODS

Human venous VSMC and endothelial cells (EC) were employed in migration, cell shape, toxicity, proliferation and p65 nuclear translocation assays. Murine RAW 264.7 cells were utilized to test the effect of pro-resolving compounds on phagocytic activity. A model of rat carotid angioplasty was used to evaluate the effects of 17R/S-benzo-RvD1 (benzo-RvD1) and 17R-RvD1 applied to the adventitia via 25% Pluronic gel. Immunostaining was utilized to examine Ki67 expression and leukocyte recruitment. Morphometric analysis was performed on arteries harvested 14 days after injury.

RESULTS

Exposure to benzo-RvD1 attenuated PDGF- stimulated VSMC migration across a range of concentrations (0.1-100 nM), similar to that observed with 17R-RvD1. Pre-treatment with either Benzo-RvD1 or 17R-RvD1 (10, 100nM) attenuated PDGF-BB-induced VSMC cytoskeletal changes to nearly baseline dimensions. Benzo-RvD1 demonstrated modest anti-proliferative activity on VSMC and EC at various concentrations, without significant cytotoxicity. Benzo-RvD1 (10nM) inhibited p65 nuclear translocation in cytokine-stimulated EC by 21% (p<0.05), similar to 17R-RvD1. Consistent with pro-resolving activities of other SPM, both 17R-RvD1 and benzo-RvD1 increased the phagocytic activity of RAW 264.7 cells against S. Aureus and Zymosan particles. There were no significant differences in Ki-67 or CD45 staining observed on day 3 after angioplasty. Periadventitial treatment with benzo-RvD1 reduced carotid neointimal area at 14 days compared to control (0.08 mm2 v. 0.18 mm2; p<0.05), with similar efficacy to 17R-RvD1.

CONCLUSIONS

17R/S-benzo-RvD1 and 17R-RvD1 exhibit similar pro-resolving and anti-migratory activity in cell-based assays, and both compounds attenuated NIH following acute arterial injury in rats. Further studies of the mechanisms of resolution following vascular injury, and the translational potential of SPM analogues, are indicated.

Oral Resolvin D1 attenuates early inflammation but not intimal hyperplasia in a rat carotid angioplasty model

Inflammation ensuing from vascular injury promotes intimal hyperplasia (IH) and restenosis. Resolvin D1 (RvD1) is a lipid mediator that attenuates IH in vivo when delivered locally to the vessel wall in animal models. We tested the hypothesis that peri-procedural oral administration of RvD1 could blunt the local inflammatory response to angioplasty, and attenuate downstream IH. Carotid angioplasty was performed on rats fed with either RvD1 or vehicle through oral gavage, starting one day prior to injury until post-operative day (POD) 3 or 14 when arteries were harvested. To study pharmacokinetics and bioactivity of oral RvD1, we measured plasma RvD1 by ELISA, whole blood phagocytosis activity using flow cytometry, and cAMP levels in the thoracic aorta by ELISA. Carotid arteries were harvested on POD3 for staining (anti-CD45, anti-Myeloperoxidase (MPO), anti-Ki67 or dihydroethidium (DHE) for reactive oxygen species), mRNA expression of target genes (quantitative RT-PCR), or on POD14 for morphometry (elastin stain). RvD1 plasma concentration peaked 3 h after gavage in rats, at which point we concurrently observed an increase in circulating monocyte phagocytosis activity and aortic cAMP levels in RvD1-treated rats vs. vehicle. Oral RvD1 attenuated local arterial inflammation after angioplasty by reducing CD45+, MPO+, Ki67+ cells, and DHE staining intensity. Oral RvD1 also reduced the expression of several pro-inflammatory genes within the injured vessels. However, oral RvD1 did not significantly reduce IH. Oral RvD1 attenuated acute inflammation within the arterial wall after angioplasty in rats, but did not significantly affect IH.

Perivascular delivery of resolvin D1 inhibits neointimal hyperplasia in a rabbit vein graft model

OBJECTIVE

Inflammation is a key driver of excessive neointimal hyperplasia within vein grafts. Recent work demonstrates that specialized proresolving lipid mediators biosynthesized from omega-3 polyunsaturated fatty acids, such as resolvin D1 (RvD1), actively orchestrate the process of inflammation resolution. We investigated the effects of local perivascular delivery of RvD1 in a rabbit vein graft model.

METHODS

Ipsilateral jugular veins were implanted as carotid interposition grafts through an anastomotic cuff technique in New Zealand white rabbits (3-4 kg; N = 80). RvD1 (1 μg) was delivered to the vein bypass grafts in a perivascular fashion, using either 25% Pluronic F127 gel (Sigma-Aldrich, St. Louis, Mo) or a thin bilayered poly(lactic-co-glycolic acid) (PLGA) film. No treatment (bypass only) and vehicle-loaded Pluronic gels or PLGA films served as controls. Delivery of RvD1 to venous tissue was evaluated 3 days later by liquid chromatography-tandem mass spectrometry. Total leukocyte infiltration, macrophage infiltration, and cell proliferation were evaluated by immunohistochemistry. Elastin and trichrome staining was performed on grafts harvested at 28 days after bypass to evaluate neointimal hyperplasia and vein graft remodeling.

RESULTS

Perivascular treatments did not influence rates of graft thrombosis (23%), major wound complications (4%), or death (3%). Leukocyte (CD45) and macrophage (RAM11) infiltration was significantly reduced in the RvD1 treatment groups vs controls at 3 days (60%-72% reduction; P < .01). Cellular proliferation (Ki67 index) was also significantly lower in RvD1-treated vs control grafts at 3 days (40%-50% reduction; P < .01). Treatment of vein grafts with RvD1-loaded gels reduced neointimal thickness at 28 days by 61% vs bypass only (P < .001) and by 63% vs vehicle gel (P < .001). RvD1-loaded PLGA films reduced neointimal formation at 28 days by 50% vs bypass only (P < .001). RvD1 treatment was also associated with reduced collagen deposition in vein grafts at 28 days.

CONCLUSIONS

Local perivascular delivery of RvD1 attenuates vein graft hyperplasia without associated toxicity in a rabbit carotid bypass model. This effect appears to be mediated by both reduced leukocyte recruitment and decreased cell proliferation within the graft. Perivascular PLGA films may also impart protection through biomechanical scaffolding in this venous arterialization model. Our studies provide further support for the potential therapeutic role of specialized proresolving lipid mediators such as D-series resolvins in modulating vascular injury and repair.

Thyroid Status and Nephron Loss - A study in Patients with Chronic Renal Failure, End Stage Renal Disease and/or on Hemodialysis

Thyroid function was measured in 30 healthy subjects and 84 patients with various degrees of nephron loss (GRF: 70 ± 15 m/min, 30 ± 16 ml/min, 10 ± 7 ml/min and 2.1 ± 1.3 ml/min).

A low T3 and T4 syndrome is evident when GRF is reduced to 30 ± 16 ml/min while a blunted TSH response is detected earlier in the course of nephron loss. T3 response to TRH was normal and FT4 was not affected by renal dysfunction. The data indicate that in nephron loss hypothalamic-pituitary abnormalities occur.

Resolution of vascular injury: Specialized lipid mediators and their evolving therapeutic implications

Acute vascular injury occurs in a number of important clinical contexts, including spontaneous disease-related events (e.g. plaque rupture, thrombosis) and therapeutic interventions such as angioplasty, stenting, or bypass surgery. Endothelial cell (EC) disruption exposes the underlying matrix, leading to a rapid deposition of platelets, coagulation proteins, and leukocytes. A thrombo-inflammatory response ensues characterized by leukocyte recruitment, vascular smooth muscle cell (VSMC) activation, and the elaboration of cytokines, reactive oxygen species and growth factors within the vessel wall. A resolution phase of vascular injury may be described in which leukocyte efflux, clearance of debris, and re-endothelialization occurs. VSMC migration and proliferation leads to the development of a thickened neointima that may lead to lumen compromise. Subsequent remodeling involves matrix protein deposition, and return of EC and VSMC to quiescence. Recent studies suggest that specialized pro-resolving lipid mediators (SPM) modulate key aspects of this response, and may constitute an endogenous homeostatic pathway in the vasculature. SPM exert direct effects on vascular cells that counteract inflammatory signals, reduce leukocyte adhesion, and inhibit VSMC migration and proliferation. These effects appear to be largely G-protein coupled receptor-dependent. Across a range of animal models of vascular injury, including balloon angioplasty, bypass grafting, and experimental aneurysm formation, SPM accelerate repair and reduce lesion formation. With bioactivity in the pM-nM range, a lack of discernible cytotoxicity, and a spectrum of vasculo-protective properties, SPM represent a novel class of vascular therapeutics. This review summarizes current research in this field, including a consideration of critical next steps and challenges in translation.

Biosynthesis of proresolving lipid mediators by vascular cells and tissues

Recent evidence suggests that specialized proresolving lipid mediators (SPMs) generated from docosahexaenoic acid (DHA) can modulate the vascular injury response. However, cellular sources for these autacoids within the vessel wall remain unclear. Here, we investigated whether isolated vascular cells and tissues can produce SPMs and assessed expression and subcellular localization of the key SPM biosynthetic enzyme 5-lipoxygenase (LOX) in vascular cells. Intact human arteries incubated with DHA ex vivo produced 17-hydroxy DHA (17-HDHA) and D-series resolvins, as assessed by liquid chromatography-tandem mass spectrometry. Addition of 17-HDHA to human arteries similarly increased resolvin production. Primary cultures of human saphenous vein endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) converted 17-HDHA to SPMs, including resolvin D1 (RvD1) and other D-series resolvins and protectins. This was accompanied by a rapid translocation of 5-LOX from nucleus to cytoplasm in both ECs and VSMCs, potentially facilitating SPM biosynthesis. Conditioned medium from cells exposed to 17-HDHA inhibited monocyte adhesion to TNF-α-stimulated EC monolayers. These downstream effects were partially reversed by antibodies against the RvD1 receptors ALX/FPR2 and GPR32. These results suggest that autocrine and/or paracrine signaling via locally generated SPMs in the vasculature may represent a novel homeostatic mechanism of relevance to vascular health and disease.-Chatterjee, A., Komshian, S., Sansbury, B. E., Wu, B., Mottola, G., Chen, M., Spite, M., Conte, M. S. Biosynthesis of proresolving lipid mediators by vascular cells and tissues.

Aspirin-triggered resolvin D1 attenuates PDGF-induced vascular smooth muscle cell migration via the cyclic adenosine monophosphate/protein kinase A (cAMP/PKA) pathway

BACKGROUND AND OBJECTIVES

Resolvin D1 (RvD1) is a specialized pro-resolving lipid mediator that has been previously shown to attenuate vascular smooth muscle cell (VSMC) migration, a key process in the development of intimal hyperplasia. We sought to investigate the role of the cAMP/PKA pathway in mediating the effects of the aspirin-triggered epimer 17R-RvD1 (AT-RvD1) on VSMC migration.

METHODS

VSMCs were harvested from human saphenous veins. VSMCs were analyzed for intracellular cAMP levels and PKA activity after exposure to AT-RvD1. Platelet-derived growth factor (PDGF)-induced migration and cytoskeletal changes in VSMCs were observed through scratch, Transwell, and cell shape assays in the presence or absence of a PKA inhibitor (Rp-8-Br-cAMP). Further investigation of the pathways involved in AT-RvD1 signaling was performed by measuring Rac1 activity, vasodilator stimulated phosphoprotein (VASP) phosphorylation and paxillin translocation. Finally, we examined the role of RvD1 receptors (GPR32 and ALX/FPR2) in AT-RvD1 induced effects on VSMC migration and PKA activity.

RESULTS

Treatment with AT-RvD1 induced a significant increase in cAMP levels and PKA activity in VSMCs at 5 minutes and 30 minutes, respectively. AT-RvD1 attenuated PDGF-induced VSMC migration and cytoskeletal rearrangements. These effects were attenuated by the PKA inhibitor Rp-8-Br-cAMP, suggesting cAMP/PKA involvement. Treatment of VSMC with AT-RvD1 inhibited PDGF-stimulated Rac1 activity, increased VASP phosphorylation, and attenuated paxillin localization to focal adhesions; these effects were negated by the addition of Rp-8-Br-cAMP. The effects of AT-RvD1 on VSMC migration and PKA activity were attenuated by blocking ALX/FPR2, suggesting an important role of this G-protein coupled receptor.

CONCLUSIONS

Our results suggest that AT-RvD1 attenuates PDGF-induced VSMC migration via ALX/FPR2 and cAMP/PKA. Interference with Rac1, VASP and paxillin function appear to mediate the downstream effects of AT-RvD1 on VSMC migration.

Unidirectional and sustained delivery of the proresolving lipid mediator resolvin D1 from a biodegradable thin film device

Resolvin D1 (RvD1) belongs to a family of endogenously derived proresolving lipid mediators that have been shown to attenuate inflammation, activate proresolution signaling, and promote homeostasis and recovery from tissue injury. In this study we present a poly(lactic-co-glycolic acid) (PLGA) based thin-film device composed of layers of varying ratios of lactic and glycolic acid that elutes RvD1 unidirectionally to target tissues. The device demonstrated sustained release in vitro for 56 days with an initial burst of release over 14 days. The asymmetric design of the device released 98% of RvD1 through the layer with the lowest molar ratio of lactic acid to glycolic acid, and the remainder through the opposite side. We validated structural integrity of RvD1 released from the device by mass spectrometry and investigated its bioactivity on human vascular endothelial (EC) and smooth muscle cells (VSMC). RvD1 released from the device attenuated VSMC migration, proliferation, and TNF-α induced NF-κB activation, without evidence of cytotoxicity. Delivery of RvD1 to blood vessels was demonstrated ex vivo in a flow chamber system using perfused rabbit aortas and in vivo in a rat carotid artery model, with the devices applied as an adventitial wrap. Our results demonstrate a novel approach for sustained, local delivery of Resolvin D1 to vascular tissue at therapeutically relevant levels. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 31-41, 2017.

Abstract 31: Resolvin D1 Attenuates PDGF-induced Vascular Smooth Muscle Cell Migration via the cAMP Pathway

Introduction: Resolvin D1 (RvD1), a specialized pro-resolving lipid mediator (SPM), attenuates migration in vascular smooth muscle cells (VSMC), which is critical to the development of neointimal hyperplasia. SPM are known to interact with G-protein coupled receptors (GPCR). We sought to investigate the pathways by which RvD1 influences VSMC migration.

Methods: VSMC were harvested from human saphenous veins. cAMP levels were measured via ELISA in the absence or presence of RvD1 receptor (ALX, GPR32) blockers. NF449, a G s -protein inhibitor, was also used. PDGF-BB (10ng/ml) was used as an agonist in a VSMC scratch assay as well as the receptor blockers. PDGF-BB-induced cytoskeletal changes were measured as aspect ratio after actin staining, and a scratch assay was used to assess migration. PDGF-induced Rac1 activity was measured via ELISA; VASP phosphorylation was assessed by Western blot and Paxillin translocation by Immunofluorescence. PKA inhibitor Rp-8-Br-cAMP (10μM) was used in the phenotypic and downstream signaling studies.

Results: RvD1 treatment (10nM) of VSMC induced a significant acute flux in cAMP levels at 5 minutes (Fig. 1A; n≥3); this increase was abolished by an ALX antagonist (WRW4), the anti-GPR32 blocking Ab, and NF449. RvD1 (10nM) attenuated PDGF-induced VSMC migration (Fig. 1B-C; n≥3), cytoskeletal rearrangements (n=4), Rac1 activation (n≥3) and increased phosphorylation of VASP (n=3). These effects were negated by the addition of Rp-8-Br-cAMP, suggesting cAMP involvement. RvD1’s anti-migratory effect was reversed by blocking ALX or GPR32 (Fig. 1C; n≥8).

Conclusion: Our results suggest that RvD1 attenuates VSMC migration by increasing levels of cAMP through ALX and GPR32 via a G s -protein-mediated action. Interference with Rac1, VASP and Paxillin function appear to be important for the anti-migratory activity of RvD1.

Adenosine plasma level correlates with homocysteine and uric acid concentrations in patients with coronary artery disease

The role of hyperhomocysteinemia in coronary artery disease (CAD) patients remains unclear. The present study evaluated the relationship between homocysteine (HCys), adenosine plasma concentration (APC), plasma uric acid, and CAD severity evaluated using the SYNTAX score. We also evaluated in vitro the influence of adenosine on HCys production by hepatoma cultured cells (HuH7). Seventy-eight patients (mean age ± SD: 66.3 ± 11.3; mean SYNTAX score: 19.9 ± 12.3) and 30 healthy subjects (mean age: 61 ± 13) were included. We incubated HuH7 cells with increasing concentrations of adenosine and addressed the effect on HCys level in cell culture supernatant. Patients vs. controls had higher APC (0.82 ± 0.5 μmol/L vs 0.53 ± 0.14 μmol/L; p < 0.01), HCys (15 ± 7.6 μmol/L vs 6.8 ± 3 μmol/L, p < 0.0001), and uric acid (242.6 ± 97 vs 202 ± 59, p < 0.05) levels. APC was correlated with HCys and uric acid concentrations in patients (Pearson's R = 0.65 and 0.52; p < 0.0001, respectively). The SYNTAX score was correlated with HCys concentration. Adenosine induced a time- and dose-dependent increase in HCys in cell culture. Our data suggest that high APC is associated with HCys and uric acid concentrations in CAD patients. Whether the increased APC participates in atherosclerosis or, conversely, is part of a protective regulation process needs further investigations.

Abstract 657: Resolvin D1 Attenuates Vascular Smooth Muscle Cell Migration via the cAMP Pathway

Introduction: Resolvin D1 (RvD1), a specialized pro-resolving lipid mediator (SPM), attenuates the migratory phenotype in vascular smooth muscle cells (VSMC), which is critical to the development of atherosclerosis and neointimal hyperplasia. SPM are known to interact with G-protein coupled receptors (GPCR). We sought to investigate the biochemical pathways by which RvD1 influences VSMC migration.

Methods: VSMC were harvested from human saphenous veins. cAMP levels were measured via ELISA, in the absence or presence of WRW4, a blocking peptide for the RvD1 receptor ALX, a GPCR. PDGF-BB (10ng/ml), thrombin (1U/ml) and angiotensin (AT II; 1μM) were used as agonists in a VSMC scratch assay. PDGF-BB-induced cytoskeletal changes were measured as length to width ratio after actin-phalloidin staining. Rp-8-Br-cAMP (10μM), a selective PKA inhibitor, was used in the phenotypic assays.

Results: RvD1 treatment (10nM) of VSMC induced a significant acute flux in cAMP levels, causing a dramatic increase at 5 minutes (Fig. 1A; n≥3); this increase was abolished by WRW4. RvD1 (10nM) attenuated VSMC migration stimulated by PDGF-BB, thrombin and AT II (Fig. 1B; n≥3) and cytoskeletal rearrangements stimulated by PDGF-BB (n=4). RvD1’s effects were negated by the addition of Rp-8-Br-cAMP, suggesting a central role for the cAMP pathway.

Conclusion: Our results suggest that RvD1 attenuates VSMC migration by increasing levels of cAMP through ALX.

Abstract 300: A Biodegradable Wrap for Peri-vascular Delivery of Pro-resolving Lipid Mediators

Introduction: Persistent inflammation following vascular injury leads to excessive scarring, limiting the success of vascular interventions. Recent work has identified that endogenous specialized proresolving lipid mediators (SPM) such as resolvin D1 (RvD1) actively orchestrate the process of resolution, exerting vasculo-protective effects without associated toxicity. We propose local vascular delivery of SPM through a biodegradable wrap.

Methods: RvD1 (200 ng) was heat-sealed between thin layers of polycaprolactone (PCL) or poly-lactic-co-glycolic acid (PLGA). PLGA membranes differed in their composition of lactic versus glycolic acid (%-lactide). Directional drug release was measured via EIA in a cell-free system in vitro and into rabbit aortas exposed to pulsatile flow ex vivo. Bioactivity was confirmed on human vascular smooth muscle cells (VSMC) using migration and proliferation assays.

Results: Of the constructs tested, a 3-layered PLGA wrap consisting of 85%/75%/50%-lactide provided the most favorable drug elution (Fig1a), with sustained release of >800 pg/day for at least 14 days and nearly all elution occurring from the 50%-lactide side (Fig1b). Perivascular application of this wrap ex vivo with the 50%-lactide side facing “in” demonstrated uptake into rabbit aortic walls at 8 hours (0.4 ± 0.1 pg/mg). VSMC cultures exposed to drug-loaded wraps showed inhibition of migration (40%) and proliferation (25%).

Conclusion: We demonstrate sustained and directional elution of therapeutically relevant amounts of biologically-active RvD1 through a biodegradable perivascular wrap, providing opportunity for translational studies of SPM in vascular injury.

Abstract 279: Resolvin D2 and Maresin 1 Modulate Vascular Inflammation, Cell Migration Aad Macrophage Polarization in a Mouse Model of Arterial Injury

Introduction: Vascular injury induces a potent inflammatory response that influences vessel remodeling and patency, limitinglimits the long-term benefits of cardiovascular interventions such as angioplasty. Specialized pro-resolving lipid mediators (SPMs) derived from omega-3 polyunsaturated fatty acids (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) orchestrate resolution in diverse settings of acute inflammation. We hypothesized that systemic administration of DHA-derived SPMs (resolvin D2 [RvD2] and maresin 1 [MaR1]) would influence vessel remodelinginflammation and remodeling in a mouse model of arterial neointima formation (carotid ligation).

Methods and Results: In-vitro, SPM treatment inhibited mouse aortic smooth muscle cell (SMC) migration (IC50@1 nM) to a PDGF gradient and reduced tumor necrosis factor-α stimulated p65 translocation, superoxide production and pro-inflammatory gene expression (MCP-1). In vivo, adult FVB mice underwent unilateral carotid arteryi ligation with administration of RvD2, MaR1, or vehicle (100ng by intraperitoneal injection at 0, 1, 3, 5 and 7 days post ligation). In ligated carotid arteries at 4 days, SPM treatment was associated with reduced cell proliferation, neutrophil and macrophage recruitment, and increased polarization of M2 macrophages in the arterial wall (M2 macrophage proportion; RvD2 62%, MaR1 51% and control 43%). Neointimal hyperplasia (at 14 days) was notably attenuated in RvD2 (62%) and MaR1 (67%) treated mice, respectively. Proliferating cells at 14 days are mainly SMCs.

Conclusion: Modulation of resolution pathways may offer new opportunities to regulate the vascular injury response and promote vascular homeostasis.

Abstract 210: Biosynthesis of D-series Resolvin by Isolated Vascular Cells and Tissues

Introduction: Resolvin-D1 (RvD1) and other specialized pro-resolving lipid mediators (SPM) are synthesized in-vivo from docosahexaenoic acid (DHA) through transcellular pathways involving leukocytes. We investigated if vascular tissues, in the absence of inflammatory cells, can contribute to the local production of SPM.

Methods: Primary cultures of human saphenous vein endothelial (EC) and smooth muscle (SMC) cells were supplemented with DHA in cell culture media (10% serum) for 4h-24h. Freshly harvested rabbit aorta was incubated intact or following gentle EC denudation in medium with or without DHA for 48h. RvD1 levels were quantified by ELISA, and lipoxygenase (LO) expression by western blotting.

Results: In the absence of DHA supplementation, EC and SMC produced undetectable levels of RvD1. DHA treatment produced a dose and time-dependent increase in RvD1 production by EC and SMC (10.1 ±1.0 pg, 7.4 ±0.2 pg respectively; 1000nM DHA; 24h; Fig A, B). 5-LO expression was demonstrated in both cell types, however DHA induced increased 5-LO expression in EC (Fig C) but not in SMC. DHA-treated intact rabbit aorta segments produced 0.24±0.05 pg RvD1/mg tissue versus 0.13±0.01 pg RvD1/mg tissue in media alone. Moreover, EC-denuded aortas produced significantly less RvD1 (Fig D).

Conclusions: Human vascular cells and rabbit vascular tissue can biosynthesize RvD1 de novo from its precursor DHA, signifying a potentially important local source of SPM in the vasculature.

The pro-resolving lipid mediator maresin 1 (MaR1) attenuates inflammatory signaling pathways in vascular smooth muscle and endothelial cells

Objective

Inflammation and its resolution are central to vascular injury and repair. Maresins comprise a new family of bioactive lipid mediators synthesized from docosahexaenoic acid, an ω-3 polyunsaturated fatty acid. They have been found to exert anti-inflammatory and pro-resolving responses in macrophages, neutrophils and bronchial epithelial cells and impart beneficial actions in murine models of peritonitis and colitis. We investigated the impact of maresin-1 (MaR1) on tumor necrosis factor alpha (TNF-α) induced inflammatory responses in human vascular endothelial (EC) and smooth muscle cells (VSMC).

Methods

Primary cultures of human saphenous vein EC and VSMC were employed. We tested the naturally occurring MaR1 as modulator of TNF-α effects, with examination of monocyte adhesion, oxidant stress, and intracellular inflammatory signaling pathways.

Results

MaR1 attenuated TNF-α induced monocyte adhesion and reactive oxygen species (ROS) generation in both EC and VSMC, associated with down-regulated expression (cell surface) of the adhesion molecule E-selectin (in EC) and NADPH-oxidases (NOX4, NOX1, NOX2). MaR1 attenuated TNF-α induced release of pro-inflammatory mediators by EC and VSMC. MaR1 caused an attenuation of TNF-α induced NF-κB activation in both cell types associated with inhibition of I-κ Kinase (IKK) phosphorylation, IκB-α degradation and nuclear translocation of the NF- κB p65 subunit. MaR1 also caused a time-dependent increase in intracellular cyclic AMP (cAMP) in both naive and TNF-α stimulated VSMC and EC.

Conclusions

MaR1 has broad anti-inflammatory actions on EC and VSMC, which may be partly mediated through up-regulation of cAMP and down-regulation of the transcription factor NF-κB. The results suggest that the pro-resolving lipid mediator MaR1 exerts homeostatic actions on vascular cells that counteract pro-inflammatory signals. These findings may have direct relevance for acute and chronic states of vascular inflammation.

Abstract 187: Regulation of Vascular Smooth Muscle Cell (VSMC) Inflammation and Migration by the Pro-resolving Lipid Mediator Maresin-1 (mar1)

Introduction

Resolution of acute inflammation is regulated by endogenous lipid mediators derived from polyunsaturated fatty acids such as docosahexaenoic acid (DHA), however little is known about mechanisms of resolution in vascular injury. We investigated the effects of the DHA-derived mediator Mar1 on VSMC phenotype responses.

Methods

Primary human VSMCs were obtained from saphenous vein. VSMC were pretreated with Mar1 (10-100nM) then exposed to TNF-α (10ng/ml), and inflammatory responses assessed using a monocyte adhesion (U937) assay, expression of cell adhesion molecules and pro-inflammatory molecules (qPCR, western blot, ELISA), and production of superoxide (DHE). VSMC migration was measured in a transwell assay with PDGF-AB as the agonist, and cyotskeletal changes were assessed by actin-phalloidin staining.

Results

Mar-1 (100 nM) reduced U937 adhesion to TNF-stimulated VSMC, VCAM-1, and pro-inflammatory cytokine (IL-6, IL-8) expression. Superoxide production measured by DHE fluorescence was reduced by 57% (p=0.002) and Nox4 expression was markedly attenuated (43%, p=0.01). Mar-1 (0.01-100nM) induced rapid cytoskeletal changes with increased cell area, and reduced VSMC migration (76%, p=0.004) to PDGF-AB (50ng/ml; Figure).

Conclusions

Mar-1 attenuates TNF-α inflammatory activation of VSMC, with reduction in pro-inflammatory gene expression, oxidant stress, and monocyte adhesion. Mar-1 reduces actin polymerization and inhibits VSMC chemotaxis to PDGF. Pro-resolving mediators may represent a new class of endogenous vascular therapeutics.

D-series resolvin attenuates vascular smooth muscle cell activation and neointimal hyperplasia following vascular injury

Recent evidence suggests that specialized lipid mediators derived from polyunsaturated fatty acids control resolution of inflammation, but little is known about resolution pathways in vascular injury. We sought to determine the actions of D-series resolvin (RvD) on vascular smooth muscle cell (VSMC) phenotype and vascular injury. Human VSMCs were treated with RvD1 and RvD2, and phenotype was assessed by proliferation, migration, monocyte adhesion, superoxide production, and gene expression assays. A rabbit model of arterial angioplasty with local delivery of RvD2 (10 nM vs. vehicle control) was employed to examine effects on vascular injury in vivo. Local generation of proresolving lipid mediators (LC-MS/MS) and expression of RvD receptors in the vessel wall were assessed. RvD1 and RvD2 produced dose-dependent inhibition of VSMC proliferation, migration, monocyte adhesion, superoxide production, and proinflammatory gene expression (IC50≈0.1-1 nM). In balloon-injured rabbit arteries, cell proliferation (51%) and leukocyte recruitment (41%) were reduced at 3 d, and neointimal hyperplasia was attenuated (29%) at 28 d by RvD2. We demonstrate endogenous biosynthesis of proresolving lipid mediators and expression of receptors for RvD1 in the artery wall. RvDs broadly reduce VSMC responses and modulate vascular injury, suggesting that local activation of resolution mechanisms expedites vascular homeostasis.

Tragal cartilage in tympanoplasty: anatomic and functional results in 306 cases

Cartilage is the grafting material of choice in advanced disorders of the middle ear while the indications for its routine use remain controversial due to the possible detrimental effect on post-operative hearing. Aim of the present study was to report personal experience with "tragal cartilage shield" tympanoplasty. The study focused on 306 adult patients (236 primary procedures and 70 revisions from January 2003 to June 2007). Mean post-operative follow-up was 37 months (range 1-66). The following parameters were evaluated: graft take, change between the pre- and post-operative pure-tone average air-bone gap (PTA-ABG), post-operative complications. Graft take was achieved in 304 patients (99.35%) and there were no immediate post-operative complications. The overall average pre-operative pure-tone average air-bone gap was 43.79 +/- 7.07 dB, whereas the post-operative (1 year after surgery) pure-tone average air-bone gap was 10.43 +/- 5.25 dB (p < 0.0001). Statistically significant improvement was observed up to 5 years after surgery. This study reveals that tragal cartilage shield tympanoplasty is a reliable technique, in fact it has a high degree of graft take and hearing results are satisfactory. Furthermore, the cartilage is a satisfactory grafting material because it is easily accessible, easy to adapt, resistant to negative middle ear pressures, stable, elastic, well tolerated by the middle ear, resistant to resorption. Therefore, we also recommend its use in less severe middle ear disorders, in which the functional outcome is more essential.

Negative stress echo: Further prognostic stratification with assessment of pressure–volume relation

BACKGROUND

A maximal negative stress echo identifies a low risk for subsequent hard events subset. However, the potentially prognostically relevant information on global contractile reserve on the left ventricle is missed by standard regional wall motion assessment, and can be obtained by end-systolic pressure-volume relationship (PVR) evaluation.

AIM

To assess the relative prognostic value of PVR in patients with negative stress echo.

METHODS

We enrolled 99 consecutive patients (age=61+/-14 years; 81 males, LVEF 47+/-14%, WMSI=1.42+/-0.50) with negative exercise stress echo for standard wall motion criteria. To build the PVR, the force was determined at rest and peak stress as the ratio of the systolic pressure/end-systolic volume index. All patients were followed-up on medical therapy.

RESULTS

Median follow-up was 21 months (interquartile range 12-26). Twenty-nine events have been observed: 6 deaths, 10 heart failure related hospitalization and 13 worsening NYHA class of >or=1 grade. Using Cox's proportional hazard model the best independent predictor of total events was SP/ESV index change (rest-stress) <1.5 mm Hg/ml/m(2) as determined by ROC analysis cut-off (RR=29, p=0.001, sensitivity=80%, specificity=93%). The overall survival and event-free survival was 34% in patients with change (rest-stress) SP/ESV index<1.5 mm Hg/ml/m(2) and 97% in whose with >1.5 mm Hg/ml/m(2).

CONCLUSIONS

In patients with negative stress echo, a preserved global contractility response can be easily identified through stress-induced variation in SP/ESV index, with powerful further risk stratification.

Stress induced cardiomyopathy presenting as acute coronary syndrome: Tako-Tsubo in Mercogliano, Southern Italy

BACKGROUND

Tako-tsubo syndrome (TTS) in its typical (apical) and atypical (non-apical) forms is being increasingly recognized in the West owing to early systematic coronary angiography in acute coronary syndromes (ACS).

AIM OF THE STUDY

To assess the incidence, the clinical characteristics and the outcome of TTS in a single high volume cath lab in Southern Italy over the last 6 years.

METHODS

Among 1674 consecutive patients (pts) referred to our coronary care units in the last 6 years (2001-2006) for ACS we selected 6 (0.5%) pts (6 women; age 57 +/- 6 years) who fulfilled the following 4 criteria: 1) transient left ventricular wall motion abnormalities resulting in ballooning at contrast ventricolographic or echocardiographic evaluation; 2) normal coronary artery on coronary angiography performed 5 +/- 9 hours from hospitalization; 3) new electrocardiographic ischemic-like abnormalities (either ST-segment elevation or T-wave inversion) and 4) emotional or physical trigger event.

RESULTS

At admission all pts had presumptive diagnosis of ACS and ECG revealed ST elevation in 3 (50%) and T wave inversion with QT elongation in 3 (50%). In the acute phase cardiogenic shock occurred in 2 (33%) and heart failure in 1(16%). Presenting symptoms were chest pain in 6 (100%), dyspnoea in 2 (33%) and lipotimia in 1 (16%). At echocardiographic-ventricolographic assessment, the mechanical dysfunction (ballooning) was apical in all 6 pts ("classic" TTS). In all patients wall motion abnormalities completely reversed within 4.5 +/- 1.5 days. The region of initial recovery was the anterior and lateral wall in 4 cases and the lateral wall in 2 cases. Ejection fraction was 35 +/- 8% in the acute phase and increased progressively at discharge (55 +/- 6%) and at 41 +/- 20 months follow-up (60 +/- 4%, p < 0.001 vs. baseline). All patients remained asymptomatic with minimal (aspirin, beta blockers, antihypertensive and antidislipidemic therapy) treatment.

CONCLUSION

Classic TTS is a frequent serendipitous diagnosis after coronary angiography showed "surprisingly" normal findings in a clinical setting mimicking an ACS. Despite its long-term good prognosis life threatening complications in the acute phase can occur.

Evaluation of ultrasound lung comets by hand-held echocardiography

BACKGROUND

Ultrasound lung comets (ULCs) are a clinically useful sign of extravascular lung water. They require very limited technology (2 D-echo), and a short learning curve. The aim of the present study is to compare ULCs information obtained by experienced echocardiologists using a full feature echocardiographic platform and by inexperienced sonographers using a hand-held echocardiography system.

METHODS

20 consecutive in-hospital patients underwent, within 15' and in random order, 2 ultrasound examinations for ULCs by 2 observers with different specific expertise and different technology: 1) "high-tech veteran": ULCs assessment with full feature echocardiographic platform (HP Sonos 7500 Philips Medical Systems, Andover, MA, USA) by a trained echocardiologist, with > or =2 years expertise in ULCs assessment and accredited by the European Association of Echocardiography; 2) and a "low-tech beginner": ULCs assessment with hand-held echocardiography (Optigo; Philips, Andover, MA) by an echocardiographer with very limited (30') dedicated training on ULCs assessment. In each patient, ULC score was obtained by summing the number of comets from each of the scanning spaces in the anterior right and left hemithorax, from the second to the fifth intercostal space.

RESULTS

There was a significant, tight correlation (r = .958, p < 0.001) between the 2 observations in the same patient by "high-tech veteran" and "low-tech beginner".

CONCLUSION

ULCs are equally reliable in the hands of highly experienced echocardiologists using full feature echocardiographic platforms and in the hands of absolute beginners with miniaturized, compact, and battery-equipped echocardiographic systems. From the technological and expertise viewpoint, ULCs are the "kindergarten" of echocardiography, ideally suited for bedside evaluation of patients with both known or suspected heart failure.

Assembly of HCV E1 and E2 glycoproteins into coronavirus VLPs

Hepatitis C virus (HCV) is believed to assemble by budding into membranes of the early secretory pathway, consistent with the membrane location where the viral envelope glycoproteins E1 and E2 accumulate when expressed. Coronavirus assembly also takes place at pre-Golgi membranes. Here, we generated coronavirus-like particles carrying in their envelope chimeric HCV glycoproteins composed of the ectodomains of E1 and E2, each fused to the transmembrane plus endodomain of the mouse hepatitis coronavirus spike glycoprotein. The chimeric particle system will enable structural and functional studies of the HCV glycoproteins.

Stress echocardiography

Stress echocardiography is the combination of 2D echocardiography with a physical, pharmacological or electrical stress. The diagnostic end point for the detection of myocardial ischemia is the induction of a transient worsening in regional function during stress. Stress echocardiography provides similar diagnostic and prognostic accuracy as radionuclide stress perfusion imaging, but at a substantially lower cost, without environmental impact, and with no biohazards for the patient and the physician. Among different stresses of comparable diagnostic and prognostic accuracy, semisupine exercise is the most used, dobutamine the best test for viability, and dipyridamole the safest and simplest pharmacological stress and the most suitable for combined wall motion--coronary flow reserve assessment. The additional clinical benefit of myocardial contrast echocardiography, tissue Doppler imaging and real time 3-D echocardiography has been inconsistent and disappointing, whereas the potential of adding coronary flow reserve evaluation of left anterior descending coronary artery by transthoracic Doppler echocardiography adds another potentially important dimension to stress echocardiography. In spite of its dependence upon operator's training, stress echocardiography is today the best possible imaging choice to achieve the still elusive target of sustainable cardiac imaging in the field of noninvasive diagnosis of coronary artery disease.

Benign paroxysmal positional vertigo: a study of two manoeuvres with and without betahistine

Efficacy of the liberatory manoeuvre and of gradual otolitis dispersion technique, with or without associated drug therapy, have been compared. Included in this prospective study were 103 patients with benign paroxysmal positional vertigo seen in the Outpatient Department. Patients were classified into 4 groups according to treatment: Liberatory Manoeuvre according to methods described by Semont et al., with and without betahistine, Gradual Otolitis Dispersion Technique according to Brandt and Daroff, with and without betahistine. Evaluation was performed at baseline and at 3, 7, 14, 30, 60 and 90 days after start of treatment. Response to treatment was evaluated using criteria of Epley. At day 14, liberatory manoeuvre-betahistine and Brandt and Daroff-betahistine groups did significantly better than liberatory manoeuvre and Brandt and Daroff groups (p < 0.05). Improvement reached at day 30 was: 100% in liberatory manoeuvre-betahistine group; 96.30% (p > 0.05) in Brandt and Daroff-betahistine group; these results were significantly better (p < 0.05) than those of liberatory manoeuvre (54.17%) and Brandt and Daroff (25%) groups. As far as concerns differences between disease onset and start of therapy (less and more than 2 weeks), and age (< or =60 years and > or =60 years), response to treatment was similar. In conclusion, both liberatory manoeuvre and Brandt and Daroff, when associated with betahistine, were significantly more effective than manoeuvres alone (p < 0.05). Improvement in liberatory manoeuvre-betahistine group, in the initial phase, was greater that in Brandt and Daroff-betahistine group, albeit, differences were not significant (p > 0.05). Age-related effects of manoeuvres were compared in 71 patients < 60 years and 32 patients > or =60 years, showing a similar improvement rate at the end of the investigation in both groups. In our opinion, liberatory manoeuvre and Brandt and Daroff associated with betahistamine produces faster recovery compared to liberatory manoeuvre and Brandt and Daroff alone. Nevertheless, 3 months after onset of treatment, all patients showed complete recovery due to spontaneous evolution of paroxysmal positional vertigo, in other words, treatment does not appear to influence the final improvement rate and its role should be accepted as a significant reduction in persistence of symptoms.

A new determinant of endoplasmic reticulum localization is contained in the juxtamembrane region of the ectodomain of hepatitis C virus glycoprotein E1

Hepatitis C virus glycoproteins E1 and E2 do not reach the plasma membrane of the cell but accumulate intracellularly, mostly in the endoplasmic reticulum. Previous studies based on transient expression assays have shown that the transmembrane domains of both glycoproteins are sufficient to localize reporter proteins in the endoplasmic reticulum and that other localization signals may be contained in the ectodomain of E1 protein. To identify such signals we generated chimeric proteins between E1 and two reporter proteins, the human CD8 glycoprotein and the human alkaline phosphatase, and analyzed their subcellular localization in stable as well as transient transfectants. Our results showed that (i) an independent localization determinant for the endoplasmic reticulum is present in the juxtamembrane region of the ectodomain of E1 protein and (ii) the localization dictated by this determinant is either due to direct retention or to a recycling mechanism from the intermediate compartment/cis-Golgi complex region, which is clearly different from those previously described for other retrieval signals. These results show for the first time in mammalian cells that the localization in the endoplasmic reticulum of transmembrane protein can be determined by specific targeting signals acting in the lumen of the compartment.

A different intracellular distribution of a single reporter protein is determined at steady state by KKXX or KDEL retrieval signals

To establish the specific contribution to protein topology of KKXX and KDEL retrieval motifs, we have determined by immunogold electron microscopy and cell fractionation the intracellular distribution at steady state of the transmembrane and anchorless versions of human CD8 protein, tagged with KKXX (CD8-E19) and KDEL (CD8-K), respectively, and stably expressed in epithelial rat cells (Martire, G., Mottola, G., Pascale, M. C., Malagolini, N., Turrini, I., Serafini-Cessi, F., Jackson, M. R., and Bonatti, S. (1996) J. Biol. Chem. 271, 3541-3547). The CD8-E19 protein is represented by a single form, initially O-glycosylated: only about half of it is located in the endoplasmic reticulum, whereas more than 30% of the total is present in the intermediate compartment and cis-Golgi complex. In the latter compartments, CD8-E19 colocalizes with beta-coat protein (COP) (COPI component) and shows the higher density of labeling. Conversely, about 90% of the total CD8-KDEL protein is localized in clusters on the endoplasmic reticulum, where significant co-localization with Sec-23p (COPII component) is observed, and unglycosylated and initially O-glycosylated forms apparently constitute a single pool. Altogether, these results suggest that KKXX and KDEL retrieval motifs have different topological effects on theirs own at steady state: the first results in a specific enrichment in the intermediate compartment and cis-Golgi complex, and the latter dictates residency in the endoplasmic reticulum.

Sex-related influence of body size and sexual maturation on blood pressure in adolescents

OBJECTIVE

This study is aimed at investigating the influence of body size, body fat and sexual maturation on blood pressure (BP) in adolescents.

DESIGN

A cross-sectional study.

SETTING

A suburban student population of Southern Italy.

SUBJECTS

One hundred ninety students attending the first and second year of a secondary school. Five were excluded because they were affected by major diseases. The remaining were 98 M and 87 F (mean age for either group = 12.0+/-0.8 y).

METHODS

Blood pressure was measured by a mercury sphygmomanometer, body weight by a platform beamscale, other measurements included height, biceps, triceps, subscapular and suprailiac skinfolds by a caliper; sexual maturation was evaluated according to Tanner.

RESULTS

Body size was greater than in Tanner's population: in particular body weight (but not height) in our sample markedly exceeded that of the children of the same age in Tanner's population. Boys had higher systolic blood pressure (SBP) than girls (BP = 109/64+/-12/10 vs. 103/63+/-11/8 mm Hg, P<0.02 for SBP), while heart rate and waist/hip ratio were lower. During puberty evaluated on the basis of pubic hair growth BP in girls was higher than in the prepubertal phase (107/66+/-9/7 vs. 99/61+/-10/7, P<0.01). Pubertal boys showed a reduced percent of body fat (calculated from four skinfold measurements) in comparison to prepubertal ones (21.0%+/-4.5 vs. 24.5%+/-7.1, P<0.01). In linear correlation analysis, height, BW, BMI and lean body mass were found to be significantly associated with SBP in both sexes and to diastolic blood pressure (DBP) in girls. Percent body fat was correlated with SBP in boys, while sexual maturation was associated to SBP and DBP in girls only. Multiple regression analysis indicated a significant contribution of body size to BP variability, particularly in the girls. Sexual maturation was excluded from the final regression equations when height, BW or lean body mass were present.

CONCLUSIONS

These data indicate that body weight in these adolescents is greater that in Tanner's population of the same age and sex. Body size appears to be a major determinant of BP, whereas sexual maturation seems to influence BP levels mainly through body growth. The influence of percent body fat on BP setting seems to be of limited importance.

Different fate of a single reporter protein containing KDEL or KKXX targeting signals stably expressed in mammalian cells

In mammalian cells, resident luminal and type I transmembrane proteins of the endoplasmic reticulum usually contain KDEL and KKXX at the carboxyl terminus. These sequences induce retrieval from compartments located downstream in the secretory pathway. It has been suggested that the retrieval may occur from multiple sites, ranging from the intermediate compartment to the trans-Golgi network. To compare the retrieval of luminal and type I membrane proteins, we have used different forms of a single reporter, the human CD8 glycoprotein, stably expressed in FRT cells. Metabolic labeling and oligosaccharide analysis show that the mechanism based on the KDEL signal is leaky. With time, the KDEL-containing CD8 form reaches the trans/trans-Golgi network compartments, where the protein is terminally glycosylated. At this stage, the retrieval mechanism stops being effective and the protein is consequently secreted. Conversely, the mechanism based on the KKXX signal guarantees that most of the KKXX-containing CD8 form resides in the endoplasmic reticulum, little in the Golgi complex and undetectable levels at the plasma membrane. The O-glycosylation of this protein comprises for the vast majority the sole addition of peptide-bound GalNAc that occurs in an early Golgi compartment.

[A proposed hepatic pie chart]

The AA. have chosen 12 tests to organize an "hepatic flash" after a selection out of 180 cases scheduled as the table no. I through a set of tests showing step by step any modifications in compliance with the sensibility, reliability, statistical clinical and physio-pathological meaning of each test. The 12 tests are set out by circular abscissae of a circus according to the pathogenetic mechanisms leading to their modifications. By the radial ordinates, instead, it is shown the decreasing and increasing values which every test may assume. An hypothetic line (hepatogram) links then the values set out during the process of the disease in such a manner that the particular shapes assumed by the line itself show quickly and visually the spreading rate of the disease process.