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

Multibranched endovascular aortic aneurysm repair in patients with and without chronic aortic dissections

ObjectiveThe objective of this study was to compare multibranched endovascular aneurysm repair (MBEVAR) of postdissection thoracoabdominal aortic aneurysms (TAAAs) and pararenal aortic aneurysms (PRAAs) with MBEVAR of degenerative TAAAs and PRAAs and to assess the role played by the preoperative correction of potential complicating factors, such as true lumen compression and false lumen origin of vital branches, using adjunctive maneuvers.MethodsFrom July 2005 to July 2017, there were 162 patients who underwent elective MBEVAR of TAAAs and PRAAs. Data on demographics, procedural details, and outcomes were collected prospectively.ResultsThe mean age was 73 ± 8 years, and 119 of 162 (74%) were men; 19 of 162 (12%) had prior aortic dissections. Patients with dissections were younger (65 ± 11 years vs 74 ± 7 years; P = .002) and were less likely to have smoked (13/19 [68%] vs 135/143 [94%]; P = .002) or to have peripheral artery disease (0/19 [0%] vs 35/143 [24%]; P = .01) compared with those without dissections. Patients with prior dissections were more likely to have Crawford type II (10/19 [53%] vs 22/143 [15%]; P = .001) and type III (6/19 [32%] vs 16/143 [11%]; P = .03) TAAAs and were more likely to require at least one pre-MBEVAR adjunctive procedure (14/19 [74%] vs 55/143 [38%]; P = .006) compared with those without dissection. There was no difference in perioperative death, stroke, or paraplegia rates between the two groups. Median follow-up was 2.4 years (interquartile range, 0.8-4.7) and did not differ significantly between the two groups. There were no significant differences in branch vessel occlusion, endoleak rate, or aneurysm-related death between the two groups.ConclusionsPatients with chronic type B aortic dissection are more likely to have extensive aneurysms and more likely to require adjunctive procedures to provide the appropriate anatomic substrate for MBEVAR, but this does not appear to affect the conduct of MBEVAR or its outcomes

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

BackgroundPersistent 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.MethodsHuman 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.ResultsExposure 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.Conclusions17R/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

Supplemental arginine vasopressin during the resuscitation of severe hemorrhagic shock preserves renal mitochondrial function

<div><p>Arginine vasopressin (AVP), a hormone secreted by the posterior pituitary, plays a vital role in maintaining vasomotor tone during acute blood loss. We hypothesized that decompensated hemorrhagic shock is associated with decreased AVP stores and supplementation during resuscitation would improve both blood pressure and renal function. Using a decompensated hemorrhagic shock model, male Long-Evans rats were bled to mean arterial blood pressure (MAP) of 40mmHg and maintained until the MAP could not be sustained without fluid. Once 40% of the shed volume was returned in lactated Ringer’s (Severe Shock), animals were resuscitated over 60 minutes with 4x the shed volume in lactated Ringer’s (LR) or the same fluids with AVP (0.5 units/kg+ 0.03 units/kg/min). Animals (n = 6-9/group) were sacrificed before hemorrhage (Sham), at Severe Shock, following resuscitation (60R, 60R with AVP) or 18 hours post-resuscitation (18hr, 18hr with AVP). Blood samples were taken to measure AVP levels and renal function. Pituitaries were harvested and assayed for AVP. Kidney samples were taken to assess mitochondrial function, histology, and oxidative damage. Baseline pituitary AVP stores (30,364 ± 5311 pg/mg) decreased with severe shock and were significantly depressed post-resuscitation (13,910 ± 3016 pg/ml. p<0.05) and at 18hr (15,592 ±1169 pg/ml, p<0.05). Resuscitation with LR+AVP led to higher serum AVP levels at 60R (31±8 vs 79±12; p<0.01) with an improved MAP both at 60R (125±3 vs 77±7mmHg; p<0.01) and 18hr (82±6 vs 69±5mmHg;p<0.05). AVP supplementation preserved complex I respiratory capacity at 60R and both complex I and II function at 18hr (p<0.05). AVP was also associated with decreased reactive oxygen species at 60R (856±67 vs 622±48F RFU) and significantly decreased oxidative damage as measured by mitochondrial lipid peroxidation (0.9±0.1 vs 1.7±0.1 fold change, p<0.01) and nitrosylation (0.9±0.1 vs 1.4±0.2 fold change, p<0.05). With AVP, renal damage was mitigated at 60R and histologic architecture was conserved at 18 hours. In conclusion, pituitary and serum AVP levels decrease during severe hemorrhage and may contribute to the development of decompensated hemorrhagic shock. Supplementing exogenous AVP during resuscitation improves blood pressure, preserves renal mitochondrial function, and mitigates acute kidney injury.</p></div

Laboratory values.

<p>Laboratory values.</p

AVP supplementation during hemorrhagic shock is associated with improved mitochondrial function.

<p>(<b>A</b>) Complex I (CI) and (<b>B</b>) Complex II (CII) dependent respiratory capacity in isolated intact mitochondria was assessed by respirometry. Resuscitation with lactated Ringer’s (Control) resulted in impaired CI and CII respiration at 60 minutes and 18 hours. Addition of AVP (0.5u/kg bolus + 0.03u/kg/hr) during resuscitation preserved CI respiration and improved CII dependent respiration. (<b>C)</b>. The electron transport from CI to Complex III (CIII) was measured spectrophotometrically in isolated mitochondrial membranes. While control animals demonstrated impaired electron transfer, AVP supplementation preserved CI to CIII electron transfer. (<b>D</b>) The production of radical oxygen species (ROS) in isolated mitochondria was measured using the fluorescent signal from dichlorofluorescein (DCF). The increase in ROS following resuscitation (60R) was mitigated with AVP. (<b>E</b>) Mitochondrial stability was assessed by measuring calcium uptake as a marker of mitochondrial permeability transition. At 18 hours post resuscitation, control mitochondria were less stable than mitochondria isolated from AVP resuscitated animals. N = 6–7 animals per time point. Values are mean ± SEM. Data were analyzed using one-way ANOVA with a post hoc Tukey’s test. *<i>p</i><0.05 <i>vs</i>. Sham; #<i>p</i><0.05 Control <i>vs</i>. AVP treated.</p

AVP levels decline despite persistent hypotension following hemorrhagic shock.

<p>Pituitary and serum AVP levels were sampled at baseline (Sham), Severe Shock, after 60 minutes of resuscitation (60R) and at 18 hours post resuscitation (n = 6–7 per time point). (<b>A</b>) Posterior pituitary levels (pg/ml ± SEM) of AVP decrease during hemorrhagic shock and were significantly depressed at both 60R and at 18 hours. (<b>B</b>) AVP serum levels (pg/ml ± SEM) appropriately increased but fell significantly following Decompensation. Data were analyzed using one-way ANOVA with a post hoc Tukey’s test. Values are mean ± SEM. Sham <i>vs</i>. other time points; *<i>p</i><0.05, **p<0.01,***p<0.001, ****p<0.0001. AVP <i>vs</i>. Control; #p<0.05.</p

AVP supplementation during hemorrhagic shock is associated with decreased reactive species damage and preserved histologic architecture.

<p>Kidney protein lystates (20μg) were analyzed by SDS-Page using antibodies directed toward 4-hydroxynonenal (HNE) and 3-nitrotyrosine as a measure of oxidative damage. Kidney samples were sectioned, stained with hematoxylin and eosin, and imaged at 10X. (<b>A, B</b>) AVP significantly decreased oxidative damage following resuscitation (60R). (<b>C</b>) AVP also preserved renal architecture with normal glomeruli (depicted by black arrows) observed 18 hours post-resuscitation. N = 6 animals per time point. Values are mean ± SEM. <i>N</i> = 6–7 per time point. Data were analyzed using one-way ANOVA with a post hoc Tukey’s test. Histologic grading was analyzed using a Mann Whiney U test. *<i>p</i><0.05 <i>vs</i>. Sham; #<i>p</i><0.05 Control <i>vs</i>. AVP treated.</p

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

ObjectiveInflammation 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.MethodsIpsilateral jugular veins were implanted as carotid interposition grafts through an anastomotic cuff technique in New Zealand white rabbits (3-4&nbsp;kg; N&nbsp;= 80). RvD1 (1&nbsp;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&nbsp;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&nbsp;days after bypass to evaluate neointimal hyperplasia and vein graft remodeling.ResultsPerivascular 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&nbsp;days (60%-72% reduction; P&nbsp;&lt; .01). Cellular proliferation (Ki67 index) was also significantly lower in RvD1-treated vs control grafts at 3&nbsp;days (40%-50% reduction; P&nbsp;&lt; .01). Treatment of vein grafts with RvD1-loaded gels reduced neointimal thickness at 28&nbsp;days by 61% vs bypass only (P&nbsp;&lt; .001) and by 63% vs vehicle gel (P&nbsp;&lt; .001). RvD1-loaded PLGA films reduced neointimal formation at 28&nbsp;days by 50% vs bypass only (P&nbsp;&lt; .001). RvD1 treatment was also associated with reduced collagen deposition in vein grafts at 28&nbsp;days.ConclusionsLocal 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

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

ObjectiveInflammation 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.MethodsIpsilateral 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.ResultsPerivascular 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 &lt; .01). Cellular proliferation (Ki67 index) was also significantly lower in RvD1-treated vs control grafts at 3 days (40%-50% reduction; P &lt; .01). Treatment of vein grafts with RvD1-loaded gels reduced neointimal thickness at 28 days by 61% vs bypass only (P &lt; .001) and by 63% vs vehicle gel (P &lt; .001). RvD1-loaded PLGA films reduced neointimal formation at 28 days by 50% vs bypass only (P &lt; .001). RvD1 treatment was also associated with reduced collagen deposition in vein grafts at 28 days.ConclusionsLocal 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