Inhibition of interleukin-1 suppresses angiotensin II-induced aortic inflammation and aneurysm formation

Elastin-specific MR probe for visualization and evaluation of an interleukin-1β targeted therapy for atherosclerosis

Atherosclerosis is a chronic inflammatory condition of the arteries and represents the primary cause of various cardiovascular diseases. Despite ongoing progress, finding effective anti-inflammatory therapeutic strategies for atherosclerosis remains a challenge. Here, we assessed the potential of molecular magnetic resonance imaging (MRI) to visualize the effects of 01BSUR, an anti-interleukin-1β monoclonal antibody, for treating atherosclerosis in a murine model. Male apolipoprotein E-deficient mice were divided into a therapy group (01BSUR, 2 × 0.3 mg/kg subcutaneously, n = 10) and control group (no treatment, n = 10) and received a high-fat diet for eight weeks. The plaque burden was assessed using an elastin-targeted gadolinium-based contrast probe (0.2 mmol/kg intravenously) on a 3 T MRI scanner. T1-weighted imaging showed a significantly lower contrast-to-noise (CNR) ratio in the 01BSUR group (pre: 3.93042664; post: 8.4007067) compared to the control group (pre: 3.70679168; post: 13.2982156) following administration of the elastin-specific MRI probe (p < 0.05). Histological examinations demonstrated a significant reduction in plaque size (p < 0.05) and a significant decrease in plaque elastin content (p < 0.05) in the treatment group compared to control animals. This study demonstrated that 01BSUR hinders the progression of atherosclerosis in a mouse model. Using an elastin-targeted MRI probe, we could quantify these therapeutic effects in MRI.

Medical treatments for abdominal aortic aneurysm: an overview of clinical trials

INTRODUCTION

Abdominal aortic aneurysm is a progressive, segmental, abdominal aortic dilation associated with a high mortality rate. Abdominal aortic aneurysms with diameters larger than 55 mm are associated with a high risk of rupture, and the most effective treatment options are surgical repair. Close observation and lifestyle adjustments are recommended for smaller abdominal aortic aneurysms with lower rupture risk. The development of medical therapies that limit or prevent the progression, expansion, and eventual rupture of abdominal aortic aneurysms remains an unmet clinical need.

AREAS COVERED

This review provides an overview of completed and ongoing clinical trials examining the efficacies of various drug classes, including antibiotics, antihypertensive drugs, hypolipidemic drugs, hypoglycemic drugs, and other potential therapies for abdominal aortic aneurysms. A search of PubMed, Web of Science, Clinical Trials, and another six clinical trial registries was conducted in January 2024.

EXPERT OPINION

None of the drugs have enough evidence to indicate that they can effectively inhibit the dilation of abdominal aortic aneurysm. More clinical trial data is required to support the efficacy of propranolol. Future research should also explore different drug delivery mechanisms, such as nanoparticles, to elevate drug concentration at the aneurysm wall.

M1 Macrophage-Derived Exosome LncRNA PVT1 Promotes Inflammation and Pyroptosis of Vascular Smooth Muscle Cells in Abdominal Aortic Aneurysm by Inhibiting miR-186-5p and Regulating HMGB1

Abdominal aortic aneurysm (AAA) is a chronic vascular degenerative disease. Vascular smooth muscle cells (VSMCs) are essential for maintaining the integrity of healthy blood vessels. Macrophages play an important role in the inflammatory process of AAA. However, the effect of macrophage-derived exosome LncRNA PVT1 on VSMCs is unclear. Exosomes from M1 macrophages (M1φ-exos) were isolated and identified. The expression of LncRNA PVT1 in M1φ-exos was determined. AAA cell model was constructed by treating VSMCs with Ang-II. AAA cell model was treated with M1φ exosomes transfected with si-LncRNA PVT1 (M1φsi-LncRNA PVT1-exo). VSMCs were transfected with miR-186-5p mimic and oe-HMGB1. Cell viability was detected by CCK-8. The accumulation of LDH was detected by ELISA. Western blot was used to detect the expression of HMGB1, inflammatory factors (IL-6, TNF-α and IL-1β) and pyroptosis-related proteins (GSDMD, N-GSDMD, ASC, NLRP3, Caspase-1 and Cleaved-Capase-1). Cell pyroptosis rate was detected by flow cytometry. At the same time, the targeting relationship between miR-186-5p and LncRNA PVT1 and HMGB1 was verified by double fluorescein experiment. Exosomes from M1φ were successfully extracted. The expression of LncRNA PVT1 in M1φ-exos was significantly increased. M1φ-exo promotes inflammation and pyroptosis of VSMCs. M1φsi-LncRNA PVT1-exos inhibited the inflammation and pyroptosis of VSMCs. LncRNA PVT1 can sponge miR-186-5p mimic to regulate HMGB1 expression. MiR-186-5p mimic further inhibited inflammation and pyroptosis induced by M1φsi-LncRNA PVT1-exos. However, oe-HMGB1 could inhibit the reversal effect of miR-186-5p mimic. LncRNA PVT1 in exosomes secreted by M1φ can regulate HMGB1 by acting as ceRNA on sponge miR-186-5p, thereby promoting cell inflammatory and pyroptosis and accelerating AAA progression.

Aortic aneurysms: current pathogenesis and therapeutic targets

Aortic aneurysm is a chronic disease characterized by localized expansion of the aorta, including the ascending aorta, arch, descending aorta, and abdominal aorta. Although aortic aneurysms are generally asymptomatic, they can threaten human health by sudden death due to aortic rupture. Aortic aneurysms are estimated to lead to 150,000 ~ 200,000 deaths per year worldwide. Currently, there are no effective drugs to prevent the growth or rupture of aortic aneurysms; surgical repair or endovascular repair is the only option for treating this condition. The pathogenic mechanisms and therapeutic targets for aortic aneurysms have been examined over the past decade; however, there are unknown pathogenic mechanisms involved in cellular heterogeneity and plasticity, the complexity of the transforming growth factor-β signaling pathway, inflammation, cell death, intramural neovascularization, and intercellular communication. This review summarizes the latest research findings and current pathogenic mechanisms of aortic aneurysms, which may enhance our understanding of aortic aneurysms.

CARMA3 Deficiency Aggravates Angiotensin II-Induced Abdominal Aortic Aneurysm Development Interacting Between Endoplasmic Reticulum and Mitochondria

BACKGROUND

Abdominal aortic aneurysm (AAA) is life threatening and associated with vascular walls' chronic inflammation. However, a detailed understanding of the underlying mechanisms is yet to be elucidated. CARMA3 assembles the CARMA3-BCL10-MALT1 (CBM) complex in inflammatory diseases and is proven to mediate angiotensin II (Ang II) response to inflammatory signals by modulating DNA damage-induced cell pyroptosis. In addition, interaction between endoplasmic reticulum (ER) stress and mitochondrial damage is one of the main causes of cell pyroptosis.

METHODS

Male wild type (WT) or CARMA3-/- mice aged 8 to 10 weeks were subcutaneously implanted with osmotic minipumps, delivering saline or Ang II at the rate of 1 μg/kg/min for 1, 2, and 4 weeks.

RESULTS

We discovered that CARMA3 knockout promoted formation of AAA and prominently increased diameter and severity of the mice abdominal aorta infused with Ang II. Moreover, a significant increase in the excretion of inflammatory cytokines, expression levels of matrix metalloproteinases (MMPs) and cell death was found in the aneurysmal aortic wall of CARMA3-/- mice infused with Ang II compared with WT mice. Further studies found that the degree of ER stress and mitochondrial damage in the abdominal aorta of CARMA3-/- mice was more severe than that in WT mice. Mechanistically, CARMA3 deficiency exacerbates the interaction between ER stress and mitochondrial damage by activating the p38MAPK pathway, ultimately contributing to the pyroptosis of vascular smooth muscle cells (VSMCs).

CONCLUSIONS

CARMA3 appears to play a key role in AAA formation and might be a potential target for therapeutic interventions of AAA.

Rivaroxaban in patients with abdominal aortic aneurysm and high-sensitivity C-reactive protein elevation (BANBOO): study protocol for a randomized, controlled trial

BACKGROUND

Abdominal aortic aneurysm (AAA) is a fatal disease due to the tendency to rupture. The drug treatment for small AAA without surgical indications has been controversial. Previous studies showed that high-sensitivity C-reactive protein (hs-CRP) had become a potential biomarker of the disease, and the anti-inflammatory effect of rivaroxaban for AAA had been well established. Thus, we hypothesized that rivaroxaban could control the progression of AAA in patients with hs-CRP elevation.

METHODS

The study is a prospective, open-label, randomized, controlled clinical trial. Sixty subjects are recruited from the General Hospital of Northern Theatre Command of China. Subjects are randomly assigned (1:1) to the intervention arm (rivaroxaban) or control arm (aspirin). The primary efficacy outcome is the level of serum hs-CRP at 6 months. The secondary outcomes include imaging examination (the maximal diameter of AAA, the maximal thickness of mural thrombus, and the length of aneurysm), major adverse cardiovascular and cerebrovascular events (MACCE, including AAA transformation, non-fatal myocardial infarction, acute congestive heart failure, stent thrombosis, ischemia-driven target vessel revascularization, vascular amputation, stroke, cardiovascular death, and all-cause death), and other laboratory tests (troponin T, interleukin 6, D-dimer, and coagulation function).

DISCUSSION

The BANBOO trial tested the effect of rivaroxaban on the progression of AAA in patients with elevated Hs-CRP for the first time.

TRIAL REGISTRATION

ChiCTR2100051990, ClinicalTrials.gov, registered on 12 October 2021.

The mechanism and therapy of aortic aneurysms

Aortic aneurysm is a chronic aortic disease affected by many factors. Although it is generally asymptomatic, it poses a significant threat to human life due to a high risk of rupture. Because of its strong concealment, it is difficult to diagnose the disease in the early stage. At present, there are no effective drugs for the treatment of aneurysms. Surgical intervention and endovascular treatment are the only therapies. Although current studies have discovered that inflammatory responses as well as the production and activation of various proteases promote aortic aneurysm, the specific mechanisms remain unclear. Researchers are further exploring the pathogenesis of aneurysms to find new targets for diagnosis and treatment. To better understand aortic aneurysm, this review elaborates on the discovery history of aortic aneurysm, main classification and clinical manifestations, related molecular mechanisms, clinical cohort studies and animal models, with the ultimate goal of providing insights into the treatment of this devastating disease. The underlying problem with aneurysm disease is weakening of the aortic wall, leading to progressive dilation. If not treated in time, the aortic aneurysm eventually ruptures. An aortic aneurysm is a local enlargement of an artery caused by a weakening of the aortic wall. The disease is usually asymptomatic but leads to high mortality due to the risk of artery rupture.

Potential of Disease-Modifying Anti-Rheumatic Drugs to Limit Abdominal Aortic Aneurysm Growth

Inflammation is strongly implicated in the pathogenesis of abdominal aortic aneurysms (AAA). This review examined the potential role of biologic disease-modifying anti-rheumatic drugs (bDMARDs) as repurposed drugs for treating AAA. Published evidence from clinical and preclinical studies was examined. Findings from animal models suggested that a deficiency or inhibition of tumour necrosis factor-α (TNF-α) (standard mean difference (SMD): −8.37, 95% confidence interval (CI): −9.92, −6.82), interleukin (IL)-6 (SMD: −1.44, 95% CI: −2.85, −0.04) and IL-17 (SMD: −3.36, 95% CI: −4.21, −2.50) led to a significantly smaller AAA diameter compared to controls. Human AAA tissue samples had significantly increased TNF-α (SMD: 1.68, 95% CI: 0.87, 2.49), IL-1β (SMD: 1.93, 95% CI: 1.08, 2.79), IL-6 (SMD: 2.56, 95% CI: 1.79, 3.33) and IL-17 (SMD: 6.28, 95% CI: 3.57, 8.99) levels compared to non-AAA controls. In human serum, TNF-α (SMD: 1.11, 95% CI: 0.25, 1.97) and IL-6 (SMD: 1.42, 95% CI: 0.91, 1.92) levels were significantly elevated compared to non-AAA controls. These findings implicate TNF-α, IL-17 and IL-6 in AAA pathogenesis. Randomised controlled trials testing the value of bDMARDs in limiting AAA growth may be warranted.

Cytokines in Abdominal Aortic Aneurysm: Master Regulators With Clinical Application

Abdominal aortic aneurysm (AAA) is a potentially life-threatening disorder with a mostly asymptomatic course where the abdominal aorta is weakened and bulged. Cytokines play especially important roles (both positive and negative) among the molecular actors of AAA development. All the inflammatory cascades, extracellular matrix degradation and vascular smooth muscle cell apoptosis are driven by cytokines. Previous studies emphasize an altered expression and a changed epigenetic regulation of key cytokines in AAA tissue samples. Such cytokines as IL-6, IL-10, IL-12, IL-17, IL-33, IL-1β, TGF-β, TNF-α, IFN-γ, and CXCL10 seem to be crucial in AAA pathogenesis. Some data obtained in animal studies show a protective function of IL-10, IL-33, and canonical TGF-β signaling, as well as a dual role of IL-4, IFN-γ and CXCL10, while TNF-α, IL-1β, IL-6, IL-12/IL-23, IL-17, CCR2, CXCR2, CXCR4 and the TGF-β noncanonical pathway are believed to aggravate the disease. Altogether data highlight significance of cytokines as informative markers and predictors of AAA. Pathologic serum/plasma concentrations of IL-1β, IL-2, IL-6, TNF-α, IL-10, IL-8, IL-17, IFN-γ, and PDGF have been already found in AAA patients. Some of the changes correlate with the size of aneurysms. Moreover, the risk of AAA is associated with polymorphic variants of genes encoding cytokines and their receptors: CCR2 (rs1799864), CCR5 (Delta-32), IL6 (rs1800796 and rs1800795), IL6R (rs12133641), IL10 (rs1800896), TGFB1 (rs1800469), TGFBR1 (rs1626340), TGFBR2 (rs1036095, rs4522809, rs1078985), and TNFA (rs1800629). Finally, 5 single-nucleotide polymorphisms in gene coding latent TGF-β-binding protein (LTBP4) and an allelic variant of TGFB3 are related to a significantly slower AAA annual growth rate.

Angiotensin II is a crucial factor in retinal aneurysm formation

Retinal arterial macroaneurysms are characterized by the acquired fusiform or saccular dilatations of the retinal artery. Angiotensin II (Ang II) is a major signal molecule of the renin-angiotensin system, which exerts a range of pathogenic actions that are relevant to retinal vascular abnormalities. We aimed to study the effect of Ang II on retinal vessels and explore its relationship with retinal aneurysmal disease. C57BL/6J male mice were administered Ang II at 1000 ng/kg/min for 28 days, and the mice given saline served as controls. The mice in the treatment group were treated once daily by gastric gavage of candesartan cilexetil (an antagonist of Ang II type 1 (AT1) receptor) at 100 mg/kg/day. The in vivo imaging of murine retinas was performed using fundus photography, optical coherence tomography, fluorescein angiography, and indocyanine green angiography at 7th, 14th, and 28th days of infusion. At the end of the infusion and treatment, the morphological changes were evaluated by histopathological examination and electron microscopy; the levels of related proteins in murine retinas were examined by antibody array and Western blot analyses. We found that Ang II infusion induced aneurysm formation in mice retina, which presented as either solitary aneurysms or retinal arterial beading. The aneurysm formation was often accompanied with vessel leakage. Moreover, Ang II infusion itself may result in increased vascular permeability and ganglion cell and inner plexiform layer thickening. The blockade of AT1 receptors by systemic administration of candesartan cilexetil alleviated the Ang II-induced retinal vasculopathy. The protein level analysis further showed that Ang II upregulated IL-1β, PDGFR-β, and MMP-9 expression, and the expression of IL-1β could be inhibited by AT1 receptor antagonist. Our study provides evidence that Ang II is a crucial factor in retinal aneurysm formation and vessel leakage. It is probably the combined effect of Ang II on vessel inflammatory response, pericyte function, and extracellular matrix remodeling that predisposes the retinal arterial wall to aneurysm formation and blood-retinal barrier breakdown.

A Novel Mechanism Underlying Inflammatory Smooth Muscle Phenotype in Abdominal Aortic Aneurysm

[Figure: see text].

Immune checkpoint programmed death-1 mediates abdominal aortic aneurysm and pseudoaneurysm progression

PURPOSE

The causes and pathogenetic mechanisms underlying abdominal aortic aneurysms (AAAs) and pseudoaneurysms are not fully understood. We hypothesized that inhibiting programmed death-1 (PD-1) can decrease AAA and pseudoaneurysm formation in mouse and rat models.

METHODS

Human AAA samples were examined in conjunction with an adventitial calcium chloride (CaCl2) application mouse model and an aortic patch angioplasty rat model. Single-dose PD-1 antibody (4 mg/kg) or BMS-1 (PD-1 inhibitor-1) (1 mg/kg) was administered by intraperitoneal (IP) or intraluminal injection. In the intramural injection group, PD-1 antibody was injected after CaCl2 incubation. The rats were divided into three groups: (1) the control group was only decellularized without other special treatment, (2) the PD-1 antibody-coated patch group, and (3) the BMS-1 coated patch group. Patches implanted in the rat abdominal aorta were harvested on day 14 after implantation and analyzed.

RESULTS

Immunohistochemical analysis showed PD-1-positive cells, PD-1 and CD3, PD-1 and CD68, and PD-1 and α-actin co-expressed in the human AAA samples. Intraperitoneal (IP) injection or intraluminal injection of PD-1antibody/BMS-1 significantly inhibited AAA progression. PD-1 antibody and BMS-1 were each successfully conjugated to decellularized rat thoracic artery patches, respectively, by hyaluronic acid. Patches coated with either humanized PD-1 antibody or BMS-1 can also inhibit pseudoaneurysm progression and inflammatory cell infiltration.

CONCLUSION

PD-1 pathway inhibition may be a promising therapeutic strategy for inhibiting AAA and pseudoaneurysm progression.

Neutrophils as Regulators and Biomarkers of Cardiovascular Inflammation in the Context of Abdominal Aortic Aneurysms

Neutrophils represent up to 70% of circulating leukocytes in healthy humans and combat infection mostly by phagocytosis, degranulation and NETosis. It has been reported that neutrophils are centrally involved in abdominal aortic aneurysm (AAA) pathogenesis. The natural course of AAA is growth and rupture, if left undiagnosed or untreated. The rupture of AAA has a very high mortality and is currently among the leading causes of death worldwide. The use of noninvasive cardiovascular imaging techniques for patient screening, surveillance and postoperative follow-up is well established and recommended by the current guidelines. Neutrophil-derived biomarkers may offer clinical value to the monitoring and prognosis of AAA patients, allowing for potential early therapeutic intervention. Numerous promising biomarkers have been studied. In this review, we discuss neutrophils and neutrophil-derived molecules as regulators and biomarkers of AAA, and our aim was to specifically highlight diagnostic and prognostic markers. Neutrophil-derived biomarkers may potentially, in the future, assist in determining AAA presence, predict size, expansion rate, rupture risk, and postoperative outcome once validated in highly warranted future prospective clinical studies.

Inflammasomes in the Pathophysiology of Aortic Disease

Aortic diseases comprise aneurysms, dissections, and several other pathologies. In general, aging is associated with a slow but progressive dilation of the aorta, along with increased stiffness and pulse pressure. The progression of aortic disease is characterized by subclinical development or acute presentation. Recent evidence suggests that inflammation participates causally in different clinical manifestations of aortic diseases. As of yet, diagnostic imaging and surveillance is mainly based on ultrasonography, computed tomography (CT), and magnetic resonance imaging (MRI). Little medical therapy is available so far to prevent or treat the majority of aortic diseases. Endovascular therapy by the introduction of covered stentgrafts provides the main treatment option, although open surgery and implantation of synthetic grafts remain necessary in many situations. Because of the risks associated with surgery, there is a need for identification of pharmaceutical targets interfering with the pathophysiology of aortic remodeling. The participation of innate immunity and inflammasome activation in different cell types is common in aortic diseases. This review will thus focus on inflammasome activities in vascular cells of different chronic and acute aortic diseases and discuss their role in development and progression. We will also identify research gaps and suggest promising therapeutic targets, which may be used for future medical interventions.

The role of dipeptidyl peptidase-IV in abdominal aortic aneurysm pathogenesis: A systematic review

Abdominal aortic aneurysm (AAA) is an important vascular disease carrying significant mortality implications due to the risk of aneurysm rupture. Current management relies exclusively on surgical repair as there is no effective medical therapy. A key element of AAA pathogenesis is the chronic inflammation mediated by inflammatory cells releasing proteases, including the enzyme dipeptidyl peptidase IV (DPP-IV). This review sought to recapitulate available evidence on the involvement of DPP-IV in AAA development. Further, we assessed the experimental use of currently available DPP-IV inhibitors for AAA management in murine models. Embase, Medline, PubMed, and Web of Science databases were utilised to access the relevant studies. The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). A narrative synthesis approach was used. Sixty-four studies were identified from the searched databases; a final 11 were included in the analysis. DPP-IV was reported to be significantly increased in both AAA tissue and plasma of patients and correlated with AAA growth. DPP-IV inhibitors (sitagliptin, vildagliptin, alogliptin, and teneligliptin) were all shown to attenuate AAA formation in murine models by reducing monocyte differentiation, the release of reactive oxygen species (ROS), and metalloproteinases (MMP-2 and MMP-9). DPP-IV seems to play a role in AAA pathogenesis by propagating the inflammatory microenvironment. This is supported by observations of decreased AAA formation and reduction in macrophage infiltration, ROS, matrix MMPs, and interleukins following the use of DPP-IV inhibitors in murine models. There is an existing translational gap from preclinical observations to clinical trials in this important and novel mechanism of AAA pathogenesis. This prior literature highlights the need for further research on molecular targets involved in AAA formation.

Risk of non-typhoidal Salmonella vascular infections is increased with degree of atherosclerosis and inflammation: A multicenter study in southern Taiwan

BACKGROUND

Atherosclerosis and vascular inflammatory response have been considered as risk factors for non-typhoidal Salmonella (NTS) vascular infection. The study aims to assess the risk of vascular infection by measuring atherosclerosis severity, NTS vascular infection (NTSVI) score, and serum levels of inflammatory markers in people with NTS bacteremia.

METHODS

A prospective observational study was conducted in two medical centers and two regional hospitals. Adults aged ≥50 years with NTS bacteremia who underwent computed tomography (CT) scan for revealing vascular infections were enrolled. The degree of atherosclerosis was scaled by a calcium score determined by a CT scan. Serum concentrations of inflammatory biomarkers were determined in the patients enrolled in a medical center.

RESULTS

Fourteen (20.3%) of 69 patients with NTS bacteremia had vascular infections. Calcium scores over the thoracic (12,540 vs. 3,261, P = 0.0005) and abdominal (9755 vs. 3,461, P = 0.0006) aorta of those with vascular infections were higher than those without vascular infection. All vascular infections were present in the high-risk group (NTSVI score ≥1), yielding a sensitivity of 100% and specificity of 30.9%. Among 17 low-risk patients (NTSVI score <1), none had vascular infections, resulting in a negative predictive value of 100%. Higher plasma concentrations of IL-1β were detected in the cases of vascular infection than those in the control group (23.6 vs. 1.06 pg/mL, P = 0.001).

CONCLUSION

Atherosclerosis of the aorta which is associated with a positive NTSVI score can predict the occurrence of vascular infections and serum IL-1β could be a biomarker for vascular infection in patients with NTS bacteremia.

Importance of NLRP3 Inflammasome in Abdominal Aortic Aneurysms

Abdominal aortic aneurysm (AAA) is a chronic inflammatory degenerative aortic disease, which particularly affects older people. Nucleotide-binding oligomerization domain-like receptor family protein 3 (NLRP3) inflammasome is a multi-protein complex and mediates inflammatory responses by activating caspase 1 for processing premature interleukin (IL)-1β and IL-18. In this review, we first summarize the principle of NLRP3 inflammasome activation and the functionally distinct classes of small molecule NLRP3 inflammasome inhibitors. Next, we provide a comprehensive literature review on the expression of NLRP3 inflammasome effector mediators (IL-1β and IL-18) and components (caspase 1, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) and NLRP3) in clinical and experimental AAAs. Finally, we discuss the influence of genetic deficiency or pharmacological inhibition of individual effector mediators and components of NLRP3 inflammasome on experimental AAAs. Accumulating clinical and experimental evidence suggests that NLRP3 inflammasome may be a promise therapeutic target for developing pharmacological strategies for clinical AAA management.

Novel Blood Biomarkers for a Diagnostic Workup of Acute Aortic Dissection

Acute aortic dissection (AAD) is a rare condition, but together with acute myocardial infarction (AMI) and pulmonary embolism (PE) it belongs to the most relevant and life-threatening causes of acute chest pain. Until now, there has been no specific blood test in the diagnostic workup of AAD. To identify clinically relevant biomarkers for AAD, we applied Proseek^® Multiplex assays to plasma samples from patients with AAD, AMI, PE, thoracic aortic aneurysm (TAA), and non-cardiovascular chest pain (nonCVD). Subsequently, we validated top hits using conventional immunoassays and examined their expression in the aortic tissue. Interleukin 10 (IL-10) alone showed the best performance with a sensitivity of 55% and a specificity of 98% for AAD diagnosis. The combination of D-dimers, high-sensitive troponin T (hs-TnT), interleukin 6 (IL-6), and plasminogen activator inhibitor 1 (PAI1) correctly classified 75% of AAD cases, delivering a sensitivity of 83% and specificity of 95% for its diagnosis. Moreover, this model provided the correct classification of 77% of all analyzed cases. Our data suggest that IL-10 shows potential to be a rule-in biomarker for AAD. Moreover, the addition of PAI1 and IL-6 to hs-TnT and D-dimers may improve the discrimination of suspected AAD, AMI, and PE in patients presenting with acute chest pain.

Steroid-sparing effect of anakinra in giant-cell arteritis: a case series with clinical, biological and iconographic long-term assessments

OBJECTIVES

The treatment of giant cell arteritis (GCA) relies on corticosteroids but is burdened by a high rate of relapses and adverse effects. Anti-interleukin-6 treatments show a clear benefit with a significant steroid-sparing effect, but late relapses occur after treatment discontinuation. In addition to interleukin-6, interleukin-1 also appears to play a significant role in GCA pathophysiology. We report herein the efficacy of anakinra, an interleukin-1 receptor antagonist, in 6 GCA patients exhibiting corticosteroid dependence or resistance, specifically analyzing the outcome of aortitis in 4 of them.

METHODS

This retrospective study analyzed the cases of all GCA patients treated with anakinra from the French Study Group for Large Vessel Vasculitis.

RESULTS

After a median duration of anakinra therapy of 19 [18-32] months, all 6 patients exhibited complete clinical and biological remission. Among the 4 patients with large-vessel involvement, 2 had a disappearance of aortitis under anakinra, and 2 showed a decrease in vascular uptake. After a median follow-up of 56 [48-63] months, corticosteroids were discontinued in 4 patients, and corticosteroid dosage could be decreased to 5 mg/day in 2 patients. One patient relapsed 13 months after anakinra introduction in the context of increasing the daily anakinra injection interval to every 48 hours. Three patients experienced transient injection-site reactions, and 1 patient had pneumonia.

CONCLUSION

In this short series, anakinra appears to be an efficient and safe steroid-sparing agent in refractory GCA, with a possible beneficial effect on large-vessel involvement.

Targeting the Extracellular Matrix in Abdominal Aortic Aneurysms Using Molecular Imaging Insights

This review outlines recent preclinical and clinical advances in molecular imaging of abdominal aortic aneurysms (AAA) with a focus on molecular magnetic resonance imaging (MRI) of the extracellular matrix (ECM). In addition, developments in pharmacologic treatment of AAA targeting the ECM will be discussed and results from animal studies will be contrasted with clinical trials. Abdominal aortic aneurysm (AAA) is an often fatal disease without non-invasive pharmacologic treatment options. The ECM, with collagen type I and elastin as major components, is the key structural component of the aortic wall and is recognized as a target tissue for both initiation and the progression of AAA. Molecular imaging allows in vivo measurement and characterization of biological processes at the cellular and molecular level and sets forth to visualize molecular abnormalities at an early stage of disease, facilitating novel diagnostic and therapeutic pathways. By providing surrogate criteria for the in vivo evaluation of the effects of pharmacological therapies, molecular imaging techniques targeting the ECM can facilitate pharmacological drug development. In addition, molecular targets can also be used in theranostic approaches that have the potential for timely diagnosis and concurrent medical therapy. Recent successes in preclinical studies suggest future opportunities for clinical translation. However, further clinical studies are needed to validate the most promising molecular targets for human application.

Molecular MR-Imaging for Noninvasive Quantification of the Anti-Inflammatory Effect of Targeting Interleukin-1β in a Mouse Model of Aortic Aneurysm

Background:

Molecular-MRI is a promising imaging modality for the assessment of abdominal aortic aneurysms (AAAs). Interleukin-1β (IL-1β) represents a new therapeutic tool for AAA-treatment, since pro-inflammatory cytokines are key-mediators of inflammation. This study investigates the potential of molecular-MRI to evaluate therapeutic effects of an anti-IL-1β-therapy on AAA-formation in a mouse-model.

Methods:

Osmotic-minipumps were implanted in apolipoprotein-deficient-mice (N = 27). One group (Ang-II+01BSUR group, n = 9) was infused with angiotensin-II (Ang-II) for 4 weeks and received an anti-murine IL-1β-antibody (01BSUR) 3 times. One group (Ang-II-group, n = 9) was infused with Ang-II for 4 weeks but received no treatment. Control-group (n = 9) was infused with saline and received no treatment. MR-imaging was performed using an elastin-specific gadolinium-based-probe (0.2 mmol/kg).

Results:

Mice of the Ang-II+01BSUR-group showed a lower aortic-diameter compared to mice of the Ang-II-group and control mice (p < 0.05). Using the elastin-specific-probe, a significant decrease in elastin-destruction was observed in mice of the Ang-II+01BSUR-group. In vivo MR-measurements correlated well with histopathology (y = 0.34x-13.81, R² = 0.84, p < 0.05), ICP-MS (y = 0.02x+2.39; R² = 0.81, p < 0.05) and LA-ICP-MS. Immunofluorescence and western-blotting confirmed a reduced IL-1β-expression.

Conclusions:

Molecular-MRI enables the early visualization and quantification of the anti-inflammatory-effects of an IL-1β-inhibitor in a mouse-model of AAAs. Responders and non-responders could be identified early after the initiation of the therapy using molecular-MRI.

Itaconate prevents abdominal aortic aneurysm formation through inhibiting inflammation via activation of Nrf2

BACKGROUND

Identifying effective drugs to suppress vascular inflammation is a promising strategy to delay the progression of abdominal aortic aneurysm (AAA). Itaconate has a vital role in regulating inflammatory activation in various inflammatory diseases. However, the role of itaconate in the progression of AAA is unknown. In this study, we explored the inhibitory effect of itaconate on AAA formation and its underlying mechanisms.

METHODS

Quantitative PCR, western blotting and immunohistochemistry were used to determine Irg1 and downstream Nrf2 expression in human and mouse AAA samples. Liquid chromatograph-mass spectrometry (LC-MS) analysis was performed to measure the abundance of itaconate. OI treatment and Irg1 knockdown were performed to study the role of OI in AAA formation. Nrf2 intervention in vivo was performed to detect the critical role of Nrf2 in the beneficial effect of OI on AAA.

FINDINGS

We found that itaconate suppressed the formation of angiotensin II (Ang II)-induced AAA in apolipoprotein E-deficient (Apoe^-/-) mice, while Irg1 deficiency exerted the opposite effect. Mechanistically, itaconate inhibited vascular inflammation by enabling Nrf2 to function as a transcriptional repressor of downstream inflammatory genes via alkylation of Keap1. Moreover, Nrf2 deficiency significantly aggravated inflammatory factor expression and promoted AAA formation. In addition, Keap1 overexpression significantly promoted Ang II-induced AAA formation, which was inhibited by itaconate.

INTERPRETATION

Itaconate inhibited AAA formation by suppressing vascular inflammation, and therapeutic approaches to increase itaconate are potentially beneficial for preventing AAA formation.

FUNDING

National Natural Science Foundations of China and Guangzhou regenerative medicine and Health Laboratory of Guangdong.

IL (Interleukin)-1 Receptor Antagonist Increases Ang (Angiotensin [1–7]) and Decreases Blood Pressure in Obese Individuals

IL (Interleukin)-1 antagonism decreases blood pressure in obese individuals. The underlying mechanisms are unknown. Based on experimental data, we hypothesized an effect of IL-1 antagonism via modulation of the renin-angiotensin-aldosterone system. In this explorative study, we examined shorter- (2 days) and longer-term effects (4 weeks) of IL-1 antagonism (anakinra/Kineret) on renin-angiotensin system peptide profiles and on hemodynamic parameters assessed by noninvasive measurement in obese (body mass index ≥30 kg/m 2 ) individuals from 2 interventional trials (a prospective interventional trial [n=73] and a placebo controlled-double blinded interventional trial [n=67]). A total of 140 patients were included. Systolic blood pressure decreased after short-term (absolute difference −5.2 mm Hg [95% CI, −8.5 to −1.8]; P =0.0006) and after longer-term treatment with anakinra (absolute difference −3.9 mm Hg [95% CI, −7.59 to −0.21]; P =0.04), with no change in blood pressure in the placebo group. Upon IL-1 antagonism, equilibrium levels of Ang II (angiotensin II), Ang I, aldosterone, and renin remained unchanged. In contrast, Ang (1–7) peptide levels increased after 4 weeks (between-group difference 16.35 pmol/L [95% CI, 1.22–30.17], P =0.03), as well as the Ang (1–7)/Ang II ratio (between-group difference 0.42 [95% CI, 0.17–0.67], P =0.02) in comparison to placebo. Consistently, the stroke systemic vascular resistance index significantly decreased in the anakinra group (between-group difference of −62.65 dyn/sec per cm −5 per m 2 [95% CI, −116.94 to −18.36], P =0.008, consistent with a 25% decrease). IL-1 antagonism increased the vasodilatory Ang (1–7) peptide after 4 weeks of treatment in obese individuals, paralleled by a decrease in peripheral vascular resistance. These findings point to an IL-1 mediated blood pressure-lowering mechanism via modulation of Ang (1–7).

Registration—

URL: https://www.clinicaltrials.gov . Unique identifiers: NCT02227420 and NCT02672592.

The role of IL-1β in aortic aneurysm

Interleukin-1β (IL-1β) is a vital cytokine that plays an important role in regulating immune responses to infectious challenges and sterile insults. In addition, two endogenous inhibitors of functional receptor binding, IL-1 receptor antagonist (IL-1Ra), complete the family. To gain biological activity, IL-1β requires processing by the protease caspase-1 and activation of inflammasomes. Numerous clinical association studies and experimental approaches have implicated members of the IL-1 family, their receptors, or components of the processing machinery in the underlying processes of cardiovascular diseases. Here, we summarize the current state of knowledge regarding the pro-inflammatory and disease-modulating role of the IL-1 family in aneurysm. We discuss clinical evidence, signalling pathway, and mechanism of action and last, lend a perspective on currently developing therapeutic strategies involving IL-1β in aneurysm.

Comprehensive Cardiac Rehabilitation as a Therapeutic Strategy for Abdominal Aortic Aneurysm

Abdominal aortic aneurysms (AAA) are referred to as “time bombs”. The only way to prevent AAA rupture is elective repair beforehand using surgical replacement or an endovascular procedure. Non-surgical strategies to prevent AAA expansion are under intense investigation. At each AAA stage, that is, occurrence, expansion, and rupture, the mechanisms and risk factors are different, as discussed in this review. Based on the mechanism and risk factors for AAA expansion, the most effective strategy against AAA expansion need to be identified, but so far none has. Exercise is known to be essential for preventing atherosclerosis related to the coexistence of AAA and CAD, but some doctors are hesitant to prescribe exercise programs to AAA patients given that BP elevation during exercise can cause AAA expansion or rupture. In our retrospective study and prospective study on the safety and effectiveness of exercise for AAA patients, the protective role of mild-moderate exercise against expansion of small AAA was clearly shown. The stability of AAA on exercise might be related to reduced inflammatory activity in the aortic wall, stabilized elevation in BP during exercise, increased aortic blood flow, upregulation of transforming growth factor-β1, moderated BMI and/or fat, or improved endothelial function. Until a revolutionary drug emerges that can regress AAA, cardiac rehabilitation remains the best strategy for preventing AAA expansion and rupture.

Formononetin attenuates monocrotaline‑induced pulmonary arterial hypertension via inhibiting pulmonary vascular remodeling in rats

Pulmonary arterial hypertension (PAH) is a life‑threatening disease induced by the excessive proliferation and reduced apoptosis of pulmonary artery smooth muscle cells (PASMCs). Formononetin (FMN) is a natural isoflavone with numerous cardioprotective properties, which can inhibit the proliferation and induce the apoptosis of tumor cells; however, whether FMN has a therapeutic effect on PAH remains unclear. In the present study, PAH was induced in rats with monocrotaline (MCT, 60 mg/kg); rats were then administered FMN (10, 30 or 60 mg/kg/day). At the end of the experiment, hemodynamic changes, right ventricular hypertrophy and lung morphological characteristics were evaluated. α‑smooth muscle actin (α‑SMA), proliferating cell nuclear antigen (PCNA), and TUNEL were detected by immunohistochemical staining. The expression of PCNA, Bcl‑2‑associated X protein (Bax), Bcl‑2 and, cleaved caspase‑3, and activation of AKT and ERK were examined by western blot analysis. The results demonstrated that FMN significantly ameliorated the right ventricular systolic pressure, right ventricular hypertrophy, and pulmonary vascular remodeling induced by MCT. FMN also attenuated MCT‑induced increased expression of α‑SMA and PCNA. The ratio of Bax/Bcl‑2 and cleaved caspase‑3 expression increased in rat lung tissue in response to FMN treatment. Furthermore, reduced phosphorylation of AKT and ERK was also observed in FMN‑treated rats. Therefore, FMN may provide protection against MCT‑induced PAH by preventing pulmonary vascular remodeling, potentially by suppressing the PI3K/AKT and ERK pathways in rats.

Inflammasome activity in leucocytes decreases with abdominal aortic aneurysm progression

Abdominal aortic aneurysms (AAAs) are characterized by chronic inflammatory cell infiltration. The present extended immunohistochemistry study aimed to characterize inflammation in AAA and aortic control samples. In specific, the composition of the infiltrating immune cells and the expression of five inflammasome components in these immune cells were evaluated, in order to characterize their role in AAA development. A total of 104 biopsies from 48 AAA patients and 40 healthy specimens from organ donors were evaluated for their grade of inflammation. Infiltrating leukocytes were characterized by specific markers (CD3, CD20 and CD68), intramural localization and inflammasome protein expression [NLR family pyrin domain containing 3 (NLRP3), absent in melanoma 2 (AIM2), apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), Caspase-1 and Caspase-5]. Macrophages, B and T lymphocytes were detected to a similar extent in grade 1, 2 and 3 AAA specimens, whereas in control samples, B and T lymphocytes were rarely observed in grade 1 lesions. Expression frequencies of NLRP3, AIM2 and Caspase-5 were significantly higher in grade 1 lesions of AAA samples compared with grade 1 lesions in control samples. Finally, AIM2, ASC, and Caspase-5 displayed significantly lower expression frequencies in grade 3 compared with grade 2 AAA specimens, and all inflammasome components were less frequently detected in grade 3 than in grade 1 lesions of AAA. This indicates that inflammasome activities decrease with AAA progression in infiltrating leukocytes. No statistically significant association was found for grade 2 and grade 3 lesions and total leukocyte count, C-reactive protein levels, maximal aortic diameter, plasma cholesterol level or biomechanical parameters (derived from finite element analysis) of the respective patients. Overall, the aortic wall of AAA contained lymphocytes and macrophages with different states of activity. The present data suggested that therapeutic inhibition of specific inflammasome components might counteract AAA development and progression.

The potential of cardiac rehabilitation as a method of suppressing abdominal aortic aneurysm expansion: a pilot study

This study is a prospective evaluation of the effectiveness of cardiac rehabilitation (CR) in terms of clinical outcomes for small abdominal aortic aneurysms (AAA) that were previously reported in a retrospective cohort study. We conducted a prospective non-randomized trial on patients with small AAA (N = 40; mean age 75.0 ± 6.6 years). Patients were enrolled into one of two groups, rehabilitation (CR) or non-rehabilitation (non-CR) group. Only CR group participated in a supervised-CR program including bicycle ergometer for 150 days. The AAA expansion rate and the risk of AAA repair were compared between two groups. We also researched the relationship between AAA expansion rate and body composition, blood IL-6 and TGFβ1 levels. The CR (N = 15) and non-CR groups (N = 25) were comparable in terms their baseline data. The CR group had a significantly smaller change in the maximal AAA size (- 1.3 ± 2.4 mm/years) compared to the non-CR group (2.0 ± 3.6 mm/years) (p < 0.01). The IL-6, and TGFβ1 levels were unrelated to the changes in AAA size. There was mild positive correlation between the change in systolic blood pressure from rest to exercise and the AAA expansion rate (p = 0.06). The risk of AAA repair after 12 months was lower in the CR group compared to the non-CR group (0% vs. 28%, respectively). CR in patients with small AAA significantly suppressed AAA expansion and resulted in a lowered risk of AAA repair.Clinical trial Trial name: The study of the profitability and protective effect of cardiac rehabilitation on abdominal aortic aneurysm. Number: UMIN000028237. UTL: https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R0000323.

Angiotensin-(1-7) and Alamandine Promote Anti-inflammatory Response in Macrophages In Vitro and In Vivo

The renin-angiotensin system (RAS) peptides play an important role in inflammation. Resolution of inflammation contributes to restore tissue homeostasis, and it is characterized by neutrophil apoptosis and their subsequent removal by macrophages, which are remarkable plastic cells involved in the pathophysiology of diverse inflammatory diseases. However, the effects of RAS peptides on different macrophage phenotypes are still emerging. Here, we evaluated the effects of angiotensin-(1-7) (Ang-(1-7)) and the most novel RAS peptide, alamandine, on resting (M0), proinflammatory M(LPS+IFN-γ), and anti-inflammatory M(IL-4) macrophage phenotypes in vitro, as well as on specific immune cell populations and macrophage subsets into the pleural cavity of LPS-induced pleurisy in mice. Our results showed that Ang-(1-7) and alamandine, through Mas and MrgD receptors, respectively, do not affect M0 macrophages but reduce the proinflammatory TNF-α, CCL2, and IL-1β transcript expression levels in LPS+IFN-γ-stimulated macrophages. Therapeutic administration of these peptides in LPS-induced inflammation in mice decreased the number of neutrophils and M1 (F4/80lowGr1+CD11bmed) macrophage frequency without affecting the other investigated macrophage subsets. Our data suggested that both Ang-(1-7) and alamandine, through their respective receptors Mas and MrgD, promote an anti-inflammatory reprogramming of M(LPS+IFN-γ)/M1 macrophages under inflammatory circumstances and potentiate the reprogramming induced by IL-4. In conclusion, our work sheds light on the emerging proresolving properties of Ang-(1-7) and alamandine, opening new avenues for the treatment of inflammatory diseases.

Statins, metformin, proprotein-convertase-subtilisin-kexin type-9 (PCSK9) inhibitors and sex hormones: Immunomodulatory properties?

The immune system is closely intertwined with the endocrine system. Many effects of medications used for various clinical endocrine conditions such as the metabolic syndrome, hypercholesterolemia, diabetes mellitus, hypertension, Graves' disease and others also have an impact on the immune system. Some drugs including statins, metformin, angiotensin converting enzyme and proprotein-convertase-subtilisin-kexin type-9 (PCSK9) inhibitors and sex hormones are known to have immunomodulatory properties. We here review the literature on this topic and provide some clinical examples including the use of statins in Graves' orbitopathy, rheumatoid arthritis, multiple sclerosis, and adult-onset Still's disease. In that context, we introduce a special immunodiagnostics method developed at the Institute of  Diabetes "Gerhardt Katsch" in Karlsburg, Germany, to not only measure but also monitor immune disease activity.