Aortic aneurysms: current pathogenesis and therapeutic targets

Impact of Sorbs2 dysfunction on cardiovascular diseases

Despite significant advancements in prevention and treatment over the past decades, cardiovascular diseases (CVDs) remain the leading cause of death worldwide. CVDs involve multifactorial inheritance, but our understanding of the genetic impact on these diseases is still incomplete. Sorbin and SH3 domain-containing protein 2 (Sorbs2) is ubiquitously expressed in various tissues, including the cardiovascular system. Increasing evidence suggests that Sorbs2 malfunction contributes to CVDs. This manuscript will review our current understanding of the potential mechanisms underlying Sorbs2 dysregulation in the development of CVDs.

Y-box binding protein 1: A critical target for understanding and treating cardiovascular disease

Cardiovascular diseases (CVDs) remain a significant public health burden, characterized by escalating morbidity and mortality rates and demanding novel therapeutic approaches. Cold shock protein Y-box binding protein 1 (YB-1), a highly conserved RNA/DNA-binding protein, has emerged as a pivotal regulator in various pathophysiological processes, including CVDs. YB-1 exerts pleiotropic functions by modulating gene transcription, pre-mRNA splicing, mRNA translation, and stability. The expression and function of YB-1 are intricately regulated by its subcellular localization, post-translational modifications, upstream regulatory signals. YB-1 plays a multifaceted role in CVDs, influencing inflammation, oxidative stress, cell proliferation, apoptosis, phenotypic switching of smooth muscle cells, and mitochondrial dysfunction. However, the regulation of YB-1 expression and function in CVDs is complex and context-dependent, exhibiting divergent effects even in the same disease across different cell types or at disease stages. This review comprehensively explores the structure, regulation, and functional significance of YB-1 in CVDs. We delve into the transcriptional and translational control mechanisms of YB-1, as well as its post-translational modifications. Furthermore, we elucidate the upstream signaling pathways that influence YB-1 expression, with a particular emphasis on non-coding RNAs and specific upstream molecules. Finally, we systematically examine the role of YB-1 in CVDs, summarizing its expression patterns, regulatory mechanisms, and therapeutic potential as a promising target for novel therapeutic interventions. By providing a comprehensive overview of YB-1's involvement in CVDs, this review aims to stimulate further research and facilitate the development of targeted therapies to improve cardiovascular health.

The active mechanical characteristics of arterial smooth muscle during aneurysm remodeling

Introduction

Abdominal Aortic Aneurysm (AAA) is a common vascular disease characterized by progressive expansion and remodeling of the aortic wall. However, with the gradual expansion of blood vessels, the walls of blood vessels cannot withstand the tension and rupture, jeopardizing people's health.

Methods

The aim of the experiment was to establish an abdominal aortic aneurysm model in rats by applying porcine pancreatic elastase externally, to measure the diameter and thickness of blood vessels as well as hemodynamics using animal ultrasound, to measure the active contraction of blood vessels, the rate of contraction, and the contraction stress using vascular mechanics equipment, and to observe the pathological changes in the process of AAA growth using vascular pathological staining.

Results

This study revealed that with the escalation of the inflammatory response, there is a breakdown of elastic fibers and collagen fibers, leading to a decrease in the active contraction force of the arteries. However, it was observed that by alleviating the inflammation, there was a notable enhancement in the active contraction force of the arteries.

Discussion

To describe the development process of AAA from a biomechanical point of view, to reveal the histopathological mechanism, and thus to identify the theoretical basis for clinical treatment.

Computational fluid dynamics in cardiac surgery and perfusion: A review

Cardiovascular diseases persist as a leading cause of mortality and morbidity, despite significant advances in diagnostic and surgical approaches. Computational Fluid Dynamics (CFD) represents a branch of fluid mechanics widely used in industrial engineering but is increasingly applied to the cardiovascular system. This review delves into the transformative potential for simulating cardiac surgery procedures and perfusion systems, providing an in-depth examination of the state-of-the-art in cardiovascular CFD modeling. The study first describes the rationale for CFD modeling and later focuses on the latest advances in heart valve surgery, transcatheter heart valve replacement, aortic aneurysms, and extracorporeal membrane oxygenation. The review underscores the role of CFD in better understanding physiopathology and its clinical relevance, as well as the profound impact of hemodynamic stimuli on patient outcomes. By integrating computational methods with advanced imaging techniques, CFD establishes a quantitative framework for understanding the intricacies of the cardiac field, providing valuable insights into disease progression and treatment strategies. As technology advances, the evolving synergy between computational simulations and clinical interventions is poised to revolutionize cardiovascular care. This collaboration sets the stage for more personalized and effective therapeutic strategies. With its potential to enhance our understanding of cardiac pathologies, CFD stands as a promising tool for improving patient outcomes in the dynamic landscape of cardiovascular medicine.

SERCA2 dysfunction accelerates angiotensin II-induced aortic aneurysm and atherosclerosis by induction of oxidative stress in aortic smooth muscle cells

BACKGROUND AND AIM

Our previous research indicates that sarcoplasmic/endoplasmic reticulum calcium ATPase 2 (SERCA2) dysfunction facilitates the phenotypic transformation of aortic smooth muscle cells (ASMCs) and intensifies aortic aneurysm through the regulation of calcium-dependent pathways and endoplasmic reticulum stress. Our hypothesis is that additional mechanisms are involved in aortic aneurysm and atherosclerosis induced by SERCA2 dysfunction from the perspective of ASMC phenotypic transformation.

METHODS & RESULTS

In SERCA2 dysfunctional mice and their control littermates, ASMCs were isolated to analyze protein expression and cell functions, and angiotensin II was infused into these mice that were backcrossed into LDL receptor deficient background to induce aortic aneurysm and atherosclerosis. In ASMCs from SERCA2 dysfunctional mice, the cell cycle was accelerated, and proliferation and migration were enhanced, which could be reversed by SERCA agonist CDN1163 or calcium chelator BAPTA-AM. In ASMCs, SERCA2 dysfunction increased reactive oxygen species (ROS) production, activating extracellular signal-regulated kinases 1 and 2 (ERK1/2) and angiotensin II/angiotensin II type 1 receptor (AT1R) pathways. Both ERK1/2 and angiotensin II/AT1R activations are implicated in SERCA2 dysfunction-induced ASMC phenotypic transformation and ROS production. The redox modulator Tempol suppressed ERK1/2 and angiotensin II/AT1R pathways, inhibiting ASMC phenotypic transformation and alleviating angiotensin II-induced aortic aneurysm and atherosclerosis.

CONCLUSION

SERCA2 dysfunction accelerates aortic aneurysm and atherosclerosis by inducing oxidative stress in ASMCs, with activations of ERK1/2 and angiotensin II/AT1R involved in ASMC phenotypic transformation. Inhibition of oxidative stress in ASMCs is beneficial in alleviating angiotensin II-induced aortic aneurysm and atherosclerosis caused by SERCA2 dysfunction.

Network pharmacology and molecular analysis of mechanisms underlying the therapeutic effects of Rhubarb in treating atherosclerosis and abdominal aortic aneurysm

Aim of the study

The aim of this study was to systematically investigate the effects and mechanisms of Rhubarb in the treatment of Atherosclerosis (AS) and Abdominal Aortic Aneurysm (AAA) by utilizing network pharmacology and molecular docking techniques.

Materials and methods

TCMSP systematic pharmacology database was utilized to search for active chemical components of Rhubarb. Disease-related targets were retrieved from the GEO dataset and Disgenet database. Gene interactions were utilized to identify common targets of Rhubarb with AS/AAA, and interaction networks were constructed using Cytoscape 3.9.1. Protein-protein interaction (PPI) networks for the core targets were constructed using the STRING database. GO and KEGG pathway enrichment analysis was performed using DAVID. Molecular docking is used to assess the potential target-active compound interactions.

Results

In our study, 16 active compounds were screened from Rhubarb, along with 310 targets. Additionally, 110 AS/AAA target genes were screened out. Topological analysis of the PPI protein network yielded 23 core targets. The targets, biological functions and signaling pathways of Rhubarb in AS/AAA were further investigated. The analysis indicated that Rhubarb may be effective in treating AS/AAA through processes such as lipids, atherosclerosis, extracellular matrix catabolism, collagenolytic metabolic processes, and the extracellular environment. Five core pharmacological targets were also identified: TNF, IL-1β MMP9, TP53, and PPARG. Molecular docking showed a strong binding ability between the active compounds and the screened targets.

Conclusions

This study successfully predicted the molecular functions, pharmacological targets, and pathways associated with Rhubarb for treating AS/AAA. In addition, identified potential active ingredients can be used as a source for AS/AAA drug screening.

The protective role of SGLT2 inhibitors on aortic aneurysm mediated by oxidative stress and inflammation in type 2 diabetes mellitus

BACKGROUND

Sodium-glucose transport protein 2 inhibitors (SGLT2i) have been widely used to treat patients with type 2 diabetes mellitus (T2DM) and have demonstrated protective effects against certain cardiovascular diseases. However, no clinical research has been conducted to explore the relationship between SGLT2i and the risk of aortic aneurysm (AA).

METHODS

We extracted and analyzed the data of 4964 patients with T2DM from the First Affiliated Hospital of Zhengzhou University during July 2017 to January 2023. Multivariate Cox models, interaction analysis and Kaplan-Meier curves were performed to approximate the associations of SGLT2i therapy on the risk of AA. A sensitivity analysis was performed to test the robustness of results. Mediation analyses explored the roles of inflammatory (neutrophils, lymphocytes, C-reactive protein and alkaline phosphatase) and oxidative stress (gamma glutamyl transferase, total bilirubin, and uric acid) markers in the associations between SGLT2i and AA.

RESULTS

A total of 1942 SGLT2 inhibitor (SGLT2i) users (39.12%) and 3022 non-SGLT2 inhibitor (NonSGLT2i) users were included in final analysis. After full adjustment for potential risk factors, SGLT2i patients were associated with a lower risk of aortic aneurysm (HR, 95% CI 0.91, 0.89-0.98, p = 0.001). Dapagliflozin showed the greatest difference for reduction of aortic aneurysm incidence (HR, 95% CI 0.84, 0.80-0.95, p = 0.011). Subgroup analysis indicated that use of SGLT2i lower the risk of aortic aneurysm in some subgroups of T2DM patients. The sensitivity analysis demonstrated the robustness of the results. CRP, lymphocytes, neutrophils, and uric acid were significantly associated with both SGLT2i and AA, with mediation proportions of 13.35%, 8.83%, 9.67% and 31.17%, respectively.

CONCLUSIONS

Our study suggested that patients using SGLT2i may have a lower risk of aortic aneurysm, and this effect could potentially be mediated by inflammation and oxidative stress. Further mechanistic and prospective studies are required to verify this association.

Hemodynamic disturbance and mTORC1 activation: Unveiling the biomechanical pathogenesis of thoracic aortic aneurysms in Marfan syndrome

Thoracic aortic aneurysm (TAA) significantly endangers the lives of individuals with Marfan syndrome (MFS), yet the intricacies of their biomechanical origins remain elusive. Our investigation delves into the pivotal role of hemodynamic disturbance in the pathogenesis of TAA, with a particular emphasis on the mechanistic contributions of the mammalian target of rapamycin (mTOR) signaling cascade. We uncovered that activation of the mTOR complex 1 (mTORC1) within smooth muscle cells, instigated by the oscillatory wall shear stress (OSS) that stems from disturbed flow (DF), is a catalyst for TAA progression. This revelation was corroborated through both an MFS mouse model (Fbn1 +/C1039G) and clinical MFS specimens. Crucially, our research demonstrates a direct linkage between the activation of the mTORC1 pathway and the intensity in OSS. Therapeutic administration of rapamycin suppresses mTORC1 activity, leading to the attenuation of aberrant SMC behavior, reduced inflammatory infiltration, and restoration of extracellular matrix integrity-collectively decelerating TAA advancement in our mouse model. These insights posit the mTORC1 axis as a strategic target for intervention, offering a novel approach to manage TAAs in MFS and potentially pave insights for current treatment paradigms.

Persistent pain and fever unmasking aortic angiosarcoma at the site of previous endovascular aortic repair

Aortic angiosarcomas are extremely rare and difficult to diagnose. Here, we report a case of persistent pain and fever of unknown origin, culminating in the diagnosis of aortic epithelioid angiosarcoma at the site of a previous Dacron aortic graft.

Olfactory Receptors and Aortic Aneurysm: Review of Disease Pathways

Aortic aneurysm, the pathological dilatation of the aorta at distinct locations, can be attributed to many different genetic and environmental factors. The resulting pathobiological disturbances generate a complex interplay of processes affecting cells and extracellular molecules of the tunica interna, media and externa. In short, aortic aneurysm can affect processes involving the extracellular matrix, lipid trafficking/atherosclerosis, vascular smooth muscle cells, inflammation, platelets and intraluminal thrombus formation, as well as various endothelial functions. Many of these processes are interconnected, potentiating one another. Newer discoveries, including the involvement of odorant olfactory receptors in these processes, have further shed light on disease initiation and pathology. Olfactory receptors are a varied group of G protein coupled-receptors responsible for the recognition of chemosensory information. Although they comprise many different subgroups, some of which are not well-characterized or identified in humans, odorant olfactory receptors, in particular, are most commonly associated with recognition of olfactory information. They can also be ectopically localized and thus carry out additional functions relevant to the tissue in which they are identified. It is thus the purpose of this narrative review to summarize and present pathobiological processes relevant to the initiation and propagation of aortic aneurysm, while also incorporating evidence associating these ectopically functioning odorant olfactory receptors with the overall pathology.

Affinity-Enriched Plasma Proteomics for Biomarker Discovery in Abdominal Aortic Aneurysms

Abdominal aortic aneurysm (AAA) is a life-threatening condition characterized by the weakening and dilation of the abdominal aorta. Few diagnostic biomarkers have been proposed for this condition. We performed mass spectrometry-based proteomics analysis of affinity-enriched plasma from 45 patients with AAA and 45 matched controls to identify changes to the plasma proteome and potential diagnostic biomarkers. Gene ontology analysis revealed a significant upregulation of the proteins involved in inflammation, coagulation, and extracellular matrix in AAA patients, while proteins related to angiogenesis were among those downregulated. Using recursive feature elimination, we identified a subset of 10 significantly regulated proteins that were highly predictive of AAA. A random forest classifier trained on these proteins achieved an area under the curve (AUC) of 0.93 [95% CI: 0.91-0.95] using cross-validation. Further validation in a larger cohort is necessary to confirm these results.

Case Report: Surgical treatment of type B aortic dissection in an adult with double aortic arch

Background

Double aortic arch (DAA) with type B aortic dissection in adults is a rare aortic vascular disease. The abnormal anatomical structure of the aortic arch in such patients presents significant challenges in the selection of surgical approaches, and there is a notable lack of exploration into endovascular repair approaches that simultaneously preserve asymptomatic vascular rings.

Case description

A 43-year-old female patient was admitted due to recurrent chest and back pain lasting for over a month. Computed tomography angiography (CTA) indicated a double aortic arch anomaly with localized dissection of the descending aorta. Esophagography with barium swallow revealed vascular indentation on the upper and middle thoracic esophagus, with mild to moderate local narrowing. Based on a comprehensive preoperative evaluation of the imaging and the patient's clinical history, a thoracic endovascular aortic repair (TEVAR) procedure was performed. Considering that the deformity did not cause any clinical symptoms and that the vessel diameter and distance from the proximal anchoring area were sufficient, the posterior section of the dominant arch was chosen as the proximal anchorage zone, and a stent with proximal bare zone was deployed to maintain blood flow to the distal non-dominant arch and preserve the integrity of the vascular ring. Follow-up CTA scans at one- and six-month post-operation showed that the aortic stent was well-positioned, with no visible primary lesion. The patient reported complete resolution of chest pain and no difficulties with swallowing or breathing.

Conclusion

In adult patients with DAA complicated by aortic dissection, the abnormal anatomy of the aortic arch poses significant challenges in making treatment decisions. After a comprehensive, multidimensional evaluation of the patient's medical history, CTA, and esophagography, we successfully performed TEVAR procedure. This case provides new insights into the surgical strategy for treating such rare conditions.

Inflammation in Abdominal Aortic Aneurysm: Cause or Comorbidity?

Aortic aneurysm is a potentially deadly disease. It is chronic degeneration of the aortic wall that involves an inflammatory response and the immune system, aberrant remodelling of the extracellular matrix, and maladaptive transformation of the aortic cells. This review article focuses on the role of the inflammatory cells in abdominal aortic aneurysm. Studies in human aneurysmal specimens and animal models have identified various inflammatory cell types that could contribute to formation or expansion of aneurysms. These include the commonly studied leukocytes (neutrophils and macrophages) as well as the less commonly explored natural killer cells, dendritic cells, T cells, and B cells. Despite the well-demonstrated contribution of inflammatory cells and the related signalling pathways to development and expansion of aneurysms, anti-inflammatory therapy approaches have demonstrated limitations and may require additional considerations such as a combinational approach in targeting multiple pathways for significant beneficial outcomes.

Vascular Mesenchymal Stromal Cells and Cellular Senescence: A Two-Case Study Investigating the Correlation Between an Inflammatory Microenvironment and Abdominal Aortic Aneurysm Development

An abdominal aortic aneurysm (AAA) is described as a gradual and localized permanent expansion of the aorta resulting from the weakening of the vascular wall. The key aspects of AAA's progression are high proteolysis of the structural elements of the vascular wall, the depletion of vascular smooth muscle cells (VSMCs), and a chronic immunoinflammatory response. The pathological mechanisms underpinning the development of an AAA are complex and still unknown. At present, there are no successful drug treatments available that can slow the progression of an AAA or prevent the rupture of the aneurysmal vascular wall. Recently, it has been suggested that endothelial cellular senescence may be involved in vascular aging and vascular aging diseases, but there is no clear correlation between cellular senescence and AAAs. Therefore, the aim of this study was to identify the presence of senescent cells on the vascular wall of aneurysmatic abdominal aortas and to correlate their distribution with the morphological markers of AAAs. Pathological and healthy segments of abdominal aortas were collected during repair surgery and immediately processed for histological and immunohistochemical analyses. Hematoxylin/eosin, Verhoeff-van Gieson, and Goldner's Masson trichrome staining procedures were carried out to investigate the morphological features related to the pathology. Immunohistochemical investigations for the p21cip1/waf1, p53, and NFkB markers were carried out to selectively identify positive cells in the vascular wall of the AAA samples related to cellular senescence and an inflammatory microenvironment. The results revealed the presence of a few senescent vascular cells on the aneurysmatic wall of the abdominal aortas, surrounded by a highly inflamed microenvironment that was highly expressed in the tunica media and adventitia of both pathological and healthy segments. Our data demonstrate the presence of senescent vascular cells in AAA samples, which could enhance the promotion of a high inflammatory vascular microenvironment, supporting the evolution of the pathology. Although this study was based on only two cases, the results highlight the importance of targeting cellular senescence to reduce an inflammatory microenvironment, which can support the progression of age-related diseases.

ScRNA-seq and bulk RNA-seq identified NUPR1 as novel biomarkers related to CD4 + T cells infiltration for abdominal aortic aneurysm

BACKGROUND

Developing a molecular signature associated with CD4 + T cell infiltration is essential for identifying biomarkers in abdominal aortic aneurysms (AAA). Establishing such a signature is vital for improving diagnostic accuracy and therapeutic strategies for AAA. This study focuses on CD4 + T cells, which are pivotal in the immune microenvironment of AAA, to pinpoint key targets.

METHODS AND RESULTS

We identified CD4 + T cell-related biomarkers in AAA using bulk and single-cell RNA sequencing data from the GEO database. We employed CIBERSORT to assess immune cell infiltration and applied weighted gene co-expression network analysis and differential expression analyses to pinpoint key genes. A nomogram and related score were developed based on these genes. Single-cell RNA sequencing further analyzed their expression across cell types, and KEGG/GO analyses were conducted for candidate genes. Four genes (NUPR1, CCL4L2, CCL3L3, MMP9) were identified finally. Validation via qPCR and immunohistochemistry showed NUPR1 downregulation in aneurysms and an inverse relationship with CD4 + T cells infiltration. Immunofluorescence results indicated NUPR1 was mainly expressed in the cytoplasm of vascular smooth muscle cells (VSMCs). After VSMCs-specific overexpression of NUPR1 via adeno-associated virus, the AAA diameter decreased, while treatment with the NUPR1 nuclear translocation inhibitor ZZW-115 hydrochloride had no effect on AAA size. Overexpression of NUPR1 in VSMCs suppresses the migration of CD4 + T cells.

CONCLUSION

The four-gene signature accurately predicts CD4 + T cell infiltration in AAA patients and may serve as a clinical index. NUPR1 could be a therapeutic target for the interaction between CD4 + T cells and AAA.

Potential effects of a human milk oligosaccharide 6'-sialyllactose on angiotensin II-induced aortic aneurysm via p90RSK/TGF-β/SMAD2 signaling pathway

The aberrant phenotypic transformation of vascular smooth muscle cells (VSMCs) is a key factor in the formation of aortic aneurysm (AA). This study aimed to explore the effects of 6'-sialyllactose (6'-SL), a human milk oligosaccharide, on angiotensin II (Ang II)-induced VSMC dysfunction and AA formation both in vitro and in vivo. An AA model was established in male C57BL/6 mice challenged with Ang II via osmotic pumps and a lysyl oxidase inhibitor, β-aminopropionitrile (BAPN), in drinking water. The mice were administered with 6'-SL, FMK (a p90RSK inhibitor), or losartan (as a positive control). In vitro, VSMCs were pretreated with 6'-SL before Ang II stimulation. We found that p90RSK inhibition abolished Ang II/BAPN-induced thoracic AA and abdominal AA formation. Treatment with 100 mg/kg 6'-SL significantly attenuated Ang II/BAPN-induced aortic dilatation. 6'-SL attenuated Ang II-induced collagen deposition, calcification, and immune cell accumulation. Consistently, 6'-SL downregulated p-p90RSK, p90RSK, and p-SMAD2, and mitigated VSMC contractility loss, as indicated by α-SMA expression in vivo. Interestingly, Ang II-induced transforming growth factor-beta (TGF-β) signaling pathway was suppressed by p90RSK inhibition in VSMCs. 6'-SL treatment significantly reduced TGF-β/SMAD2 targets, including dedifferentiation markers such as osteopontin and vimentin, and elastin degradation factors MMP2 and MMP9. Overexpression of p90RSK in VSMCs enhanced TGF-β and abrogated the effects of 6'-SL. Furthermore, 6'-SL co-treatment abolished high phosphate-induced calcification in vitro via p90RSK/TGF-β signaling pathway. Altogether, our findings suggest that 6'-SL could be a potential therapeutic candidate for protecting against Ang II-induced AA formation by inhibiting the p90RSK/TGF-β/SMAD2 signaling pathway.

Artificial intelligence-driven multiomics predictive model for abdominal aortic aneurysm subtypes to identify heterogeneous immune cell infiltration and predict disease progression

BACKGROUND

Abdominal aortic aneurysm (AAA) poses a significant health risk and is influenced by various compositional features. This study aimed to develop an artificial intelligence-driven multiomics predictive model for AAA subtypes to identify heterogeneous immune cell infiltration and predict disease progression. Additionally, we investigated neutrophil heterogeneity in patients with different AAA subtypes to elucidate the relationship between the immune microenvironment and AAA pathogenesis.

METHODS

This study enrolled 517 patients with AAA, who were clustered using k-means algorithm to identify AAA subtypes and stratify the risk. We utilized residual convolutional neural network 200 to annotate and extract contrast-enhanced computed tomography angiography images of AAA. A precise predictive model for AAA subtypes was established using clinical, imaging, and immunological data. We performed a comparative analysis of neutrophil levels in the different subgroups and immune cell infiltration analysis to explore the associations between neutrophil levels and AAA. Quantitative polymerase chain reaction, Western blotting, and enzyme-linked immunosorbent assay were performed to elucidate the interplay between CXCL1, neutrophil activation, and the nuclear factor (NF)-κB pathway in AAA pathogenesis. Furthermore, the effect of CXCL1 silencing with small interfering RNA was investigated.

RESULTS

Two distinct AAA subtypes were identified, one clinically more severe and more likely to require surgical intervention. The CNN effectively detected AAA-associated lesion regions on computed tomography angiography, and the predictive model demonstrated excellent ability to discriminate between patients with the two identified AAA subtypes (area under the curve, 0.927). Neutrophil activation, AAA pathology, CXCL1 expression, and the NF-κB pathway were significantly correlated. CXCL1, NF-κB, IL-1β, and IL-8 were upregulated in AAA. CXCL1 silencing downregulated NF-κB, interleukin-1β, and interleukin-8.

CONCLUSION

The predictive model for AAA subtypes demonstrated accurate and reliable risk stratification and clinical management. CXCL1 overexpression activated neutrophils through the NF-κB pathway, contributing to AAA development. This pathway may, therefore, be a therapeutic target in AAA.

Macrophages in vascular disease: Roles of mitochondria and metabolic mechanisms

Macrophages are a dynamic cell type of the immune system implicated in the pathophysiology of vascular diseases and are a major contributor to pathological inflammation. Excessive macrophage accumulation, activation, and polarization is observed in aortic aneurysm (AA), atherosclerosis, and pulmonary arterial hypertension. In general, macrophages become activated and polarized to a pro-inflammatory phenotype, which dramatically changes cell behavior to become pro-inflammatory and infiltrative. These cell types become cumbersome and fail to be cleared by normal mechanisms such as autophagy. The result is a hyper-inflammatory environment causing the recruitment of adjacent cells and circulating immune cells to further augment the inflammatory response. In AA, this leads to excessive ECM degradation and chemokine secretion, ultimately causing macrophages to dominate the immune cell landscape in the aortic wall. In atherosclerosis, monocytes are recruited to the vascular wall, where they polarize to the pro-inflammatory phenotype and induce inflammatory pathway activation. This leads to the development of foam cells, which significantly contribute to neointima and necrotic core formation in atherosclerotic plaques. Pro-inflammatory macrophages, which affect other vascular diseases, present with fragmented mitochondria and corresponding metabolic dysfunction. Targeting macrophage mitochondrial dynamics has proved to be an exciting potential therapeutic approach to combat vascular disease. This review will summarize mitochondrial and metabolic mechanisms of macrophage activation, polarization, and accumulation in vascular diseases.

The Year in Aortic Surgery: Selected Highlights From 2023

This article reviews the recent and relevant literature to the field of aortic surgery. Specific areas highlighted include outcomes of Stanford type A dissection, management of acute aortic syndromes, management of aortic aneurysms, and traumatic aortic injury. Although the focus was on articles from 2023, literature from prior years also was included, given that this article is the first of a series. Notably, the pertinent sections from the 2022 American College of Cardiology/American Heart Association Guidelines for the Diagnosis and Management Aortic Disease are discussed.

Deciphering the causal association and underlying transcriptional mechanisms between telomere length and abdominal aortic aneurysm

Background

The purpose of this study is to investigate the causal effect and potential mechanisms between telomere length and abdominal aortic aneurysm (AAA).

Methods

Summary statistics of telomere length and AAA were derived from IEU open genome-wide association studies and FinnGen R9, respectively. Bi-directional Mendelian randomization (MR) analysis was conducted to reveal the causal relationship between AAA and telomere length. Three transcriptome datasets were retrieved from the Gene Expression Omnibus database and telomere related genes was down-loaded from TelNet. The overlapping genes of AAA related differentially expressed genes (DEGs), module genes, and telomere related genes were used for further investigation. Telomere related diagnostic biomarkers of AAA were selected with machine learning algorisms and validated in datasets and murine AAA model. The correlation between biomarkers and immune infiltration landscape was established.

Results

Telomere length was found to have a suggestive negative associations with AAA [IVW, OR 95%CI = 0.558 (0.317-0.701), P < 0.0001], while AAA showed no suggestive effect on telomere length [IVW, OR 95%CI = 0.997 (0.990-1.004), P = 0.4061]. A total of 40 genes was considered as telomere related DEGs of AAA. PLCH2, PRKCQ, and SMG1 were selected as biomarkers after multiple algorithms and validation. Immune infiltration analysis and single cell mRNA analysis revealed that PLCH2 and PRKCQ were mainly expressed on T cells, while SMG1 predominantly expressed on T cells, B cells, and monocytes. Murine AAA model experiments further validated the elevated expression of biomarkers.

Conclusion

We found a suggestive effect of telomere length on AAA and revealed the potential biomarkers and immune mechanism of telomere length on AAA. This may shed new light for diagnosis and therapeutics on AAA.

Plant Antioxidants: Therapeutic Potential in Cardiovascular Diseases

Cardiovascular diseases (CVDs) are a global health problem. The mortality associated with them is one of the highest. Essentially, CVDs occur when the heart or blood vessels are damaged. Oxidative stress is an imbalance between the production of reactive oxygen species (free radicals) and antioxidant defenses. Increased production of reactive oxygen species can cause cardiac and vascular injuries, leading to CVDs. Antioxidant therapy has been shown to have beneficial effects on CVDs. Plants are a rich source of bioactive antioxidants on our planet. Several classes of these compounds have been identified. Among them, carotenoids and phenolic compounds are the most potent antioxidants. This review summarizes the role of some carotenoids (a/β-carotene, lycopene and lutein), polyphenols such as phenolic acids (caffeic, p-coumaric, ferulic and chlorogenic acids), flavonoids (quercetin, kaempferol and epigallocatechin gallate), and hydroxytyrosol in mitigating CVDs by studying their biological antioxidant mechanisms. Through detailed analysis, we aim to provide a deeper understanding of how these natural compounds can be integrated into cardiovascular health strategies to help reduce the overall burden of CVD.

Association of triglyceride-glucose index with the risk of incident aortic dissection and aneurysm: a large-scale prospective cohort study in UK Biobank

BACKGROUND

Triglyceride-glucose (TyG) index is an emerging surrogate indicator of insulin resistance, which has been demonstrated as a risk factor for various cardiovascular diseases including coronary syndrome, in-stent restenosis, and heart failure. However, association of TyG index with incident aortic dissection (AD) and aortic aneurysm (AA) remains to be investigated.

METHODS

This study included 420,292 participants without baseline AD/AA from the large-scale prospective UK Biobank cohort. The primary outcome was incident AD/AA, comprising AD and AA. Multivariable-adjusted Cox proportional hazards regression models and restricted cubic spline (RCS) analyses were applied to assess the relationship between TyG index and the onset of AD/AA. In addition, the association between TyG index and incident AD/AA was examined within subgroups defined by age, gender, smoking status, drinking status, diabetes, hypertension, and BMI.

RESULTS

Over a median follow-up period of 14.8 (14.1, 15.5) years, 3,481 AD/AA cases occurred. The incidence of AD/AA rose along with elevated TyG index. RCS curves showed a linear trend of TyG index with risk of incident AD/AA. TyG index was positively associated with risk of incident AD/AA after adjusting for age, gender, smoking status, drinking status, BMI, hypertension, LDL-c, and HbA1c, with adjusted HRs of 1.0 (reference), 1.20 (95% CI 1.08-1.35), 1.21 (95% CI 1.08-1.35), and 1.30 (95% CI 1.16-1.45) for TyG index quartiles 2, 3, and 4, respectively. Especially, participants in the highest TyG index quartile had highest risk of developing AA, with an adjusted HR of 1.35 (95% CI 1.20-1.52).

CONCLUSIONS

TyG index is independently associated with a higher risk of incident AD/AA, indicating the importance of using TyG index for risk assessment of AD/AA, especially for AA.

Exploiting the anti-fibrotic effects of statins on thoracic aortic aneurysm progression: results from a meta-analysis and experimental data

Aims

Thoracic aortic aneurysm (TAA) that progress to acute aortic dissection is often fatal and there is no pharmacological treatment that can reduce TAA progression. We aim to evaluate statins' effects on TAA growth rate and outcomes using a meta-analysis approach.

Methods and results

A detailed search related to the effects of statins on TAA was conducted according to PRISMA guidelines. The analyses of statins' effects on TAA growth rate were performed on 4 studies (n = 1850), while the impact on outcomes was evaluated on 3 studies (n = 2,867). Patients under statin treatment showed a reduced TAA growth rate (difference in means = -0.36 cm/year; 95%CI: -0.64, -0.08; p = 0.013) when compared to controls, patients not taking statins. Regarding the outcomes (death, dissection, or rupture of the aorta, and the need for operative repair), statins exhibited a protective effect reducing the number of events (log odds ratio = -0.56; 95%CI: -1.06, -0.05; p = 0.030). In vitro, the anti-fibrotic effect of atorvastatin was tested on vascular smooth muscle cells (VMSC) isolated from patients with TAA. Our results highlighted that, in transforming growth factor beta 1 (TGF-β1) pro-fibrotic condition, VSMC expressed a significant lower amount of collagen type I alpha 1 chain (COL1A1) when treated with atorvastatin (untreated = +2.66 ± 0.23 fold-change vs. treated = +1.63 ± 0.09 fold-change; p = 0.014).

Conclusion

Statins show a protective effect on TAA growth rate and adverse outcomes in patients with TAA, possibly via their anti-fibrotic properties on VSMC. Given the current lack of effective drug treatments for TAA, we believe our findings highlight the need for more in-depth research to explore the potential benefits of statins in this context.

Is Serum Matrix Metalloproteinase 9 and/or D-Dimer Levels a Marker for Identifying Abdominal Aortic Aneurysms in Patients with Significant Coronary Atherosclerosis?

Our research aims to find a connection between the levels of MMP-9 and D-dimers in the blood and the prevalence of AAAs in subjects with atherosclerotic coronary disease. We selected fifty patients from each group and measured their MMP-9 and D-dimer levels in the blood. We discovered that in subjects with significant coronary disease and angina pectoris, the level of MMP-9 is higher compared to the subjects with angina pectoris but without significant coronary disease. When comparing this group with those with significant coronary disease and AAA, the level of MMP-9 is lower. Additionally, the D-dimer level was significantly higher in subjects with both AAA and significant coronary atherosclerosis compared to patients with significant coronary disease alone or those without significant coronary disease or AAAs. Subjects with significant coronary disease and AAA have elevated levels of MMP-9 and D-dimer compared to patients with significant coronary disease alone or without coronary artery disease or AAAs. These two factors could be used as indicators for diagnosing AAA in patients with angina pectoris.

Therapeutic potential of natural products and underlying targets for the treatment of aortic aneurysm

Aortic aneurysm is a vascular disease characterized by irreversible vasodilatation that can lead to dissection and rupture of the aortic aneurysm, a life-threatening condition. Thoracic aortic aneurysm (TAA) and abdominal aortic aneurysm (AAA) are two main types. The typical treatments for aortic aneurysms are open surgery and endovascular aortic repair, which are only indicated for more severe patients. Most patients with aneurysms have an insidious onset and slow progression, and there are no effective drugs to treat this stage. The inability of current animal models to perfectly simulate all the pathophysiological states of human aneurysms may be the key to this issue. Therefore, elucidating the molecular mechanisms of this disease, finding new therapeutic targets, and developing effective drugs to inhibit the development of aneurysms are the main issues of current research. Natural products have been applied for thousands of years to treat cardiovascular disease (CVD) in China and other Asian countries. In recent years, natural products have combined multi-omics, computational biology, and integrated pharmacology to accurately analyze drug components and targets. Therefore, the multi-component and multi-target complexity of natural products have made them a potentially ideal treatment for multifactorial diseases such as aortic aneurysms. Natural products have regained popularity worldwide. This review provides an overview of the known natural products for the treatment of TAA and AAA and searches for potential cardiovascular-targeted natural products that may treat TAA and AAA based on various cellular molecular mechanisms associated with aneurysm development.

Increased vascular smooth muscle cell senescence in aneurysmal Fibulin-4 mutant mice

Aortic aneurysms are dilatations of the aorta that can rupture when left untreated. We used the aneurysmal Fibulin-4R/R mouse model to further unravel the underlying mechanisms of aneurysm formation. RNA sequencing of 3-month-old Fibulin-4R/R aortas revealed significant upregulation of senescence-associated secretory phenotype (SASP) factors and key senescence factors, indicating the involvement of senescence. Analysis of aorta histology and of vascular smooth muscle cells (VSMCs) in vitro confirmed the senescent phenotype of Fibulin-4R/R VSMCs by revealing increased SA-β-gal, p21, and p16 staining, increased IL-6 secretion, increased presence of DNA damage foci and increased nuclei size. Additionally, we found that p21 luminescence was increased in the dilated aorta of Fibulin-4R/R|p21-luciferase mice. Our studies identify a cellular aging cascade in Fibulin-4 aneurysmal disease, by revealing that Fibulin-4R/R aortic VSMCs have a pronounced SASP and a senescent phenotype that may underlie aortic wall degeneration. Additionally, we demonstrated the therapeutic effect of JAK/STAT and TGF-β pathway inhibition, as well as senolytic treatment on Fibulin-4R/R VSMCs in vitro. These findings can contribute to improved therapeutic options for aneurysmal disease aimed at reducing senescent cells.

Macrophages in cardiovascular diseases: molecular mechanisms and therapeutic targets

The immune response holds a pivotal role in cardiovascular disease development. As multifunctional cells of the innate immune system, macrophages play an essential role in initial inflammatory response that occurs following cardiovascular injury, thereby inducing subsequent damage while also facilitating recovery. Meanwhile, the diverse phenotypes and phenotypic alterations of macrophages strongly associate with distinct types and severity of cardiovascular diseases, including coronary heart disease, valvular disease, myocarditis, cardiomyopathy, heart failure, atherosclerosis and aneurysm, which underscores the importance of investigating macrophage regulatory mechanisms within the context of specific diseases. Besides, recent strides in single-cell sequencing technologies have revealed macrophage heterogeneity, cell-cell interactions, and downstream mechanisms of therapeutic targets at a higher resolution, which brings new perspectives into macrophage-mediated mechanisms and potential therapeutic targets in cardiovascular diseases. Remarkably, myocardial fibrosis, a prevalent characteristic in most cardiac diseases, remains a formidable clinical challenge, necessitating a profound investigation into the impact of macrophages on myocardial fibrosis within the context of cardiac diseases. In this review, we systematically summarize the diverse phenotypic and functional plasticity of macrophages in regulatory mechanisms of cardiovascular diseases and unprecedented insights introduced by single-cell sequencing technologies, with a focus on different causes and characteristics of diseases, especially the relationship between inflammation and fibrosis in cardiac diseases (myocardial infarction, pressure overload, myocarditis, dilated cardiomyopathy, diabetic cardiomyopathy and cardiac aging) and the relationship between inflammation and vascular injury in vascular diseases (atherosclerosis and aneurysm). Finally, we also highlight the preclinical/clinical macrophage targeting strategies and translational implications.

Identification of biomarkers for abdominal aortic aneurysm in Behçet's disease via mendelian randomization and integrated bioinformatics analyses

Behçet's disease (BD) is a complex autoimmune disorder impacting several organ systems. Although the involvement of abdominal aortic aneurysm (AAA) in BD is rare, it can be associated with severe consequences. In the present study, we identified diagnostic biomarkers in patients with BD having AAA. Mendelian randomization (MR) analysis was initially used to explore the potential causal association between BD and AAA. The Limma package, WGCNA, PPI and machine learning algorithms were employed to identify potential diagnostic genes. A receiver operating characteristic curve (ROC) for the nomogram was constructed to ascertain the diagnostic value of AAA in patients with BD. Finally, immune cell infiltration analyses and single-sample gene set enrichment analysis (ssGSEA) were conducted. The MR analysis indicated a suggestive association between BD and the risk of AAA (odds ratio [OR]: 1.0384, 95% confidence interval [CI]: 1.0081-1.0696, p = 0.0126). Three hub genes (CD247, CD2 and CCR7) were identified using the integrated bioinformatics analyses, which were subsequently utilised to construct a nomogram (area under the curve [AUC]: 0.982, 95% CI: 0.944-1.000). Finally, the immune cell infiltration assay revealed that dysregulation immune cells were positively correlated with the three hub genes. Our MR analyses revealed a higher susceptibility of patients with BD to AAA. We used a systematic approach to identify three potential hub genes (CD247, CD2 and CCR7) and developed a nomogram to assist in the diagnosis of AAA among patients with BD. In addition, immune cell infiltration analysis indicated the dysregulation in immune cell proportions.

Deciphering the role of CX3CL1-CX3CR1 in aortic aneurysm pathogenesis: insights from Mendelian randomization and transcriptomic analyses

Background

The crucial role of inflammation in aortic aneurysm (AA) is gaining prominence, while there is still a lack of key cytokines or targets for effective clinical translation.

Methods

Mendelian randomization (MR) analysis was performed to identify the causal relationship between 91 circulating inflammatory proteins and AA and between 731 immune traits and AA. Bulk RNA sequencing data was utilized to demonstrate the expression profile of the paired ligand-receptor. Gene enrichment analysis, Immune infiltration, and correlation analysis were employed to deduce the potential role of CX3CR1. We used single-cell RNA sequencing data to pinpoint the localization of CX3CL1 and CX3CR1, which was further validated by multiplex immunofluorescence staining. Cellchat analysis was utilized to infer the CX3C signaling pathway. Trajectory analysis and the Cytosig database were exploited to determine the downstream effect of CX3CL1-CX3CR1.

Results

We identified 4 candidates (FGF5, CX3CL1, IL20RA, and SCF) in multiple two-sample MR analyses. Subsequent analysis of the expression profile of the paired receptor revealed the significant upregulation of CX3CR1 in AA and its positive correlation with pro-inflammatory macrophages. Two sample MR between immune cell traits and AA demonstrated the potential causality between intermediate monocytes and AA. We finally deciphered in single-cell sequencing data that CX3CL1 sent by endothelial cells (ECs) acted on CX3CR1 of intermediated monocytes, leading to its recruitment and pro-inflammatory responses.

Conclusion

Our study presented a genetic insight into the pathogenetic role of CX3CL1-CX3CR1 in AA, and further deciphered the CX3C signaling pathway between ECs and intermediate monocytes.

Neutrophil Extracellular Traps in Cardiovascular and Aortic Disease: A Narrative Review on Molecular Mechanisms and Therapeutic Targeting

Neutrophil extracellular traps (NETs), composed of DNA, histones, and antimicrobial proteins, are released by neutrophils in response to pathogens but are also recognized for their involvement in a range of pathological processes, including autoimmune diseases, cancer, and cardiovascular diseases. This review explores the intricate roles of NETs in different cardiovascular conditions such as thrombosis, atherosclerosis, myocardial infarction, COVID-19, and particularly in the pathogenesis of abdominal aortic aneurysms. We elucidate the mechanisms underlying NET formation and function, provide a foundational understanding of their biological significance, and highlight the contribution of NETs to inflammation, thrombosis, and tissue remodeling in vascular disease. Therapeutic strategies for preventing NET release are compared with approaches targeting components of formed NETs in cardiovascular disease. Current limitations and potential avenues for clinical translation of anti-NET treatments are discussed.

CNS-associated macrophages contribute to intracerebral aneurysm pathophysiology

Intracerebral aneurysms (IAs) are pathological dilatations of cerebral arteries whose rupture leads to subarachnoid hemorrhage, a significant cause of disability and death. Inflammation is recognized as a critical contributor to the formation, growth, and rupture of IAs; however, its precise actors have not yet been fully elucidated. Here, we report CNS-associated macrophages (CAMs), also known as border-associated macrophages, as one of the key players in IA pathogenesis, acting as critical mediators of inflammatory processes related to IA ruptures. Using a new mouse model of middle cerebral artery (MCA) aneurysms we show that CAMs accumulate in the IA walls. This finding was confirmed in a human MCA aneurysm obtained after surgical clipping, together with other pathological characteristics found in the experimental model including morphological changes and inflammatory cell infiltration. In addition, in vivo longitudinal molecular MRI studies revealed vascular inflammation strongly associated with the aneurysm area, i.e., high expression of VCAM-1 and P-selectin adhesion molecules, which precedes and predicts the bleeding extent in the case of IA rupture. Specific CAM depletion by intracerebroventricular injection of clodronate liposomes prior to IA induction reduced IA formation and rupture rate. Moreover, the absence of CAMs ameliorated the outcome severity of IA ruptures resulting in smaller hemorrhages, accompanied by reduced neutrophil infiltration. Our data shed light on the unexplored role of CAMs as main actors orchestrating the progression of IAs towards a rupture-prone state.