Taxifolin ameliorates abdominal aortic aneurysm by preventing inflammation and apoptosis and extracellular matrix degradation via inactivating TLR4/NF-κB axis

Inhibition of VSMC Ferroptosis Mitigates Pathological Vascular Remodeling: A Novel Therapeutic Strategy for Abdominal Aortic Aneurysm

Ferroptosis plays a key role in abdominal aortic aneurysm (AAA) development. This study explores whether and how ferroptosis regulates AAA progression. Ferroptosis was confirmed in human AAA tissue. In vitro experiments with primary mouse vascular smooth muscle cells (VSMCs) and abdominal aortic rings revealed that angiotensin II (Ang II) triggered ferroptosis in VSMCs. Ferrostatin-1 (Fer-1), a potent ferroptosis inhibitor, effectively suppressed this effect. Additionally, the ferroptosis inducer erastin and Ang II can both promoted pathological remodeling of abdominal aortic rings, but Fer-1 significantly suppressed these effects. In AAA mouse model, Fer-1 treatment reduced AAA formation. Mechanistically, RNA-sequencing analysis revealed that Fer-1 regulates VSMC contractile function, suppresses inflammation, and mitigates extracellular matrix remodeling. These findings highlight the critical role of VSMC ferroptosis in AAA pathogenesis and demonstrate that ferroptosis inhibition effectively reduces pathological vascular remodeling, making it a promising therapeutic strategy for preventing AAA.

RAGE deficiency ameliorates abdominal aortic aneurysm progression

BACKGROUND

Abdominal aortic aneurysm (AAA) is a vascular disease characterized by inflammation and arterial wall degradation. The receptor for advanced glycation end products (RAGE) plays a pivotal role in regulating inflammatory pathways, but its specific contribution to AAA pathogenesis remains unclear.

PURPOSE

This study aimed to investigate the role of RAGE in AAA development by examining its expression in human and mice AAA tissues and exploring the effects of RAGE deficiency on aneurysm progression, macrophage polarization, and inflammatory responses.

METHODS

RAGE expression was analyzed in human AAA samples and porcine pancreatic elastase (PPE) induced AAA mouse models using Western blotting, immunohistochemistry, and immunofluorescence. In vivo RAGE-deficient (RAGE-/-) mice were generated to assess the impact of RAGE knockout on AAA progression. In vitro experiments utilized RAW264.7 transfected with RAGE-targeting siRNA to study macrophage polarization and NF-κB signaling.

RESULTS

RAGE expression was elevated in AAA tissues, particularly in macrophages. RAGE-/- mice exhibited reduced AAA incidence, mortality, and aortic dilation compared to wild-type mice. Histological analysis showed preserved elastic fibers and smooth muscle layers, along with decreased inflammatory cell infiltration and MMP2/MMP9 expression. RAGE deficiency inhibited M1-like macrophage polarization and pro-inflammatory cytokine secretion, mediated through suppression of the NF-κB pathway.

CONCLUSIONS

RAGE deficiency mitigates AAA progression by modulating macrophage polarization and reducing inflammation via the NF-κB pathway. These findings highlight RAGE as a potential therapeutic target for AAA treatment.

EUGENOL RESTRAINS ANGIOTENSIN II-INDUCED DEATH, INFLAMMATION AND FERROPTOSIS OF VASCULAR SMOOTH MUSCLE CELLS BY TARGETING STAT3/HMGB2 AXIS

ABSTRACT

Background: Eugenol has been found to inhibit a variety of disease processes, including abdominal aortic aneurysm (AAA) formation. However, the specific role and the underlying molecular mechanism of Eugenol in AAA progression need to be further revealed. Methods: Vascular smooth muscle cells (VSMCs) were pretreated with Eugenol, followed by treated with Angiotensin II (Ang-II). VSMCs were transfected with HMGB2 siRNA or overexpression vector and treated with Ang-II to confirm the effect of HMGB2 on AAA progression. Cell proliferation and death were determined using cell counting kit 8 assay, 5-ethynyl-2'-deoxyuridine assay, and flow cytometry. Inflammatory factors were examined by ELISA. Fe 2+ , glutathione, and malondialdehyde levels were tested to evaluate cell ferroptosis. The protein levels of ferroptosis-related markers, high mobility group box 2 (HMGB2), and STAT3 were measured using western blot. Human AAA tissues and normal abdominal aortic tissues were collected to detect HMGB2 mRNA expression by quantitative real-time PCR. The interaction between HMGB2 and STAT3 was confirmed by chromatin immunoprecipitation assay and dual-luciferase reporter assay. Results: Eugenol enhanced VSMCs proliferation, while restrained Ang-II-induced death, inflammation, and ferroptosis. HMGB2 was upregulated in AAA tissues and Ang-II-induced VSMCs, and Eugenol significantly decreased HMGB2 expression. HMGB2 knockdown reduced Ang-II-induced VSMCs death, inflammation, and ferroptosis, Besides, HMGB2 overexpression abolished the effect of Eugenol on Ang-II-induced VSMCs injury. Transcription factor STAT3 bound to HMGB2 promoter region to increase its expression. In addition, Eugenol decreased STAT3 expression to regulate HMGB2. Conclusion: Eugenol could slow down the development of AAA, which might be achieved by regulating STAT3/HMGB2 axis.

A bibliometric and visualization analysis of global trends and frontiers on macrophages in abdominal aortic aneurysms research

BACKGROUND

Macrophages are key regulators of the inflammatory and innate immune responses. Researchers have shown that aberrant expression of macrophages contributes to the development of abdominal aortic aneurysms (AAA). However, a comprehensive bibliometric analysis exploring the research status and knowledge mapping of this area is lacking. This study aimed to explore the research status, knowledge mapping and hotspots of macrophages in AAA research from a bibliometric perspective.

METHODS

In this study, we retrieved articles published between 2000 and 2022 on macrophages associated with AAA research from the Web of Science Core Collection (WoSCC) database. The retrieved literature data were further analyzed using Citespace and VOSviewer software.

RESULTS

A total of 918 qualified publications related to AAA-associated macrophages were retrieved. The number of publications in this field has been increasing annually. China and the United States were the 2 main drivers in this field, contributing to more than 64% of the publications. In addition, the US had the most publications, top institutions, and expert researchers, dominating in research on macrophages in AAA. The Harvard University was the most productive institution, with 60 publications. The journal with the most publications was Arteriosclerosis, Thrombosis, and Vascular Biology (86). Daugherty Alan was the most prolific author (28 publications) and he was also the most cited co- author. Furthermore, the exploration of established animal models, macrophage-related inflammatory-microenvironment, macrophage-related immune mechanism, clinical translation and molecular imaging research remained future research directions in this field.

CONCLUSIONS

Our findings offered new insights for scholars in this field. They will help researchers explore new directions for their work.

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.

The role of transcription factors in the pathogenesis and therapeutic targeting of vascular diseases

Transcription factors (TFs) constitute an essential component of epigenetic regulation. They contribute to the progression of vascular diseases by regulating epigenetic gene expression in several vascular diseases. Recently, numerous regulatory mechanisms related to vascular pathology, ranging from general TFs that are continuously activated to histiocyte-specific TFs that are activated under specific circumstances, have been studied. TFs participate in the progression of vascular-related diseases by epigenetically regulating vascular endothelial cells (VECs) and vascular smooth muscle cells (VSMCs). The Krüppel-like family (KLF) TF family is widely recognized as the foremost regulator of vascular diseases. KLF11 prevents aneurysm progression by inhibiting the apoptosis of VSMCs and enhancing their contractile function. The presence of KLF4, another crucial member, suppresses the progression of atherosclerosis (AS) and pulmonary hypertension by attenuating the formation of VSMCs-derived foam cells, ameliorating endothelial dysfunction, and inducing vasodilatory effects. However, the mechanism underlying the regulation of the progression of vascular-related diseases by TFs has remained elusive. The present study categorized the TFs involved in vascular diseases and their regulatory mechanisms to shed light on the potential pathogenesis of vascular diseases, and provide novel insights into their diagnosis and treatment.

Chemokine Receptor 2 Is A Theranostic Biomarker for Abdominal Aortic Aneurysms

Abdominal aortic aneurysm (AAA) is a degenerative vascular disease impacting aging populations with a high mortality upon rupture. There are no effective medical therapies to prevent AAA expansion and rupture. We previously demonstrated the role of the monocyte chemoattractant protein-1 (MCP-1) / C-C chemokine receptor type 2 (CCR2) axis in rodent AAA pathogenesis via positron emission tomography/computed tomography (PET/CT) using CCR2 targeted radiotracer 64 Cu-DOTA-ECL1i. We have since translated this radiotracer into patients with AAA. CCR2 PET showed intense radiotracer uptake along the AAA wall in patients while little signal was observed in healthy volunteers. AAA tissues collected from individuals scanned with 64 Cu-DOTA-ECL1i and underwent open-repair later demonstrated more abundant CCR2+ cells compared to non-diseased aortas. We then used a CCR2 inhibitor (CCR2i) as targeted therapy in our established male and female rat AAA rupture models. We observed that CCR2i completely prevented AAA rupture in male rats and significantly decreased rupture rate in female AAA rats. PET/CT revealed substantial reduction of 64 Cu-DOTA-ECL1i uptake following CCR2i treatment in both rat models. Characterization of AAA tissues demonstrated decreased expression of CCR2+ cells and improved histopathological features. Taken together, our results indicate the potential of CCR2 as a theranostic biomarker for AAA management.