Novel pharmacological approaches in abdominal aortic aneurysm

Role of Inflammatory and Proresolving Mediators in Endothelial Dysfunction

Excessive local inflammation is a common mechanism in many cardiovascular diseases (CVDs) such as hypertension, atherosclerosis and aortic aneurysms. In endothelial cells, inflammatory cytokines such as interferons, tumour necrosis factor alpha or interleukins increase oxidative stress and contractile prostanoids and the expression of adhesion molecules that reduce nitric oxide (NO) availability and bind leucocytes, thereby impairing endothelial function. Despite this evidence, anti-inflammatory therapies are not yet indicated for the treatment of most CVD. Resolution of inflammation is mediated by a family of specialized pro-resolving mediators (SPMs) that act on cognate G protein-coupled receptors to limit immune cell infiltration and initiate tissue repair. SPMs, generated from omega-3 and omega-6 polyunsaturated fatty acids, belong to four major families: lipoxins, resolvins, protectins and maresins. SPM receptors are expressed in immune and vascular cells where they regulate important processes such as phagocytosis and polarization, production of cytokines, NO and prostacyclin, and modulation of smooth muscle cell phenotype. Growing evidence in animal models demonstrates that activation of SPM receptors can protect vascular function and structure and provide beneficial effects in various CVD. We will review recent advances in the role of inflammation and SPMs in vascular (dys)function in hypertension, atherosclerosis, and aortic aneurysms.

The Molecular Mechanisms of Bergapten Against Abdominal Aortic Aneurysm: Evidence From Network Pharmacology, Molecular Docking/Dynamics, and Experimental Validation

This study endeavors to assess the potential protective role of bergapten (BP) in mitigating abdominal aortic aneurysm (AAA) and to decipher the underlying mechanisms and molecular targets. Network pharmacology was utilized to search for potential targets of BP against AAA. Molecular docking and molecular dynamics simulations were utilized to validate the interaction of BP with core targets, and then the therapeutic effect and mechanism of BP on AAA were verified by using an elastase-induced AAA model. Network pharmacology analysis identified five pharmacological targets for BP, including EGFR, SRC, PIK3CA, PIK3CB, and JAK2. Molecular docking and molecular dynamics simulations further prioritized JAK2 as the most promising candidate for the potential treatment of AAA. The results of animal experiments demonstrated that BP significantly reduced the expression of inflammatory cytokines IL-6, TNF-α, and IL-1β in the aortic tissue of AAA mouse model, and inhibited the phosphorylation of JAK2 and STAT3. BP plays an important role in the treatment of AAA, and it may become a promising drug to combat AAA progression. The inhibitory effect of BP on AAA vascular progression and the attenuation of inflammatory cell infiltration may be related to the regulation of JAK2/STAT3 signaling pathway.

Identification of endoplasmic reticulum stress-associated lncRNAs influencing inflammation and VSMC function in abdominal aortic aneurysm

Endoplasmic reticulum (ER) stress plays a critical role in the abdominal aortic aneurysm (AAA), a life-threatening disease characterized by inflammation, destructive remodeling, and vascular smooth muscle cells (VSMCs) dysfunction. The current therapy relies on surgical repair, but no effective pharmacological strategies are available to limit aneurysm progression. Long non-coding RNAs (lncRNAs) are essential factors in health and disease; however, their specific contribution to AAA development and its relationship with ER stress remain unexplored. Here, we have performed a whole-genome transcriptomic analysis characterizing the expression profile of lncRNAs in AAA. RNA sequencing was carried out in abdominal aorta from patients with AAA and healthy donors. We identified 6576 differentially expressed (DE)-mRNAs and 1283 DE-lncRNAs. Interestingly, bioinformatic analysis revealed a set of 368 DE-lncRNAs related to ER stress. The differential expression of the most induced lncRNAs (IL-21-AS1, ITPKB-IT, PCED1B-AS1, TCL-6, LINC00494, LINC00582, LINC00626, LINC00861, and LINC00892) was validated in a large cohort of patients with AAA. The ability of these selected lncRNAs to discriminate patients with AAA from healthy subjects was established by receiveroperating characteristic curves and logistic regression analysis. In human aortic VSMC and Jurkat T-cells, tunicamycin-induced ER stress triggered the expression of IL21-AS1, LINC00626, LINC00494, LINC00892, PCED1B-AS1, ITPKB-IT, and TCL-6, while tauroursodeoxycholic acid counteracted these effects. Finally, an integrated analysis of mRNA-lncRNA co-expression revealed the correlation between the selected lncRNAs and the DE-mRNAs involved in immune response and muscle contraction. Therefore, these DE-lncRNAs potentially implicated in the ER stress response, a pathological process in AAA, could be considered as potential therapeutic target to handle AAA.

Efficacy and safety of endovascular repair versus open surgery for ruptured abdominal aortic aneurysm: a comparative study

OBJECTIVE

Ruptured abdominal aortic aneurysm (rAAA) is a life-threatening condition with high mortality. This study compared the efficacy and safety of open surgical repair (OSR) and endovascular aortic repair (EVAR) in the treatment of rAAA.

METHODS

A retrospective analysis of clinical data was conducted for 232 rAAA patients treated at Taizhou Central Hospital and the First Affiliated Hospital of Wenzhou Medical College. Patients were divided into two groups based on surgical methods: OSR group (n=84) and EVAR group (n=148). Perioperative indicators, perioperative complication rates, and 1-year mortality rates were compared. Patients were further divided into a survival group (n=160) and a death group (n=72) based on their 1-year survival status, and the risk factors affecting the prognosis of rAAA patients were analyzed. Postoperative pain was evaluated using the Visual Analog Scale (VAS), Verbal Rating Scale (VRS), and Present Pain Intensity (PPI). Serum levels of C-reactive protein (CRP) and white blood cells (WBC), pro-inflammatory interleukins (IL-1α, IL-6, IL-8), and tumor necrosis factor-α (TNF-α) were measured before and after treatment using enzyme-linked immunosorbent assays (ELISA).

RESULTS

Compared with the OSR group, the EVAR group had significantly shorter surgical time, less intraoperative bleeding (IOB) and intraoperative blood transfusion volume, reduced intraoperative infusion volume, shorter fasting and first walk time, and shorter ICU and hospital days. The incidence of complications in the EVAR group was significantly lower than that in the OSR group (P<0.05). Pain scores (VAS, VRS, and PPI) and serum levels of CRP, WBC, IL-1α, IL-6, IL-8, and TNF-α were significantly lower in the EVAR group than those in the OSR group (all P<0.05). There was no significant difference in perioperative mortality between the two groups (28.95% vs. 11.80%, P>0.05). However, the 1-year mortality rate was significantly lower in the EVAR group (38.1% vs. 27.0%, P<0.05). Multivariate logistic regression analysis identified Alb<40 g/L (P=0.004), Cre≥1.5 mg/dL (P=0.007), urea nitrogen ≥25 mg/dL (P=0.001), ALT≥40 U/L (P=0.002), and treatment method (OSR) (P=0.024) as independent risk factors for poor postoperative prognosis.

CONCLUSION

EVAR demonstrates significant advantages over OSR in reducing surgical trauma, decreasing postoperative complications, alleviating pain and inflammatory responses, and improving postoperative survival rates.

Inhibition of ATP-citrate lyase by bempedoic acid protects against abdominal aortic aneurysm formation in mice

Abdominal aortic aneurysm (AAA) is a prevalent degenerative disease characterized by an exacerbated inflammation and destructive vascular remodeling. Unfortunately, effective pharmacological tools for the treatment of this disease remain a challenge. ATP-citrate lyase (ACLY), the primary enzyme responsible for acetyl-CoA biosynthesis, is a key regulator of inflammatory signaling in macrophages and lymphocytes. Here, we found increased levels of the active (phosphorylated) form of ACLY (p-ACLY) in the inflammatory infiltrate of AAA from patients and in aneurysmal lesions from angiotensin II (Ang II)-infused apolipoprotein E-deficient mice (ApoE-/-). Furthermore, plasma ACLY levels positively correlates with IL6 and IFNγ levels in patients with AAA, while inflammatory stimuli strongly upregulated ACLY expression in macrophages and Jurkat cells. The administration of the ACLY inhibitor bempedoic acid (BemA) protected against Ang II-induced AAA formation in ApoE-/- mice, limiting the progression of aortic dilatation and reducing mortality due to aortic rupture. BMS-303141, another ACLY inhibitor, also ameliorated AAA formation, although to a lesser extent. BemA attenuated vascular remodeling and the disorganization and rupture of elastic fibers induced by Ang II, as well as vascular inflammation, decreasing the recruitment of macrophages (CD68 +) and neutrophils (Ly-6G+) into the aortic wall. Moreover, BemA shifted splenic monocytes toward a functionally anti-inflammatory phenotype, and increased the percentage of CD4+CD69+ cells. Taken together, these results support the contribution of ACLY to AAA and point to BemA as a promising tool to be considered for future clinical trials addressing the management of this disease which is quite often associated with disorders of lipoprotein metabolism.

Angiotensin Dysregulation in Patients with Arterial Aneurysms

Besides playing a critical role in maintaining cardiovascular homeostasis, the renin-angiotensin-aldosterone system (RAS) has been strongly implicated in (aortic) aneurysm pathogenesis. This study aims to investigate systemic and local levels of angiotensin (Ang) and its metabolites in patients with arterial aneurysms, predominantly abdominal aortic aneurysms, using advanced biochemical profiling techniques to provide new insights into the involvement of RAS in aneurysm genesis. A prospective, single-center study was conducted between October 2023 and July 2024. Serum Ang metabolite levels were measured using RAS Fingerprint technology. Aortic tissue samples were analyzed for local RAS activity, including Ang levels and enzyme activity. Additionally, pre- and postoperative serum samples were obtained in a select group of patients. In total, 37 aneurysm patients and 56 controls were included. Aneurysm patients exhibited higher systemic levels of nearly all Ang metabolites compared to controls, with significant differences in Ang I (p = 0.002), Ang II (p = 0.047), Ang 1-5 (p = 0.004), and Renin (p = 0.014) in patients without pharmacological RAS interference. Aneurysm patients receiving ACE inhibitors showed lower serum concentrations in ACE2 activity (p = 0.042) and increased Ang IV levels (p = 0.049) compared to controls. Postoperative measurements indicated different dynamics regarding angiotensin metabolite changes in patients with or without ACE inhibition. This study provides the first comprehensive characterization of RAS profiles in aneurysm patients. These findings add to the body of evidence regarding associations between of RAS and the pathogenesis of arterial aneurysms.

Atractylenolide-I prevents abdominal aortic aneurysm formation through inhibiting inflammation

Background

Abdominal aortic aneurysm (AAA) is a degenerative disease with high mortality. Chronic inflammation plays a vital role in the formation of AAA. Atractylenolide-I (ATL-I) is a major bioactive component of Rhizoma Atractylodis Macrocephalae that exerts anti-inflammatory effects in various diseases. The purpose of this study is to investigate the role of ATL-I in the progression of AAA.

Methods

AAA was constructed in C57BL/6 mice by porcine pancreatic elastase (PPE)-incubation, and the diameter of the aorta was measured by ultrasound. ATL-I was administered by gavage on the second day after modeling to explore its significance in AAA. The pathological and molecular alteration was investigated by immunostaining, ELISA, qRT-PCR and Western blotting.

Results

ATL-I inhibited the dilatation of the abdominal aorta and decreased the incidence of AAA. ATL-I alleviated the infiltration of macrophages in the adventitia and reduced the levels of proinflammatory factor IL-1β and IL-6 in the aorta and circulatory system, while increasing the expression of anti-inflammatory factor IL-10. Moreover, ATL-I restrained loss of smooth muscle cells and elastic fiber degradation by suppressing MMP-2 and MMP-9 expression. Mechanistically, phospho-AMPK expression was elevated in AAA groups, and ATL-I administration suppressed its expression to improve the pathological damage of aorta.

Conclusions

ATL-I meliorated vascular inflammation by targeting AMPK signaling, ultimately inhibiting AAA formation, which provided an alternative agent for AAA treatment.

A Comprehensive Review on Computational Analysis, Research Advances, and Major Findings on Abdominal Aortic Aneurysms for the Years 2021 to 2023

BACKGROUND

Abdominal aortic aneurysm (AAA) is a pathological condition characterized by the dilation of the lower part of the aorta, where significant hemodynamic forces are present. The prevalence and high mortality risk associated with AAA remain major concerns within the scientific community. There is a critical need for extensive research to understand the underlying mechanisms, pathophysiological characteristics, and effective detection methods for abdominal aortic abnormalities. Additionally, it is imperative to develop and refine both medical and surgical management strategies. This review aims to indicate the role of computational analysis in the comprehension and management of AAAs and covers recent research studies regarding the computational analysis approach conducted between 2021 and 2023. Computational analysis methods have emerged as sophisticated and noninvasive approaches, providing detailed insights into the complex dynamics of AAA and enhancing our ability to study and manage this condition effectively.

METHODS

Computational analysis relies on fluid mechanics principles applied to arterial flow, using the Navier-Stokes equations to model blood flow dynamics. Key hemodynamic indicators relevant to AAAs include Time-Average Wall Shear Stress, Oscillatory Shear Index, Endothelial Cell Activation Potential, and Relative Residence Time. The primary methods employed for simulating the abdominal aorta and studying its biomechanical environment are computational fluid dynamics and Finite Element Methods. This review article encompasses a thorough examination of recent literature, focusing on studies conducted between 2021 and 2023.

RESULTS

The latest studies have elucidated crucial insights into the blood flow characteristics and geometric attributes of AAAs. Notably, blood flow patterns within AAAs are associated with increased rupture risk, along with elevated intraluminal thrombus volume and specific calcification thresholds. Asymmetric AAAs exhibit heightened risks of rupture and thrombus formation due to low and oscillating wall shear stresses. Moreover, larger aneurysms demonstrate increased wall stress, pressure, and energy loss. Advanced modeling techniques have augmented predictive capabilities concerning growth rates and surgical thresholds. Additionally, the influence of material properties and thrombus volume on wall stress levels is noteworthy, while inlet velocity profiles significantly modulate blood flow dynamics within AAAs.

CONCLUSIONS

This review highlights the potential utility of computational modeling. However, the clinical applicability of computational modeling has been limited by methodological variability despite the ongoing accumulation of evidence supporting the prognostic significance of biomechanical and hemodynamic indices in this field. The establishment of standardized reporting is critical for clinical implementation.

Intervention effect of regulating GABA-A receptor activity on the formation of experimental abdominal aortic aneurysm in rats

Abdominal aortic aneurysm is a potentially fatal vascular inflammatory disease characterized by infiltration of various inflammatory cells.The GABA-A receptor is expressed in many inflammatory cells such as macrophages and T cells and has anti-inflammatory and antioxidant effects. Therefore, the GABA-A receptor may become a potential therapeutic target for abdominal aortic aneurysms. The purpose of this study was to investigate the effect of regulating the activity of the GABA-A receptor on the formation of experimental abdominal aortic aneurysm in rats. In this study, the abdominal aortic aneurysm model of rats was established by aorta intracavitary perfusion of elastase combined with aorta extracavitary infiltration of calcium chloride. GABA-A receptor agonist (topiramate) and antagonist (bicuculline) were used to treating the abdominal aortic aneurysm model rats, which were divided into sham operation group, model group, topiramate group, and bicuculline group(n = 10). Histopathology, immunohistochemistry, fluorescence quantitative PCR, Western blotting, ELISA and Gelatine zymogram were used to study. Regulation of GABA-A receptor activity can interfere with the development and severity of abdominal aortic aneurysms in rats. The GABA-A receptor agonist topiramate reduces the infiltration of inflammatory cells, particularly T cells, into the abdominal aortic wall, while also modulating the balance of Th1/Th2 cytokines in peripheral blood, leading to a significant reduction in inflammatory responses. Additionally, topiramate decreases the secretion of matrix metalloproteinases MMP2 and MMP9, thereby inhibiting extracellular matrix degradation and slowing the progression of aneurysms. In contrast, the GABA-A receptor antagonist bicuculline exacerbates inflammation and promotes aneurysm development. At the molecular level, the mechanisms of action of the GABA-A receptor agonist topiramate and the antagonist bicuculline may involve inhibition or activation of the p38 MAPK signaling pathway. Regulation of GABA-A receptor activity can effectively intervene in the occurrence and development of abdominal aortic aneurysms in rats.

Cysteine Leukotriene Receptor Antagonist-Montelukast-Treatment Improves Experimental Abdominal Aortic Aneurysms in Mice

Background: Cysteinyl leukotrienes (LTs) and their receptors are involved in the pathogenesis of abdominal aortic aneurysms (AAAs). However, whether CysLT1 receptor antagonists such as montelukast can influence experimental nondissecting AAA remains unclear. Methods: Nondissecting AAAs were induced in C57BL/6J mice by transient aortic luminal infusion of porcine pancreatic elastase (PPE). All animals were administrated montelukast (1 or 10 mg/kg, daily) or vehicle by gavage beginning 1 day before PPE infusion for 14 days. On day 0 (baseline) and day 14 after PPE infusion, abdominal aortic diameters were directly measured. Aortic aneurysmal segment samples were collected, and histopathological analysis was performed. Results: Compared to vehicle treatment, montelukast significantly decreased PPE infusion-induced aortic expansion in a dose-dependent manner (0.09-mm reduction at a low dose and 0.19-mm reduction at a high dose). Histopathological analysis also revealed that compared with vehicle treatment, montelukast treatment, especially in the high-dose group, significantly improved PPE-induced aortic elastin degradation and medial smooth muscle cell depletion. Both doses of montelukast also markedly decreased the number of local leucocytes, including macrophages, CD4+ T cells, CD8+ T cells, and B cells, infiltration and accumulation in aortic aneurysmal lesions. Montelukast treatment also downregulated matrix metalloproteinase 2 (MMP2) and MMP9 expression and inhibited mural angiogenesis in aneurysmal aortas. Conclusion: Montelukast treatment improves experimental nondissected AAAs in mice partly by improving aortic inflammation.

Endovascular Aneurysm Repair Versus Open Surgical Repair in Treating Abdominal Aortic Aneurysm

Abdominal aortic aneurysm (AAA) denotes an abdominal aorta dilation exceeding 3 cm, typically asymptomatic until rupture, posing severe consequences, including fatality. Therefore, continual screening is imperative, and surgical intervention is recommended upon reaching a diameter of 5.5 cm to prevent rupture. The primary surgical approaches are open surgical repair or open repair (OR) and endovascular aneurysm repair (EVAR). This review juxtaposes EVAR's short- and long-term effectiveness, safety, and perioperative complications in AAA patients versus OR, elucidating clinical benefits and avenues for further research. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, an extensive literature review was conducted using the PubMed and Clinicaltrials.gov databases. The review specifically focused on clinical studies directly comparing EVAR versus OR. The comprehensive literature review revealed that EVAR confers a survival advantage for up to four years post-procedure. However, the benefit shifts to OR after four to eight years due to aneurysm-related complications, such as ruptures, underscoring the necessity of lifelong post-EVAR monitoring. Following EVAR, AAA patients necessitate significantly more frequent secondary interventions due to graft-related issues, including endoleaks, thereby escalating long-term complexity and care costs. Conversely, following OR, a notably higher proportion of patients require mechanical ventilation and blood transfusions and experience prolonged intensive-care and mid-care unit stays, consequently extending hospitalization. After EVAR, patients recover substantially faster, returning to normal activities sooner. Nonetheless, the long-term quality of life between the two procedures becomes comparable. While EVAR presents itself as a less invasive alternative to OR, especially for high surgical risk patients, the imperative of long-term surveillance and the risk of secondary interventions pose significant challenges. Advancements in EVAR technology and technique are broadening its utility. Yet, continual research is crucial to optimize patient selection, improve long-term outcomes, and ensure that EVAR's benefits outweigh the risks. Therefore, choosing EVAR over OR in treating AAA patients must factor in a patient's overall health, anatomical considerations, and the probability of long-term success.

Establishment of Mouse Models of Abdominal Aortic Aneurysm

Abdominal aortic aneurysm (AAA) is a chronic vascular disease that commonly affects elderly individuals but has recently increased in younger populations. As the aneurysm grows, it can cause compression symptoms such as abdominal pain, rupture, and bleeding, which are absent in the early stages. Once an AAA ruptures and causes bleeding, the mortality rate is alarmingly high. Currently, the pathogenesis for AAA is unknown, and therapeutic options are limited, necessitating improvement in treatment efficacy. An essential research method for studying the processes and potential treatment of AAA is establishing animal models using mice. The present study provides a detailed overview of the widely used AAA mouse animal models and their construction strategies, advantages, disadvantages, scope of applications, and prospects.

P4HA3 promotes head and neck squamous cell carcinoma progression via the WNT/β-catenin signaling pathway

Here, we explored the role of Prolyl 4-Hydroxylase Subunit Alpha 3 (P4HA3), the most recently identified member of the prolyl-4-hydroxylase (P4H) family, in head and neck squamous cell carcinoma (HNSCC) progression. P4HA3 is upregulated during cancer progression; however, its specific role in HNSCC progression remains elusive. Thus, this study aimed to elucidate the regulatory function of P4HA3 in HNSCC development and progression and to describe the underlying mechanisms. Initially, we analyzed the correlation between the expression of P4HA3 and the WNT pathway genes and clinicopathologic features in HNSCC based on microarray data from The Cancer Genome Atlas (TCGA). Next, we used Gene Oncology (GO) functional data to describe several potentially associated pathways in HNSCC. Then, we knocked down P4HA3 in SCC15 and SCC25 cells, two classic HNSCC cell lines, and assessed the resulting changes using RT-qPCR. Furthermore, we used Western blot to evaluate the regulatory role of P4HA3 in the epithelial-to-mesenchymal transition (EMT) and the WNT/β-catenin signaling pathway. To explore the effect of P4HA3 knockdown on tumor progression, in vivo experiments were conducted using a murine model. Immunohistochemistry assays were then employed to identify proteins associated with EMT and the WNT/β-catenin signaling pathway in tumor tissues. Upregulated P4HA3 in HNSCC patient tumor tissues was positively correlated with poor prognosis. Notably, P4HA3 knockdown significantly inhibited the proliferative and invasive abilities of HNSCC. The levels of genes and proteins associated with EMT and the WNT/β-catenin signaling pathway were also markedly reduced by P4HA3 knockdown. Importantly, the in vivo experiments demonstrated that P4HA3 can promote subcutaneous tumorigenesis in nude mice and knockdown of P4HA3 induce a significant ihibitation of EMT and WNT/β-catenin pathway detected by immunohistochemistry assay in tumor tissues. In summary, we demonstrated that P4HA3 is a promising diagnostic and therapeutic biomarker for HNSCC. As an oncogene, P4HA3 increases HNSCC proliferation by inducing the EMT and activating the WNT/β-catenin signaling pathway.

Bridging the gap: Navigating the impact of dietary supplements on abdominal aortic aneurysm progression- A systematic review

BACKGROUND

Vitamins D, E, A, B, C, and Omega-3 play crucial roles in modulating inflammatory and oxidative stress pathways, both implicated in abdominal aortic aneurysm (AAA) development. Recent research has explored the potential impact of dietary supplements on AAA progression. The systematic review aims to assess interventional studies investigating the effects of various dietary supplements on the development and severity of abdominal aortic aneurysms.

METHOD

A systematic search using relevant keywords related to abdominal aortic aneurysm and dietary supplements was conducted across four databases (PubMed, Embase, Scopus, and Web of Science). Quality assessment for animal studies employed SYRCLE and the Cochrane Collaboration Risk of Bias Tool for randomized control trials. The study protocol is registered in PROSPERO under the registry code CRD42023455958.

RESULTS

Supplementation with Omega-3, Vitamins A, C, D, E, and the Vitamin B family exhibited positive effects in AAA progression. These supplements contributed to a reduction in AAA diameter, elastin degradation, inflammatory responses, and reactive oxygen species. Additional supplements such as Zinc, methionine, and phytoestrogen also played roles in mitigating AAA progression.

CONCLUSION

The findings of this study underscore the potential role of dietary supplements in the progression of AAA. Predominantly based on animal studies, the results indicate that these supplements can limit AAA progression, primarily evidenced by their ability to mitigate inflammatory processes and oxidative stress pathways.

Epigenetic modifications in abdominal aortic aneurysms: from basic to clinical

Abdominal Aortic Aneurysm (AAA) is a disease characterized by localized dilation of the abdominal aorta, involving multiple factors in its occurrence and development, ultimately leading to vessel rupture and severe bleeding. AAA has a high mortality rate, and there is a lack of targeted therapeutic drugs. Epigenetic regulation plays a crucial role in AAA, and the treatment of AAA in the epigenetic field may involve a series of related genes and pathways. Abnormal expression of these genes may be a key factor in the occurrence of the disease and could potentially serve as promising therapeutic targets. Understanding the epigenetic regulation of AAA is of significant importance in revealing the mechanisms underlying the disease and identifying new therapeutic targets. This knowledge can contribute to offering AAA patients better clinical treatment options beyond surgery. This review systematically explores various aspects of epigenetic regulation in AAA, including DNA methylation, histone modification, non-coding RNA, and RNA modification. The analysis of the roles of these regulatory mechanisms, along with the identification of relevant genes and pathways associated with AAA, is discussed comprehensively. Additionally, a comprehensive discussion is provided on existing treatment strategies and prospects for epigenetics-based treatments, offering insights for future clinical interventions.

Rolipram impacts on redox homeostasis and cellular signaling in an experimental model of abdominal aortic aneurysm

INTRODUCTION

Cyclic nucleotide phosphodiesterases (PDEs) of the PDE4 subfamily are responsible for the hydrolysis and subcellular compartmentalization of cAMP, a second messenger that modulates vascular functionality. We had shown that PDE4B is induced in abdominal aortic aneurysms (AAA) and that PDE4 inhibition by rolipram limits experimental aneurysms. In this study we have delved into the mechanisms underlying the beneficial effect of rolipram on AAA.

METHODS

AAA were induced in ApoE-/- mice by angiotensin II (Ang II) infusion. Aneurysm formation was evaluated by ultrasonography. The expression of enzymes involved in rédox homeostasis was analyzed by real-time RT-PCR and the activation of signaling pathways by Western blot.

RESULTS

Induction of PDE4B in human AAA has been confirmed in a second cohort of patients. In Ang II-infused ApoE-/- mice, rolipram increased the percentage of animals free of aneurysms without affecting the percentage of aortic ruptures. Quantitative analyses determined that this drug significantly attenuated aortic collagen deposition. Additionally, rolipram reduced the increased Nox2 expression triggered by Ang II, exacerbated Sod1 induction, and normalized Sod3 expression. Likewise, PDE4 inhibition decreased the activation of both ERK1/2 and the canonical Wnt pathway, while AKT activity was not altered.

CONCLUSIONS

The inhibition of PDE4 activity modulates the expression of enzymes involved in rédox homeostasis and affects cell signaling pathways involved in the development of AAA.

PDE4 Phosphodiesterases in Cardiovascular Diseases: Key Pathophysiological Players and Potential Therapeutic Targets

3',5'-cyclic adenosine monophosphate (cAMP) is a second messenger critically involved in the control of a myriad of processes with significant implications for vascular and cardiac cell function. The temporal and spatial compartmentalization of cAMP is governed by the activity of phosphodiesterases (PDEs), a superfamily of enzymes responsible for the hydrolysis of cyclic nucleotides. Through the fine-tuning of cAMP signaling, PDE4 enzymes could play an important role in cardiac hypertrophy and arrhythmogenesis, while it decisively influences vascular homeostasis through the control of vascular smooth muscle cell proliferation, migration, differentiation and contraction, as well as regulating endothelial permeability, angiogenesis, monocyte/macrophage activation and cardiomyocyte function. This review summarizes the current knowledge and recent advances in understanding the contribution of the PDE4 subfamily to cardiovascular function and underscores the intricate challenges associated with targeting PDE4 enzymes as a therapeutic strategy for the management of cardiovascular diseases.

Colchicine protects against the development of experimental abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) is characterized by at least 1.5-fold enlargement of the infrarenal aorta, a ruptured AAA is life-threatening. Colchicine is a medicine used to treat gout and familial Mediterranean fever, and recently, it was approved to reduce the risk of cardiovascular events in adult patients with established atherosclerotic disease. With an AAA mice model created by treatment with porcine pancreatic elastase (PPE) and β-aminopropionitrile (BAPN), this work was designed to explore whether colchicine could protect against the development of AAA. Here, we showed that colchicine could limit AAA formation, as evidenced by the decreased total aortic weight per body weight, AAA incidence, maximal abdominal aortic diameter and collagen deposition. We also found that colchicine could prevent the phenotypic switching of vascular smooth muscle cells from a contractile to synthetic state during AAA. In addition, it was demonstrated that colchicine was able to reduce vascular inflammation, oxidative stress, cell pyroptosis and immune cells infiltration to the aortic wall in the AAA mice model. Finally, it was proved that the protective action of colchicine against AAA formation was mainly mediated by preventing immune cells infiltration to the aortic wall. In summary, our findings demonstrated that colchicine could protect against the development of experimental AAA, providing a potential therapeutic strategy for AAA intervention in the clinic.