Gasdermin D Deficiency in Vascular Smooth Muscle Cells Ameliorates Abdominal Aortic Aneurysm Through Reducing Putrescine Synthesis

AKAP1-STABILIZED TIMP-4 ATTENUATES ANG-II-INDUCED OXIDATIVE STRESS AND INFLAMMATION IN VASCULAR SMOOTH MUSCLE CELLS BY INACTIVATING THE NF-ΚB SIGNALING

ABSTRACT

Background: Oxidative stress and inflammation are key factors contributing to the complex pathogenesis of abdominal aortic aneurysm (AAA). Tissue inhibitor of metalloproteinases-4 (TIMP-4) expression is reduced in AAA patients. In this study, we investigated the impact of TIMP-4 on the phenotype alterations induced by angiotensin II (Ang-II) in human vascular smooth muscle cells (VSMCs). Methods: The expression profiling of TIMP-4 and A-kinase anchoring protein (AKAP1) in AAA samples was analyzed using the GSE7084 and GSE140947 datasets. Levels of TIMP-4 and AKAP1 in Ang-II-exposed VSMCs and AAA tissues and serum samples were detected. RNA immunoprecipitation (RIP) experiment and mRNA stability analysis were used to examine the interaction between AKAP1 and TIMP-4 mRNA. The impact of the AKAP1/TIMP-4 cascade on Ang-II-induced VSMC phenotype alterations was determined by evaluating cell viability, apoptosis, oxidative stress, and inflammation. Results: TIMP-4 and AKAP1 levels were decreased in Ang-II-exposed VSMCs. Increased TIMP-4 expression protected VSMCs against Ang-II-evoked growth impairment in vitro . Moreover, TIMP-4 upregulation diminished Ang-II-evoked oxidative stress and inflammation in VSMCs. Mechanistically, RNA binding protein (RBP) AKAP1 stabilized TIMP-4 mRNA to elevate TIMP-4 expression. TIMP-4 reduction partially abrogated AKAP1-driven suppression on oxidative stress, inflammation, matrix metalloproteinase (MMP9) expression, and nuclear factor kappa B (NF-κB) pathway activation in Ang-II-exposed VSMCs. Additionally, TIMP-4 and AKAP1 levels were downregulated in AAA patients in their AAA tissues and serum samples. TIMP-4 and AKAP1 had good diagnostic values for AAA with high area under the ROC curve. Conclusion: Our study provides evidence for the role of the AKAP1/TIMP-4/NF-κB pathway in Ang-II-induced VSMC inflammation and oxidative stress.

GSDMD Deficiency Attenuates the Development of Ascending Aortic Dissections in a Novel Mouse Model

BACKGROUND

Mechanisms driving the development of type A aortic dissection (TAD) are currently poorly understood, and animal models of spontaneous TAD are limited. In the present study, we developed a novel mouse TAD model and evaluated the role of GSDMD (gasdermin D) in TAD development.

METHODS

TADs were created by treating the ascending aorta of adult C57BL/6J mice with Act E (active elastase) and β-aminopropionitrile. The temporal progress of the TAD pathology was rigorously characterized by histological evaluation and scanning electron microscopy, while potential mechanisms were explored using bulk RNA sequencing of specimens collected at multiple time points. With this novel TAD model, we conducted additional experiments to investigate the impact of GSDMD deficiency on TAD formation.

RESULTS

Ascending aortas challenged with Act E and β-aminopropionitrile developed pathology featuring the early onset of intimomedial tears (complete penetration) and intramural hematomas, followed by progressive medial loss and aortic dilation. Ingenuity pathway analysis and functional annotation of differentially expressed genes suggested that a unique inflammatory microenvironment, rather than general inflammation, promotes the onset of TADs by specifically recruiting neutrophils to the aortic wall. At later stages, T cell-mediated immune injury emerged as the primary driver of pathology. Gsdmd deficiency attenuated medial loss, adventitial fibrosis, and dilation of TADs. This protective effect correlated with a reduced cell death and decreased T-cell infiltration in TADs. Notably, cleaved GSDMD was detected in human TADs but was absent in healthy aortas.

CONCLUSIONS

A novel mouse TAD model was developed, specifically targeting the ascending aorta. This model generates a unique microenvironment that activates specific immune cell subsets, driving the onset and subsequent remodeling of TADs. Consistently, Gsdmd deficiency mitigates TAD development, likely by modulating cell death and T-cell responses. This model provides a valuable tool for studying immune injury mechanisms in TAD pathogenesis.

Design, Synthesis, and Biological Evaluation of Naphthalimide-Polyamine Conjugate as a Potential Anti-Colorectal Cancer Agent

Colorectal cancer is the second most common cause of cancer-related death worldwide, with a rising incidence, highlighting an urgent need for novel therapeutics. In this study, we developed several polyamine conjugates. Compound 6 (C6) was selected as the lead compound and was evaluated for anticancer activity in vitro and in vivo. In vitro experiments showed that C6 inhibited cell proliferation, colony formation, migration, and invasion of colorectal cancer cells while inducing apoptosis, pyroptosis, and autophagosome formation. Genetic or pharmacological inhibition of autophagy weakened C6-induced apoptosis and gasdermin E (GSDME)-dependent pyroptosis. Inactivation of caspase 3 activity by AC-DEVD-CHO decreased the levels of N-terminal GSDME induced by C6. Furthermore, animal models exhibited suppressed tumor growth and dissemination after treatment with C6. Taken together, our findings highlight C6 as a potential drug against colorectal cancer.

TRAF6 promotes abdominal aortic aneurysm development by activating macrophage pyroptosis via the NLRP3/Caspase1/GSDMD pathway

Abdominal aortic aneurysm represents a critical pathology of the aorta that currently lacks effective pharmacological interventions. TNF receptor-associated factor 6 (TRAF6) has been established to be involved in cardiovascular diseases such as atherosclerosis, hypertension, and heart failure. However, its role in abdominal aortic aneurysm (AAA) remains unclear. This study aimed to explore the role of TRAF6 on AAA formation and its underlying mechanisms. Single-cell RNA sequencing of human AAA tissues demonstrated that TRAF6 was significantly upregulated in aortic macrophages. Moreover, overexpression of TRAF6 promotes AAA formation in elastase-induced C57BL/6 mice, while TRAF6 pharmacological inhibition could attenuate AAA development. Consistently, inhibition of TRAF6 in macrophages through in vitro methods notably limits their pyroptosis, while also diminishing proinflammatory responses in these cells. Mechanistically, TRAF6 can modulate macrophage pyroptosis through the NLRP3/Caspase1/GSDMD signaling pathway. Our study highlights the crucial role of the TRAF6/NLRP3/Caspase1/GSDMD axis in macrophage pyroptosis and AAA, offering potential biomarkers and therapeutic targets for AAA.

Diabetes in China: epidemiology, pathophysiology and multi-omics

Although diabetes is now a global epidemic, China has the highest number of affected people, presenting profound public health and socioeconomic challenges. In China, rapid ecological and lifestyle shifts have dramatically altered diabetes epidemiology and risk factors. In this Review, we summarize the epidemiological trends and the impact of traditional and emerging risk factors on Chinese diabetes prevalence. We also explore recent genetic, metagenomic and metabolomic studies of diabetes in Chinese, highlighting their role in pathogenesis and clinical management. Although heterogeneity across these multidimensional areas poses major analytic challenges in classifying patterns or features, they have also provided an opportunity to increase the accuracy and specificity of diagnosis for personalized treatment and prevention. National strategies and ongoing research are essential for improving diabetes detection, prevention and control, and for personalizing care to alleviate societal impacts and maintain quality of life.

A bibliometric analysis of abdominal aortic aneurysm (2014-2024)

Background

Abdominal aortic aneurysm (AAA) is a localized bulge of the abdominal aorta, which mainly manifests as a pulsatile mass in the abdomen. Once an abdominal aortic aneurysm ruptures, the patient's life is seriously endangered. Surgery is the preferred treatment for abdominal aortic aneurysm. At present, there has been no comprehensive review of the current status of abdominal aortic aneurysm research. Therefore, this study aimed to identify global trends in abdominal aortic aneurysm research over the last 10 years through bibliometric analysis and to inform clinical practice, research funding allocation, and decision-making.

Methods

We downloaded research articles and reviews on abdominal aortic aneurysm from 1 January 2014, to 1 March 2024, from the Web of Science core collection. CiteSpace (version 6.2.1), RStudio and VOSviewer (version 1.6.18) were used for visual analysis of regional distribution, institutions, authors, keywords and other information.

Results

The number of documents on abdominal aortic aneurysm research increased continuously and has stabilized in recent years. A total of 9,905 publications from 67 countries were published from 1 January 2014, to 1 March 2024. A total of 2,142 (29.52%) studies were from the United States, 1,293 (13.05%) were from China, and 919 (9.28%) were from the United Kingdom. A total of 205 studies were conducted at Stanford University, 172 were conducted at Harvard Medical School, and 165 were conducted at the Mayo Clinic. The top three coauthorship authors were Schermerhorn, Marc L (114); Golledge, Jonathan (102); and De Vries, Jean Paul P.M. (74). The most cocited reference was Chaikof EL, 2018, J Vasc Surg, v67, p. 2; the most cocited journal was the Journal of Vascular Surgery; and the most cocited author was Lederle, FA. "Abdominal aortic aneurysm" was the most frequently used author keyword (2,492). Twenty-five references with strong citation bursts were identified by "CiteSpace". "Artificial intelligence", "clinical outcomes" and "bridging stent" were the primary keywords of emerging research hotspots.

Conclusion

This is the first bibliometric study to comprehensively summarize the research trends in abdominal aortic aneurysm research. This information can help us to identify the current research hotspots and directions. This study will provide extensive help for future research.

Edwardsiella tarda induces airways inflammation and production of autoantibodies against lung tissues through regulation of the IL-33-ST2 axis

Chronic obstructive pulmonary disease (COPD) is a highly prevalent chronic respiratory disease characterised by irreversible airways obstruction associated with chronic airways inflammation and remodelling, while the pathogenesis and the mechanistic differences between patients remain to be fully elucidated. We previously reported that alarmin cytokine IL-33 may contribute to the production of autoantibodies against respiratory epithelial cells. Here we expand the hypothesis that pulmonary autoimmune responses induced by airway microbiota also contribute to the progression of COPD. We focused on Edwardsiella tarda which we detected uniquely in the induced sputum of patients with acute exacerbations of COPD. Pernasal challenge of the airways of WT mice with supernatants of cultured E. tarda induced marked, elevated expression of IL-33 in the lung tissues. Immunisation of animals with supernatants of cultured E. tarda resulted in significantly elevated airways inflammation, the formation of tertiary lymphatic structures and significantly elevated proportions of T follicular helper T cells in the lung tissue and mediastinal lymph nodes. Interestingly, such challenge also induced production of IgG autoantibodies directed against lung tissue lysate, alveolar epithelial cell proteins and elastin fragment, while putrescine, one of metabolites generated by the bacterium, might play an important role in the autoantibody production. Furthermore, all of these effects were partly but significantly abrogated in mice with deletion of the IL-33 receptor ST2. Collectively, these data support the hypothesis that COPD is progressed at least partly by airways microbiota such as E. tarda initiating autoimmune attack of the airways epithelium mediated at least partly through the IL-33-ST2 axis.

Potential implications of natural compounds on aging and metabolic regulation

Aging is generally accompanied by a progressive loss of metabolic homeostasis. Targeting metabolic processes is an attractive strategy for healthy-aging. Numerous natural compounds have demonstrated strong anti-aging effects. This review summarizes recent findings on metabolic pathways involved in aging and explores the anti-aging effects of natural compounds by modulating these pathways. The potential anti-aging effects of natural extracts rich in biologically active compounds are also discussed. Regulating the metabolism of carbohydrates, proteins, lipids, and nicotinamide adenine dinucleotide is an important strategy for delaying aging. Furthermore, phenolic compounds, terpenoids, alkaloids, and nucleotide compounds have shown particularly promising effects on aging, especially with respect to metabolism regulation. Moreover, metabolomics is a valuable tool for uncovering potential targets against aging. Future research should focus on identifying novel natural compounds that regulate human metabolism and should delve deeper into the mechanisms of metabolic regulation using metabolomics methods, aiming to delay aging and extend lifespan.

Regulated vascular smooth muscle cell death in vascular diseases

Regulated cell death (RCD) is a complex process that involves several cell types and plays a crucial role in vascular diseases. Vascular smooth muscle cells (VSMCs) are the predominant elements of the medial layer of blood vessels, and their regulated death contributes to the pathogenesis of vascular diseases. The types of regulated VSMC death include apoptosis, necroptosis, pyroptosis, ferroptosis, parthanatos, and autophagy-dependent cell death (ADCD). In this review, we summarize the current evidence of regulated VSMC death pathways in major vascular diseases, such as atherosclerosis, vascular calcification, aortic aneurysm and dissection, hypertension, pulmonary arterial hypertension, neointimal hyperplasia, and inherited vascular diseases. All forms of RCD constitute a single, coordinated cell death system in which one pathway can compensate for another during disease progression. Pharmacologically targeting RCD pathways has potential for slowing and reversing disease progression, but challenges remain. A better understanding of the role of regulated VSMC death in vascular diseases and the underlying mechanisms may lead to novel pharmacological developments and help clinicians address the residual cardiovascular risk in patients with cardiovascular diseases.

Construction of the miRNA/Pyroptosis-Related Molecular Regulatory Axis in Abdominal Aortic Aneurysm: Evidence From Transcriptome Data Combined With Multiple Machine Learning Approaches Followed by Experiment Validation

Background: Abdominal aortic aneurysm (AAA) represents a permanent and localized widening of the abdominal aorta, posing a potentially lethal risk of aortic rupture. Several recent studies have highlighted the role of pyroptosis, a pro-inflammatory programed cell death, as critical molecular regulators in AAA occurrence, progression, and rupture. However, the potential effects of pyroptosis in AAA and its upstream microRNA (miRNA) have not been comprehensively clarified. Methods: Through a search of the gene expression omnibus (GEO) database, the expression profiles of mRNAs (GSE7084, GSE57691, and GSE98278) and miRNAs (GSE62179) and corresponding clinical features were downloaded, respectively. Expression profiles of 15 AAA and 10 normal vascular samples were consecutively collected for in vitro experimentation and subsequent analysis. Various machine learning techniques were employed to identify hub pyroptosis-related genes (PRGs), leading to the development of a predictive model termed the PRG classifier. Quantitative real-time-polymerase chain reaction (qRT-PCR), western blot (WB), and enzyme-linked immunosorbent assay (ELISA) were used to confirm the expression of the hub PRGs. The diagnostic and predictive capabilities of the model were comprehensively evaluated in GEO and hospital cohorts. Then, the crucial immune cell infiltration and molecular pathways implicated in the initiation and rupture of AAA and their association with pyroptosis were explored. Lastly, a miRNA/hub pyroptosis-related molecular regulatory axis was constructed using the TargetScan dataset, which was further explored through loss-of-function assays. Results: Differential analysis, enrichment score analysis, and principal component analysis (PCA) revealed that pyroptosis-related molecules were significantly involved in the occurrence of AAA. Utilizing multiple machine learning algorithms, eight key PRGs (cysteinyl aspartate specific proteinase [CASP]1, infiltrating lymphocyte [IL]1B, IL18, IL6, NOD-, LRR- and pyrin domain-containing protein [NLRP]1, NLRP2, NLRP3, and tumor necrosis factor [TNF]) were integrated to establish a PRG classifier. Demonstrating robust diagnostic capabilities (area under curve [AUC] > 0.90), the PRG classifier provided clinical insights across two GEO datasets and effectively differentiated small AAA from large AAA, elective stable AAA (eAAA), and ruptured AAA (rAAA), respectively. qRT-PCR, WB, and ELISA verified the mRNA and protein expression of the hub PRGs. Notably, in hospital cohorts, a substantial positive link was unveiled between the PRG classifier and AAA risk factors (hypertension history, diastolic pressure, triglyceride levels, and aneurysm diameter). Furthermore, immune cell infiltration and functional enrichment analysis revealed significant associations of the PRG classifier/PRGs with M2 macrophage infiltration, activated dendritic cells, and enrichment scores of the cytosolic deoxyribonucleic acid (DNA) sensing pathway and tryptophan metabolism, potentially mediating AAA onset and rupture. Finally, based on 90 differentially expressed miRNAs (DEmiRNAs) and eight hub PRGs through TargetScan dataset, a hsa-miR-331-3p/TNF regulatory axis was constructed, wherein upregulation of hsa-miR-331-3p expression significantly reduced TNF and CASP1 protein levels. Conclusion: A predictive model (PRG classifier) incorporating eight PRGs through multiple machine learning algorithms was developed and validated. This model may stand as a potent tool for diagnosing AAA and assessing disease severity. The identification of the cytosolic DNA sensing pathway and the hsa-miR-331-3p/TNF interaction axis may represent crucial targets for AAA treatment, offering deeper insights into its potential pathogenesis.

Targeting the smooth muscle cell Keap1-Nrf2-GSDMD-pyroptosis axis by cryptotanshinone prevents abdominal aortic aneurysm formation

Rationale: Abdominal aortic aneurysm (AAA) is an inflammatory, fatal aortic disease that currently lacks any effective drugs. Cryptotanshinone (CTS) is a prominent and inexpensive bioactive substance derived from Salvia miltiorrhiza Bunge, a well-known medicinal herb for treating cardiovascular diseases through its potent anti-inflammatory properties. Nevertheless, the therapeutic effect of CTS on AAA formation remains unknown. Methods: To investigate the therapeutic effect of CTS in AAA, variety of experimental approaches were employed, majorly including AAA mouse model establishment, real-time polymerase chain reaction (PCR), RNA sequencing, western blot, co-immunoprecipitation, scanning/transmission electron microscopy (SEM/TEM), enzyme-linked immunosorbent assay (ELISA), seahorse analysis, immunohistochemistry, and confocal imaging. Results: In this study, we demonstrated that CTS suppressed the formation of AAA in apolipoprotein E knock-out (ApoE-/-) mice infused with Ang II. A combination of network pharmacology and whole transcriptome sequencing analysis indicated that activation of the Keap1-Nrf2 pathway and regulation of programmed cell death in vascular smooth muscle cells (VSMCs) are closely linked to the anti-AAA effect of CTS. Mechanistically, CTS promoted the transcription of Nrf2 target genes, particularly Hmox-1, which prevented the activation of NLRP3 and GSDMD-initiated pyroptosis in VSMCs, thereby mitigating VSMC inflammation and maintaining the VSMC contractile phenotype. Subsequently, by utilizing molecular docking, together with the cellular thermal shift assay (CETSA) and isothermal titration calorimetry (ITC), a particular binding site was established between CTS and Keap1 at Arg415. To confirm the binding site, site-directed mutagenesis was performed, which intriguingly showed that the Arg415 mutation eliminated the binding between CTS and the Keap1-Nrf2 protein and abrogated the antioxidant and anti-pyroptosis effects of CTS. Furthermore, VSMC-specific Nrf2 knockdown in mice dramatically reversed the protective action of CTS in AAA and the inhibitory effect of CTS on VSMC pyroptosis. Conclusion: Naturally derived CTS exhibits promising efficacy as a treatment drug for AAA through its targeting of the Keap1-Nrf2-GSDMD-pyroptosis axis in VSMCs.

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.

Gasdermin D deficiency attenuates development of ascending aortic dissections in a novel mouse model

Background

Thoracic aortic dissection (TAD) is a silent killer. Approximately two-thirds of the cases occur in the ascending aorta (i.e. type A dissection) and majority of them are unrelated to genetic mutations. However, animal models of spontaneous type A dissection are not widely available. In the present study, a novel mouse TAD model was created. Further, the role of gasdermin D (GSDMD) in TAD development was evaluated.

Methods

TADs were created by treating ascending aorta of adult mice (C57BL/6J) with active elastase (40.0 U/ml) and β-aminopropionitrile (Act E+BAPN). The temporal progress of the TAD pathology was rigorously characterized by histological evaluation and scanning electron microscopy, while potential mechanisms explored with bulk RNA sequencing of specimens collected at multiple timepoints. With this novel TAD model, further experiments were performed with Gsdmd -/- mice to evaluate its impact on TAD formation.

Results

The ascending aorta challenged with Act E+BAPN developed pathology characterized by an early onset of intimomedial tears (complete penetration) and intramural hematoma, followed by progressive medial loss and aortic dilation. Ingenuity Pathway Analysis and functional annotation of differentially expressed genes suggested that a unique inflammatory micro-environment, rather than general inflammation, promoted the onset of TADs by specifically recruiting neutrophils to the aortic wall, while the pathology at the advanced stage was driven by T-cell mediated immune injury. Gsdmd -/- attenuated medial loss, adventitial fibrosis, and dilation of TADs. This protective effect was associated with a reduced number of TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) positive cells and T-cells in TADs.

Conclusions

A novel mouse TAD model was created in the ascending aorta. It produces a unique microenvironment to activate different immune cell subsets, promoting onset and subsequent remodeling of TADs. Consistently, Gsdmd -/- attenuates TAD development, with modulation of cell death and T-cell response likely acting as the underlying mechanism.

NINJ1 Facilitates Abdominal Aortic Aneurysm Formation via Blocking TLR4-ANXA2 Interaction and Enhancing Macrophage Infiltration

Abdominal aortic aneurysm (AAA) is a common and potentially life-threatening condition. Chronic aortic inflammation is closely associated with the pathogenesis of AAA. Nerve injury-induced protein 1 (NINJ1) is increasingly acknowledged as a significant regulator of the inflammatory process. However, the precise involvement of NINJ1 in AAA formation remains largely unexplored. The present study finds that the expression level of NINJ1 is elevated, along with the specific expression level in macrophages within human and angiotensin II (Ang II)-induced murine AAA lesions. Furthermore, Ninj1flox/flox and Ninj1flox/floxLyz2-Cre mice on an ApoE-/- background are generated, and macrophage NINJ1 deficiency inhibits AAA formation and reduces macrophage infiltration in mice infused with Ang II. Consistently, in vitro suppressing the expression level of NINJ1 in macrophages significantly restricts macrophage adhesion and migration, while attenuating macrophage pro-inflammatory responses. Bulk RNA-sequencing and pathway analysis uncover that NINJ1 can modulate macrophage infiltration through the TLR4/NF-κB/CCR2 signaling pathway. Protein-protein interaction analysis indicates that NINJ1 can activate TLR4 by competitively binding with ANXA2, an inhibitory interacting protein of TLR4. These findings reveal that NINJ1 can modulate AAA formation by promoting macrophage infiltration and pro-inflammatory responses, highlighting the potential of NINJ1 as a therapeutic target for AAA.

Gasdermin D Inhibitor Necrosulfonamide Alleviates Angiotensin II-Induced Abdominal Aortic Aneurysms in Apolipoprotein E-Deficient Mice

Abdominal aortic aneurysm (AAA) is a chronic aortic disease that lacks effective pharmacological therapies. This study was performed to determine the influence of treatment with the gasdermin D inhibitor necrosulfonamide on experimental AAAs. AAAs were induced in male apolipoprotein E-deficient mice by subcutaneous angiotensin II infusion (1000 ng/kg body weight/min), with daily administration of necrosulfonamide (5 mg/kg body weight) or vehicle starting 3 days prior to angiotensin II infusion for 30 days. Necrosulfonamide treatment remarkably suppressed AAA enlargement, as indicated by reduced suprarenal maximal external diameter and surface area, and lowered the incidence and reduced the severity of experimental AAAs. Histologically, necrosulfonamide treatment attenuated medial elastin breaks, smooth muscle cell depletion, and aortic wall collagen deposition. Macrophages, CD4+ T cells, CD8+ T cells, and neovessels were reduced in the aneurysmal aortas of necrosulfonamide- as compared to vehicle-treated angiotensin II-infused mice. Atherosclerosis and intimal macrophages were also substantially reduced in suprarenal aortas from angiotensin II-infused mice following necrosulfonamide treatment. Additionally, the levels of serum interleukin-1β and interleukin-18 were significantly lower in necrosulfonamide- than in vehicle-treated mice without affecting body weight gain, lipid levels, or blood pressure. Our findings indicate that necrosulfonamide reduced experimental AAAs by preserving aortic structural integrity as well as reducing mural leukocyte accumulation, neovessel formation, and systemic levels of interleukin-1β and interleukin-18. Thus, pharmacologically inhibiting gasdermin D activity may lead to the establishment of nonsurgical therapies for clinical AAA disease.

The gasdermin family: emerging therapeutic targets in diseases

The gasdermin (GSDM) family has garnered significant attention for its pivotal role in immunity and disease as a key player in pyroptosis. This recently characterized class of pore-forming effector proteins is pivotal in orchestrating processes such as membrane permeabilization, pyroptosis, and the follow-up inflammatory response, which are crucial self-defense mechanisms against irritants and infections. GSDMs have been implicated in a range of diseases including, but not limited to, sepsis, viral infections, and cancer, either through involvement in pyroptosis or independently of this process. The regulation of GSDM-mediated pyroptosis is gaining recognition as a promising therapeutic strategy for the treatment of various diseases. Current strategies for inhibiting GSDMD primarily involve binding to GSDMD, blocking GSDMD cleavage or inhibiting GSDMD-N-terminal (NT) oligomerization, albeit with some off-target effects. In this review, we delve into the cutting-edge understanding of the interplay between GSDMs and pyroptosis, elucidate the activation mechanisms of GSDMs, explore their associations with a range of diseases, and discuss recent advancements and potential strategies for developing GSDMD inhibitors.

Promising dawn in the management of pulmonary hypertension: The mystery veil of gut microbiota

The gut microbiota is a complex community of microorganisms inhabiting the intestinal tract, which plays a vital role in human health. It is intricately involved in the metabolism, and it also affects diverse physiological processes. The gut-lung axis is a bidirectional pathway between the gastrointestinal tract and the lungs. Recent research has shown that the gut microbiome plays a crucial role in immune response regulation in the lungs and the development of lung diseases. In this review, we present the interrelated factors concerning gut microbiota and the associated metabolites in pulmonary hypertension (PH), a lethal disease characterized by elevated pulmonary vascular pressure and resistance. Our research team explored the role of gut-microbiota-derived metabolites in cardiovascular diseases and established the correlation between metabolites such as putrescine, succinate, trimethylamine N-oxide (TMAO), and N, N, N-trimethyl-5-aminovaleric acid with the diseases. Furthermore, we found that specific metabolites, such as TMAO and betaine, have significant clinical value in PH, suggesting their potential as biomarkers in disease management. In detailing the interplay between the gut microbiota, their metabolites, and PH, we underscored the potential therapeutic approaches modulating this microbiota. Ultimately, we endeavor to alleviate the substantial socioeconomic burden associated with this disease. This review presents a unique exploratory analysis of the link between gut microbiota and PH, intending to propel further investigations in the gut-lung axis.

Ferroptosis in age-related vascular diseases: Molecular mechanisms and innovative therapeutic strategies

Aging, an inevitable aspect of human existence, serves as one of the predominant risk factors for vascular diseases. Delving into the mystery of vascular disease's pathophysiology, the profound involvement of programmed cell death (PCD) has been extensively demonstrated. PCD is a fundamental biological process that plays a crucial role in both normal physiology and pathology, including a recently discovered form, ferroptosis. Ferroptosis is characterized by its reliance on iron and lipid peroxidation, and its significant involvement in vascular disease pathophysiology has been increasingly acknowledged. This phenomenon not only offers a promising therapeutic target but also deepens our understanding of the complex relationship between ferroptosis and age-related vascular diseases. Consequently, this article aims to thoroughly review the mechanisms that enable the effective control and inhibition of ferroptosis. It focuses on genetic and pharmacological interventions, with the goal of developing innovative therapeutic strategies to combat age-related vascular diseases.

ADORA3: A Key Player in the Pathogenesis of Intracranial Aneurysms and a Potential Diagnostic Biomarker

BACKGROUND

The effects of genes on the development of intracranial aneurysms (IAs) remain to be elucidated, and reliable blood biomarkers for diagnosing IAs are yet to be established. This study aimed to identify genes associated with IAs pathogenesis and explore their diagnostic value by analyzing IAs datasets, conducting vascular smooth muscle cells (VSMC) experiments, and performing blood detection.

METHODS

IAs datasets were collected and the differentially expressed genes were analyzed. The selected genes were validated in external datasets. Autophagy was induced in VSMC and the effect of selected genes was determined. The diagnostic value of selected gene on the IAs were explored using area under curve (AUC) analysis using IAs plasma samples.

RESULTS

Analysis of 61 samples (32 controls and 29 IAs tissues) revealed a significant increase in expression of ADORA3 compared with normal tissues using empirical Bayes methods of "limma" package; this was further validated by two external datasets. Additionally, induction of autophagy in VSMC lead to upregulation of ADORA3. Conversely, silencing ADORA3 suppressed VSMC proliferation and autophagy. Furthermore, analysis of an IAs blood sample dataset and clinical plasma samples demonstrated increased ADORA3 expression in patients with IA compared with normal subjects. The diagnostic value of blood ADORA3 expression in IAs was moderate when analyzing clinical samples (AUC: 0.756). Combining ADORA3 with IL2RB or CCR7 further enhanced the diagnostic ability for IAs, with the AUC value over 0.83.

CONCLUSIONS

High expression of ADORA3 is associated with IAs pathogenesis, likely through its promotion of VSMC autophagy. Furthermore, blood ADORA3 levels have the potential to serve as an auxiliary diagnostic biomarker for IAs.

Maresin-1 ameliorates hypertensive vascular remodeling through its receptor LGR6

Hypertensive vascular remodeling is defined as the changes in vascular function and structure induced by persistent hypertension. Maresin-1 (MaR1), one of metabolites from Omega-3 fatty acids, has been reported to promote inflammation resolution in several inflammatory diseases. This study aims to investigate the effect of MaR1 on hypertensive vascular remodeling. Here, we found serum MaR1 levels were reduced in hypertensive patients and was negatively correlated with systolic blood pressure (SBP). The treatment of MaR1 reduced the elevation of blood pressure and alleviated vascular remodeling in the angiotensin II (AngII)-infused mouse model. In addition, MaR1-treated vascular smooth muscle cells (VSMCs) exhibited reduced excessive proliferation, migration, and phenotype switching, as well as impaired pyroptosis. However, the knockout of the receptor of MaR1, leucine-rich repeat-containing G protein-coupled receptor 6 (LGR6), was seen to aggravate pathological vascular remodeling, which could not be reversed by additional MaR1 treatment. The mechanisms by which MaR1 regulates vascular remodeling through LGR6 involves the Ca2+/calmodulin-dependent protein kinase II/nuclear factor erythroid 2-related factor 2/heme oxygenase-1 signaling pathway. Overall, supplementing MaR1 may be a novel therapeutic strategy for the prevention and treatment of hypertension.

Macrophage-derived GSDMD promotes abdominal aortic aneurysm and aortic smooth muscle cells pyroptosis

Macrophage is a vital factor in determining the fate of abdominal aortic aneurysm (AAA). The crosstalk between macrophage and other cells plays a crucial role in the development of aneurysm. Gasdermin D (GSDMD) is a vital executive protein of pyroptosis, which is a novel programmed cell death associated with inflammation. In this study, we identified aortic macrophage as the main expressing cell of GSDMD in AAA. Using Gsdmd-/-ApoE-/- mouse and AAV-F4/80-shGSDMD, we demonstrated the potential role of macrophage-derived GSDMD in AAA and aortic pyroptosis induced by Ang II in vivo. In vitro experiments showed that GSDMD promotes the pyroptosis of mouse primary peritoneal macrophages (MPMs), murine aortic vascular smooth muscle cells (MOVAS) and primary smooth muscle cells. Mechanistically, a mouse cytokine antibody array showed that Gsdmd-/- inhibited LPS + nigericin (LN)- induced secretion of multiple cytokines from MPMs. Furthermore, GSDMD is involved in the crosstalk between MPMs and MOVAS via cytokine secretion. This study provides a novel fundamental insight into macrophage-derived GSDMD in AAA and showed that GSDMD could be a promising therapeutic target for AAA.

PANoptosis in vascular smooth muscle cells regulated by TNF-α/IL-1β can be a new target for alleviating the progression of abdominal aortic aneurysm

PANoptosis is an inflammatory programmed cell death (PCD) regulated by multifaceted PANoptosome complexes with major features of pyroptosis, apoptosis, and/or necroptosis that cannot be accounted for by any of these PCD pathways alone. The aim of this study was to investigate the role of PANoptosis on the occurrence and development of abdominal aortic aneurysm (AAA). Clinical samples of patients with AAA, angiotensin II (ANG II)-induced AAA mouse model, and ANG II-induced vascular smooth muscle cells (VSMCs) in vitro model were used for investigation on PANoptosis features. The expressions of ZBP1, AIM2, and other markers related to pyroptosis, apoptosis, and necroptosis elevated obviously in aortic wall tissues of patients with AAA, mice with AAA, and ANG II-treated VSMCs. ANG II treatment increased inflammatory cytokines levels in VSMCs. The stimulation of tumor necrosis factor-α (TNF-α) or interleukin-1β (IL-1β) alone promoted VSMCs death, and the effect of TNF-α combined with IL-1β is more obvious. The expressions of ZBP1, AIM2, and related markers of pyroptosis, apoptosis, and necroptosis were increased by TNF-α and IL-1β combined treatment. Inhibition of TNF-α and/or IL-1β in mice with AAA improved the AAA pathology, reduced the loss of VSMCs, decreased the expression of ZBP1 and AIM2, and markers associated with pyroptosis, apoptosis, and necroptosis. PANoptosis features were observed in aortic wall tissues of patients with AAA, mice with AAA, and ANG II-treated VSMCs. The inhibition of TNF-α and IL-1β can alleviate PANoptosis in mice with AAA, which provides a new strategy for the prevention and treatment of AAA.NEW & NOTEWORTHY Early detection, diagnosis, and treatment are very important to improve the quality of life and prognosis of patients with abdominal aortic aneurysm (AAA). Based on the findings of apoptosis, necroptosis, and pyroptosis (PANoptosis) in AAA clinical samples, this study further explored the molecular mechanism in vivo and in vitro. Specifically, inhibition of tumor necrosis factor-α and interleukin-1β can reduce PANoptosis in vascular smooth muscle cell and thus alleviate the process of AAA.

Integrated analysis of bulk RNA-seq and single-cell RNA-seq reveals the function of pyrocytosis in the pathogenesis of abdominal aortic aneurysm

Pyrocytosis is involved in the development of abdominal aortic aneurysm (AAA), we explored the pyrocytosis-related hub genes in AAA and conducted a diagnostic model based on the pyrocytosis-related genes score (PRGs). A total of 2 bulk RNA-seq (GSE57691 and GSE47472) datasets and pyrocytosis-related genes were integrated to obtain 24 pyrocytosis-related different expression genes (DEGs). The LASSO Cox regression analysis was conducted to filter out 7 genes and further establish the nomogram signature based on the PRGs that exhibited a good diagnosis value. Weighted gene co-expression network analysis (WGCNA) established 14 gene modules and further identified 6 hub genes which were involved in the regulatory process of pyrocytosis in AAA. At the single cell level, we further identified 3 immune cells were highly associated with the pyrocytosis process in AAA. Finally, the cell-cell communication demonstrated that fibroblasts and endothelial cells and myeloid cells maintained close communications. Here, we identified the dysfunctional expressed pyrocytosis-related genes and immune cells in AAA, which provide a comprehensive understanding of the pathogenesis of AAA.

ER stress mediates Angiotensin II-augmented innate immunity memory and facilitates distinct susceptibilities of thoracic from abdominal aorta to aneurysm development

To determine the roles of endoplasmic reticulum (ER) stress and trained immunity, we performed transcriptome analyses on the thoracic aorta (TA) and abdominal aorta (AA) from the angiotensin II (Ang II)-HFD-ApoE-KO aneurysm model and made significant findings: 1) Ang II bypassed HFD-induced metabolic reprogramming and induced stronger inflammation in AA than in TA; 2) Ang II and HFD upregulated 890 genes in AA versus TA and induced cytokine signaling; 3) Ang II AA and TA upregulated 73 and 68 cytokines, scRNA-Seq identified markers of macrophages and immune cells, cell death regulators, respectively; transdifferentiation markers of neuron, glial, and squamous epithelial cells were upregulated by Ang II-AA and TA; and pyroptosis signaling with IL-1β and caspase-4 were more upregulated in Ang II-AA than in TA; 4) Six upregulated transcriptomes in patients with AAA, Ang II AA, Ang II TA, additional aneurysm models, PPE-AAA and BAPN-Ang II-AAA, were partially overlapped with 10 lists of new ER stress gene sets including 3 interaction protein lists of ER stress regulators ATF6, PERK, and IRE1, HPA ER localization genes, KEGG signal genes, XBP1 transcription targets, ATF4 (PERK) targets, ATF6 targets, thapsigargin ER stress genes, tunicamycin-ER stress genes, respectively; 5) Ang II-AA and TA upregulated ROS regulators, MitoCarta genes, trained immunity genes, and glycolysis genes; and 6) Gene KO transcriptomes indicated that ATF6 and PERK played more significant roles than IRE1 in promoting AAA and trained immunity whereas antioxidant NRF2 inhibited them. Our unprecedented ER-focused transcriptomic analyses have provided novel insights on the roles of ER as an immune organelle in sensing various DAMPs and initiating ER stress that triggers Ang II-accelerated trained immunity and differs susceptibilities of thoracic and abdominal aortas to diseases.

Pleiotropic activities of succinate: The interplay between gut microbiota and cardiovascular diseases

Cardiovascular diseases (CVDs) continue to be a significant contributor to global mortality, imposing a substantial burden and emphasizing the urgent need for disease control to save lives and prevent disability. With advancements in technology and scientific research, novel mechanisms underlying CVDs have been uncovered, leading to the exploration of promising treatment targets aimed at reducing the global burden of the disease. One of the most intriguing findings is the relationship between CVDs and gut microbiota, challenging the traditional understanding of CVDs mechanisms and introducing the concept of the gut-heart axis. The gut microbiota, through changes in microbial compositions and functions, plays a crucial role in influencing local and systemic effects on host physiology and disease development, with its metabolites acting as key regulators. In previous studies, we have emphasized the importance of specific metabolites such as betaine, putrescine, trimethylamine oxide, and N,N,N-trimethyl-5-aminovaleric acid in the potential treatment of CVDs. Particularly noteworthy is the gut microbiota-associated metabolite succinate, which has garnered significant attention due to its involvement in various pathophysiological pathways closely related to CVDs pathogenesis, including immunoinflammatory responses, oxidative stress, and energy metabolism. Furthermore, we have identified succinate as a potential biomarker, highlighting its therapeutic feasibility in managing aortic dissection and aneurysm. This review aims to comprehensively outline the characteristics of succinate, including its biosynthetic process, summarize the current evidence linking it to CVDs causation, and emphasize the host-microbial crosstalk involved in modulating CVDs. The insights presented here offer a novel paradigm for future management and control of CVDs.

Pharmacological Inhibition of Gasdermin D Suppresses Angiotensin II-Induced Experimental Abdominal Aortic Aneurysms

BACKGROUND

Gasdermin D, a molecule downstream of the nucleotide-binding oligomerization domain-like receptor family pyrin domain containing inflammasome, forms the membrane pore for the secretion of interleukin (IL)-1β and IL-18, and also mediates pyroptosis. This study was to explore the influence of treatment with disulfiram, a small molecule inhibitor to gasdermin D, on the formation and progression of experimental abdominal aortic aneurysms (AAA).

METHODS

AAAs were induced in 10-week-old male apolipoprotein E deficient mice by subcutaneous infusion of angiotensin II (1000 ng/min/kg body weight) for 28 days via osmotic minipumps. Three days prior to angiotensin II infusion, disulfiram (50 mg/kg) or an equal volume of saline as the vehicle control was administered daily via oral gavage. The influence on experimental AAAs was analyzed by serial measurements of aortic diameters via ultrasonography, grading AAA severity and histopathology at sacrifice. Serum IL-1β and IL-18 levels, systolic blood pressure, total cholesterol, and triglyceride were also measured. Additional experiments assayed the influences on the cell viability and IL-1β secretion of in vitro activated macrophages.

RESULTS

Disulfiram significantly reduced the enlargement, incidence, and severity of angiotensin II-induced experimental AAAs with attenuation of medial elastin breaks, mural macrophage accumulation, and systolic blood pressure. The AAA suppression was also associated with reduced systemic levels of IL-1β but not IL-18. However, disulfiram treatment had no impact on body weight gain and lipid levels in aneurysmal mice. Additionally, disulfiram treatment also markedly reduced the secretion of IL-1β from activated macrophages with a limited effect on cell viability in vitro.

CONCLUSIONS

Gasdermin D inhibition by disulfiram attenuated angiotensin II-induced experimental AAAs with reduced systemic IL-1β levels and in vitro activated macrophage IL-1β secretion. Our study suggests that pharmacological gasdermin D inhibition may have translational potential for limiting clinical AAA progression.