[Progress in research of incidence of aortic dissection and risk factors].

The incidence rate of aortic dissection (AD) is low, but it is highly fatal in the acute phase. Miss diagnosis and misdiagnosis can occur occasionally, resulting the miss of the best intervention time. Research on the epidemiological characteristics and of AD and related risk factors can identify high-risk groups, make screening and diagnosis as soon as possible and effectively control the changeable risk factors to reduce the incidence of AD and improve the outcome of AD cases. This paper summarizes the progress in research of the epidemiological characteristics of AD and related risk factors in order to promote early prevention and diagnosis of AD, improve the AD case management and intervention level.

Dietary vitamin C and vitamin E with the risk of aortic aneurysm and dissection: A prospective population-based cohort study.

BACKGROUND AND AIMS: The associations between dietary vitamin C (VC), vitamin E (VE) intake and aortic aneurysm and dissection (AAD) remain unclear. This study aimed to prospectively investigate the associations between dietary VC and VE with the incident risk of AAD. METHODS AND RESULTS: A total of 139 477 participants of UK Biobank cohort were included in the analysis. Dietary VC and VE consumptions were acquired through a 24-h recall questionnaire. Cox proportional regression models were used to examine the associations between VC, VE intake and the risk of AAD. Incident AAD was ascertained through hospital inpatient records and death registers. During a median follow-up of 12.5 years, 962 incident AAD events were documented. Both dietary VC [adjusted hazard ratio (HR), 0.77; 95 % confidence intervals (CI), 0.63-0.93; P-trend = 0.008] and VE (adjusted HR, 0.70; 95 % CI, 0.57-0.87; P-trend = 0.002) were inversely associated with incident AAD when comparing the participants in the highest quartile with those in the lowest. In subgroup analyses, the associations were more pronounced in participants who were over 60 years old, participants with smoking history, hypertension or hyperlipidemia, who were under the high risk of AAD. CONCLUSION: Higher dietary VC and VE intakes are associated with reduced risk of AAD. Our study emphasizes the importance of diet adjustment strategies targeted on VC and VE to lower the incidence rate of AAD especially in the high-risk population.

Ncf1 knockout in smooth muscle cells exacerbates angiotensin II-induced aortic aneurysm and dissection by activating the STING pathway.

AIMS: Aortic aneurysm and dissection (AAD) is caused by the progressive loss of aortic smooth muscle cells (SMCs) and is associated with a high mortality rate. Identifying the mechanisms underlying SMC apoptosis is crucial for preventing AAD. Neutrophil cytoplasmic factor 1 (Ncf1) is essential in reactive oxygen species production and SMC apoptosis; Ncf1 absence leads to autoimmune diseases and chronic inflammation. Here, the role of Ncf1 in angiotensin II (Ang II)-induced AAD was investigated. METHODS AND RESULTS: Ncf1 expression increased in injured SMCs. Bioinformatic analysis identified Ncf1 as a mediator of AAD-associated SMC damage. Ncf1 expression is positively correlated with DNA replication and repair in SMCs of AAD aortas. AAD incidence increased in Ang II-challenged Sm22CreNcf1fl mice. Transcriptomics showed that Ncf1 knockout activated the stimulator of interferon genes (STING) and cell death pathways. The effects of Ncf1 on SMC death and the STING pathway in vitro were examined. Ncf1 regulated the hydrogen peroxide-mediated activation of the STING pathway and inhibited SMC apoptosis. Mechanistically, Ncf1 knockout promoted the ubiquitination of nuclear factor erythroid 2-related factor 2 (NRF2), thereby inhibiting the negative regulatory effect of NRF2 on the stability of STING mRNA and ultimately promoting STING expression. Additionally, the pharmacological inhibition of STING activation prevented AAD progression. CONCLUSION: Ncf1 deficiency in SMCs exacerbated Ang II-induced AAD by promoting NRF2 ubiquitination and degradation and activating the STING pathway. These data suggest that Ncf1 may be a potential therapeutic target for AAD treatment.

Liraglutide attenuates angiotensin II-induced aortic dissection and aortic aneurysm via inhibiting M1 macrophage polarization in APOE -/- mice.

BACKGROUND: Aortic Aneurysm and Dissection (AAD) are severe cardiovascular conditions with potentially lethal consequences such as aortic rupture. Existing studies suggest that liraglutide, a long-acting glucagon-like peptide receptor (GLP-1R) agonist, offers protective benefits across various cardiovascular diseases. However, the efficacy of liraglutide in mitigating AAD development is yet to be definitively elucidated. METHODS: Ang II (Angiotension II) infusion of APOE-/- mouse model with intraperitoneal injection of liraglutide (200 µg/kg) to study the role of GLP-1R in AAD formation. Bone Marrow Derived Macrophages (BMDM) and Raw264.7 were incubated with LPS, liraglutide, exendin 9-39 or LY294002 alone or in combination. SMC phenotype switching was examined in a macrophage and vascular smooth muscle cell (VSMC) co-culture system. An array of analytical methods, including Western Blot, Immunofluorescence Staining, Enzyme-LinkedImmunosorbent Assay, Real-Time Quantitative Polymerase Chain Reaction, RNA-seq, and so on were employed. RESULTS: Our investigation revealed a significant increase in M1 macrophage polarization and GLP-1R expression in aortas of AD patients and Ang II-induced AAD APOE-/- mice. Administering liraglutide in APOE-/- mice notably reduced Ang II-induced AAD incidence and mortality. It was found that liraglutide inhibits M1 macrophage polarization primarily via GLP-1R activation, and subsequently modulates vascular smooth muscle cell phenotypic switching was the primary mechanism. RNA-Seq and subsequent KEGG enrichment analysis identified CXCL3, regulated by the PI3K/AKT signaling pathway, as a key element in liraglutide's modulation of M1 macrophage polarization. CONCLUSION: Our study found liraglutide exhibits protective effects against AAD by modulating M1 macrophage polarization, suppressing CXCL3 expression through the PI3K/AKT signaling pathway. This makes it a promising therapeutic target for AAD, offering a new avenue in AAD management.

S-adenosylmethionine attenuates angiotensin II-induced aortic dissection formation by inhibiting vascular smooth muscle cell phenotypic switch and autophagy.

It is well known that aortic dissection (AD) is a very aggressive class of vascular diseases. S-adenosylmethionine (SAM) is an autophagy inhibitor with anti-inflammatory and anti-oxidative stress effects; however, the role of SAM in AD is unknown. In this study, we constructed an animal model of AD using subcutaneous minipump continuous infusion of AngII-induced ApoE-/-mice and a cytopathic model using AngII-induced primary vascular smooth muscle cells (VSMCs) to investigate the possible role of SAM in AD. The results showed that mice in the AngII + SAM group had significantly lower AD incidence, significantly prolonged survival, and reduced vascular elastic fiber disruption compared with mice in the AngII group. In addition, SAM significantly inhibited autophagy in vivo and in vitro. Meanwhile, SAM also inhibited the cellular phenotypic switch, mainly by up regulating the expression levels of contractile marker proteins [α-smooth muscle actin (α-SMA) and smooth muscle 22α (SM22α)] and down regulating the expression levels of synthetic marker proteins [osteoblast protein (OPN), matrix metalloproteinase-2 (MMP2), and matrix metalloproteinase-9 (MMP9)]. Molecularly, SAM inhibited AD formation mainly by activating the PI3K/AKT/mTOR signaling pathway. Using a PI3K inhibitor (LY294002) significantly reversed the protective effect of SAM in AngII-induced mice and VSMCs.Our study demonstrates the protective effect of SAM on mice under AngII-induced AD for the first time. SAM prevented AD formation mainly by inhibiting cellular phenotypic switch and autophagy, and activation of the PI3K/AKT/mTOR signaling pathway is a possible molecular mechanism. Thus, SAM may be a novel strategy for the treatment of AD.

Urate-Lowering Therapy Inhibits Thoracic Aortic Aneurysm and Dissection Formation in Mice.

BACKGROUND: Thoracic aortic aneurysm and dissection (TAAD) is a highly lethal vascular disease without effective drug therapy. Whether elevated serum concentrations of uric acid are involved in TAAD development remains unclear. METHODS: Serum uric acid levels were detected in different TAAD mouse models and patients. The urate-lowering drug allopurinol was administered in the drinking water of TAAD mice. Adenine diet-induced mice were established to investigate the role of hyperuricemia in TAAD formation and RNA-sequencing of thoracic aortas from these mice was performed. RESULTS: We found serum uric acid levels were elevated in various mouse TAAD models, including mice fed a ß-aminopropionitrile diet, Marfan mice with fibrillin-1 haploinsufficiency (Fbn1C1041G/+), and ApoE-/- mice infused with Ang II (angiotensin II), as well as in patients with TAAD. Administration of urate-lowering drug allopurinol in the drinking water significantly alleviated TAAD formation in ß-aminopropionitrile-treated mice, Fbn1C1041G/+ mice, and Ang II-infused ApoE-/- mice. Moreover, an adenine diet was used to induce hyperuricemia in mice. Intriguingly, a 4-week adenine diet feeding directly induced TAAD formation characterized by increased maximal thoracic aortic diameters and severe elastin degradation, which were ameliorated by allopurinol. Unbiased RNA-sequencing in mouse thoracic aortas suggested that FcγR (Fc gamma receptor) was upregulated upon adenine diet, but reciprocally repressed by allopurinol. Mechanistically, hyperuricemia activated FcγR-mediated ERK1/2 (extracellular signal-regulated kinase 1/2) phosphorylation to induce macrophage inflammation and TAAD development, which was abrogated by allopurinol or FcγR deficiency. CONCLUSIONS: This study uncovered an important and previously unrecognized role of hyperuricemia in mediating the pathogenesis of TAAD, and uric acid-lowering drug may represent a promising therapeutic approach for TAAD.

Aortic Stress Activates an Adaptive Program in Thoracic Aortic Smooth Muscle Cells That Maintains Aortic Strength and Protects Against Aneurysm and Dissection in Mice.

BACKGROUND: When aortic cells are under stress, such as increased hemodynamic pressure, they adapt to the environment by modifying their functions, allowing the aorta to maintain its strength. To understand the regulation of this adaptive response, we examined transcriptomic and epigenomic programs in aortic smooth muscle cells (SMCs) during the adaptive response to AngII (angiotensin II) infusion and determined its importance in protecting against aortic aneurysm and dissection (AAD). METHODS: We performed single-cell RNA sequencing and single-cell sequencing assay for transposase-accessible chromatin (scATAC-seq) analyses in a mouse model of sporadic AAD induced by AngII infusion. We also examined the direct effects of YAP (yes-associated protein) on the SMC adaptive response in vitro. The role of YAP in AAD development was further evaluated in AngII-infused mice with SMC-specific Yap deletion. RESULTS: In wild-type mice, AngII infusion increased medial thickness in the thoracic aorta. Single-cell RNA sequencing analysis revealed an adaptive response in thoracic SMCs characterized by upregulated genes with roles in wound healing, elastin and collagen production, proliferation, migration, cytoskeleton organization, cell-matrix focal adhesion, and PI3K-PKB/Akt (phosphoinositide-3-kinase-protein kinase B/Akt) and TGF-ß (transforming growth factor beta) signaling. ScATAC-seq analysis showed increased chromatin accessibility at regulatory regions of adaptive genes and revealed the mechanical sensor YAP/transcriptional enhanced associate domains as a top candidate transcription complex driving the expression of these genes (eg, Lox, Col5a2, Tgfb2). In cultured human aortic SMCs, cyclic stretch activated YAP, which directly bound to adaptive gene regulatory regions (eg, Lox) and increased their transcript abundance. SMC-specific Yap deletion in mice compromised this adaptive response in SMCs, leading to an increased AAD incidence. CONCLUSIONS: Aortic stress triggers the systemic epigenetic induction of an adaptive response (eg, wound healing, proliferation, matrix organization) in thoracic aortic SMCs that depends on functional biomechanical signal transduction (eg, YAP signaling). Our study highlights the importance of the adaptive response in maintaining aortic homeostasis and preventing AAD in mice.

Current state and future directions of genomic medicine in aortic dissection: A path to prevention and personalized care.

Aortic dissection confers high mortality and morbidity rates despite advances in treatment, impacts quality of life, and contributes immense burden to the healthcare system globally. Efforts to prevent aortic dissection through screening and management of modifiable risk factors and early detection of aneurysms should incorporate genomic information, as it is integral to stratifying risk. However, effective integration of genomic-guided risk assessment into clinical practice will require addressing implementation barriers that currently permeate our healthcare systems. The Aortic Dissection Collaborative was established to define aortic dissection research priorities through patient engagement. Using a collaborative patient-centered feedback model, our Genomic Medicine Working Group identified related research priorities that could be investigated by pragmatic interventional studies aimed at aortic dissection prevention, utilization of genomic information to improve patient outcomes, and access to genomic medicine services. Further research is also needed to identify the genomic, lifestyle, and environmental risk factors that contribute to aortic dissection so these data can be incorporated into future comparative effectiveness studies to prevent aortic dissection.

Anxa1 in smooth muscle cells protects against acute aortic dissection.

AIMS: Acute aortic dissection (AAD) is a life-threatening disease with high morbidity and mortality. Previous studies have showed that vascular smooth muscle cell (VSMC) phenotype switching modulates vascular function and AAD progression. However, whether an endogenous signalling system that protects AAD progression exists remains unknown. Our aim is to investigate the role of Anxa1 in VSMC phenotype switching and the pathogenesis of AAD. METHODS AND RESULTS: We first assessed Anxa1 expression levels by immunohistochemical staining in control aorta and AAD tissue from mice. A strong increase of Anxa1 expression was seen in the mouse AAD tissues. In line with these findings, micro-CT scan results indicated that Anxa1 plays a role in the development of AAD in our murine model, with systemic deficiency of Anxa1 markedly progressing AAD. Conversely, administration of Anxa1 mimetic peptide, Ac2-26, rescued the AAD phenotype in Anxa1-/- mice. Transcriptomic studies revealed a novel role for Anxa1 in VSMC phenotype switching, with Anxa1 deficiency triggering the synthetic phenotype of VSMCs via down-regulation of the JunB/MYL9 pathway. The resultant VSMC synthetic phenotype rendered elevated inflammation and enhanced matrix metalloproteinases (MMPs) production, leading to augmented elastin degradation. VSMC-restricted deficiency of Anxa1 in mice phenocopied VSMC phenotype switching and the consequent exacerbation of AAD. Finally, our studies in human AAD aortic specimens recapitulated key findings in murine AAD, specifically that the decrease of Anxa1 is associated with VSMC phenotype switch, heightened inflammation, and enhanced MMP production in human aortas. CONCLUSIONS: Our findings demonstrated that Anxa1 is a novel endogenous defender that prevents AAD by inhibiting VSMC phenotype switching, suggesting that Anxa1 signalling may be a potential target for AAD pharmacological therapy.

Inhibition on CXCL5 reduces aortic matrix metalloproteinase 9 expression and protects against acute aortic dissection.

Acute aortic dissection (AAD) is an acute inflammatory vascular condition associated with significant morbidity and mortality. Depletion of neutrophils can attenuate the development of AAD. The CXC-motif chemokine 5 (CXCL5) can attract and activate neutrophils. This study aimed to investigate whether direct inhibition of CXCL5 could protect against AAD formation. A set of AAD animal models was designed using an angiotensin II infusion for 3 days after treatment with the lysyl oxidase inhibitor beta-aminopropionitrile for 4 weeks in 4-week-old male BALB/c mice. While AAD developed successfully in all the animals, approximately 31% of the mice died before sacrifice. The morphological changes at different time points during the experimental period indicated that angiotensin II could trigger AAD formation in this model. CXCL5 protein expression in the aorta tissue was increased after treatment with angiotensin II. Moreover, the ex vivo and in vitro study showed that vascular smooth muscle cells and monocytes isolated from the animals could generate CXCL5. CXCL5 inhibition by a specific monoclonal antibody significantly decreased the severity of AAD evaluated by ultrasound, aorta wet weight, and en face assay. The immunohistochemical analysis showed that the aortic tissues from AAD mice had higher expressions of matrix metalloproteinase (MMP) 9 and neutrophil-positive areas in the medial layer compared to control mice. Treatment with a CXCL5 antibody reduced MMP9 and neutrophil expressions as well as neutrophil and CXCL5 double-positive areas compared to untreated AAD mice. In conclusion, direct inhibition on CXCL5 reduced aortic MMP9 expression as well as neutrophil infiltration and attenuated the development of AAD, suggesting the mechanistic role of CXCL5 in neutrophil-triggered AAD. CXCL5 may be a potential therapeutic target for AAD.

Current progress of fluoroquinolones-increased risk of aortic aneurysm and dissection.

Aortic aneurysm (AA) and aortic dissection (AD) are major life-threatening diseases around the world. AA is a localized or diffuse dilation of the aorta, while AD is the separation of the layers creating a false lumen within the aortic wall. Fluoroquinolones (FQ) remain one of the most important kind of antibiotics and have a wider clinical use and broad antibacterial spectrum. FQ were also reported to treat infected AA. The most common adverse events (AEs) of FQ are mild and reversible, like headaches, diarrhea and nausea. Due to FQ-related serious AEs, such as tendonitis and tendon rupture, chondrotoxicity, or retinal detachment, QT-prolongation and dysglycemia, the United States Food and Drug Administration (FDA) issued a black box warning for FQ for systemic use in 2016 and updated warnings for FQ several times since then. Of note, in December 2018, FDA issued several "black box warnings" against FQ with the latest safety announcement warning about an increased risk of ruptures in the aorta blood vessel in certain patients. Recently, many studies have indicated an association between FQ and an increase risk of AA and AD. However, the exact mechanism of FQ-induced AA/AD remains unclear. This review aims to highlight the latest research progress of the alarming association between FQ and AA/AD. Moreover, molecular mechanisms of FQ in increasing risk of AA and AD are explored. Hopefully, this review can provide novel insights into FQ-increased the risk of AA/AD and a starting place for stewardship interventions.

Pregnancy-Related Aortic Complications in Women With Marfan Syndrome.

BACKGROUND: The risk of pregnancy-associated vascular complications in Marfan syndrome (MFS) is uncertain because of ascertainment bias, prepartum lack of knowledge of diagnosis, and insufficient peripartum imaging data. Furthermore, U.S. and European guidelines differ in pregnancy recommendations in MFS. OBJECTIVES: This study describes a single-center experience of 169 MFS women to address these gaps. METHODS: Clinical, imaging, and pregnancy history were compared in never vs ever-pregnant MFS women, and pregnancy-associated vascular complications were described. RESULTS: A total of 74 ever-pregnant women had 112 live births. Elective aortic root replacement occurred at a younger age in never-pregnant women (33 years vs 42 years; P = 0.0026). Although aortic dissection prevalence did not differ between never-pregnant vs ever-pregnant women (23% vs 31%; P = 0.25), it tended to occur at an earlier age in the former group (38 years vs 45 years; P = 0.07). Of observed "sanctioned" pregnancies with prepartum diameters ≤4.5 cm, mean pregnancy-related aortic diameters remained stable. In total, 5 dissections were associated with pregnancy: 2 type A in women unaware of their diagnosis; and 2 type B and 1 isolated coronary artery dissection in women aware of their diagnosis. Dissection rates were 5-fold higher in the pregnancy vs nonpregnancy period. CONCLUSIONS: Pregnancy-related type A dissection only occurred in patients unaware of their diagnosis. Type B dissection remains an unpredictable complication. Although there were baseline differences between the never- and ever-pregnant groups, no difference in dissection risk was observed outside the peripartum period. Those with prepartum aortic diameters between 4.0 and 4.5 cm demonstrated stable aortic dimensions throughout pregnancy. These findings provide a rationale to update existing U.S. guidelines for the management of pregnancy in MFS.

Inhibition of HIPK2 Alleviates Thoracic Aortic Disease in Mice With Progressively Severe Marfan Syndrome.

Objective: Despite considerable research, the goal of finding nonsurgical remedies against thoracic aortic aneurysm and acute aortic dissection remains elusive. We sought to identify a novel aortic PK (protein kinase) that can be pharmacologically targeted to mitigate aneurysmal disease in a well-established mouse model of early-onset progressively severe Marfan syndrome (MFS). Approach and Results: Computational analyses of transcriptomic data derived from the ascending aorta of MFS mice predicted a probable association between thoracic aortic aneurysm and acute aortic dissection development and the multifunctional, stress-activated HIPK2 (homeodomain-interacting protein kinase 2). Consistent with this prediction, Hipk2 gene inactivation significantly extended the survival of MFS mice by slowing aneurysm growth and delaying transmural rupture. HIPK2 also ranked among the top predicted PKs in computational analyses of DEGs (differentially expressed genes) in the dilated aorta of 3 MFS patients, which strengthened the clinical relevance of the experimental finding. Additional in silico analyses of the human and mouse data sets identified the TGF (transforming growth factor)-ß/Smad3 signaling pathway as a potential target of HIPK2 in the MFS aorta. Chronic treatment of MFS mice with an allosteric inhibitor of HIPK2-mediated stimulation of Smad3 signaling validated this prediction by mitigating thoracic aortic aneurysm and acute aortic dissection pathology and partially improving aortic material stiffness. Conclusions: HIPK2 is a previously unrecognized determinant of aneurysmal disease and an attractive new target for antithoracic aortic aneurysm and acute aortic dissection multidrug therapy.