LncRNA SENCR suppresses abdominal aortic aneurysm formation by inhibiting smooth muscle cells apoptosis and extracellular matrix degradation

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.

Pathogenetic Significance of Long Non-Coding RNAs in the Development of Thoracic and Abdominal Aortic Aneurysms

Aortic aneurysm (AA) is a life-threatening condition with a high prevalence and risk of severe complications. The aim of this review was to summarize the data on the role of long non-coding RNAs (lncRNAs) in the development of AAs of various location. Within less than a decade of studies on the role of lncRNAs in AA, using experimental and bioinformatic approaches, scientists have obtained the data confirming the involvement of these molecules in metabolic pathways and pathogenetic mechanisms critical for the aneurysm development. Regardless of the location of pathological process (thoracic or abdominal aorta), AA was found to be associated with changes in the expression of various lncRNAs in the tissue of the affected vessels. The consistency of changes in the expression level of lncRNA, mRNA and microRNA in aortic tissues during AA development has been recordedand regulatory networks implicated in the AA pathogenesis in which lncRNAs act as competing endogenous RNAs (ceRNA networks) have been identified. It was found that the same lncRNA can be involved in different ceRNA networks and regulate different biochemical and cellular events; on the other hand, the same pathological process can be controlled by different lncRNAs. Despite some similarities in pathogenesis and overlapping of involved lncRNAs, the ceRNA networks described for abdominal and thoracic AA are different. Interactions between lncRNAs and other molecules, including those participating in epigenetic processes, have also been identified as potentially relevant to the AA pathogenesis. The expression levels of some lncRNAs were found to correlate with clinically significant aortic features and biochemical parameters. Identification of regulatory RNAs functionally significant in the aneurysm development is important for clarification of disease pathogenesis and will provide a basis for early diagnostics and development of new preventive and therapeutic drugs.

The Role of Epigenetic Modifications in Abdominal Aortic Aneurysm Pathogenesis

Abdominal aortic aneurysm (AAA) is a life-threatening disease associated with high morbidity and mortality in the setting of acute rupture. Recently, advances in surgical and endovascular repair of AAA have been achieved; however, pharmaceutical therapies to prevent AAA expansion and rupture remain lacking. This highlights an ongoing need to improve the understanding the pathological mechanisms that initiate formation, maintain growth, and promote rupture of AAA. Over the past decade, epigenetic modifications, such as DNA methylation, posttranslational histone modifications, and non-coding RNA, have emerged as important regulators of cellular function. Accumulating studies reveal the importance of epigenetic enzymes in the dynamic regulation of key signaling pathways that alter cellular phenotypes and have emerged as major intracellular players in a wide range of biological processes. In this review, we discuss the roles and implications of epigenetic modifications in AAA animal models and their relevance to human AAA pathology.

Nuclear Paraspeckle Assembly Transcript 1 Enhances Hydrogen Peroxide-Induced Human Vascular Smooth Muscle Cell Injury by Regulating miR-30d-5p/A Disintegrin and Metalloprotease 10

BACKGROUND

Nuclear paraspeckle assembly transcript 1 (NEAT1) has been reported to be involved in the progression of many cancers; however, the role and mechanisms underlying NEAT1 in abdominal aortic aneurysm (AAA) remain unclear.Methods and Results:The expression of NEAT1, miR-30d-5p and A disintegrin and metalloprotease 10 (ADAM10) was measured by qRT-PCR and western blot. Functional experiments were conducted by using a CCK-8 assay, EDU assay, flow cytometry, western blot, ELISA, and commercial kits. The target relation was confirmed by dual-luciferase reporter assay and the RIP assay. It was then found that NEAT1 was upregulated in peripheral blood of AAA patients ~3.46-fold, smooth muscle cells (SMCs) isolated from AAA tissues ~2.6-fold and in a hydrogen peroxide (H₂O₂)-induced injury model of human vascular SMC (HVSMCs) ~2.0- and 3.9-fold at 50 µmol/L and 200 µmol/L H₂O₂treatment, respectively. NEAT1 deletion attenuated H₂O₂-induced cell proliferation promotion (40.0% vs. 74.3%), apoptosis inhibition (25.0% vs. 13.5%), and reduction of inflammatory response and oxidative stress in HVSMCs. Mechanistically, NEAT1 targeted miR-30d-5p to prevent the degradation of its target, ADAM10, in HVSMCs. Further rescue experiments suggested miR-30d-5p inhibition mitigated the effects of NEAT1 deletion on H₂O₂-induced HVSMCs. Moreover, ADAM10 overexpression counteracted the inhibitory functions of miR-30d-5p on H₂O₂-evoked HVSMC injury.

CONCLUSIONS

NEAT1 promoted H₂O₂-induced HVSMC injury by inducing cell apoptosis, inflammation and oxidative stress through miR-30d-5p/ADAM10 axis, indicating the possible involvement of NEAT1 in the pathogenesis of AAA.

Circular RNA RBM33 contributes to extracellular matrix degradation via miR-4268/EPHB2 axis in abdominal aortic aneurysm

Background

Abdominal aortic aneurysm (AAA) is a complex vascular disease involving expansion of the abdominal aorta. Extracellular matrix (ECM) degradation is crucial to AAA pathogenesis, however, the specific molecular mechanism remains unclear. This study aimed to investigate differentially expressed circular RNAs (DEcircRNAs) involved in ECM degradation of AAA.

Methods

Transcriptome sequencing was used to analyze the DEcircRNAs between the AAA tissues and normal tissues. The expression of circRNAs in tissues and cells was validated using quantitative reverse transcription PCR (RT-qPCR). Overexpression of circRNAs in vascular smooth muscle cells (VSMCs) treated with angiotensin II (Ang II) was employed to explore its effect on ECM degradation of AAA. Bioinformatic technology, luciferase reporter gene assay, RT-qPCR, and rescue experiment were employed to evaluate the regulatory mechanism of circRNA.

Results

We identified 65 DEcircRNAs in AAA tissues compared with normal abdominal aortic tissues, including 30 up-regulated and 35 down-regulated circRNAs, which were mainly involved in inflammation and ECM-related functions and pathways. Moreover, circRBM33 was significantly increased in AAA tissues and Ang II-induced VSMCs compared with control samples. Overexpression of circRBM33 increased the expression of ECM-related molecule matrix metalloproteinase-2 and reduced the tissue inhibitor of matrix metalloproteinases-1 expression. Mechanistically, miR-4268 targeted binding to circRBM33 and inhibited the luciferase activity of circRBM33. Overexpression of circRBM33 induced the expression of EPH receptor B2 (EPHB2), and this effect was countered by miR-4268 mimics.

Conclusions

Overall, our data suggest that circRBM33 might be involved in AAA progression by regulating ECM degradation via the miR-4268/EPHB2 axis.

LncRNA ANRIL Facilitates Vascular Smooth Muscle Cell Proliferation and Suppresses Apoptosis via Modulation of miR-7/FGF2 Pathway in Intracranial Aneurysms

BACKGROUND

Proliferation and apoptosis of vascular smooth muscle cells (VSMCs) are linked to intracranial aneurysm (IA) formation and progression. Long antisense noncoding RNA in the INK4 locus (ANRIL) has been reported to regulate VSMC functions in several cardiovascular diseases. However, little is known about how ANRIL influences VSMC proliferation and apoptosis during IA pathogenesis.

METHODS

The expression level of ANRIL in the plasma and arterial wall tissues of patients with IA was detected by real-time quantitative polymerase chain reaction. The functional role of ANRIL in the regulation of VSMC proliferation and apoptosis and its downstream regulatory mechanism were determined using Cell Counting Kit 8, immunofluorescence, terminal-deoxynucleotidyl transferase-mediated UTP nick end labeling, western blotting, luciferase reporter assay, and RNA immunoprecipitation assay.

RESULTS

ANRIL was downregulated in the plasma and arterial wall tissues of patients with IA, when compared with control groups. Overexpression of ANRIL significantly promoted VSMC proliferation and blocked cell apoptosis. Mechanistic studies demonstrated that ANRIL directly bound to microRNA-7 (miR-7) and that overexpression of miR-7 overturned the increased cell proliferation and decreased cell apoptosis, which was induced by ANRIL restoration. Besides, further study showed that ANRIL positively regulated fibroblast growth factor 2 (FGF2) expression via targeting miR-7.

CONCLUSIONS

These results suggested that ANRIL affects VSMC proliferation and apoptosis via regulation of the miR-7/FGF2 pathway in IA, which provided a potential novel strategy for the treatment of IA.

Curcumin nicotinate suppresses abdominal aortic aneurysm pyroptosis via lncRNA PVT1/miR-26a/KLF4 axis through regulating the PI3K/AKT signaling pathway

Abdominal aortic aneurysm (AAA) is a chronic dilated disease of the aorta that is characterized by chronic inflammation. Curcumin (Cur) is previously showed to attenuate AAA by inhibiting inflammatory response in ApoE -/- mice. Since Cur has the limitations of aqueous solubility and instability. Here, we focus on the role of curcumin nicotinate (CurTn), a Cur derivative is derived from Cur and nicotinate. An in vitro model of AAA was established by treating vascular smooth muscle cells (VSMCs) with II (Ang-II). Gene and protein expressions were examined by quantitative real-time PCR (qPCR) or western blotting. Cell migration and pyroptosis were determined by transwell assay and flow cytometry. The interaction between plasmacytoma variant translocation 1 (PVT1), miR-26a and krüppel-like factor 4 (KLF4) was predicted by online prediction tool and confirmed by luciferase reporter assay. CurTn reduced Ang-II-induced AAA-associated proteins, inflammatory cytokine expressions, and attenuated pyroptosis in VSMCs. PVT1 overexpression suppressed the inhibitory effect of CurTn on AngII-induced pyroptosis and inflammatory in VSMCs by sponging miR-26a. miR-26a directly targeted KLF4 and suppressed its expression, which eventually led to the deactivation of the PI3K/AKT signaling pathway. Besides, the regulatory effect of CurTn on pyroptosis of VSMCs induced by Ang-II was reversed through the PVT1/miR-26a/KLF4 pathway. In short, CurTn suppressed VSMCs pyroptosis and inflammation though mediation PVT1/miR-26a/KLF4 axis by regulating the PI3K/AKT signaling pathway, CurTn might consider as a potential therapeutic target in the treatment of AAA.