Circulating microRNAs signature correlates with positive [18F]fluorodeoxyglucose-positron emission tomography in patients with abdominal aortic aneurysm

Can Biomarkers and PET Imaging Predict Abdominal Aortic Aneurysm Growth Rate?

Background: Abdominal aortic aneurysm (AAA) is a life-threatening condition due to the risk of aneurysm growth and rupture. Biomarkers linked to AAA pathogenesis are attractive candidates for AAA diagnosis and prognosis. The aim of this study was to assess circulating biomarkers levels relationship with PET imaging positivity and their predictive value in AAA growth rate. Methods: A total of 164 patients with AAA had whole body [18F]FDG PET/CT examination and blood drawn for biomarkers analysis at inclusion. Of these, 121 patients had at least one follow-up imaging assessment for AAA progression. Median (quartiles) imaging follow-up period was 32.8 months (15.2-69.6 months). Results: At baseline, PET was visually positive in 28 (17%) patients. Among PET+ patients, female proportion was higher compared to PET-patients (respectively, n = 6, 21.4% vs. n = 11, 8.1%, p = 0.046). Biomarkers of inflammation (CRP, CCL18), of proteolytic activity (MMP9), of extracellular matrix, and calcification regulation (OPN, OPG) were all significantly increased in PET+ patients (p < 0.05). During follow-up, rapid AAA growth (increase in size ≥ 1 cm per year) was observed in 36 (29.8%) patients and several biomarkers (CRP, MMP9, OPN, and OPG) were increased in those patients compared to patients without rapid growth (p < 0.05). Conclusions: Although PET positivity at baseline was not associated with rapid growth, CRP levels showed a significant association.

Circulating miRNAs as biomarkers for diagnosis, surveillance and post-operative follow-up of abdominal aortic aneurysms

OBJECTIVE

To provide a summary of the current state of research in English medical literature on circulating miRNAs, as biomarkers for AAA. Additionally, for the most commonly mentioned circulating miRNAs in the literature, to attempt a documentation of the biological mechanisms underlying their role in AAA development.

METHODS

A literature search was undertaken in the MEDLINE database. Only reports that involved peripheral blood samples (whole blood, plasma, serum) were included. The following terms were used in combination: microrna, mirna, abdominal aortic aneurysm, human, circulating, plasma, serum, endovascular and EVAR.

RESULTS

A total of 25 reports, published from 2012 to 2022 were included with a total of 1259 patients with AAA, predominantly men (N= 1040, 90%). Six of these reports recruited healthy donors who underwent ultrasound screening for AAA as control samples. The majority of studies were undertaken in plasma samples and the most preferred microRNA profiling method was Real - Time quantitative polymerase chain reaction (qRT-PCR). The following nine miRNAs (out of a total of 76) were studied in more than two references: miR-145, miR-24, miR-33, miR-125, let-7, miR-15, miR-191, miR-29 and miR-133.

CONCLUSION

The nine miRNAs described in this study, are implicated in known pathogenetic mechanisms of AAA such as atherosclerosis, vascular smooth muscle cell phenotype switch and apoptosis, vascular inflammation, extracellular matrix degradation and lipid metabolism. Identifying disease-specific miRNAs, in combination with other clinical parameters, as indicators of AAA, is crucial for early diagnosis as well as follow-up of AAAs. For future research on miRNAs as AAA biomarkers, strict case and control group definitions, sample acquisition protocols, and miRNA expression profiling techniques are warranted.

Reactive oxygen species-induced long intergenic noncoding RNA p21 accelerates abdominal aortic aneurysm formation by promoting secretary smooth muscle cell phenotypes

Whether long noncoding RNAs participate in the formation of abdominal aortic aneurysms (AAAs) through the regulation of SMC phenotypic switching is unknown. lincRNA-p21 induced by reactive oxygen species (ROS) is likely functionally associated with SMC phenotypic switching. We thus investigated the role of lincRNA-p21 in SMC phenotypic switching-associated AAA formation and its underlying mechanisms. An analysis of human and mouse abdominal aortic samples revealed that the lincRNA-p21 levels were significantly higher in AAA tissue. Stimulation with hydrogen peroxide upregulated the expression of lincRNA-p21 in a dose-dependent manner and converted SMCs from a contractile phenotype to a synthetic, proteolytic, and proinflammatory phenotype in vitro. Moreover, lincRNA-p21 promoted fracture of elastic fibres, reconstruction of the vascular wall, and AAA formation in vivo by modulating SMC phenotypic switching in two mouse models of AAA induced by angiotensin II or porcine pancreatic elastase (PPE) perfusion. Using a bioinformatics prediction method and luciferase reporter gene assays, we further proved that lincRNA-p21 sponged miR-204-5p to release the transcriptional activity of Mekk3 and promoted the NF-κB pathway and thereby played a role in the SMC phenotypic switch and AAA formation. The ROS levels were positively correlated with the lincRNA-p21 levels in human and mouse AAA tissues. The knockdown of lincRNA-p21 in a PPE-induced mouse AAA model increased the miR-204-5p levels and reduced the expression of Mekk3, whereas lincRNA-p21 overexpression had the opposite effect. Collectively, the results indicated that ROS-induced lincRNA-p21 sponges miR-204-5p to accelerate synthetic and proinflammatory SMC phenotypes through the Mekk3/NF-κB pathway in AAA formation. Thus, lincRNA-p21 may have therapeutic potential for AAA formation.

Towards Precritical Medical Therapy of the Abdominal Aortic Aneurysm

Pharmacotherapy for abdominal aortic aneurysm (AAA) can be useful for prevention, especially in people at higher risk, for slowing down AAA progression, as well as for post-surgery adjuvant treatment. Our review focuses on novel pharmacotherapy approaches targeted towards slowing down progression of AAA, known also as secondary prevention therapy. Guidelines for AAA are not specific to slow down the expansion rate of an abdominal aortic aneurysm, and therefore no medical therapy is recommended. New ideas are urgently needed to develop a novel medical therapy. We are hopeful that in the future, pharmacologic treatment will play a key role in the prevention and treatment of AAA.

Circulating microRNAs in patients with aneurysmal dilatation of coronary arteries

To understand the mechanism underlying coronary artery abnormal dilatation (CAAD), the present study identified and compared the expression of circulating microRNAs (miRNAs) in three groups of patients. Group 1 included 20 patients with CAAD, Group 2 included 20 patients with angiographically confirmed coronary artery disease (CAD), and Group 3 included 20 patients with normal coronary arteries (control). miRNAs were isolated from plasma samples and were profiled using PCR arrays and miRCURY LNA Serum/Plasma Focus PCR Panels. The present study demonstrated that the plasma miRNA levels were significantly different in Group 1 compared with in Group 2 and Group 3 (fold change >2 and P<0.05). The comparison of Group 1 with Group 3 identified 21 significantly upregulated and two downregulated miRNAs in patients with CAAD compared with in the control group. Moreover, six upregulated and two downregulated miRNAs were identified in patients with CAD compared with in the controls. The third comparison revealed four upregulated and three downregulated miRNAs in Group 1, when compared with patients with CAD. In conclusion, the present study identified a specific signature of plasma miRNAs, which were upregulated and downregulated in patients with CAAD compared with in patients with CAD and control individuals.

Can 18Fluoro-deoxy-glukose-Positron Emission Tomography/Computed Tomography be a Useful for Decision of Elective Surgery in Thoracic Aortic Aneurysm

Thoracic aortic aneurysm (TAA) should be treated before the complications with prophylactic surgery. However, important number of ruptures have been occurred below the cut-off size for surgery. In addition, in some cases, who in the cut-off value limit, decision of surgery may sometimes be difficult. ¹⁸Fluoro-deoxy-glukose positron emission tomography/computed tomography (¹⁸FDG-PET/CT) may useful such situations. We present a case that, TAA in ¹⁸FDG-PET/CT in a patient with larynx carcinoma. He had a TAA with near the cut-off value and increased metabolic activity in baseline imaging. After 3 months, SUV_max value increased and elective surgery was performed. We think that aneurysms may be another pathology that ¹⁸FDG-PET/CT potentially be useful apart from imaging malignant diseases.

Involvement of Angiogenesis in the Pathogenesis of Coronary Aneurysms

The present study aimed to evaluate the plasma concentration of pro and antiangiogenic factors and their role in the pathogenesis of coronary artery abnormal dilation (CAAD). We measured the plasma concentration of matrix metalloproteinase-8 (MMP-8), transforming growth factor beta 1 (TGF-β1), Angiopoietin-2, vascular endothelial growth factor (VEGF), and fibroblast growth factor (FGF) using a sandwich ELISA technique in the plasma of patients with coronary artery abnormal dilation (CAAD, Group 1), coronary artery disease (CAD, Group 2), and normal coronary arteries (NCA, Group 3). Patients suffering from CAAD showed significantly higher plasma concentrations of VEGF (p = 0.002) than those from the control group. Both pathological angiogenesis and inflammation appear to be crucial in the pathogenesis of aneurysmal dilatation of the coronary arteries.

MicroRNA-194 acts as a suppressor during abdominal aortic aneurysm via inhibition of KDM3A-mediated BNIP3

AIMS

Abdominal aortic aneurysm (AAA) is a serious disorder with a high disability rates and mortality rates. Accumulating evidence has identified the vital functions of microRNAs (miRNAs) in the treatment of AAA. Hence, this study is aimed at exploring the modulatory role of miR-194 in the development of AAA.

MAIN METHODS

After the establishment of mouse AAA models, the expression of miR-194 was determined by quantitative reverse transcription polymerase chain reaction (RT-qPCR), while lysine demethylase 3A (KDM3A) was determined by Western blot analysis in vascular smooth muscle cells (VSMCs) from the abdominal aorta. Cell apoptosis, levels of inflammatory factors as well as expressions of matrix metallopeptidase 2 (MMP2) and matrix metallopeptidase 9 (MMP9) were measured after altering the expression of miR-194 and KDM3A in VSMCs. Moreover, the interactions among miR-194, KDM3A, and BCL2 interacting protein 3 (BNIP3) were investigated by chromatin immunoprecipitation (ChIP) assay and dual-luciferase reporter gene assay.

KEY FINDINGS

miR-194 was poorly expressed while the expression of KDM3A was up-regulated in mice with AAA. miR-194 inhibited the expression of KDM3A while BNIP3 was positively mediated by KDM3A. More importantly, the number of macrophages was significantly reduced whereas the rate of apoptosis in VSMCs was enhanced. miR-194 reduced the inflammatory response and oxidative stress by repressing KDM3A-mediated BNIP3 expression.

SIGNIFICANCES

miR-194 played a suppressive role in the progression of AAA by inhibiting the expression of BNIP3 via KDM3A, representing a promising target for AAA management.

MicroRNA-125b in vascular diseases: An updated systematic review of pathogenetic implications and clinical applications

Epigenetic changes, particularly non‐coding RNAs, have been implicated extensively in the pathogenesis of vascular diseases. Specific miRNAs are involved in the differentiation, phenotypic switch, proliferation, apoptosis, cytokine production and matrix deposition of endothelial cells and/or vascular smooth muscle cells. MicroRNA‐125b has been studied in depth for its role in carcinogenesis with a double‐edged role; that is, it can act as an oncogene in some cancer types and as a tumour suppressor gene in others. However, cumulative evidence from the use of advanced miRNA profiling techniques and bioinformatics analysis suggests that miR‐125b can be a potential mediator and useful marker of vascular diseases. Currently, the exact role of miR‐125b in vascular diseases is not known. In this systematic review, we intend to provide an updated compilation of all the recent findings of miR‐125b in vascular diseases, using a systematic approach of retrieving data from all available reports followed by data summarization. MiR‐125b serves as a pathogenic player in multiple vascular pathologies involving endothelia and vascular smooth muscle cells and also serves as a diagnostic marker for vascular diseases. We further provide a computational biologic presentation of the complex network of miR‐125b and its target genes within the scope of vascular diseases.