Abstract 260: Identification of Micrornas Specifically Expressed in Isolated Cells of Human Abdominal Aortic Aneurysm

Abdominal aortic aneurysm (AAA) is a vascular asymptomatic disease responsible for 4% of mortality in the elderly population. MicroRNAs (miRNA) have recently been shown to be potential biomarkers due to their stability in plasma. The aim of this study was to investigate the potentiality of miRNAS as biomarkers of AAA by identifying miRNAs specifically expressed in the key cells present in the human AAA tissue. The distribution of inflammatory cells such as smooth muscle cells (SMC), M1 and M2 macrophages, neutrophils, B and T lymphocytes and mast cells were located by immunohistochemistry in 20 human AAA biopsies, showing a specific distribution towards the aneurysmal aortic wall and the presence of adventitial tertiary lymphoid organs (ATLOs) in 10 samples. We isolated by laser microdissection (LMD) area enriched in aneurysmal SMC, M1 and M2 macrophages, and ATLOs and SMC from control aorta. RNA extracted from 2 samples of LMD-isolated cells was screened on human miRNAs microarray. Out of the 850 human miRNAs, more than 200 miRNAs were detected in LMD-isolated aneurysmal cells, with 164 detected in ATLOs, 49 in SMC, and 87 miRNAs in macrophages. We selected the 3 miRs with the highest expression for ATLOs and 10 miRs (based on their miR-29b levels) for SMC and macrophages for validation by qRT-PCR in LMD-isolated samples (n=4). We found that miR-15a-3p (0.1 fold) and miR-30a-5p (0.2 fold) were down-regulated and miR-489-3p up-regulated (2 fold) in ATLOs which was inversed for miR-489-3p in the whole aneurysmal aorta. Of the 10 miRNAs selected, six (miR-199a-3p and miR-451 upregulated and miR-24, miR-29a, miR-29b, and miR-29c downregulated) were modulated similarly in SMC and macrophages and whole aneurysmal aorta, except for miR-199-3p. Let-7f and miR-34a were similarly upregulated ed in both subtypes of macrophages and aneurysmal aorta. Expression in the plasma of AAA (n=24) compared to PAD (n=18) patients was significantly down-regulated for miR-15a-3p (p = 0.03) and miR-30a-5p (p = 0.04) and upregulated for let-7f (p=0.048) and miR-29b (p=0.035). In conclusion, this non-hypothesis driven screening of miRNAs expressed in isolated aneurysmal cells allowed to identify four miRNAs as potential AAA biomarkers.

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Let-7f: A New Potential Circulating Biomarker Identified by miRNA Profiling of Cells Isolated from Human Abdominal Aortic Aneurysm

International Journal of Molecular Sciences ◽

10.3390/ijms20215499 ◽

2019 ◽

Vol 20 (21) ◽

pp. 5499 ◽

Cited By ~ 1

Author(s):

Rafaelle Spear ◽

Ludovic Boytard ◽

Renaud Blervaque ◽

Maggy Chwastyniak ◽

David Hot ◽

...

Keyword(s):

Abdominal Aortic Aneurysm ◽

Aortic Aneurysm ◽

Arterial Disease ◽

M2 Macrophages ◽

Isolated Cells ◽

Abdominal Aortic ◽

Potential Biomarker ◽

Peripheral Arterial ◽

Lower Expression ◽

M1 And M2 Macrophages

Abdominal aortic aneurysm (AAA) is a progressive vascular disease responsible for 1–4% of the deaths in elderly men. This study aimed to characterize specific microRNA (miRNA) expression in aneurysmal smooth muscle cells (SMCs) and macrophages in order to identify circulating miRNAs associated with AAA. We screened 850 miRNAs in aneurysmal SMCs, M1 and M2 macrophages, and in control SMCs isolated by micro-dissection from aortic biopsies using microarray analysis. In all, 92 miRNAs were detected and 10 miRNAs were selected for validation by qRT-PCR in isolated cells (n = 5), whole control and aneurysmal aorta biopsies (n = 13), and plasma from patients (n = 24) undergoing AAA (over 50 mm) repair matched to patients (n = 18) with peripheral arterial disease (PAD) with atherosclerosis but not AAA. Seven miRNAs were modulated similarly in all aneurysmal cells. The Let-7f was downregulated in aneurysmal cells compared to control SMCs with a significant lower expression in M1 compared to M2 macrophages (0.1 fold, p = 0.03), correlated with a significant downregulation in whole aneurysmal aorta compared to control aorta (0.2 fold, p = 0.03). Significant levels of circulating let-7f (p = 0.048) were found in AAA patients compared to PAD patients with no significant correlation with aortic diameter (R2 = 0.03). Our study underlines the utility of profiling isolated aneurysmal cells to identify other miRNAs for which the modulation of expression might be masked when the whole aorta is used. The results highlight let-7f as a new potential biomarker for AAA.

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Inflammatory Cells and Proteases in Abdominal Aortic Aneurysm and its Complications

Current Drug Targets ◽

10.2174/1389450119666180531103458 ◽

2018 ◽

Vol 19 (11) ◽

pp. 1289-1296 ◽

Cited By ~ 7

Author(s):

Haiying Jiang ◽

Takeshi Sasaki ◽

Enze Jin ◽

Masafumi Kuzuya ◽

Xian Wu Cheng

Keyword(s):

Abdominal Aortic Aneurysm ◽

Aortic Aneurysm ◽

Inflammatory Cells ◽

Abdominal Aortic

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Rolipram Prevents the Formation of Abdominal Aortic Aneurysm (AAA) in Mice: PDE4B as a Target in AAA

Antioxidants ◽

10.3390/antiox10030460 ◽

2021 ◽

Vol 10 (3) ◽

pp. 460

Author(s):

Saray Varona ◽

Lídia Puertas ◽

María Galán ◽

Mar Orriols ◽

Laia Cañes ◽

...

Keyword(s):

Abdominal Aortic Aneurysm ◽

Aortic Aneurysm ◽

Inflammatory Cells ◽

Progressive Increase ◽

Phosphodiesterase 4 ◽

Inflammatory Conditions ◽

Abdominal Aortic ◽

Threatening Condition ◽

Life Threatening ◽

Effective Therapeutic Strategy

Abdominal aortic aneurysm (AAA) is a common life-threatening condition characterized by exacerbated inflammation and the generation of reactive oxygen species. Pharmacological treatments to slow AAA progression or to prevent its rupture remain a challenge. Targeting phosphodiesterase 4 (PDE4) has been verified as an effective therapeutic strategy for an array of inflammatory conditions; however, no studies have assessed yet PDE4 in AAA. Here, we used angiotensin II (AngII)-infused apolipoprotein E deficient mice to study the involvement of the PDE4 subfamily in aneurysmal disease. PDE4B but not PDE4D was upregulated in inflammatory cells from both experimental and human AAA. The administration of the PDE4 selective inhibitor rolipram (3 mg/kg/day) to AngII-challenged mice (1000 ng/kg bodyweight/min) protected against AAA formation, limiting the progressive increase in the aortic diameter without affecting the blood pressure. The drug strongly attenuated the rise in vascular oxidative stress (superoxide anion) induced by AngII, and decreased the expression of inflammatory markers, as well as the recruitment of macrophages (MAC3+), lymphocytes (CD3+), and neutrophils (ELANE+) into the vessel wall. Rolipram also normalized the vascular MMP2 expression and MMP activity, preserving the elastin integrity and improving the vascular remodelling. These results point to PDE4B as a new therapeutic target for AAA.

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