Abstract 17136: MicroRNA-181b Inhibition Stabilises Abdominal Aortic Aneurysms by Promoting Collagen Accumulation and Elastin Deposition

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Karina Di Gregoli ◽  
Nur Najmi Mohamad Anuar ◽  
Sarah J George ◽  
Jason L Johnson
Keyword(s):  
Protein Expression ◽  
Collagen Fibre ◽  
Aortic Aneurysms ◽  
High Fat ◽  
Direct Role ◽  
Knockout Mouse Model ◽  
Elastin Degradation ◽  
Abdominal Aortic ◽  
Collagen Accumulation

Increased matrix metalloproteinase (MMP) activity, and related collagen and elastin degradation as a result of macrophage accumulation, are key characteristics of abdominal aortic aneurysm (AAA) progression and rupture. Accordingly targeting MMPs or promoting expression of the endogenous tissue inhibitor of metalloproteinases (TIMPs), may represent novel therapeutic strategies to prevent AAA progression and rupture. To closely mimic human AAA, we used an angiotensin II (AngII)-infused, high fat-fed apolipoprotein E knockout mouse model. Sudden death due to aortic dissection/rupture, was significantly increased (30%, p<0.001, n=20) in TIMP3 KO mice compared to wild-type controls, supporting a protective role for TIMP3 in AAA progression. Moreover Q-PCR revealed that microRNA (miR)-181b, a validated repressor of TIMP3 protein expression, was up-regulated 22-fold (n=6, p<0.001) in human AAA compared to non-aneurysmal sites. In vitro, miR181b inhibition increased macrophage TIMP3 protein expression 3-fold (n=4, p<0.05), highlighting miR181b inhibition as a potential approach to retard AAA progression. Indeed using a miR181b inhibitor, AAA development and inflammation was retarded in AngII-infused high fat-fed ApoE KO mice. This effect was characterised by a 56% reduction in macrophage content (n=5, p<0.05), augmented collagen content 1.9-fold (n=5, p<0.05) and collagen fibre thickness (+24%, p<0.05) in AAAs compared to scrambled-miR control animals. AAA elastin content was also increased (1.5-fold, n=5, p<0.05) in miR181b inhibitor treated mice versus controls. Collagen accumulation was TIMP-3 dependent as miR-181b inhibition did not affect collagen levels in TIMP-3 KO mice. However elastin content remained elevated in miR-181b inhibitor treated TIMP3 KO mice (2-fold, n=6, p=0.001), suggesting a TIMP-3 independent mechanism. In vitro miR181b inhibition in smooth muscle cells revealed a 2.5-fold increase in elastin production (n=3, p<0.05), supporting a direct role for miR-181b in elastin regulation. Collectively our data show that miR181b inhibition stabilises AAA through a dual beneficial effect, by promoting collagen preservation via TIMP3 modulation, and through directly increasing elastin production and deposition.

scholarly journals Recombinant Interleukin‐19 Suppresses the Formation and Progression of Experimental Abdominal Aortic Aneurysms

2021 ◽  
Author(s):  
Hiroki Tanaka ◽  
Baohui Xu ◽  
Haojun Xuan ◽  
Yingbin Ge ◽  
Yan Wang ◽  
...  
Keyword(s):  
Aortic Aneurysms ◽  
Matrix Metalloproteinase 2 ◽  
Cytotoxic T Cell ◽  
Alternatively Activated Macrophages ◽  
Elastin Degradation ◽  
Abdominal Aortic ◽  
Immunosuppressive Cytokine ◽  
Aneurysm Repair ◽  
Oxide Synthase

Background Interleukin‐19 is an immunosuppressive cytokine produced by immune and nonimmune cells, but its role in abdominal aortic aneurysm (AAA) pathogenesis is not known. This study aimed to investigate interleukin‐19 expression in, and influences on, the formation and progression of experimental AAAs. Methods and Results Human specimens were obtained at aneurysm repair surgery or from transplant donors. Experimental AAAs were created in 10‐ to 12‐week‐old male mice via intra‐aortic elastase infusion. Influence and potential mechanisms of interleukin‐19 treatment on AAAs were assessed via ultrasonography, histopathology, flow cytometry, and gene expression profiling. Immunohistochemistry revealed augmented interleukin‐19 expression in both human and experimental AAAs. In mice, interleukin‐19 treatment before AAA initiation via elastase infusion suppressed aneurysm formation and progression, with attenuation of medial elastin degradation, smooth‐muscle depletion, leukocyte infiltration, neoangiogenesis, and matrix metalloproteinase 2 and 9 expression. Initiation of interleukin‐19 treatment after AAA creation limited further aneurysmal degeneration. In additional experiments, interleukin‐19 treatment inhibited murine macrophage recruitment following intraperitoneal thioglycolate injection. In classically or alternatively activated macrophages in vitro, interleukin‐19 downregulated mRNA expression of inducible nitric oxide synthase, chemokine C‐C motif ligand 2, and metalloproteinases 2 and 9 without apparent effect on cytokine‐expressing helper or cytotoxic T‐cell differentiation, nor regulatory T cellularity, in the aneurysmal aorta or spleen of interleukin‐19–treated mice. Interleukin‐19 also suppressed AAAs created via angiotensin II infusion in hyperlipidemic mice. Conclusions Based on human evidence and experimental modeling observations, interleukin‐19 may influence the development and progression of AAAs.

scholarly journals Vinpocetine protects against the development of experimental abdominal aortic aneurysms

2020 ◽  
Vol 134 (22) ◽  
pp. 2959-2976
Author(s):  
Chongyang Zhang ◽  
Chia George Hsu ◽  
Amy Mohan ◽  
Hangchuan Shi ◽  
Dongmei Li ◽  
...  
Keyword(s):  
Cerebrovascular Disorders ◽  
Degenerative Disease ◽  
Aortic Aneurysms ◽  
Infrarenal Aorta ◽  
Post Intervention ◽  
Aged Population ◽  
Elastin Degradation ◽  
Abdominal Aortic ◽  
Aneurysmal Dilation

Abstract Abdominal aortic aneurysm (AAA), commonly occurring in the aged population, is a degenerative disease that dilate and weaken infrarenal aorta due to progressive degeneration of aortic wall integrity. Vinpocetine, a derivative of alkaloid vincamine, has long been used for cerebrovascular disorders and cognitive impairment in the aged population. Recent studies have indicated that vinpocetine antagonizes occlusive vascular disorders such as intimal hyperplasia and atherosclerosis. However, its role in vascular degenerative disease AAA remains unexplored. Herein, we determined the effect of vinpocetine on the formation of AAA as well as the intervention of pre-existing moderate AAA. AAA was induced by periaortic elastase application in C57BL/6J mice. Systemic vinpocetine treatment was applied daily via intraperitoneal injection. We showed that vinpocetine pre-treatment remarkably attenuated aneurysmal dilation assessed by diameter and volume. More importantly, vinpocetine also significantly suppressed the progression of pre-existing moderate AAA in a post-intervention model. Vinpocetine improved multiple cellular and molecular changes associated with AAA, such as elastin degradation, media smooth muscle cell depletion, collagen fibers remodeling and macrophage infiltration in aneurysmal tissues. Vinpocetine potently suppressed tumor necrosis factor-α-induced nuclear factor kappa-light-chain-enhancer of activated B cells activation and proinflammatory mediator expression in primary cultured macrophages in vitro, as well as in the aorta wall in vivo, suggesting vinpocetine conferred anti-AAA effect at least partially via the inhibition of inflammation. Taken together, our findings reveal a novel role of vinpocetine in AAA formation, development and progression. Given the excellent safety profile of vinpocetine, the present study suggests vinpocetine may be a novel therapeutic agent for AAA prevention and treatment.

scholarly journals Aloe-Emodin Relieves High-Fat Diet Induced QT Prolongation via MiR-1 Inhibition and IK1 Up-Regulation in Rats

2017 ◽  
Vol 43 (5) ◽  
pp. 1961-1973 ◽  
Author(s):  
Yan Bai ◽  
Zhenli Su ◽  
Hanqi Sun ◽  
Wei Zhao ◽  
Xue Chen ◽  
...  
Keyword(s):  
Action Potential ◽  
Protein Expression ◽  
High Fat Diet ◽  
Qt Prolongation ◽  
Electrical Remodeling ◽  
High Fat ◽  
Treatment Groups ◽  
Aloe Emodin

Background/Aims: High-fat diet (HFD) causes cardiac electrical remodeling and increases the risk of ventricular arrhythmias. Aloe-emodin (AE) is an anthraquinone component isolated from rhubarb and has a similar chemical structure with emodin. The protective effect of emodin against cardiac diseases has been reported in the literature. However, the cardioprotective property of AE is still unknown. The present study investigated the effect of AE on HFD-induced QT prolongation in rats. Methods: Adult male Wistar rats were randomly divided into three groups: control, HFD, and AE-treatment groups. Normal diet was given to rats in the control group, high-fat diet was given to rats in HFD and AE-treatment groups for a total of 10 weeks. First, HFD rats and AE-treatment rats were fed with high-fat diet for 4 weeks to establish the HFD model. Serum total cholesterol and triglyceride levels were measured to validate the HFD model. Afterward, AE-treatment rats were intragastrically administered with 100 mg/kg AE each day for 6 weeks. Electrocardiogram monitoring and whole-cell patch-clamp technique were applied to examine cardiac electrical activity, action potential and inward rectifier K+ current (IK1), respectively. Neonatal rat ventricular myocytes (NRVMs) were subjected to cholesterol and/or AE. Protein expression of Kir2.1 was detected by Western blot and miR-1 level was examined by real-time PCR in vivo and in vitro, respectively. Results: In vivo, AE significantly shortened the QT interval, action potential duration at 90% repolarization (APD90) and resting membrane potential (RMP), which were markedly elongated by HFD. AE increased IK1 current and Kir2.1 protein expression which were reduced in HFD rats. Furthermore, AE significantly inhibited pro-arrhythmic miR-1 in the hearts of HFD rats. In vitro, AE decreased miR-1 expression levels resulting in an increase of Kir2.1 protein levels in cholesterol-enriched NRVMs. Conclusions: AE prevents HFD-induced QT prolongation by repressing miR-1 and upregulating its target Kir2.1. These findings suggest a novel pharmacological role of AE in HFD-induced cardiac electrical remodeling.

Abstract 116: Simvastatin Affects Monocyte Adhesion and Infiltrative Activity in Patients With Abdominal Aortic Aneurysms

2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Kiana M Samadzadeh ◽  
Anthony Nguyen ◽  
Kevin C Chun ◽  
Eugene S Lee
Keyword(s):  
Abdominal Aortic Aneurysms ◽  
Statin Treatment ◽  
Aortic Aneurysms ◽  
Monocyte Adhesion ◽  
Abdominal Aortic ◽  
Monocyte Cell ◽  
High Concentrations ◽  
Statin Drugs ◽  
Monocyte Adherence

Purpose: The pleiotropic effects of statin drugs on reducing inflammation have been well regarded in decreasing AAA expansion. We hypothesize that increased monocyte activity plays a central role in AAA formation and expansion. This study examines whether statins can prevent monocyte cell adhesion, transmigration, and matrix metalloproteinase (MMP) and inhibitor (TIMP) concentrations in AAA patients compared to non-AAA patients. Methods: Peripheral blood was collected for monocyte and serum isolation from control (n=4) and AAA (n=8) patients. Monocyte adhesion and transmigration were assessed under untreated, statin treated, and statin + mevalonate (statin inhibitor) treated conditions in vitro. Luminex assays determined MMP and TIMP concentrations from cell culture and patient serum. Results: Untreated AAA patient monocytes showed higher levels of adhesion (p=0.05) and transmigration (p=0.04) compared to control subjects (Figure 1A & 1B). Statin treatment caused a decrease in AAA monocyte adherence to the endothelium (p=0.03) and high concentrations of mevalonate reversed statin treatment effects (p=0.04) (Figure 1A). A similar trend was noted in monocyte transmigration (Figure 1B). Higher concentrations of MMP-9 were found in AAA patient serum compared to controls (p=0.01) (Figure 1C). TIMP-4 concentration were decreased in AAA patients compared to controls (p=0.02) (Figure 1D). Conclusions: Statins reduce monocyte interaction with the endothelium in vitro, leading to decreased levels of MMP-9 and increased levels of TIMP-4, implying a possible mechanism by which statins reduce AAA expansion.

A Review of the In Vivo and In Vitro Biomechanical Behavior and Performance of Postoperative Abdominal Aortic Aneurysms and Implanted Stent-Grafts

2008 ◽  
Vol 15 (4) ◽  
pp. 468-484 ◽  
Author(s):  
Timothy J. Corbett ◽  
Anthony Callanan ◽  
Liam G. Morris ◽  
Barry J. Doyle ◽  
Pierce A. Grace ◽  
...  
Keyword(s):  
Abdominal Aortic Aneurysms ◽  
Aortic Aneurysms ◽  
Stent Grafts ◽  
Biomechanical Behavior ◽  
Abdominal Aortic ◽  
And Performance

Elastin degradation in abdominal aortic aneurysms

1987 ◽  
Vol 65 (1-2) ◽  
pp. 13-21 ◽  
Author(s):  
J.S. Campa ◽  
R.M. Greenhalgh ◽  
Janet T. Powell
Keyword(s):  
Abdominal Aortic Aneurysms ◽  
Aortic Aneurysms ◽  
Elastin Degradation ◽  
Abdominal Aortic

The Development of Physiological Compliant Abdominal Aortic Aneurysm Models for In Vitro Flow Studies

2009 ◽  
Author(s):  
Timothy J. Corbett ◽  
Barry J. Doyle ◽  
Anthony Callanan ◽  
Tim M. McGloughlin
Keyword(s):  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Material Properties ◽  
Abdominal Aortic Aneurysms ◽  
Aortic Aneurysms ◽  
Flow Loop ◽  
The Past ◽  
Abdominal Aortic

A vast amount of experimental research has been undertaken in the past decade to investigate different aspects of preoperative and postoperative abdominal aortic aneurysms (AAAs). Much of this research has been based on the use of mock arteries in an in vitro flow loop to mimic the behaviour of the abdominal aorta in vivo [1]. These models should be reproducible, have consistent material properties, consistent thickness and be physiological in behaviour.

Real-Time Measurement of Multi-Component Velocity Vectors Within Abdominal Aortic Aneurysms Using Echo PIV: Comparison of In Vitro and Computational Results

2007 ◽  
Author(s):  
Lingli Liu ◽  
Fuxing Zhang ◽  
Rui Wang ◽  
Robin Shandas
Keyword(s):  
Disease Process ◽  
Abdominal Aortic Aneurysms ◽  
The United States ◽  
Aneurysm Rupture ◽  
Aortic Aneurysms ◽  
Non Invasive ◽  
Abdominal Aortic ◽  
Component Velocity ◽  
Aneurysm Growth

Abdominal aortic aneurysms (AAAs) are localized balloon-shaped expansions commonly found in the infrarenal segment of the abdominal aorta, between the renal arteries and the iliac bifurcation. Abdominal aortic aneurysm rupture has been estimated to occur in as much as 3%–9% of the population, and represents the 13th leading cause of death in the United States, producing more than 10,000 deaths annually [1]. Thus, determining the significant factors for aneurysm growth and rupture has become an important clinical goal. From a biomechanical standpoint, AAA rupture risk is related to certain mechanical and hemodynamic factors such as localized flow fields and velocity patterns, and flow-induced stresses within the fluid and in the aneurysm structure [2]. Disturbed flow patterns at different levels have also been found to trigger responses within medial and adventitial layers by altering intercellular communication mechanisms. Thus, localized hemodynamics proximal, within and distal to AAA formations play an important role in modulating the disease process, and non-invasive and easy-to-implement methods to characterize and quantify these complex hemodynamics would be tremendously useful.

scholarly journals The neurotransmitter receptor Gabbr1 regulates proliferation and function of hematopoietic stem and progenitor cells

Blood ◽  
2020 ◽  
Author(s):  
Lijian Shao ◽  
Adedamola Elujoba-Bridenstine ◽  
Katherine E Zink ◽  
Laura M Sanchez ◽  
Brian J Cox ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Ex Vivo ◽  
Human Umbilical Cord Blood ◽  
Human Umbilical Cord ◽  
Direct Role ◽  
Hematopoietic Stem ◽  
Knockout Mouse Model ◽  
Immunodeficient Mice ◽  
Bm Niche

Hematopoietic and nervous systems are linked via innervation of bone marrow (BM) niche cells. Hematopoietic stem/progenitor cells (HSPCs) express neurotransmitter receptors, such as the g-aminobutyric acid (GABA) type B receptor subunit 1 (GABBR1), suggesting that HSPCs could be directly regulated by neurotransmitters like GABA that directly bind to GABBR1. We performed imaging mass spectrometry (IMS) and found that endogenous GABA molecule is regionally localized and concentrated near the endosteum of the BM niche. To better understand the role of GABBR1 in regulating HSPCs, we generated a constitutive Gabbr1 knockout mouse model. Analysis revealed that HSPC numbers were significantly reduced in the BM compared to wild-type littermates. Moreover, Gabbr1 null hematopoietic stem cells (HSCs) had diminished capacity to reconstitute irradiated recipients in a competitive transplantation model. Gabbr1 null HSPCs were less proliferative under steady-state conditions and upon stress. Colony assays demonstrated that almost all Gabbr1 null HSPCs were in a slow or non-cycling state. In vitro differentiation of Gabbr1 null HSPCs in co-cultures, produced fewer overall cell numbers with significant defects in differentiation and expansion of the B cell lineage. To determine if GABBR1 agonist could stimulate human umbilical cord blood (UCB) HSPCs, we performed brief ex vivo treatment prior to transplant into immunodeficient mice, with significant increases in long-term engraftment of HSPCs compared to GABBR1 antagonist or vehicle treatments. Our results indicate a direct role for GABBR1 in HSPC proliferation, and identify a potential target to improve HSPC engraftment in clinical transplantation.

B cell-derived anti-beta 2 glycoprotein I antibody contributes to hyperhomocysteinaemia-aggravated abdominal aortic aneurysm

2019 ◽  
Vol 116 (11) ◽  
pp. 1897-1909 ◽  
Author(s):  
Fangyu Shao ◽  
Yutong Miao ◽  
Yan Zhang ◽  
Lulu Han ◽  
Xiaolong Ma ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Specific Inhibitor ◽  
Aortic Aneurysms ◽  
Dependent Manner ◽  
Glycoprotein I ◽  
Elastin Degradation ◽  
Abdominal Aortic ◽  
Beta 2 ◽  
Activated B Cells

Abstract Aims Overactivated B cells secrete pathological antibodies, which in turn accelerate the formation of abdominal aortic aneurysms (AAAs). Hyperhomocysteinaemia (HHcy) aggravates AAA in mice; however, the underlying mechanisms remain largely elusive. In this study, we further investigated whether homocysteine (Hcy)-activated B cells produce antigen-specific antibodies that ultimately contribute to AAA formation. Methods and results ELISA assays showed that HHcy induced the secretion of anti-beta 2 glycoprotein I (anti-β2GPI) antibody from B cells both in vitro and in vivo. Mechanistically, Hcy increased the accumulation of various lipid metabolites in B cells tested by liquid chromatography-tandem mass spectrometry, which contributed to elevated anti-β2GPI IgG secretion. By using the toll-like receptor 4 (TLR4)-specific inhibitor TAK-242 or TLR4-deficient macrophages, we found that culture supernatants from Hcy-activated B cells and HHcy plasma IgG polarized inflammatory macrophages in a TLR4-dependent manner. In addition, HHcy markedly increased the incidence of elastase- and CaPO4-induced AAA in male BALB/c mice, which was prevented in μMT mice. To further determine the importance of IgG in HHcy-aggravated AAA formation, we purified plasma IgG from HHcy or control mice and then transferred the IgG into μMT mice, which were subsequently subjected to elastase- or CaPO4-induced AAA. Compared with μMT mice that received plasma IgG from control mice, μMT mice that received HHcy plasma IgG developed significantly exacerbated elastase- or CaPO4-induced AAA accompanied by increased elastin degradation, MMP2/9 expression, and anti-β2GPI IgG deposition in vascular lesions, as shown by immunofluorescence histochemical staining. Conclusion Our findings reveal a novel mechanism by which Hcy-induced B cell-derived pathogenic anti-β2GPI IgG might, at least in part, contribute to HHcy-aggravated chronic vascular inflammation and AAA formation.

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