List of Titles

Resveratrol inhibits growth of experimental abdominal aortic aneurysm associated with upregulation of angiotensin-converting enzyme 2

- Moran, Corey, Biros, Erik, Krishna, Smriti, Wang, Yutang, Tikellis, Chris, Moxon, Joseph, Cooper, Mark, Norman, Paul, Burrell, Louise, Thomas, Merlin, Golledge, Jonathan

Authors: Moran, Corey , Biros, Erik , Krishna, Smriti , Wang, Yutang , Tikellis, Chris , Moxon, Joseph , Cooper, Mark , Norman, Paul , Burrell, Louise , Thomas, Merlin , Golledge, Jonathan
Date: 2017
Type: Text , Journal article
Relation: Arteriosclerosis Thrombosis and Vascular Biology Vol. 37, no. 11 (2017), p. 2195-2203
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Description: Objective-Recent evidence suggests an important role for angiotensin-converting enzyme 2 (ACE2) in limiting abdominal aortic aneurysm (AAA). This study examined the effect of ACE2 deficiency on AAA development and the efficacy of resveratrol to upregulate ACE2 in experimental AAA. Approach and Results-Ace2 deletion in apolipoprotein-deficient mice (ApoE(-/-)Ace2(-/y)) resulted in increased aortic diameter and spontaneous aneurysm of the suprarenal aorta associated with increased expression of inflammation and proteolytic enzyme markers. In humans, serum ACE2 activity was negatively associated with AAA diagnosis. ACE2 expression was lower in infrarenal biopsies of patients with AAA than organ donors. AAA was more severe in ApoE (-/-)Ace2(-/y) mice compared with controls in 2 experimental models. Resveratrol (0.05/100-g chow) inhibited growth of pre-established AAAs in ApoE(-/-) mice fed high-fat chow and infused with angiotensin II continuously for 56 days. Reduced suprarenal aorta dilatation in mice receiving resveratrol was associated with elevated serum ACE2 and increased suprarenal aorta tissue levels of ACE2 and sirtuin 1 activity. In addition, the relative phosphorylation of Akt and ERK (extracellular signal-regulated kinase) 1/2 within suprarenal aorta tissue and gene expression for nuclear factor of kappa light polypeptide gene enhancer in B cells 1, angiotensin type-1 receptor, and metallopeptidase 2 and 9 were significantly reduced. Upregulation of ACE2 in human aortic smooth muscle cells by resveratrol in vitro was sirtuin 1-dependent. Conclusions-This study provides experimental evidence of an important role for ACE2 in limiting AAA development and growth. Resveratrol upregulated ACE2 and inhibited AAA growth in a mouse model.

Mouse models of intracranial aneurysm

- Wang, Yutang, Emeto, Theophilus, Lee, James, Marshman, Laurence, Moran, Corey, Seto, Sai-wang, Golledge, Jonathan

Authors: Wang, Yutang , Emeto, Theophilus , Lee, James , Marshman, Laurence , Moran, Corey , Seto, Sai-wang , Golledge, Jonathan
Date: 2014
Type: Text , Journal article
Relation: Brain Pathology Vol. 25, no. (2014), p. 237-247
Relation: http://purl.org/au-research/grants/nhmrc/1062671
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Description: Subarachnoid hemorrhage secondary to rupture of an intracranial aneurysm is a highly lethal medical condition. Current management strategies for unruptured intracranial aneurysms involve radiological surveillance and neurosurgical or endovascular interventions. There is no pharmacological treatment available to decrease the risk of aneurysm rupture and subsequent subarachnoid hemorrhage. There is growing interest in the pathogenesis of intracranial aneurysm focused on the development of drug therapies to decrease the incidence of aneurysm rupture. The study of rodent models of intracranial aneurysms has the potential to improve our understanding of intracranial aneurysm development and progression. This review summarizes current mouse models of intact and ruptured intracranial aneurysms and discusses the relevance of these models to human intracranial aneurysms. The article also reviews the importance of these models in investigating the molecular mechanisms involved in the disease. Finally, potential pharmaceutical targets for intracranial aneurysm suggested by previous studies are discussed. Examples of potential drug targets include matrix metalloproteinases, stromal cell-derived factor-1, tumor necrosis factor-α, the renin-angiotensin system and the β-estrogen receptor. An agreed clear, precise and reproducible definition of what constitutes an aneurysm in the models would assist in their use to better understand the pathology of intracranial aneurysm and applying findings to patients
Description: Subarachnoid hemorrhage secondary to rupture of an intracranial aneurysm is a highly lethal medical condition. Current management strategies for unruptured intracranial aneurysms involve radiological surveillance and neurosurgical or endovascular interventions. There is no pharmacological treatment available to decrease the risk of aneurysm rupture and subsequent subarachnoid hemorrhage. There is growing interest in the pathogenesis of intracranial aneurysm focused on the development of drug therapies to decrease the incidence of aneurysm rupture. The study of rodent models of intracranial aneurysms has the potential to improve our understanding of intracranial aneurysm development and progression. This review summarizes current mouse models of intact and ruptured intracranial aneurysms and discusses the relevance of these models to human intracranial aneurysms. The article also reviews the importance of these models in investigating the molecular mechanisms involved in the disease. Finally, potential pharmaceutical targets for intracranial aneurysm suggested by previous studies are discussed. Examples of potential drug targets include matrix metalloproteinases, stromal cell-derived factor-1, tumor necrosis factor-

A peptide antagonist of thrombospondin-1 promotes abdominal aortic aneurysm progression in the angiotensin II-infused apolipoprotein-E-deficient mouse

- Krishna, Smriti, Seto, Sai-Wang, Jose, Roby, Biros, Erik, Moran, Corey, Wang, Yutang, Clancy, Paula, Golledge, Jonathan

Authors: Krishna, Smriti , Seto, Sai-Wang , Jose, Roby , Biros, Erik , Moran, Corey , Wang, Yutang , Clancy, Paula , Golledge, Jonathan
Date: 2016
Type: Text , Journal article
Relation: Arteriosclerosis, Thrombosis, and Vascular Biology Vol. 35, no. 2 (2016), p. 389-398
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Description: OBJECTIVE - : Interaction of the activating sequence in thrombospondin-1 (TSP-1) with the conserved sequence (leucine-serine-lysine-leucine [LSKL]) in the latency-associated peptide region of latent transforming growth factor (TGF)-β complex is important in regulating TGF-β1 activity. We aimed to assess the effect of blocking peptide LSKL on the progression of pre-established abdominal aortic aneurysm in angiotensin II-infused apolipoprotein E-deficient (ApoE) mice. APPROACH AND RESULTS - : Abdominal aortic aneurysm was established in 3-month-old male ApoE mice with subcutaneous infusion of angiotensin II for 28 days. After this, mice received LSKL peptide or control SLLK (serine-leucine-leucine-lysine) peptide (4 mg/kg) via daily intraperitoneal injection for an additional 2 weeks. Administration of LSKL peptide promoted larger suprarenal aortic diameter, as determined by ultrasound and morphometric analysis, and stimulated more severe atherosclerosis within the aortic arch. In addition, mice receiving LSKL peptide exhibited elevated circulating proinflammatory cytokine levels and greater inflammatory cells within the suprarenal aorta compared with controls. Mice receiving LSKL peptide showed low plasma TGF-β1 activity and low levels of aortic tissue phosphorylated to total Smad2/3. Aortic gene expression of TGF-β receptor 1 (TGFBRI) and receptor 2 (TGFBRII), but not TGF-β1 and thrombospondin-1, were lower in mice receiving LSKL peptide than controls. LSKL peptide administration was associated with greater aortic elastin fragmentation and lower expression and activity of the TGF-β1-target gene lysyl oxidase like 1 (LOXL1). CONCLUSIONS - : Attenuation of thrombospondin-1-directed activation of TGF-β1 promotes abdominal aortic aneurysm and atherosclerosis progression in the angiotensin II-infused ApoE mouse model. © 2014 American Heart Association, Inc.

microRNA profiling in patients with abdominal aortic aneurysms: the significance of miR-155

- Biros, Erik, Moran, Corey, Wang, Yutang, Walker, Philip, Cardinal, John, Golledge, Jonathan

Authors: Biros, Erik , Moran, Corey , Wang, Yutang , Walker, Philip , Cardinal, John , Golledge, Jonathan
Date: 2014
Type: Text , Journal article
Relation: Clinical Science Vol. 126, no. 11 (2014), p. 795
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Description: AAA (abdominal aortic aneurysm) is a potentially life-threatening late-onset degenerative condition. miRNAs (microRNAs), the small non-coding RNA molecules that regulate gene expression, have been shown previously to be associated with a broad range of human pathologies, including cardiovascular diseases. The aim of the present study was to identify AAA-associated miRNAs potentially contributing to AAA pathology. We analysed the expression of 124 miRNAs within AAA biopsies and serum of ten patients undergoing AAA repair, and serum from ten age- and sex-matched subjects without AAA, using the FlexmiR™ MicroRNA Assay. RNA extracted from the site of main AAA dilatation (AAA body) was compared with that extracted from the macroscopically non-dilated neck of the AAA (AAA neck). Similarly, RNA extracted from the serum of AAA patients (AAA serum) was compared with that extracted from age- and sex-matched controls (control serum). qPCR (quantitative real-time PCR), Western blot analysis and histology were performed using an independent set of six paired AAA body and neck biopsies to examine the validity of findings. Seven miRNAs were up-regulated [>2-fold difference, FDR (false discovery rate) <0.5] within AAA biopsies, of which miR-155 was the most differentially expressed (11.32-fold, FDR=0.414). This finding was confirmed by qPCR with the median relative expression of miR-155 being 3.26 and 0.63 within AAA body and AAA neck biopsies respectively (P=0.031). Circulating miR-155 was also increased in AAA patients compared with controls, with a 2.67-fold up-regulation at borderline significance (FDR=0.554). Two immunologically important miR-155 target genes, CTLA4 (cytotoxic T-lymphocyte-associated protein) and SMAD2, were assessed and found to be significantly down-regulated within AAA bodies compared with AAA necks (P=0.032 and P=0.026) as determined by qPCR and Western blotting respectively. Histology demonstrated dense accumulation of T-lymphocytes within the adventitial and outer medial layers of AAA body, but not neck tissue. The results of the present study suggest that miR-155 is overexpressed in AAA with potential implications in the pathogenesis of the condition.

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Parenteral administration of factor Xa/IIa inhibitors limits experimental aortic aneurysm and atherosclerosis

- Moran, Corey, Seto, Sai-Wang, Krishna, Smriti, Sharma, Surabhi, Jose, Roby, Biros, Erik, Wang, Yutang, Morton, Susan, Golledge, Jonathan

Authors: Moran, Corey , Seto, Sai-Wang , Krishna, Smriti , Sharma, Surabhi , Jose, Roby , Biros, Erik , Wang, Yutang , Morton, Susan , Golledge, Jonathan
Date: 2017
Type: Text , Journal article
Relation: Scientific Reports Vol. 7, no. (2017), p. 1-12
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Description: Intraluminal thrombus is a consistent feature of human abdominal aortic aneurysm (AAA). Coagulation factor Xa (FXa) catalyses FII to thrombin (FIIa). We examined the effect of FXa/FIIa inhibition on experimental aortic aneurysm in apolipoprotein E-deficient (ApoE '/') mice infused with angiotensin II (AngII). The concentration of FXa within the supra-renal aorta (SRA) correlated positively with SRA diameter. Parenteral administration of enoxaparin (FXa/IIa inhibitor) and fondaparinux (FXa inhibitor) over 14 days reduced to severity of aortic aneurysm and atherosclerosis in AngII-infused ApoE '/' mice. Enteral administration of the FIIa inhibitor dabigatran had no significant effect. Aortic protease-activated receptor (PAR)-2 expression increased in response to AngII infusion. Fondaparinux reduced SRA levels of FXa, FIIa, PAR-2, matrix metalloproteinase (MMP)2, Smad2/3 phosphorylation, and MOMA-2 positive cells in the mouse model. FXa stimulated Smad2/3 phosphorylation and MMP2 expression in aortic vascular smooth muscle cells (VSMC) in vitro. Expression of MMP2 in FXa-stimulated VSMC was downregulated in the presence of a PAR-2 but not a PAR-1 inhibitor. These findings suggest that FXa/FIIa inhibition limits aortic aneurysm and atherosclerosis severity due to down-regulation of vascular PAR-2-mediated Smad2/3 signalling and MMP2 expression. Inhibition of FXa/FIIa may be a potential therapy for limiting aortic aneurysm. © The Author(s) 2017.

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Kallistatin limits abdominal aortic aneurysm by attenuating generation of reactive oxygen species and apoptosis

- Krishna, Smriti, Li, Jiaze, Wang, Yutang, Moran, Corey, Trollope, Alexandra

Authors: Krishna, Smriti , Li, Jiaze , Wang, Yutang , Moran, Corey , Trollope, Alexandra
Date: 2021
Type: Text , Journal article
Relation: Scientific Reports Vol. 11, no. 1 (2021), p.
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Description: Inflammation, vascular smooth muscle cell apoptosis and oxidative stress are believed to play important roles in abdominal aortic aneurysm (AAA) pathogenesis. Human kallistatin (KAL; gene SERPINA4) is a serine proteinase inhibitor previously shown to inhibit inflammation, apoptosis and oxidative stress. The aim of this study was to investigate the role of KAL in AAA through studies in experimental mouse models and patients. Serum KAL concentration was negatively associated with the diagnosis and growth of human AAA. Transgenic overexpression of the human KAL gene (KS-Tg) or administration of recombinant human KAL (rhKAL) inhibited AAA in the calcium phosphate (CaPO4) and subcutaneous angiotensin II (AngII) infusion mouse models. Upregulation of KAL in both models resulted in reduction in the severity of aortic elastin degradation, reduced markers of oxidative stress and less vascular smooth muscle apoptosis within the aorta. Administration of rhKAL to vascular smooth muscle cells incubated in the presence of AngII or in human AAA thrombus-conditioned media reduced apoptosis and downregulated markers of oxidative stress. These effects of KAL were associated with upregulation of Sirtuin 1 activity within the aortas of both KS-Tg mice and rodents receiving rhKAL. These results suggest KAL-Sirtuin 1 signalling limits aortic wall remodelling and aneurysm development through reductions in oxidative stress and vascular smooth muscle cell apoptosis. Upregulating KAL may be a novel therapeutic strategy for AAA. © 2021, The Author(s).

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