Abstract 114: Smooth Muscle Origin-specific Effects of LRP1 Deletion on Angiotensin II-induced Ascending Aortic Aneurysm

2018 ◽  
Vol 38 (Suppl_1) ◽  
Author(s):  
Hisashi Sawada ◽  
Debra L Rateri ◽  
Bradley C Wright ◽  
Jessica J Moorleghen ◽  
Deborah A Howatt ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Angiotensin Ii ◽  
Aortic Aneurysm ◽  
Ascending Aortic Aneurysm ◽  
Specific Effects ◽  
Muscle Origin

Abstract 19212: The Zinc-finger Protein 148(zfp148) Attenuates Aortic Aneurysm Formation and is a Novel Smooth Muscle Cell Regulator

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Morgan Salmon ◽  
Nicolas H Pope ◽  
William F Johnston ◽  
John P Davis ◽  
Gary K Owens ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Angiotensin Ii ◽  
Aortic Aneurysm ◽  
Zinc Finger ◽  
Zinc Finger Protein ◽  
Marker Genes ◽  
Aortic Dilation ◽  
Aneurysm Formation ◽  
Finger Protein

Objective: Previously, we found that the zinc-finger protein 148(ZFP148) binds to smooth muscle(SMC) genes following ligation injury; however, it has no known role in aortic aneurysm formation. The study objective was to determine whether ZFP148 is important in AA formation. Methods: ZFP148 was examined via qPCR in human aortic aneurysms(n=12/group). 8-12 week male C57/B6 mice (n=6/group) underwent elastase perfusion and were harvested at 3, 7, and 14 days for qPCR for ZFP148. Separately, 8-12 week male (n=10/group) ZFP flx/flx Myh11 Cre+(SMC tamoxifen ZFP148 KO), Myh11 ZFP148 flx/wt Cre+ and Myh11 ZFP wt/wt Cre+ underwent elastase perfusion. At 14 days, maximal aortic dilation was measured with video micrometry. ZFP148 flx/flx ERT Cre+ (n=10/group) and ZFP148 flx/flx ERT Cre-(WT) mice also underwent elastase perfusion. A separate set of mice were bred to an ApoE-/- background and administered Angiotensin II via osmotic pump. Aortic samples were evaluated with histology for α-actin, macrophages, neutrophils, T lymphocytes, caspase3, Ki67, and elastin. In vitro ZFP148 was knocked down using siRNA in smooth muscle cells and stimulated with elastase, or IL-1β. Results: ZFP148 expression was elevated in human and murine AA. Maximal aortic dilation was significantly reduced in SMC ZFP148 KO mice compared with controls (55.7 ± 6.32% versus 106.4 ± 8.43%, p<0.05). Maximal aortic dilation of ERT Cre+ ZFP148 mice was significantly decreased versus WT controls (50.4± 8.65% versus 101.3± 9.43%, p<0.05). Knock-out of ZFP148 in both elastase models demonstrated reduced macrophage, T-cell, Ki-67, Caspase3 and neutrophil staining. Kaplan-Meier curves demonstrated increased survival in SM-MHC ZFP148 flx/flx (Chi2=4.357, p=0.0421) and flx/wt mice (Chi2=4.169, p=0.0476) compared to their WT controls following Angiotensin II infusion. Knock-down of ZFP148 followed by treatment with elastase or IL-1β in SMCs attenuated the down-regulation of SM22α, SM-MHC, and SMαA. ZFP148 bound via ChIP analysis to SMC marker genes in vitro and in vivo and was found to bind within the proximal promoter region of SmαA and SM22α. Conclusions: ZFP148 KO attenuates AA formation and binds to smooth muscle marker genes. ZFP148 could represent a novel regulator of vascular disease.

Abstract 534: Deficiency of Protease-activated Receptor 2 Attenuates Angiotensin II-induced Abdominal Aortic Aneurysm Independent of Vascular Smooth Muscle Cell Tissue Factor

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
David E Hall ◽  
Adrien Mann ◽  
Shannon M Jones ◽  
Nigel Mackman ◽  
A. Phillip Owens
Keyword(s):  
Smooth Muscle ◽  
Abdominal Aortic Aneurysm ◽  
Angiotensin Ii ◽  
Aortic Aneurysm ◽  
Vascular Smooth Muscle ◽  
Tissue Factor ◽  
Factor Xa ◽  
Male Mice ◽  
Abdominal Aortic ◽  
Protease Activated Receptor 2

Objective: Tissue factor (TF) is constitutively expressed in subendothelial cells, including vascular smooth muscle cells (VSMCs), and maintains hemostasis. The TF/factor VIIa complex as well as factor Xa have been shown to activate protease-activated receptor 2 (PAR-2). We and others have shown that TF/FVIIa-PAR-2 signaling induces migration of VSMCs in vitro and this is reduced in TF and PAR-2 deficient cells. We previously demonstrated C57BL/6 mice with 1% of normal TF levels (Low TF mice) had increased suprarenal abdominal aortic diameter and incidence of abdominal aortic aneurysm (AAA) compared to littermate controls. However, the source of cellular TF and whether signaling occurred through PAR-2 has not been examined. Our objective was to determine the importance of VSMC-specific deletion of TF and PAR-2 deficiency on the etiology of AAA. Methods and Results: VSMC-specific TF deficiency was evaluated on a low-density lipoprotein receptor deficient (Ldlr -/- ) background. Male mice were fed a fat-enriched diet (21% milk fat) and infused with angiotensin II (AngII; 1,000 ng/kg/min) for 28 days. Ldlr -/- /TF flox/flox SM22αCre + mice had increased abdominal aortic luminal diameters (Cre + : 1.92 ± 0.16 (n = 12); Cre - : 1.22 ± 0.03 mm (n = 10); P = 0.001) and incidence of AAA (100% vs. 50%; P = 0.01) compared to Cre - littermates. Next, we determined the effects of PAR-2 deficiency in AAA. Ldlr -/- /PAR-2 +/+ (n = 12) and Ldlr -/- /PAR-2 -/- (n = 15) male mice were fed a fat-enriched diet and infused with AngII for 28 days. PAR-2 deficiency attenuated abdominal aortic luminal diameters (PAR-2 +/+ : 1.78 ± 0.06 mm; PAR2 -/- : 1.17 ± 0.03 mm; P = 0.001) and incidence of AAA (84% versus 40%; P = 0.048) when compared to littermate controls. Total plasma cholesterol concentrations, lipoprotein cholesterol distributions, or increased systolic blood pressure was not different between groups. Conclusion: These results suggest that TF limits AAA growth and incidence via VSMCs in a PAR-2-independent manner. To verify this hypothesis, studies are currently underway to determine the effect of Factor Xa (FXa) inhibitors in PAR-2 deficient mice.

Abstract 019: Vascular Smooth Muscle ADAM17 Contributes To Angiotensin II-induced Abdominal Aortic Aneurysm Formation But Not Hypertension In Mice

Hypertension ◽  
2014 ◽  
Vol 64 (suppl_1) ◽  
Author(s):  
Toshiyuki Tsuji ◽  
Takehiko Takayanagi ◽  
Katherine Elliott ◽  
Takashi Obama ◽  
Kevin Crawford ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Smooth Muscle ◽  
Abdominal Aortic Aneurysm ◽  
Angiotensin Ii ◽  
Aortic Aneurysm ◽  
Vascular Smooth Muscle ◽  
Saline Infusion ◽  
Internal Diameter ◽  
Egfr Activation ◽  
Abdominal Aortic

Enhancement of the renin angiotensin II (AngII) system has been implicated in the development of abdominal aortic aneurysm (AAA). However, detailed molecular mechanism(s) by which AngII promotes AAA remain uncertain. We have demonstrated the critical role of a metalloprotease, ADAM17, in AngII-induced EGFR transactivation and subsequent hypertrophy in vascular smooth muscle cells (VSMC). In caveolin 1-/- mice, AAA formation induced by AngII plus beta-aminopropionitrile (BAPN), a lysyl oxidase inhibitor, was attenuated. The attenuation of AAA formation was associated with suppression of ADAM17 induction and EGFR activation. Others have reported that systemic ADAM17 silencing attenuated CaCl2-induced AAA formation in mice. However, the cell type specific mechanism that is mediating the deleterious effect of ADAM17 in AAA is not well understood. Here, we tested our hypothesis that VSMC ADAM17 activation is required for AngII-promoted AAA formation using ADAM17flox/flox mice bred with sm22a Cre mice. 8 week old mice were co-infused with AngII 1000 ng/kg/min (4w) and BAPN 150 mg/kg/day (2w) or control saline (4w), and AAA formation was evaluated by echo (internal diameter) and measurement (external diameter) of the aortae. In control Cre-/- mice with the co-infusion, 52.4% (11/21) were dead due to aortic rupture/dissection. All surviving Cre-/- mice with co-infusion had AAA with max external/internal diameter (mm) of 2.18±0.55/1.75±0.33 vs 1.01±0.22/1.06±0.02 with saline infusion (p<0.01). In contrast, VSMC ADAM17 deficient Cre+/- with co-infusion did not die or develop AAA. The max external/internal diameter (mm) of AA in Cre+/- with co-infusion was 1.03±0.11/1.05±0.05 vs 1.01±0.12/1.27±0.21 with saline infusion. In contrast, both Cre-/- and +/- mice with the co-infusion developed hypertension assessed by telemetry (MAP mmHg: 161±15 vs 154±12). The ADAM17 deletion was also associated with less EGFR activation, ER/oxidative stress and extravascular fibrosis/matrix deposition. In conclusion, VSMC ADAM17 appears to be a critical metalloprotease contributing to AAA formation but not hypertension induced by AngII + BAPN. The mechanism by which VSMC ADAM17 promotes AAA seems to involve activation of EGFR and induction of ER/oxidative stress.

Abstract 47: Caveolin-1 is Critical for Abdominal Aortic Aneurysm Induced by Angiotensin II

Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Takashi Obama ◽  
Takehiko Takayanagi ◽  
Kevin J Crawford ◽  
Tomonori Kobayashi ◽  
Victor Rizzo ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Smooth Muscle ◽  
Abdominal Aortic Aneurysm ◽  
Angiotensin Ii ◽  
Aortic Aneurysm ◽  
Vascular Smooth Muscle Cells ◽  
Critical Role ◽  
Ang Ii ◽  
Caveolin 1 ◽  
Abdominal Aortic

Abdominal aortic aneurysm (AAA) is a significant cause of mortality for adults aged >60 years. Accumulating evidence suggests a role of angiotensin II (Ang II) in abdominal aortic aneurysm (AAA) formation. However, the Ang II-sensitive proximal signaling events primarily responsible for AAA formation remain unclear. We recently reported that caveolin-1 (Cav1) enriched membrane microdomains in vascular smooth muscle cells (VSMC) mediate a metalloprotease ADAM17-dependent EGF receptor (EGFR) transactivation, which is linked to vascular remodeling induced by Ang II. Given that ADAM17 expression is one of the key features in AAA, we have tested our hypothesis that Cav1, a major structural protein of caveolae, plays a critical role for development of AAA by Ang II via regulation of ADAM17. 8 week old male Cav1-/- and the control C57Bl/6 wild-type mice (WT) were co-infused with Ang II (1 μg/kg/min) and β-aminopropionitrile (BAPN: 150mg/kg/day) for 4 weeks to induce AAA. In WT with the co-infusion, 58% (14/24) were dead due to aortic rupture/dissection. All surviving WT with co-infusion had AAA with max diameter (mm) of 2.6±0.18 vs 0.93±0.09 with saline infusion (p<0.01). In contrast, we found that Cav1-/- with co-infusion did not die or develop AAA. The max diameter (mm) of AAA in Cav1-/- with co-infusion was 1.0±0.04 vs 1.1±0.06 with saline infusion (n=7). In contrast, both WT and Cav1-/- with the co-infusion developed hypertension assessed by telemetry (MAP mmHg: 151±5 vs 161±7). We found an increased expression of ADAM17 by IHC and qPCR, and enhanced phosphorylation of EGFR by IHC in WT abdominal aortae with aneurysms. These events were markedly attenuated in Cav1-/- aorta with co-infusion (ADAM17/18S mRNAx10,000 = 3.08±0.71 vs 0.97±0.42 p<0.05, n=4). Furthermore, Cav1-/- aortae showed less ER and oxidative stress compared to WT aortae assessed by IHC. In addition, Cav1 silencing induced by adenovirus encoding Cav1 targeting siRNA embedded miRNA in cultured vascular smooth muscle cells prevented Ang II-induced ADAM17 induction and activation. In conclusion, Cav1 and presumably vascular caveolae microdomains appear to play a critical role in the formation of AAA by Ang II via regulation of the ADAM17/EGFR signaling and subsequent ER/oxidative stress.

Extracellular matrix metalloproteinase inducer (EMMPRIN) is present in smooth muscle cells of human aneurysmal aorta and is induced by angiotensin II in vitro

2009 ◽  
Vol 116 (11) ◽  
pp. 819-826 ◽  
Author(s):  
Xiao-feng Chen ◽  
Jian-an Wang ◽  
Jun Hou ◽  
Chun Gui ◽  
Li-jiang Tang ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Smooth Muscle ◽  
Angiotensin Ii ◽  
Aortic Aneurysm ◽  
Aortic Dissection ◽  
Matrix Metalloproteinase ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Extracellular Matrix Metalloproteinase Inducer

The aim of the present study was to determine whether EMMPRIN (extracellular matrix metalloproteinase inducer) is present and is up-regulated in human aneurysmal aortas, and to assess a possible association with AngII (angiotensin II)-induced aneurysm formation. The presence of EMMPRIN was assessed in 41 surgical specimens from patients with a TAA (thoracic aortic aneurysm) (Type A aortic dissection, n=12; Type B aortic dissection, n=7; and TAA without dissection, n=7) or an AAA (abdominal aortic aneurysm, n=15) by immunohistochemistry. EMMPRIN expression in aortic aneurysm tissues was compared with 12 aortas obtained during autopsy (free of any vascular diseases), and scored for both staining intensity and the percentage of vascular cells stained. EMMPRIN protein levels in cultured human aortic SMCs (smooth muscle cells) following stimulation of AngII were analysed by Western blotting. Significant EMMPRIN immunoreactivity was detected in aortic aneurysm lesions from patients with TAAs and AAAs. In the aneurysmal wall, α-actin-positive SMCs were the main source of EMMPRIN. The frequency of EMMPRIN overexpression was significantly higher (P=0.026) in TAAs with dissection (68.4%) than TAAs without dissection (14.3%). AngII stimulation up-regulated the expression of EMMPIRN in cultured human aortic SMCs, which was suppressed by the addition of the AT1R (AngII type 1 receptor) antagonist losartan. In conclusion, the present study is the first to report the expression of EMMPRIN in aortic aneurysmal diseases, and we speculate that EMMPRIN may be important in the pathogenesis of these diseases. Whether these abnormalities are potential therapeutic targets deserve further investigation.

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