scholarly journals IKK Epsilon Deficiency Attenuates Angiotensin II-Induced Abdominal Aortic Aneurysm Formation in Mice by Inhibiting Inflammation, Oxidative Stress, and Apoptosis

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Hao Chai ◽  
ZhongHao Tao ◽  
YongChao Qi ◽  
HaoYu Qi ◽  
Wen Chen ◽  
...  
Keyword(s):  
Abdominal Aortic Aneurysm ◽  
Angiotensin Ii ◽  
Aortic Aneurysm ◽  
Molecular Mechanisms ◽  
Critical Role ◽  
Ang Ii ◽  
Elastin Degradation ◽  
Maximal Diameter ◽  
Abdominal Aortic ◽  
Primary Mouse

Abdominal aortic aneurysm (AAA) is a vascular disorder that is considered a chronic inflammatory disease. However, the precise molecular mechanisms involved in AAA have not been fully elucidated. Recently, significant progress has been made in understanding the function and mechanism of action of inhibitor of kappa B kinase epsilon (IKKε) in inflammatory and metabolic diseases. The angiotensin II- (Ang II-) induced or pharmacological inhibitors were established to test the effects of IKKε on AAA in vivo. After mice were continuously stimulated with Ang II for 28 days, morphologically, we found that knockout of IKKε reduced AAA formation and drastically reduced maximal diameter and severity. We also observed a decrease in elastin degradation and medial destruction, which were independent of systolic blood pressure or plasma cholesterol concentrations. Western blot analyses and immunohistochemical staining were carried out to measure IKKε expression in AAA tissues and cell lines. AAA phenotype of mice was measured by ultrasound and biochemical indexes. In zymography, immunohistology staining, immunofluorescence staining, and reactive oxygen species (ROS) analysis, TUNEL assay was used to examine the effects of IKKε on AAA progression in AAA mice. IKKε deficiency significantly inhibited inflammatory macrophage infiltration, matrix metalloproteinase (MMP) activity, ROS production, and vascular smooth muscle cell (VSMC) apoptosis. We used primary mouse aortic VSMC isolated from apolipoprotein E (Apoe) −/− and Apoe−/−IKKε−/− mice. Mechanistically, IKKε deficiency blunted the activation of the ERK1/2 pathway. The IKKε inhibitor, amlexanox, has the same impact in AAA. Our results demonstrate a critical role of IKKε in AAA formation induced by Ang II in Apoe−/− mice. Targeting IKKε may constitute a novel therapeutic strategy to prevent AAA progression.

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.

scholarly journals Inhibition of Peptidyl Arginine Deiminase 4-Dependent Neutrophil Extracellular Trap Formation Reduces Angiotensin II-Induced Abdominal Aortic Aneurysm Rupture in Mice

2021 ◽  
Vol 8 ◽  
Author(s):  
Ming Wei ◽  
Xia Wang ◽  
Yanting Song ◽  
Di Zhu ◽  
Dan Qi ◽  
...  
Keyword(s):  
Abdominal Aortic Aneurysm ◽  
Angiotensin Ii ◽  
Aortic Aneurysm ◽  
Tissue Injury ◽  
Arginine Deiminase ◽  
Tunel Staining ◽  
Ang Ii ◽  
Elastin Degradation ◽  
Abdominal Aortic

Objective: Neutrophil infiltration plays an important role in the initiation and development of abdominal aortic aneurysm (AAA). Recent studies suggested that neutrophils could release neutrophil extracellular traps (NETs), leading to tissue injury in cardiovascular diseases. However, the role of NETs in AAA is elusive. This study aimed to investigate the role and underlying mechanism of NETs in AAA development.Methods and Results: An angiotensin II (Ang II) infusion-induced AAA model was established to investigate the role of NETs during AAA development. Immunofluorescence staining showed that citrullinated histone 3 (citH3), myeloperoxidase (MPO), and neutrophil elastase (NE) (NET marker) expressions were significantly increased in Ang II-infused ApoE−/− mice. The circulating double-stranded DNA (dsDNA) level was also elevated, indicating the increased NET formation during AAA. PAD4 inhibitor YW3-56 inhibited Ang II-induced NET formation. Disruption of NET formation by YW3-56 markedly reduced Ang II-induced AAA rupture, as revealed by decreased aortic diameter, vascular smooth muscle cell (VSMC) apoptosis, and elastin degradation. Apoptosis of VSMC was evaluated by TUNEL staining and Annexin V-FITC/PI staining through flow cytometry. Western blot and inhibition experiments revealed that NETs induced VSMC apoptosis via p38/JNK pathway, indicating that PAD4-dependent NET formation played an important role in AAA.Conclusions: This study suggests that PAD4-dependent NET formation is critical for AAA rupture, which provides a novel potential therapeutic strategy for AAA disease.

Abstract 279: Role of Caveolin-1 in Abdominal Aortic Aneurysm induced by Angiotensin II

2013 ◽  
Vol 33 (suppl_1) ◽  
Author(s):  
Takehiko Takayanagi ◽  
Kevin Crawford ◽  
Tomonori Kobayashi ◽  
Victor Rizzo ◽  
Satoru Eguchi
Keyword(s):  
Oxidative Stress ◽  
Abdominal Aortic Aneurysm ◽  
Angiotensin Ii ◽  
Aortic Aneurysm ◽  
Egf Receptor ◽  
Critical Role ◽  
Membrane Microdomains ◽  
Structural Protein ◽  
Caveolin 1 ◽  
Abdominal Aortic

Abdominal aortic aneurysm (AAA) is a significant cause of mortality for adults aged >60 years. Accumulating evidence suggests that activation of the AT1 receptor by angiotensin II (AngII) in AAA formation. While several downstream signals and target proteins have been identified in this pathway, there is a huge void in our knowledge regarding the AngII-sensitive proximal events primarily responsible for AAA formation. We recently reported that caveolae membrane microdomains in vascular smooth muscle cells (VSMC) mediate a metalloprotease ADAM17-dependent EGF receptor (EGFR) transactivation which linked to vascular remodeling induced by AngII. Given that ADAM17 expression is one of the key features in AAA, we have tested our hypothesis that caveolin-1 (Cav1), a major structural protein of caveolae, in the vasculature plays a critical role for development of AAA via its regulation on ADAM17. 8 week old male Cav1-/- mice and the control C57Bl/6 wild-type (WT) mice were co-infused with AngII and BAPN, a lysyl oxidase inhibitor, to induce AAA. We found that Cav1-/- mice did not develop AAA compared to C57Bl/6 mice in spite of hypertension assessed by telemetry in both groups. This finding suggests that the AngII signaling essential for vascular contraction remains in place in Cav1-/- mice. We found an increased expression of ADAM17 and auto-phosphorylation of EGFR in WT abdominal aortae with aneurysms that were markedly attenuated in Cav1-/- mice infused with AngII+BAPN. Furthermore, Cav1-/- mice with the infusion showed less oxidative stress and ER stress than their WT counterparts as assessed by nitrotyrosine staining and KDEL/p-eIF2a staining, respectively. In conclusion, Cav1 and presumably vascular caveolae micro-domain appear to play a critical role in the formation of AAA in mice via regulation of the ADAM17/EGFR signaling axis and subsequent induction of ER/oxidative stress.

scholarly journals Deficiency of peroxiredoxin 2 exacerbates angiotensin II-induced abdominal aortic aneurysm

2020 ◽  
Vol 52 (9) ◽  
pp. 1587-1601
Author(s):  
Se-Jin Jeong ◽  
Min Ji Cho ◽  
Na Young Ko ◽  
Sinai Kim ◽  
In-Hyuk Jung ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Abdominal Aortic Aneurysm ◽  
Angiotensin Ii ◽  
Aortic Aneurysm ◽  
Negative Regulator ◽  
Aortic Dilatation ◽  
Ang Ii ◽  
Peroxiredoxin 2 ◽  
Structural Deterioration ◽  
Abdominal Aortic

Abstract Abdominal aortic aneurysm (AAA) is an inflammatory vascular disease characterized by structural deterioration of the aorta caused by inflammation and oxidative stress, leading to aortic dilatation and rupture. Peroxiredoxin 2 (PRDX2), an antioxidant enzyme, has been reported as a potential negative regulator of inflammatory vascular diseases, and it has been identified as a protein that is increased in patients with ruptured AAA compared to patients with nonruptured AAA. In this study, we demonstrated that PRDX2 was a pivotal factor involved in the inhibition of AAA progression. PRDX2 levels were increased in AAA compared with those in normal aortas in both humans and mice. Ultrasound imaging revealed that the loss of PRDX2 accelerated the development of AAA in the early stages and increased AAA incidence in mice infused with angiotensin II (Ang II). Prdx2−/− mice infused with Ang II exhibited increased aortic dilatation and maximal aortic diameter without a change in blood pressure. Structural deterioration of the aortas from Prdx2−/− mice infused with Ang II was associated with increases in the degradation of elastin, oxidative stress, and intramural thrombi caused by microhemorrhages, immature neovessels, and the activation of matrix metalloproteinases compared to that observed in controls. Moreover, an increase in inflammatory responses, including the production of cell adhesion molecules and the accumulation of inflammatory cells and proinflammatory cytokines due to PRDX2 deficiency, accelerated Ang II-induced AAA progression. Our data confirm that PRDX2 plays a role as a negative regulator of the pathological process of AAA and suggest that increasing PRDX2 activity may be a novel strategy for the prevention and treatment of AAA.

scholarly journals Apelin protects against abdominal aortic aneurysm and the therapeutic role of neutral endopeptidase resistant apelin analogs

2019 ◽  
Vol 116 (26) ◽  
pp. 13006-13015 ◽  
Author(s):  
Wang Wang ◽  
Mengcheng Shen ◽  
Conrad Fischer ◽  
Ratnadeep Basu ◽  
Saugata Hazra ◽  
...  
Keyword(s):  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Aortic Rupture ◽  
Critical Role ◽  
Neutral Endopeptidase ◽  
Negative Regulator ◽  
Ang Ii ◽  
Direct Role ◽  
Abdominal Aortic

Abdominal aortic aneurysm (AAA) remains the second most frequent vascular disease with high mortality but has no approved medical therapy. We investigated the direct role of apelin (APLN) in AAA and identified a unique approach to enhance APLN action as a therapeutic intervention for this disease. Loss of APLN potentiated angiotensin II (Ang II)-induced AAA formation, aortic rupture, and reduced survival. Formation of AAA was driven by increased smooth muscle cell (SMC) apoptosis and oxidative stress inApln−/yaorta and in APLN-deficient cultured murine and human aortic SMCs. Ang II-induced myogenic response and hypertension were greater inApln−/ymice, however, an equivalent hypertension induced by phenylephrine, an α-adrenergic agonist, did not cause AAA or rupture inApln−/ymice. We further identified Ang converting enzyme 2 (ACE2), the major negative regulator of the renin-Ang system (RAS), as an important target of APLN action in the vasculature. Using a combination of genetic, pharmacological, and modeling approaches, we identified neutral endopeptidase (NEP) that is up-regulated in human AAA tissue as a major enzyme that metabolizes and inactivates APLN-17 peptide. We designed and synthesized a potent APLN-17 analog, APLN-NMeLeu9-A2, that is resistant to NEP cleavage. This stable APLN analog ameliorated Ang II-mediated adverse aortic remodeling and AAA formation in an established model of AAA, high-fat diet (HFD) inLdlr−/−mice. Our findings define a critical role of APLN in AAA formation through induction of ACE2 and protection of vascular SMCs, whereas stable APLN analogs provide an effective therapy for vascular diseases.

scholarly journals Transcriptional profiling and network analysis of the murine angiotensin II-induced abdominal aortic aneurysm

2011 ◽  
Vol 43 (17) ◽  
pp. 993-1003 ◽  
Author(s):  
Joshua M. Spin ◽  
Mark Hsu ◽  
Junya Azuma ◽  
Maureen M. Tedesco ◽  
Alicia Deng ◽  
...  
Keyword(s):  
Gene Expression ◽  
Abdominal Aortic Aneurysm ◽  
Angiotensin Ii ◽  
Network Analysis ◽  
Aortic Aneurysm ◽  
Mapk Signaling ◽  
Aortic Dilatation ◽  
Ang Ii ◽  
Abdominal Aortic ◽  
Aneurysm Development

We sought to characterize temporal gene expression changes in the murine angiotensin II (ANG II)-ApoE−/− model of abdominal aortic aneurysm (AAA). Aortic ultrasound measurements were obtained over the 28-day time-course. Harvested suprarenal aortic segments were evaluated with whole genome expression profiling at 7, 14, and 28 days using the Agilent Whole Mouse Genome microarray platform and Statistical Analysis of Microarrays at a false discovery rate of <1%. A group of angiotensin-treated mice experienced contained rupture (CR) within 7 days and were analyzed separately. Progressive aortic dilatation occurred throughout the treatment period. However, the numerous early expression differences between ANG II-treated and control were not sustained over time. Ontologic analysis revealed widespread upregulation of inflammatory, immune, and matrix remodeling genes with ANG II treatment, among other pathways such as apoptosis, cell cycling, angiogenesis, and p53 signaling. CR aneurysms displayed significant decreases in TGF-β/BMP-pathway signaling, MAPK signaling, and ErbB signaling genes vs. non-CR/ANG II-treated samples. We also performed literature-based network analysis, extracting numerous highly interconnected genes associated with aneurysm development such as Spp1, Myd88, Adam17 and Lox. 1) ANG II treatment induces extensive early differential expression changes involving abundant signaling pathways in the suprarenal abdominal aorta, particularly wide-ranging increases in inflammatory genes with aneurysm development. 2) These gene expression changes appear to dissipate with time despite continued growth, suggesting that early changes in gene expression influence disease progression in this AAA model, and that the aortic tissue adapts to prolonged ANG II infusion. 3) Network analysis identified nexus genes that may constitute aneurysm biomarkers or therapeutic targets.

scholarly journals Deficiency of IL12p40 (Interleukin 12 p40) Promotes Ang II (Angiotensin II)–Induced Abdominal Aortic Aneurysm

2019 ◽  
Vol 39 (2) ◽  
pp. 212-223 ◽  
Author(s):  
Neekun Sharma ◽  
Rishabh Dev ◽  
Anthony M. Belenchia ◽  
Annayya R. Aroor ◽  
Adam Whaley-Connell ◽  
...  
Keyword(s):  
Abdominal Aortic Aneurysm ◽  
Angiotensin Ii ◽  
Aortic Aneurysm ◽  
Interleukin 12 ◽  
Ang Ii ◽  
Abdominal Aortic

scholarly journals CRP immunodeposition and proteomic analysis in abdominal aortic aneurysm

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0245361
Author(s):  
Eun Na Kim ◽  
Jiyoung Yu ◽  
Joon Seo Lim ◽  
Hwangkyo Jeong ◽  
Chong Jai Kim ◽  
...  
Keyword(s):  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Signaling Pathways ◽  
Proteomic Analysis ◽  
Molecular Mechanisms ◽  
Aortic Wall ◽  
High Serum ◽  
Maximal Diameter ◽  
Abdominal Aortic ◽  
Serum Crp

Objective The molecular mechanisms of the degeneration of the aortic wall in abdominal aortic aneurysm (AAA) are poorly understood. The monomeric form of C-reactive protein (mCRP) is deposited in damaged cardiovascular organs and aggravates the prognosis; however, it is unknown whether mCRP is deposited in the degenerated aorta of abdominal aortic aneurysm (AAA). We investigated whether mCRP is deposited in AAA and examined the associated pathogenic signaling pathways. Methods Twenty-four cases of AAA were analyzed and their histological features were compared according to the level of serum CRP and the degree of mCRP deposition. Proteomic analysis was performed in AAA cases with strong and diffuse CRP immunopositivity (n = 7) and those with weak, focal, and junctional CRP immunopositivity (n = 3). Results mCRP was deposited in the aortic specimens of AAA in a characteristic pattern that coincided with the lesion of the diminished elastic layer of the aortic wall. High serum CRP level was associated with stronger mCRP immunopositivity and a larger maximal diameter of aortic aneurysm. Proteomic analysis in AAA showed that multiple proteins were differentially expressed according to mCRP immunopositivity. Also, ingenuity pathway analysis showed that pathways associated with atherosclerosis, acute phase response, complement system, immune system, and coagulation were enriched in AAA cases with high mCRP immunopositivity. Conclusions AAA showed a characteristic deposition of mCRP, and multiple potentially pathologic signaling pathways were upregulated in AAA cases with strong CRP immunopositivity. mCRP and the aforementioned pathological pathways may serve as targets for managing the progression of AAA.

Abstract 102: Model-Dependent Influence of Prior Splenectomy on Experimental Abdominal Aortic Aneurysm Progression

2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
Baohui Xu ◽  
Yasunori Iida ◽  
Xiaolei Hu ◽  
Richard Yuan ◽  
Haojun Xuan ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Smooth Muscle Cell ◽  
Muscle Cell ◽  
Initial Step ◽  
Aortic Diameter ◽  
Ang Ii ◽  
Elastin Degradation ◽  
Abdominal Aortic

Objective: Abdominal aortic aneurysm (AAA) is a macrophage-driven, inflammatory vascular disease. Thus, mobilization of macrophage precursors from the bone marrow and/or splenic reservoir may represent a crucial initial step for AAA formation. Prior evidence suggests that splenic monocytes are important initial contributors to ischemic myocardial injury, their role in AAA pathogenesis remains unknown. We surgically removed the spleen prior to AAA creation to evaluate the influence of splenic monocytes on aneurysm pathophysiology. Methods: AAAs were created in either 1) male C57BL/6 mice by infrarenal intra-aortic porcine pancreatic elastase (PPE) infusion or 2) male ApoE deficient mice by continuous subdermal angiotensin II infusion (ApoE KO/Ang II model). Splenectomy was performed immediately prior to AAA creation in both models. Aortic diameter was serially monitored via ultrasonography, and aortae harvested at sacrifice for histopathology. Results: In sham splenectomy mice, PPE infusion led to significant aortic enlargement. AAA (≥50% aortic diameter increase) developed in all sham/PPE mice within 14 days (n=10). Splenectomy effectively eliminated PPE-induced aortic enlargement, with preservation of medial elastin and smooth muscle cell density and minimal inflammation compared to sham. In contrast, Ang II infusion in ApoE deficient produced similar-sized or larger AAA in splenectomized mice compared to sham, with elastin degradation, smooth muscle cell depletion undistinguishable between the groups. Conclusion: Splenectomy confers differential protection from AAA in mice, depending on the model/method employed for aneurysm formation. While this experiment underscores important limitations to mouse-based AAA modeling, the splenic monocyte reservoir may represent an important driver of AAA pathophysiology.

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