Angiotensin II injures the arterial wall causing increased aortic stiffening in apolipoprotein E-deficient mice

2002 ◽  
Vol 283 (6) ◽  
pp. R1442-R1449 ◽  
Author(s):  
Doris M. Tham ◽  
Baby Martin-McNulty ◽  
Yi-Xin Wang ◽  
Valdeci Da Cunha ◽  
Dennis W. Wilson ◽  
...  
Keyword(s):  
Apolipoprotein E ◽  
Arterial Wall ◽  
Ang Ii ◽  
Internal Elastic Lamina ◽  
Arterial Stiffening ◽  
Functional Changes ◽  
Apoe Ko Mice ◽  
Apoe Ko

Cardiovascular diseases, such as atherosclerosis and hypertension, are associated with arterial stiffening. Previous studies showed that ANG II exacerbated atherosclerosis and induced hypertension and aneurysm formation in apolipoprotein E-deficient (apoE-KO) mice. The aim of the present study was to examine the effects of chronic treatment of ANG II on the arterial elastic properties in apoE-KO mice. We hypothesized that ANG II will injure the arterial wall resulting in increased arterial stiffening. Male apoE-KO mice were infused with either ANG II (1.44 mg · kg−1 · day−1) or vehicle (PBS) for 30 days. ANG II treatment accelerated atherosclerosis in the carotid artery by sixfold ( P < 0.001) and increased blood pressure by 30% ( P < 0.05). Additionally, our data demonstrated that ANG II increased arterial stiffening using both in vivo and in vitro methods. ANG II significantly increased pulse wave velocity by 36% ( P< 0.01) and decreased arterial elasticity as demonstrated by a more than 900% increase in maximal stiffening (high strain Young's modulus) compared with vehicle ( P < 0.05). These functional changes were correlated with morphological and biochemical changes as demonstrated by an increase in collagen content (60%), a decrease in elastin content (74%), and breaks in the internal elastic lamina in the aortic wall. In addition, endothelium-independent vasorelaxation to sodium nitroprusside was impaired in the aortic rings of ANG II-treated mice compared with vehicle. Thus, the present data indicate that ANG II injures the artery wall in multiple ways and arterial stiffening may be a common outcome of ANG II-induced arterial damage.

Xenogenic macrophage immunization reduces atherosclerosis in apolipoprotein E knockout mice

2007 ◽  
Vol 293 (3) ◽  
pp. C865-C873 ◽  
Author(s):  
Tomoya Yamashita ◽  
Seinosuke Kawashima ◽  
Tetsuaki Hirase ◽  
Masakazu Shinohara ◽  
Tomofumi Takaya ◽  
...  
Keyword(s):  
Apolipoprotein E ◽  
Critical Role ◽  
Atherosclerotic Lesion ◽  
Plasma Lipid ◽  
Chronic Inflammatory Disease ◽  
Apolipoprotein E Knockout Mice ◽  
Apoe Ko Mice ◽  
Apoe Ko

Atherosclerosis is a complex chronic inflammatory disease in which macrophages play a critical role, and the intervention of the inflammatory process in atherogenesis could be a therapeutic strategy. In this study, we investigated the efficacy of xenogenic macrophage immunization on the atherosclerotic lesion formation in a model of murine atherosclerosis. Apolipoprotein E knockout (apoE-KO) mice were repeatedly immunized with formaldehyde-fixed cultured human macrophages (phorbol ester-stimulated THP-1 cells), using human serum albumin as a control protein or HepG2 cells as human control cells, once a week for four consecutive weeks. The vehicle phosphate-buffered saline was injected in the nonimmunized controls. THP-1 immunization induced antibodies that are immunoreactive with mouse macrophages. Although the plasma lipid levels were unchanged by the immunization, the atherosclerotic lesion area in the aortic root was significantly reduced by >50% in 16-wk-old THP-1-immunized apoE-KO mice compared with that in control mice. THP-1 immunization reduced in vivo macrophage infiltration, reduced in vitro macrophage adhesion, and changed cytokine production by macrophages to the antiatherogenic phenotype. Xenogenic macrophage immunization protects against the development of atherosclerosis in apoE-KO mice by modulating macrophage function in which antibodies induced by the immunization are likely to be involved. This method is a novel and potentially useful cell-mediated immune therapeutic technique against atherosclerosis.

Angiotensin II is associated with activation of NF-κB-mediated genes and downregulation of PPARs

2002 ◽  
Vol 11 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Doris M. Tham ◽  
Baby Martin-McNulty ◽  
Yi-xin Wang ◽  
Dennis W. Wilson ◽  
Ronald Vergona ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Adhesion Molecule ◽  
Vascular Inflammation ◽  
Aortic Aneurysms ◽  
Intercellular Adhesion Molecule ◽  
Ang Ii ◽  
Inflammatory Genes ◽  
Apoe Ko Mice ◽  
Apoe Ko

Angiotensin II (ANG II) promotes vascular inflammation through nuclear factor-κB (NF-κB)-mediated induction of pro-inflammatory genes. The role of peroxisome proliferator-activated receptors (PPARs) in modulating vascular inflammation and atherosclerosis in vivo is unclear. The aim of the present study was to examine the effects of ANG II on PPARs and NF-κB-dependent pro-inflammatory genes in the vascular wall in an in vivo model of atherosclerosis and aneurysm formation. Six-month-old male apolipoprotein E-deficient (apoE-KO) mice were treated with ANG II (1.44 mg/kg per day for 30 days). ANG II enhanced vascular inflammation, accelerated atherosclerosis, and induced formation of abdominal aortic aneurysms. These effects of ANG II in the aorta were associated with downregulation of both PPAR-α and PPAR-γ mRNA and protein and an increase in transcription of monocyte chemotactic protein-1 (MCP-1), macrophage-colony stimulating factor (M-CSF), endothelial-selectin (E-selectin), intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) throughout the entire aorta. ANG II also activated NF-κB with increases in both p52 and p65 NF-κB subunits. In summary, these in vivo results indicate that ANG II, through activation of NF-κB-mediated pro-inflammatory genes, promotes vascular inflammation, leading to acceleration of atherosclerosis and induction of aneurysm in apoE-KO mice. Downregulation of PPAR-α and -γ by ANG II may diminish the anti-inflammatory potential of PPARs, thus contributing to enhanced vascular inflammation.

scholarly journals Berberine attenuates choline-induced atherosclerosis by inhibiting trimethylamine and trimethylamine-N-oxide production via manipulating the gut microbiome

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Xingxing Li ◽  
Chunyan Su ◽  
Zhibo Jiang ◽  
Yuxin Yang ◽  
Yue Zhang ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Atherosclerotic Lesion ◽  
Chow Diet ◽  
Dose Administration ◽  
Human Volunteers ◽  
Apoe Ko Mice ◽  
Gut Microbiota Composition ◽  
Apoe Ko

AbstractTrimethylamine-N-oxide (TMAO), a derivative from the gut microbiota metabolite trimethylamine (TMA), has been identified to be an independent risk factor for promoting atherosclerosis. Evidences suggest that berberine (BBR) could be used to treat obesity, diabetes and atherosclerosis, however, its mechanism is not clear mainly because of its poor oral bioavailability. Here, we show that BBR attenuated TMA/TMAO production in the C57BL/6J and ApoE KO mice fed with choline-supplemented chow diet, and mitigated atherosclerotic lesion areas in ApoE KO mice. Inhibition of TMA/TMAO production by BBR-modulated gut microbiota was proved by a single-dose administration of d9-choline in vivo. Metagenomic analysis of cecal contents demonstrated that BBR altered gut microbiota composition, microbiome functionality, and cutC/cntA gene abundance. Furthermore, BBR was shown to inhibit choline-to-TMA conversion in TMA-producing bacteria in vitro and in gut microbial consortium from fecal samples of choline-fed mice and human volunteers, and the result was confirmed by transplantation of TMA-producing bacteria in mice. These results offer new insights into the mechanisms responsible for the anti-atherosclerosis effects of BBR, which inhibits commensal microbial TMA production via gut microbiota remodeling.

Angiotensin II modulates frizzled-2 receptor expression in rat vascular smooth muscle cells

2005 ◽  
Vol 108 (6) ◽  
pp. 523-530 ◽  
Author(s):  
Giovanna CASTOLDI ◽  
Serena REDAELLI ◽  
Willy M. M. van de GREEF ◽  
Cira R. T. di GIOIA ◽  
Giuseppe BUSCA ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Angiotensin Ii ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Ang Ii ◽  
Aortic Smooth Muscle

Ang II (angiotensin II) has multiple effects on vascular smooth muscle cells through the modulation of different classes of genes. Using the mRNA differential-display method to investigate gene expression in rat aortic smooth muscle cells in culture in response to 3 h of Ang II stimulation, we observed that Ang II down-regulated the expression of a member of the family of transmembrane receptors for Wnt proteins that was identified as Fzd2 [Fzd (frizzled)-2 receptor]. Fzds are a class of highly conserved genes playing a fundamental role in the developmental processes. In vitro, time course experiments demonstrated that Ang II induced a significant increase (P<0.05) in Fzd2 expression after 30 min, whereas it caused a significant decrease (P<0.05) in Fzd2 expression at 3 h. A similar rapid up-regulation after Ang II stimulation for 30 min was evident for TGFβ1 (transforming growth factor β1; P<0.05). To investigate whether Ang II also modulated Fzd2 expression in vivo, exogenous Ang II was administered to Sprague–Dawley rats (200 ng·kg−1 of body weight·min−1; subcutaneously) for 1 and 4 weeks. Control rats received normal saline. After treatment, systolic blood pressure was significantly higher (P<0.01), whereas plasma renin activity was suppressed (P<0.01) in Ang II- compared with the saline-treated rats. Ang II administration for 1 week did not modify Fzd2 expression in aorta of Ang II-treated rats, whereas Ang II administration for 4 weeks increased Fzd2 mRNA expression (P<0.05) in the tunica media of the aorta, resulting in a positive immunostaining for fibronectin at this time point. In conclusion, our data demonstrate that Ang II modulates Fzd2 expression in aortic smooth muscle cells both in vitro and in vivo.

Abstract MP03: ROCK2 Specific Inhibition Attenuates Angiotensin II-induced Hypertension In Mice

Hypertension ◽  
2021 ◽  
Vol 78 (Suppl_1) ◽  
Author(s):  
Daniel J Fehrenbach ◽  
Meena S Madhur
Keyword(s):  
Blood Pressure ◽  
T Cell ◽  
Angiotensin Ii ◽  
Repeated Measures ◽  
Flow Cytometric Analysis ◽  
Coiled Coil ◽  
Ang Ii ◽  
Induced Hypertension

Hypertension, or an elevated blood pressure, is the primary modifiable risk factor for cardiovascular disease, the number one cause of mortality worldwide. We previously demonstrated that Th17 activation and interleukin 17A (IL-17A)/IL-21 production is integral for the full development of a hypertensive phenotype as well as the renal and vascular damage associated with hypertension. Rho-associated coiled-coil containing protein Kinase 2 (ROCK2) serves as a molecular switch upregulating Th17 and inhibiting regulatory T cell (Treg) differentiation. We hypothesize that hypertension is characterized by excessive T cell ROCK2 activation leading to increased Th17/Treg ratios and ultimately end-organ damage. We first showed in vitro that KD025, an experimental orally bioavailable ROCK2 inhibitor inhibits Th17 cell proliferation and IL-17A/IL-21 production. To determine if hypertensive stimuli such as endothelial stretch increases T cell ROCK2 expression, we cultured human aortic endothelial cells exposed to 5% (normotensive) or 10% (hypertensive) stretch with circulating human T cells and HLA-DR+ antigen presenting cells. Hypertensive stretch increased T cell ROCK2 expression 2-fold. We then tested the effect of ROCK2 inhibition with KD025 (50mg/kg i.p. daily) in vivo on angiotensin II (Ang II)-induced hypertension. Treatment with KD025 significantly attenuated the hypertensive response within 1 week of Ang II treatment (systolic blood pressure: 139± 8 vs 108±7mmHg) and this persisted for the duration of the 4 week study reaching blood pressures 20 mmHg lower (135±13mmHg) than vehicle treated mice (158±4mmHg p<0.05 effect of treatment 2-way Repeated Measures ANOVA). Flow cytometric analysis of tissue infiltrating leukocytes revealed that KD025 treatment increased Treg/Th17 ratios in the kidney (0.61±0.03 vs 0.79±0.08, p<0.05 student’s t-test). Thus, T cell ROCK2 may be a novel therapeutic target for the treatment of hypertension.

Abstract 1444: Overexpression Of Endothelial Nitric Oxide Synthase Restores Post-natal Neovascularization In Atherosclerosis.

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Barend Mees ◽  
Ludovic Waeckel ◽  
Dong You ◽  
Dennie Tempel ◽  
Maria Godinho ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Hind Limb ◽  
Fold Increase ◽  
Tissue Perfusion ◽  
Vessel Density ◽  
Plaque Size ◽  
Angiogenic Potential ◽  
Apoe Ko Mice ◽  
Apoe Ko

Alteration in post-ischemic neovascularization is a common complication of atherosclerotic disease. This results, at least in part, from abrogation of bone-marrow mononuclear cells (BM-MNC) pro-angiogenic potential. Overexpression of eNOS has been shown to promote vessel growth in the setting of ischemia. We hypothesized that eNOS overexpression could restore impaired neovascularization in atherosclerotic (ApoE KO) mice. Hind limb ischemia was induced in mice by right femoral artery ligation. After two weeks we evaluated tissue perfusion of the foot by Laser Doppler, vessel density in the hind limb by micro-angiography and histology, and atherosclerotic plaque size. In vitro BM-MNC cell culture assays were performed. Tissue perfusion and vessel density were 1.5-fold increased in transgenic mice overexpressing eNOS (eNOStg) as compared to wild type (WT) (P<0.001, n=10). Transplantation of 1x106 WT- or eNOStg BM-MNC in WT recipients caused a 1.5-fold increase in tissue perfusion and vessel density compared to injection of PBS (P<0.001, n=10). Next, we used ApoE KO mice and crossbreeds of eNOStg and ApoE KO mice (eNOStg*ApoE KO). Tissue perfusion and vessel density were 1.8-fold increased in eNOStg*ApoE KO mice as compared to ApoE KO mice (P<0.001, n=10). Transplantation of both WT- or eNOStg*ApoE KO BM-MNC in ApoE KO recipients caused a 1.6- to 2-fold increase in tissue perfusion and vessel density compared to PBS (P<0.01, n=10), while transplantation of ApoE KO BM-MNC had no positive effect on neovascularization. Moreover, transplantation of WT BM-MNC significantly increased plaque size, while eNOStg*ApoE KO BM-MNC had no effect on plaque size. eNOS overexpression did not affect BM-MNC apoptosis and secretion of growth factors but increased their ability to differentiate in vitro into EPC. Conclusion: eNOS overexpression in the endothelium improves post-ischemic neovascularization in both physiological as atherosclerotic settings. Furthermore, eNOS overexpression in the bone marrow restores the impaired pro-angiogenic potential of atherosclerotic BM-MNC without adverse effects on plaque size. Therefore, overexpression of eNOS could play a vital part in the development of therapeutic angiogenesis for atherosclerotic disease.

Abstract 229: TNF Receptor 1 Signaling Is Critically Involved in Mediating Angiotensin II-Induced Cardiac Fibrosis and Dysfunction

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Sandra B Haudek ◽  
Jeff Crawford ◽  
Erin Reineke ◽  
Alberto A Allegre ◽  
George E Taffet ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Cardiac Fibrosis ◽  
Smooth Muscle Actin ◽  
Protein A ◽  
Ang Ii ◽  
Wild Type ◽  
Monocyte Chemoattractant Protein 1 ◽  
Reactive Fibrosis

Angiotensin-II (Ang-II) plays a key role in the development of cardiomyopathies, as it is associated with many conditions involving heart failure and pathologic hypertrophy. Using a murine model of Ang-II infusion, we found that Ang-II induced the synthesis of monocyte chemoattractant protein 1 (MCP-1) that mediated the uptake of CD34 + /CD45 + monocytic cells into the heart. These precursor cells differentiated into collagen-producing fibroblasts and were responsible for the Ang-II-induced development of reactive fibrosis. Preliminary in vitro data using our monocyte-to-fibroblast differentiation model, suggested that Ang-II required the presence of TNF to induce fibroblast maturation from monocytes. In vivo, they indicated that in mice deficient of both TNF receptors (TNFR1 and TNFR2), Ang-II-induced fibrosis was absent. We now assessed the hypothesis that specific TNFR1 signaling is necessary for Ang-II-mediated cardiac fibrosis. Mice deficient in either TNFR1 (TNFR1-KO) or TNFR2 (TNFR2-KO) were subjected to continuous infusion of Ang-II for 1 to 6 weeks (n=6-8/group). Compared to wild-type, we found that in TNFR1-KO, but not in TNFR2-KO mouse hearts, collagen deposition was attenuated, as was cardiac α-smooth muscle actin protein (a marker for activated fibroblasts). When we isolated viable cardiac fibroblasts and characterized them by flow cytometry, we found that Ang-II infusion in TNFR1-KO, but not in TNFR2-KO, resulted in a marked decrease of CD34 + /CD45 + cells. Quantitative RT-PCR demonstrated a striking reduction of type 1 and 3 collagen, as well of MCP-1 mRNA expression in TNFR1-KO mouse hearts. Further measurements of cardiovascular parameters indicated that TNFR1-KO animals developed lesser Ang-II-mediated LV remodeling, smaller changes in E-linear deceleration times/rates over time, and displayed a lower Tei index (a heart rate independent marker of cardiac function), indicating less stiffness in TNFR1-KO hearts compared to wild-type and TNFR2-KO hearts. The data suggest that Ang-II-dependent cardiac fibrosis requires TNF and its signaling through TNFR1 which enhances the induction of MCP-1 and uptake of monocytic fibroblast precursors that are associated with reactive fibrosis and cardiac remodeling and function.

Abstract 585: Endothelial Cells from Adipose Tissue of Obese Humans Display Mesenchymal Characteristics

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Bronson A Haynes ◽  
Eric J Lehrer ◽  
Giann J Bhatt ◽  
Ryan W Huyck ◽  
Ashley N James ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Adipose Tissue ◽  
Prolonged Exposure ◽  
Endothelial Permeability ◽  
Fold Increase ◽  
Atp Production ◽  
Functional Changes ◽  
Twist 1

The mechanisms underlying vascular dysfunction in adipose tissue (AT) in obesity are not clearly understood. Our hypothesis is that in response to pro-inflammatory cytokines (PIC) present in obese AT, endothelial cells (EC) can de-differentiate and acquire a mesenchymal-like phenotype (EndoMT) that leads to endothelial dysfunction. To test our hypothesis, we measured endothelial and mesenchymal markers of CD31 + CD34 + EC isolated from omental (OM) and subcutaneous (SC) AT of bariatric subjects (BAMVEC) using RT-PCR and western blot. Permeability and oxidative metabolism were determined by ECIS and Seahorse analyzer XF e 24, respectively. BAMVEC isolated from both OM and SC fat showed very low protein expression of vWF and VE-Cadherin (EC markers) and abundantly expressed αSMA and the EMT transcription factor twist-1. To determine effects of PIC on EndoMT, commercially available primary endothelial cells from AT (HAMVEC) were treated in vitro with PIC (2.5ng/mL TNFα, IFNγ and TGFβ) for 1, 3 or 6 days. We found progressive down-regulation by >2-fold (p<0.001) of the EC markers vWF, VE-Cadherin, and Occludin compared to controls. As early as 1 day of PIC treatment twist-1 (p<0.001) and snail1 (p<0.05) showed an increase by >2-fold. Similarly, OM and SC BAMVEC expressed >2-fold increase in the mesenchymal genes twist-1, FSP1, αSMA, and snail1 compared to untreated HAMVEC. Metabolically, BAMVEC had increased ATP production and maximal respiration compared to HAMVEC suggesting increased oxidative phosphorylation, a marker of mesenchymal-like cells. PIC stimulation of HAMVEC yielded significant increases in endothelial permeability and motility (p<0.001). Notably, there were no significant differences in any of the markers between OM and SC BAMVEC. These results show that EC in obese AT exhibit a mesenchymal-like phenotype which may account for functional changes such as increased permeability and migration and are not depot specific. Using primary EC from human AT we showed that prolonged exposure to PIC induces a phenotype similar to CD31+CD34+ EC from obese AT. This supports the concept that AT inflammation can promote EC de-differentiation in vivo and our in vitro model is suitable for future studies to uncover the relevant mechanisms.

Neuronal excitation by angiotensin II in the rostral ventrolateral medulla of the rat in vitro

1995 ◽  
Vol 268 (1) ◽  
pp. R272-R277 ◽  
Author(s):  
Y. W. Li ◽  
P. G. Guyenet
Keyword(s):  
Angiotensin Ii ◽  
Excitatory Amino Acid ◽  
Rostral Ventrolateral Medulla ◽  
Ventrolateral Medulla ◽  
Ang Ii ◽  
Excitatory Amino Acid Receptor ◽  
Neuronal Excitation ◽  
Uk 14,304

We examined the effects of angiotensin II (ANG II) on spontaneous unit activity in slices of the rat rostral ventrolateral medulla (RVLM), ANG II (1-3 microM) excited 61% of a population of slowly and irregularly firing RVLM neurons (predrug, 1.2 +/- 0.1 spikes/s; postdrug, 4.6 +/- 0.3 spikes/s; n = 52). ANG II had no effect on pacemaker-like rapidly firing neurons (predrug, 8.6 +/- 0.4 spikes/s; n = 33). The effect of ANG II on slowly firing cells was repeatable and was reduced 75% by 3 microM losartan (baseline, 1.7 +/- 0.4 spikes/s; ANG II, 5.3 +/- 0.7 spikes/s; ANG II+losartan, 2.4 +/- 0.6 spikes/s; n = 12). The ongoing activity of slowly firing neurons was unaffected by 0.5-1 mM kynurenic acid (an ionotropic excitatory amino acid receptor antagonist). Most ANG II-responsive neurons (10 of 11) were inhibited by the alpha 2-adrenergic receptor agonist UK-14,304, but pacemaker-like neurons were not. In conclusion, the RVLM contains neurons excited by AT1 receptor agonists. These neurons are distinct from the previously described pacemaker nonadrenergic presympathetic cells. They may be responsible for the pressor effects produced by injecting ANG II into the RVLM in vivo.

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