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Mortensen MB, Nilsson L, Larsen TG, Espeseth E, Bek M, Bjørklund MM, Hagensen MK, Wolff A, Gunnersen S, Füchtbauer EM, Boedtkjer E, Bentzon JF. Prior renovascular hypertension does not predispose to atherosclerosis in mice. Atherosclerosis 2016; 249:157-63. [PMID: 27100924 DOI: 10.1016/j.atherosclerosis.2016.03.030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 03/14/2016] [Accepted: 03/22/2016] [Indexed: 11/19/2022]
Abstract
BACKGROUND Hypertension is a major risk factor for development of atherosclerotic cardiovascular disease (ASCVD). Although lowering blood pressure with antihypertensive drugs reduces the increased risk of ASCVD, residual increased risk still remains, suggesting that hypertension may cause chronic changes that promote atherosclerosis. Thus, we tested the hypothesis that hypertension increases the susceptibility to atherosclerosis in mice even after a period of re-established normotension. METHODS We used the 2-kidney, 1-clip (2K1C) technique to induce angiotensin-driven renovascular hypertension, and overexpression of the proprotein convertase subtilisin/kexin type 9 (PCSK9) gene to cause severe hypercholesterolemia and atherosclerosis. RESULTS First, we performed 2K1C (n = 8) or sham surgery (n = 9) in PCSK9 transgenic mice before they were fed a high fat diet for 14 weeks. As expected, 2K1C did not affect cholesterol levels, but induced cardiac hypertrophy and significantly increased the atherosclerotic lesion area compared to sham mice (1.8 fold, p < 0.01). Next, we performed 2K1C (n = 13) or sham surgery (n = 14) in wild-type mice but removed the clipped/sham-operated kidney after 10 weeks to eliminate hypertension, and subsequently induced hypercholesterolemia by way of adeno-associated virus-mediated hepatic gene transfer of PCSK9 combined with high-fat diet. After 14 weeks of hypercholesterolemia, atherosclerotic lesion areas were not significantly different in mice with or without prior 2K1C hypertension (0.95 fold, p = 0.35). CONCLUSION Renovascular hypertension in mice does not induce pro-atherogenic changes that persist beyond the hypertensive phase. These results indicate that hypertension only promotes atherogenesis when coinciding temporally with hypercholesterolemia.
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Affiliation(s)
- Martin Bødtker Mortensen
- Department of Clinical Medicine, Aarhus University, Denmark; Department of Cardiology, Aarhus University Hospital, Denmark.
| | - Line Nilsson
- Department of Clinical Medicine, Aarhus University, Denmark
| | - Tore G Larsen
- Department of Clinical Medicine, Aarhus University, Denmark
| | | | - Marie Bek
- Department of Clinical Medicine, Aarhus University, Denmark
| | - Martin M Bjørklund
- Department of Clinical Medicine, Aarhus University, Denmark; Department of Cardiology, Aarhus University Hospital, Denmark
| | - Mette K Hagensen
- Department of Clinical Medicine, Aarhus University, Denmark; Department of Cardiology, Aarhus University Hospital, Denmark
| | - Anne Wolff
- Department of Clinical Medicine, Aarhus University, Denmark
| | - Stine Gunnersen
- Department of Clinical Medicine, Aarhus University, Denmark; Department of Cardiology, Aarhus University Hospital, Denmark
| | | | | | - Jacob F Bentzon
- Department of Clinical Medicine, Aarhus University, Denmark; Department of Cardiology, Aarhus University Hospital, Denmark
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Pathak AS, Huang J, Rojas M, Bazemore TC, Zhou R, Stouffer GA. Effects of Restoration of Blood Flow on the Development of Aortic Atherosclerosis in ApoE-/- Mice With Unilateral Renal Artery Stenosis. J Am Heart Assoc 2016; 5:e002953. [PMID: 27039929 PMCID: PMC4859283 DOI: 10.1161/jaha.115.002953] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Background Chronic unilateral renal artery stenosis (RAS) causes accelerated atherosclerosis in apolipoprotein E–deficient (ApoE−/−) mice, but effects of restoration of renal blood flow on aortic atherosclerosis are unknown. Methods and Results Male ApoE−/− mice underwent sham surgery (n=16) or had partial ligation of the right renal artery (n=41) with the ligature being removed 4 days later (D4LR; n=6), 8 days later (D8LR; n=11), or left in place for 90 days (chronic RAS; n=24). Ligature removal at 4 or 8 days resulted in improved renal blood flow, decreased plasma angiotensin II levels, a return of systolic blood pressure to baseline, and increased plasma levels of neutrophil gelatinase associated lipocalin. Chronic RAS resulted in increased lipid staining in the aortic arch (33.2% [24.4, 47.5] vs 11.6% [6.1, 14.2]; P<0.05) and descending thoracic aorta (10.2% [6.4, 25.9] vs 4.9% [2.8, 7.8]; P<0.05), compared to sham surgery. There was an increased amount of aortic arch lipid staining in the D8LR group (22.7% [22.1, 32.7]), compared to sham‐surgery, but less than observed with chronic RAS. Lipid staining in the aortic arch was not increased in the D4LR group, and lipid staining in the descending aorta was not increased in either the D8LR or D4LR groups. There was less macrophage expression in infrarenal aortic atheroma in the D4LR and D8LR groups compared to the chronic RAS group. Conclusions Restoration of renal blood flow at either 4 or 8 days after unilateral RAS had a beneficial effect on systolic blood pressure, aortic lipid deposition, and atheroma inflammation.
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Affiliation(s)
- Alokkumar S Pathak
- McAllister Heart Institute, University of North Carolina, Chapel Hill, NC
| | - Jianhua Huang
- McAllister Heart Institute, University of North Carolina, Chapel Hill, NC
| | - Mauricio Rojas
- McAllister Heart Institute, University of North Carolina, Chapel Hill, NC
| | | | - Ruihai Zhou
- McAllister Heart Institute, University of North Carolina, Chapel Hill, NC Division of Cardiology, University of North Carolina, Chapel Hill, NC
| | - George A Stouffer
- McAllister Heart Institute, University of North Carolina, Chapel Hill, NC Division of Cardiology, University of North Carolina, Chapel Hill, NC
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Intravital microscopy reveals endothelial dysfunction in resistance arterioles in Angiotensin II-induced hypertension. Hypertens Res 2012; 35:855-61. [PMID: 22573204 DOI: 10.1038/hr.2012.58] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
It is known that hypertension is associated with endothelial dysfunction and that Angiotensin II (Ang II) is a key player in the pathogenesis of hypertension. We aimed to elucidate whether endothelial dysfunction is a specific feature of Ang II-mediated hypertension or a common finding of hypertension, independently of underlying etiology. We studied endothelial-dependent vasorelaxation in precapillary resistance arterioles and in various large-caliber conductance arteries in wild-type mice with Ang II-dependent hypertension (2-kidney 1-clip (2K1C) model) or Ang II-independent (volume overload) hypertension (1-kidney 1-clip model (1K1C)). Normotensive sham mice were used as controls. Aortic mechanical properties were also evaluated. Intravital microscopy of precapillary arterioles revealed a significantly impaired endothelium-dependent vasorelaxation in 2K1C mice compared with sham mice, as quantified by the ratio of acetylcholine (ACh)-induced over S-nitroso-N-acetyl-D,L-penicillamine (SNAP)-induced vasorelaxation (2K1C: 0.49±0.12 vs. sham: 0.87±0.11, P=0.018). In contrast, the ACh/SNAP ratio in volume-overload hypertension 1K1C mice was not significantly different from sham mice, indicating no specific endothelial dysfunction (1K1C: 0.77±0.27 vs. sham: 0.87±0.11, P=0.138). Mechanical aortic wall properties and endothelium-dependent vasorelaxation, assessed ex vivo in rings of large-caliber conductance (abdominal and thoracic aorta, carotid and femoral arteries), were not different between 2K1C, 1K1C and sham mice. Endothelial dysfunction is an early feature of Ang II- but not volume-overload-mediated hypertension. This occurs exclusively at the level of precapillary arterioles and not in conduit arteries. Our findings, if confirmed in clinical studies, will provide a better understanding of the pathophysiological mechanisms of hypertension.
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Effect of overexpression of human SR-AI on oxLDL uptake and apoptosis in 293T cells. Int Immunopharmacol 2011; 11:1752-7. [DOI: 10.1016/j.intimp.2011.07.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Revised: 07/01/2011] [Accepted: 07/01/2011] [Indexed: 12/15/2022]
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Griol-Charhbili V, Sabbah L, Colucci J, Vincent MP, Baudrie V, Laude D, Elghozi JL, Bruneval P, Picard N, Meneton P, Alhenc-Gelas F, Richer C. Tissue kallikrein deficiency and renovascular hypertension in the mouse. Am J Physiol Regul Integr Comp Physiol 2009; 296:R1385-91. [DOI: 10.1152/ajpregu.90411.2008] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The kallikrein kinin system (KKS) is involved in arterial and renal functions. It may have an antihypertensive effect in both essential and secondary forms of hypertension. The role of the KKS in the development of two-kidneys, one-clip (2K1C) hypertension, a high-renin model, was investigated in mice rendered deficient in tissue kallikrein (TK) and kinins by TK gene inactivation (TK−/−) and in their wild-type littermates (TK+/+). Four weeks after clipping the renal artery, blood flow was reduced in the clipped kidney (2K1C-TK+/+: −90%, 2K1C-TK−/−: −93% vs. sham-operated mice), and the kidney mass had also decreased (2K1C-TK+/+: −65%, 2K1C-TK−/−: −66%), whereas in the unclipped kidney, blood flow (2K1C-TK+/+: +19%, 2K1C-TK−/−: +17%) and kidney mass (2K1C-TK+/+: +32%, 2K1C-TK−/−: +30%) had both increased. The plasma renin concentration (2K1C-TK+/+: +78%, 2K1C-TK−/−: +65%) and renal renin content of the clipped kidney (2K1C-TK+/+: +58%, 2K1C-TK−/−: +65%) had increased significantly. There was no difference for these parameters between 2K1C-TK+/+ and 2K1C-TK−/− mice. Blood pressure monitored by telemetry and by plethysmography, rose immediately after clipping in both genotypes, and reached similar levels (2K1C-TK+/+: +24%, 2K1C-TK−/−: +21%). 2K1C-TK+/+ and 2K1C-TK−/− mice developed similar concentric left ventricular hypertrophy (+24% and +17%, respectively) with normal cardiac function. These findings suggest that in the context of chronic unilateral reduction in renal blood flow, TK and kinins do not influence the trophicity of kidneys, the synthesis and secretion of renin, blood pressure increase, and cardiac remodeling due to renin angiotensin system activation.
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Prostaglandin F2alpha elevates blood pressure and promotes atherosclerosis. Proc Natl Acad Sci U S A 2009; 106:7985-90. [PMID: 19416858 DOI: 10.1073/pnas.0811834106] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Little is known about prostaglandin F(2alpha) in cardiovascular homeostasis. Prostaglandin F(2alpha) dose-dependently elevates blood pressure in WT mice via activation of the F prostanoid (FP) receptor. The FP is expressed in preglomerular arterioles, renal collecting ducts, and the hypothalamus. Deletion of the FP reduces blood pressure, coincident with a reduction in plasma renin concentration, angiotensin, and aldosterone, despite a compensatory up-regulation of AT1 receptors and an augmented hypertensive response to infused angiotensin II. Plasma and urinary osmolality are decreased in FP KOs that exhibit mild polyuria and polydipsia. Atherogenesis is retarded by deletion of the FP, despite the absence of detectable receptor expression in aorta or in atherosclerotic lesions in Ldlr KOs. Although vascular TNF(alpha), inducible nitric oxide enzyme and TGF(beta) are reduced and lesional macrophages are depleted in the FP/Ldlr double KOs, this result reflects the reduction in lesion burden, as the FP is not expressed on macrophages and its deletion does not alter macrophage cytokine generation. Blockade of the FP offers an approach to the treatment of hypertension and its attendant systemic vascular disease.
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Cassis LA, Gupte M, Thayer S, Zhang X, Charnigo R, Howatt DA, Rateri DL, Daugherty A. ANG II infusion promotes abdominal aortic aneurysms independent of increased blood pressure in hypercholesterolemic mice. Am J Physiol Heart Circ Physiol 2009; 296:H1660-5. [PMID: 19252100 DOI: 10.1152/ajpheart.00028.2009] [Citation(s) in RCA: 171] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Infusion of ANG II in hyperlipidemic mice augments atherosclerosis and causes formation of abdominal aortic aneurysms (AAAs). The purpose of this study was to define the contribution of ANG II-induced hypertension to these vascular pathologies. Male apolipoprotein E (apoE)- and LDL receptor (LDLr)-deficient mice were infused with ANG II (1,000 ng.kg(-1).min(-1)) or norepinephrine (NE; 5.6 mg.kg(-1).day(-1)) for 28 days. Infusion of ANG II or NE increased mean arterial pressure (MAP; ANG II, 133 +/- 2.8; NE, 129 +/- 13 mmHg) to a similar extent compared with baseline blood pressures (MAP, 107 +/- 2 mmHg). Abdominal aortic width increased in both apoE-deficient (apoE(-/-)) or LDLr-deficient (LDLr(-/-)) mice infused with ANG II (apoE(-/-): 1.4 +/- 0.1; LDLr(-/-): 1.6 +/- 0.2 mm). In contrast, NE did not change diameters of abdominal aortas (apoE(-/-): 0.91 +/- 0.03; LDLr(-/-): 0.87 +/- 0.02 mm). Similarly, atherosclerotic lesions in aortic arches were much greater in mice infused with ANG II compared with NE. At a subpressor infusion rate of ANG II (500 ng.kg(-1).min(-1)), AAAs developed in 50% of apoE(-/-) mice. Alternatively, administration of hydralazine (250 mg/l) to ANG II-infused apoE(-/-) mice (1,000 ng.kg(-1).min(-1)) lowered systolic blood pressure (day 28: ANG II, 157 +/- 6; ANG II/hydralazine, 135 +/- 6 mmHg) but did not prevent AAA formation or atherosclerosis. These results demonstrate that infusion of ANG II to hyperlipidemic mice induces AAAs and augments atherosclerosis independent of increased blood pressure.
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Affiliation(s)
- Lisa A Cassis
- Rm. 521b, Wethington Bldg., Graduate Center for Nutritional Sciences, Univ. of Kentucky, Lexington, KY 40536-0200, USA.
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Gross DR. Other Transgenic Animal Models Used in Cardiovascular Studies. ANIMAL MODELS IN CARDIOVASCULAR RESEARCH 2009. [PMCID: PMC7121723 DOI: 10.1007/978-0-387-95962-7_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Previous chapters have described a large number of transgenic animal models used to study specific cardiovascular syndromes. This chapter will fill in some gaps. Many of these transgenic animals were developed to study normal and/or abnormal physiological responses in other organ systems, or to study basic biochemical and molecular reactions or pathways. These models were then discovered to also have effects on the cardiovascular system, some of them unanticipated. A word of caution, particularly when highly inbred mouse strains are used to develop transgenic models - not all strains of a particular species are created equal. When cardiovascular parameters of age- and sex-matched A/J and C57BL/6J inbred mice were compared the C57BL/6J mice demonstrated eccentric physiologic ventricular hypertrophy, increased ventricular function, lower heart rates, and increased exercise endurance.1
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Nogueira BV, Peotta VA, Meyrelles SS, Vasquez EC. Evaluation of aortic remodeling in apolipoprotein E-deficient mice and renovascular hypertensive mice. Arch Med Res 2007; 38:816-21. [PMID: 17923260 DOI: 10.1016/j.arcmed.2007.06.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2007] [Accepted: 05/31/2007] [Indexed: 11/16/2022]
Abstract
BACKGROUND The apolipoprotein E-deficient mouse (ApoE) spontaneously develops hypercholesterolemia and atherosclerotic lesions in large arteries. It is also known that angiotensin II-induced hypertension accelerates the development of atherosclerosis in ApoE mice. The objective of this study was to evaluate the aortic remodeling process in ApoE mice during the early phase of atherosclerosis in two-kidney one-clip hypertensive (2K1C) mice and in mice with the coexistence of atherosclerosis and arterial hypertension. METHODS Renovascular hypertension was induced in 8- to 9-week-old C57BL/6 (C57) and ApoE and compared to sham animals 28 days later. C57-2K1C and ApoE-2K1C mice showed hypertension, tachycardia, and cardiac hypertrophy of similar magnitude. RESULTS ApoE and ApoE-2K1C mice showed high levels of plasma cholesterol (4.8- and 3.6-fold) and aorta lipid deposition (85- and 101-fold) compared to C57 mice. The aorta lumen area was increased in C57-2K1C and ApoE-2K1C mice (0.57 +/- 0.04 and 0.55 +/- 0.02 mm(2)) compared to C57 mice (0.50 +/- 0.02 mm(2), p <0.05). The aorta wall area was increased by 20% in C57-2K1C and by 12% in ApoE-2K1C mice compared to C57 and ApoE. CONCLUSIONS The main finding of this study was the absence of aorta remodeling in ApoE mice at the early stage of atherosclerosis and an outward remodeling of similar magnitude in C57-2K1C and ApoE-2K1C mice.
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Affiliation(s)
- Breno V Nogueira
- Laboratory of Transgenes and Cardiovascular Control, Physiological Sciences Graduate Program, Health Sciences Center, Federal University of Espirito Santo, Vitoria, ES, Brazil
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