Faculty Opinions recommendation of Deletion of mineralocorticoid receptors from macrophages protects against deoxycorticosterone/salt-induced cardiac fibrosis and increased blood pressure.

Author(s):  
Anne Dorrance
Hypertension ◽  
2009 ◽  
Vol 54 (3) ◽  
pp. 537-543 ◽  
Author(s):  
Amanda J. Rickard ◽  
James Morgan ◽  
Greg Tesch ◽  
John W. Funder ◽  
Peter J. Fuller ◽  
...  

Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Huey Wen Lee ◽  
Melita Brdar ◽  
Robert Widdop ◽  
Anthony Dear ◽  
Tracey Gaspari

Glucagon-like peptide-1 (GLP-1) based therapies are used to treat type II diabetes via increasing insulin secretion and inhibiting glucagon production. Recent evidence suggests that activating the GLP-1 receptor may also mediate direct vaso-protective effects. Therefore the objective of the study was to determine whether GLP-1R stimulation conferred cardio- and vaso-protection in a non-diabetic setting using the angiotensin (Ang) II infusion model of hypertension and cardiovascular dysfunction. Male C57Bl/6J mice (4-6 months) were assigned to one of the following 4 week treatment protocols: 1) vehicle (saline), 2) Ang II (800ng/kg/day), 3) Ang II + liraglutide (30μg/kg/day), 4) Ang II + liraglutide (300μg/kg/day). All treatments were administered via osmotic mini-pumps (s.c). After 4 weeks the effect of liraglutide treatment on blood pressure, vascular function and cardiac remodelling was examined. Liraglutide (both doses) attenuated Ang II-induced increase in systolic blood pressure (Ang II: 175.3 ± 8.6mmHg vs Ang II+Lirag (30) 150.2 ± 6.4 mmHg or Ang II+Lirag (300): 145.4 ± 6.9 mmHg) without affecting blood glucose levels. Liraglutide (both doses) completely prevented Ang II-induced endothelial dysfunction (% maximum relaxation: Ang II=50.7 ± 7.8%; Ang II+Lirag (30)=82.7 ± 5.8; Ang II+Lirag (300)=81.5 ± 6.1%). In the heart, liraglutide prevented Ang II-induced cardiomyocyte hypertrophy (n=7-10; p<0.05) and reduced collagen deposition (% collagen expression: Ang II=4.4 ± 0.5 vs Ang II+Lirag(300)=2.9 ± 0.3; n=7-9; p<0.01). This anti-fibrotic effect was attributed to reduced fibroblast/myofibroblast expression as well as decreased inflammation with reduced NFκB and MCP-1 expression and decreased oxidative stress with a significant reduction in superoxide production using high dose of liraglutide. Overall, stimulation of GLP-1R in a non-diabetic setting protected against Ang II-mediated cardiac hypertrophy, cardiac fibrosis and vascular dysfunction, indicating potential for use of GLP-1 based therapies in treatment of cardiovascular disease independent of diabetes.


2012 ◽  
Vol 18 (9) ◽  
pp. 1429-1433 ◽  
Author(s):  
Amy McCurley ◽  
Paulo W Pires ◽  
Shawn B Bender ◽  
Mark Aronovitz ◽  
Michelle J Zhao ◽  
...  

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 52-52
Author(s):  
Ana Clara Melo ◽  
Pooja Patil ◽  
Patricia Gallagher ◽  
Elisabeth Tallant

Abstract Objectives Hypertension affects over a billion people world-wide and is a major risk factor for cardiovascular disease. Macrophages, the most abundant innate immune cells, home to the heart and secrete cytokines, inducing a heightened inflammatory response which results in fibrosis and cardiac damage. Muscadine grapes are rich in polyphenols, compounds with anti-proliferative, anti-fibrotic, and anti-inflammatory properties. Our aim was to determine whether a muscadine grape extract (MGE) rich in polyphenols prevents the macrophage inflammatory response induced by hypertension. Methods A proprietary extract was prepared from muscadine grape seeds and skins. Male Sprague-Dawley rats (8 weeks old) received drinking water (control), MGE at 0.2 mg total phenolics/mL, 24 μg/kg/h of angiotensin II (Ang II) via osmotic minipump to induce hypertension, or both Ang II and MGE (Ang II/MGE) for 4 weeks. Rats were pre-treated with MGE for 1 week prior to Ang II treatment. Blood pressure was measured weekly by tail cuff plethysmography. Tissues were collected and fixed for immunohistochemistry. Proliferation and migration of macrophage-like RAW264.7 cells were quantified in real-time. Results MGE had no effect on blood pressure in normotensive or hypertensive rats. MGE ameliorated Ang II-induced diastolic dysfunction (E/E’ ratio: 19.9 ± 0.8 control, 28.1 ± 1.1 Ang II, 22.3 ± 2.0 Ang II/MGE rats; n = 8; P &lt; 0.05), interstitial cardiac fibrosis (P &lt; 0.05) and collagen III deposition (0.9 ± 0.2% Control, 6.8 ± 1.0% Ang II, 2.8 ± 0.4% Ang II/MGE; P &lt; 0.01). Thus, MGE may improve diastolic dysfunction in part through a reduction in pathological fibrosis. Ang II caused a significant increase in CD68-positive macrophages in cardiac tissue, which was blocked by MGE (% positive cells/field: control 6.1 ± 0.4, Ang II 12.5 ± 2.0, Ang II/MGE 5.4 ± 0.5, P &lt; 0.01). Treatment of RAW264.6 cells with MGE (20 μg/mL total phenolics) for 18 h attenuated stimulated cell migration by 2-fold with no effect on proliferation (n = 3, P &lt; 0.5), indicating that MGE may reduce the Ang II-mediated increase in cardiac macrophages by blocking migration. Conclusions MGE may serve as medical food to protect the heart from hypertension-induced inflammation thereby reducing cardiac fibrosis to improve diastolic dysfunction. Funding Sources Chronic Disease Research Fund.


2017 ◽  
Vol 41 (1) ◽  
pp. 286-295 ◽  
Author(s):  
Jing Liang ◽  
Kun Yin ◽  
Xuefeng Cao ◽  
Zhenbo Han ◽  
Qi Huang ◽  
...  

Background/Aims: It is well documented that myocardial hypertrophy is associated with low ambient temperature. Atorvastatin (Atv) has been shown to protect against atherosclerosis, cardiac fibrosis, ischemia/reperfusion injury, etc. In this study, we aim to determine whether atorvastatin is effective in the treatment of myocardial hypertrophy induced by cold exposure and to shed light on underlying mechanism. Methods: The mice aged 4-week were randomized to Control (Ctl) group (raised at room temperature), Cold group (raised at 3-5ºC) and Atv treatment group (raised at 3-5ºC followed by 10mg/kg/day Atv infusion). Echocardiography (ECG), HE, TUNEL and Masson’s trichrome staining, and Transmission electronic microscopy were performed to analyze cardiac function, myocardial hypertrophy, cardiac fibrosis, apoptosis and cardiomyocyte ultrastructure, respectively. Western blot was carried out to determine the involvement of MAPK and apoptosis pathways. Results: Exposure of mice to low temperature induced myocardial hypertrophic growth characterized by the elevation of heart/body weight index and heart weight /tibia length index, compared with control mice. Atv treatment attenuated cardiac hypertrophy induced by cold exposure; Atv also attenuated the increase of cross-sectional area of cardiomyocytes and cardiac collagen content fraction in mice exposed to cold. ECG showed that the decline of cardiac functions including the elevated left ventricular systolic/diastolic internal dimension (LVIDs/d) and fractional shortening (FS) in mice with cold exposure was also inhibited by Atv treatment. Transmission electronic microscopy uncovered that Atv attenuated mitochondrial injury induced by cold exposure in mice. In addition, systolic blood pressure was gradually increased in mice exposed to cold temperature, and Atv treatment significantly inhibited the elevation of blood pressure in cold-treated mice. Mechanistically, mitogen-activated protein kinase (MAPK) signal was not altered in mice exposed to cold, and Atv did not affect MAPK signal in cold-treated mice. But Atv mitigated the reduction of Bcl-2/Bax level in heart of cold-treated mice. Conclusion: Atv attenuated myocardial hypertrophy induced by cold exposure through inhibiting the downregulation of Bcl-2 in heart. It may provide a novel strategy for low temperature-induced myocardial hypertrophy treatment.


2021 ◽  
Author(s):  
Kun Zhao ◽  
Yukang Mao ◽  
Xiaoman Ye ◽  
Jiazheng Ma ◽  
Litao Sun ◽  
...  

Abstract Background: The aim of the present study was to explore whether high salt diet (HSD) caused cardiac fibrosis regardless of blood pressure in rats, and to determine the effects of microRNA (miR)-210-5p on sodium chloride (NaCl)-induced fibrosis in neonatal rat cardiac fibroblasts (NRCFs) and its target. Methods: The rats received 8% HSD in vivo, and NRCFs were treated with NaCl in vitro. Results: The levels of collagen I, alpha-smooth muscle actin (α-SMA) and transforming growth factor-beta (TGF-β) were increased in the heart of hypertension (HTN), hypertension-prone (HP) and hypertension-resistant (HR) rats on HSD. Middle and high doses (50 mM and 100 mM) of NaCl increased the levels of collagen I, α-SMA and TGF-β in NRCFs. The expression level of miR-210-5p was reduced in NaCl-treated NRCFs by miR high-throughput sequencing. The NaCl-induced increases of collagen I, α-SMA and TGF-β were inhibited by miR-210-5p agomiR, and further enhanced by miR-210-5p antagomiR. Bioinformatics analysis and luciferase reporter assays demonstrated that TGF-β type I receptor (TGFβRI) was a direct target gene of miR-210-5p. These results indicated that HSD resulted in cardiac fibrosis regardless of blood pressure. Conclusion: The upregulation of miR-210-5p could attenuate NRCF fibrosis via targeting TGFβRI. Thus, upregulating miR-210-5p to inhibit TGF-β signaling pathway might be a strategy for the treatment of cardiac fibrosis.


2020 ◽  
Vol 41 (Supplement_1) ◽  
Author(s):  
C W Liu ◽  
W C Chang ◽  
R H Pan

Abstract Funding Acknowledgements TSGH 108-11 Background Elevated serum uric acid (SUA) is associated with cardiac fibrosis and hypertrophy. A growing body of evidence showed the positive correlation between hyperuricemia (HUA) and left ventricular hypertrophy (LVH), but most studies defined LVH by a single method such as electrocardiogram or echocardiogram; the former is generally used in massive screen but the latter take advantage of the accuracy of LVH. Purpose We conducted this study to concomitantly investigate the association between SUA and electrocardiographic and echocardiographic LVH. Methods We initially enrolled 17,913 healthy individuals, who routinely underwent an annual health exam at our hospital between 2016/1/1∼2016/12/31. Of them, 347 individuals received transthoracic echocardiography because of abnormal results in their electrocardiogram. Amplitudes of 12-lead electrocardiogram were artificially measured by a study assistant under the supervision and by artificial intelligence. HUA is defined as an SUA level of ≥7 mg/dl in men and ≥6 mg/dl in women. Electrocardiographic LVH is defined by the criteria of Cornel voltage and product and Sokolow-Lyon and the Minnesota Code ECG classification. Echocardiographic LVH is defined by LV mass index ≥115g/m² in men or ≥95g/m² in women. Results The HUA group (n = 233) vs. normouricemic group (n = 114) was older and predominant male with greater values of body mass index, systolic and diastolic blood pressure and laboratory biomarkers, including non-high density total cholesterol, fasting glucose impairment, creatinine clearance, and haemoglobin. The two groups had comparable lifestyle choices, including tobacco use, alcohol intake, and physical activities per week. The HUA group compared with the normouricemic group had greater values of S amplitude of V1 plus R amplitude of V5 (3031 ± 2055 uV vs. 2566 ± 1021 uV, P = 0.005), R amplitude in lead I plus S amplitude in lead III (842 ± 443 uV vs. 696 ± 386 uV, P = 0.002) and LV mass index (95 ± 23 g/m² vs. 85 ± 30 g/m², P = 0.001). The prevalence of electrocardiographic and echocardiographic LVH was greater in the HUA group than the normouricemic group (7.0% vs. 2.1%, P = 0.034 for electrocardiographic LVH and 15.8% vs. 7.7%, P = 0.025 for echocardiographic LVH). In multivariate logistic regression analyses, elevated SUA was associated with LVH after the confounders were fully adjusted (OR: 1.38, 95% CI: 1.07-1.77, P = 0.012 for electrocardiographic LVH and OR: 1.58, 95% CI 1.15-2.17, P = 0.004 for echocardiographic LVH). Conclusion Elevated SUA is independently associated with the prevalence of both electrocardiographic and echocardiographic LVH in healthy individuals from Taiwan. Future studies might evaluate urate-lowering effects on the regression of LVH.


2000 ◽  
Vol 4 (1) ◽  
pp. 67-73 ◽  
Author(s):  
GARY PRESCOTT ◽  
DAVID W. SILVERSIDES ◽  
SUI MEI LINDA CHIU ◽  
TIMOTHY L. REUDELHUBER

The activity of a local cardiac renin-angiotensin system (RAS) has long been suspected in the promotion of cardiac pathologies including hypertrophy, ischemia, and infarction. All of the components of the RAS cascade have been demonstrated to be synthesized within the heart with the possible exception of the first enzyme in the cascade, renin. In the current study, we provide direct evidence that circulating renin can contribute to cardiac-specific synthesis of angiotensin peptides. Furthermore, we demonstrate this effect is independent of blood pressure and that in animals of comparable blood pressure, elevated circulating renin significantly enhances cardiac fibrosis. These results may serve to explain some of the cardiac pathologies associated with the RAS.


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