scholarly journals Cardiac inflammation associated with a Western diet is mediated via activation of RAGE by AGEs

2008 ◽  
Vol 295 (2) ◽  
pp. E323-E330 ◽  
Author(s):  
Christos Tikellis ◽  
Merlin C. Thomas ◽  
Brooke E. Harcourt ◽  
Melinda T. Coughlan ◽  
Josepha Pete ◽  
...  

A diet high in fat induces cardiac hypertrophy, inflammation, and oxidative stress. Although such actions have largely been ascribed to fat deposition, the accumulation of advanced glycation end products (AGEs) and subsequent activation of the receptor for AGEs (RAGE) may also represent important mediators of cardiac injury following exposure to a Western diet. In this study, male C57BL6J and RAGE knockout mice were placed on either a standard diet (7% fat) or a Western “fast-food” diet (21% fat). Animals receiving a high-fat diet were further randomized to receive the AGE inhibitor alagebrium chloride (1 mg·kg−1·day−1) and followed for 16 wk. A Western diet was associated with cardiac hypertrophy, inflammation, mitochondrial-dependent superoxide production, and cardiac AGE accumulation in wild-type mice. Although RAGE-KO mice fed a Western diet also became obese and accumulated intramyocardial lipid, cardiomyocyte hypertrophy, inflammation, and oxidative stress were attenuated compared with wild-type mice. Similarly, mice of both strains receiving alagebrium chloride had reduced levels of inflammation and oxidative stress, in association with a reduction in cardiac AGEs and RAGE. This study suggests that AGEs represent important mediators of cardiac injury associated with a Western fast-food diet. These data point to the potential utility of AGE-reducing strategies in the prevention and management of cardiac disease.

2021 ◽  
Vol 12 ◽  
Author(s):  
Nan Zhang ◽  
Hai-Han Liao ◽  
Hong Feng ◽  
Shan-Qi Mou ◽  
Wen-Jing Li ◽  
...  

Objectives: Sestrin2 (Sesn2) has been demonstrated to be a cysteine sulfinyl reductase and protects cells from multiple stress insults, including hypoxia, endoplasmic reticulum stress, and oxidative stress. However, the roles and mechanisms of Sesn2 in pressure overload-induced mouse cardiac hypertrophy have not been clearly clarified. This study intended to investigate whether sestrin2 (Sesn2) overexpression could prevent pressure overload-induced cardiac hypertrophy via an AMPKα2 dependent pathway through conditional knockout of AMPKα2.Methods and results: Sesn2 expression was significantly increased in mice hearts at 2 and 4 weeks after aortic banding (AB) surgery, but decreased to 60–70% of the baseline at 8 weeks. Sesn2 overexpression (at 3, 6, and 9 folds) showed little cardiac genetic toxicity in transgenic mice. Cardiac dysfunctions induced by pressure overload were attenuated by cardiomyocyte-specific Sesn2 overexpression when measured by echocardiography and hemodynamic analysis. Results of HE and PSR staining showed that Sesn2 overexpression significantly alleviated cardiac hypertrophy and fibrosis in mice hearts induced by pressure overload. Meanwhile, adenovirus-mediated-Sesn2 overexpression markedly suppressed angiotensin II-induced neonatal rat cardiomyocyte hypertrophy in vitro. Mechanistically, Sesn2 overexpression increased AMPKα2 phosphorylation but inhibited mTORC1 phosphorylation. The cardiac protections of Sesn2 overexpression were also via regulating oxidative stress by enhancing Nrf2/HO-1 signaling, restoring SOD activity, and suppressing NADPH activity. Particularly, we first proved the vital role of AMPKα2 in the regulation of Sesn2 with AMPKα2 knockout (AMPKα2-/-) mice and Sesn2 transgenic mice crossed with AMPKα2-/-, since Sesn2 overexpression failed to improve cardiac function, inhibit cardiac hypertrophy and fibrosis, and attenuate oxidative stress after AMPKα2 knockout.Conclusion: This study uniquely revealed that Sesn2 overexpression showed little genetic toxicity in mice hearts and inhibited mTORC1 activation and oxidative stress to protect against pressure overload-induced cardiac hypertrophy in an AMPKα2 dependent pathway. Thus, interventions through promoting Sesn2 expression might be a potential strategy for treating pathological cardiac hypertrophy and heart failure.


2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Yan Gao ◽  
Di Zhao ◽  
Wen-zhi Xie ◽  
Tingting Meng ◽  
Chunxiao Xu ◽  
...  

Abnormal autophagy and oxidative stress contribute to angiotensin II- (Ang II-) induced cardiac hypertrophy and heart failure. We previously showed that Ang II increased Rap1GAP gene expression in cardiomyocytes associated with hypertrophy and autophagy disorders. Using real-time PCR and Western blot, we found that Rap1GAP expression was increased in the heart of Sprague Dawley (SD) rats infused by Ang II compared with saline infusion and in Ang II vs. vehicle-treated rat neonatal cardiomyocytes. Overexpression of Rap1GAP in cultured cardiomyocytes exacerbated Ang II-induced cardiomyocyte hypertrophy, reactive oxygen species (ROS) generation, and cell apoptosis and inhibited autophagy. The increased oxidative stress caused by Rap1GAP overexpression was inhibited by the treatment of autophagy agonists. Knockdown of Rap1GAP by siRNA markedly attenuated Ang II-induced cardiomyocyte hypertrophy and oxidative stress and enhanced autophagy. The AMPK/AKT/mTOR signaling pathway was inhibited by overexpression of Rap1GAP and activated by the knockdown of Rap1GAP. These results show that Rap1GAP-mediated pathway might be a new mechanism of Ang II-induced cardiomyocyte hypertrophy, which could be a potential target for the future treatment of cardiac hypertrophy and heart failure.


2020 ◽  
Author(s):  
Huiming Ye ◽  
Guiyu Xu ◽  
Dexian Zhang ◽  
Rupeng Wang

Abstract Background: Cardiac hypertrophy is a common pathological process of many cardiac diseases and persistent cardiac hypertrophy is the main cause of heart failure and sudden cardiogenic death. It is of great value to elucidate the mechanism of cardiac hypertrophy for better prevention and treatment. Methods: The protein levels were measured by western blotting or RT-qPCR. cardiomyocytes hypertrophy was evaluated by [3H]-leucine incorporation assay. oxidative stress was measured by corresponding detection kits. The target relationship was measured by Luciferase reporter gene assay. Morphological change of cardiomyocyte was measured by immunofluorescence staining. Results: In our study, we for the first time revealed the effects and regulatory mechanism of miR-296-5p in cardiac hypertrophy in vitro . We found suppressed expression of miR-129-5p and elevated expression of keap-1 in Ang II-induced cardiomyocyte hypertrophy model. MiR-129-5p mimic effectively suppressed Ang II-induced hypertrophic responses and oxidative stress. Further experiments showed that keap-1 is a target of miR-129-5p, and miR-129-5p inhibitor promoted cardiomyocyte hypertrophy and oxidative stress by elevating keap-1. Besides, si-keap-1 mediated the activation of Nrf2 pathway, while miR-129-5p inhibitor inactivated the Nrf2 pathway by further elevating keap-1. Conclusions: MiR-129-5p mimic protects against Ang II induced cardiomyocyte hypertrophy via activating Nrf2 pathway by targeting keap-1.


2017 ◽  
Vol 117 (2) ◽  
pp. 218-229 ◽  
Author(s):  
K. Gil-Cardoso ◽  
I. Ginés ◽  
M. Pinent ◽  
A. Ardévol ◽  
X. Terra ◽  
...  

AbstractThe gastrointestinal alterations associated with the consumption of an obesogenic diet, such as inflammation, permeability impairment and oxidative stress, have been poorly explored in both diet-induced obesity (DIO) and genetic obesity. The aim of the present study was to examine the impact of an obesogenic diet on the gut health status of DIO rats in comparison with the Zucker (fa/fa) rat leptin receptor-deficient model of genetic obesity over time. For this purpose, female Wistar rats (n 48) were administered a standard or a cafeteria diet (CAF diet) for 12, 14·5 or 17 weeks and were compared with fa/fa Zucker rats fed a standard diet for 10 weeks. Morphometric variables, plasma biochemical parameters, myeloperoxidase (MPO) activity and reactive oxygen species (ROS) levels in the ileum were assessed, as well as the expressions of proinflammatory genes (TNF-α and inducible nitric oxide synthase (iNOS)) and intestinal permeability genes (zonula occludens-1, claudin-1 and occludin). Both the nutritional model and the genetic obesity model showed increased body weight and metabolic alterations at the final time point. An increase in intestinal ROS production and MPO activity was observed in the gastrointestinal tracts of rats fed a CAF diet but not in the genetic obesity model. TNF-α was overexpressed in the ileum of both CAF diet and fa/fa groups, and ileal inflammation was associated with the degree of obesity and metabolic alterations. Interestingly, the 17-week CAF group and the fa/fa rats exhibited alterations in the expressions of permeability genes. Relevantly, in the hyperlipidic refined sugar diet model of obesity, the responses to chronic energy overload led to time-dependent increases in gut inflammation and oxidative stress.


2021 ◽  
pp. 096032712110228
Author(s):  
AA Hafez ◽  
Z Jamali ◽  
S Samiei ◽  
S Khezri ◽  
A Salimi

Doxorubicin (DOX) is an anticancer drug which is used for treatment of several types of cancers. But the clinical use of doxorubicin is limited because of its cardiotoxicity and cardiomyopathy. Mitochondrial-dependent oxidative stress and cardiac inflammation appear to be involved in doxorubicin-induced cardiotoxicity. Betanin as a bioactive compound in Beetroot ( Beta vulgaris L.) displays anti-radical, antioxidant gene regulatory and cardioprotective activities. In this current study, we investigated the protective effect of betanin on doxorubicin-induced cytotoxicity and mitochondrial-dependent oxidative stress in isolated cardiomyocytes and mitochondria. Isolated cardiomyocytes and mitochondria were treated with three concentrations of betanin (1, 5 and 10 µM) and doxorubicin (3.5 µM) for 6 h. The parameters of cellular and mitochondrial toxicity were analyzed using biochemical and flow cytometric methods. Our results showed a significant toxicity in isolated cardiomyocytes and mitochondria in presence of doxorubicin which was related to reactive oxygen species (ROS) formation, increase in malondialdehyde (MDA), increase in oxidation of GSH to GSSG, lysosomal/mitochondrial damages and mitochondrial swelling. While betanin pretreatment reverted doxorubicin-induced cytotoxicity and oxidative stress in isolated cardiomyocytes and mitochondria. These results suggest that betanin elicited a typical protective effect on doxorubicin-induced cytotoxicity and oxidative stress. It is possible that betanin could be used as a useful adjuvant in combination with doxorubicin chemotherapy for reduction of cardiotoxicity and cardiomyopathy.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yan Huang ◽  
Gang Wang ◽  
Zhan Zhou ◽  
Zhengshan Tang ◽  
Ningning Zhang ◽  
...  

The gasotransmitter H2S is involved in various physiological and pathophysiological processes. The aim of this study was to investigate the physiological functions of H2S in the lungs. In the model of mouse with genetic deficiency in a H2S natural synthesis enzyme cystathionine-γ-lyase (CSE), we found that arterial oxygen saturation (SaO2) was decreased compared with wild type mice. Hypoxyprobe test showed that mild hypoxia occurred in the tissues of heart, lungs and kidneys in Cse-/- mice. H2S donor GYY4137 treatment increased SaO2 and ameliorated hypoxia state in cardiac and renal tissues. Further, we revealed that lung blood perfusion and airway responsiveness were not linked to reduced SaO2 level. Lung injury was found in Cse-/- mice as evidenced by alveolar wall thickening, diffuse interstitial edema and leukocyte infiltration in pulmonary tissues. IL-8, IL-1β, and TNF-α levels were markedly increased and oxidative stress levels were also significantly higher with increased levels of the pro-oxidative biomarker, MDA, decreased levels of the anti-oxidative biomarkers, T-AOC and GSH/GSSG, and reduced superoxide dismutase (SOD) activity in lung tissues of Cse-/- mice compared with those of wild type mice. GYY4137 treatment ameliorated lung injury and suppressed inflammatory state and oxidative stress in lung tissues of Cse-/- mice. A decrease in SaO2 was found in normal mice under hypoxia. These mice displayed lung injury as evidenced by alveolar wall thickening, interstitial edema and leukocyte infiltration. Increased levels of inflammatory cytokines and oxidative stress were also found in lung tissues of the mice with hypoxia insult. GYY4137 treatment increased SaO2 and ameliorated lung injury, inflammation and oxidative stress. Our data indicate that endogenous H2S is an important factor in maintaining normal SaO2 by preventing oxidative stress and inflammation in the lungs.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Srinivas Sriramula ◽  
Nithya Mariappan ◽  
Elizabeth McILwain ◽  
Joseph Francis

Tumor necrosis factor-alpha (TNF-α) and angiotensin II (Ang II) play an important role in the pathophysiology of cardiovascular disease in part by inducing the cardiac hypertrophic response and oxidative stress. Recently we demonstrated that angiotensin induced hypertensive response is attenuated in mice lacking the gene for TNF-α. In this study, we examined whether Ang II induced cardiac hypertrophy and increased oxidative stress is mediated through TNF-α. Methods and results: Male TNF-α (−/−) and age matched control (WT) mice were subcutaneously implanted with osmotic minipumps containing Ang II (1 μg/kg/min) or saline for 14 days. Human recombinant TNF-α was injected in one group of TNF-α (−/−) mice (10 μg/kg/day) for 14 days. In WT+Ang mice, a temporal increase in blood pressure was observed during the study as measured by radio telemetry transmitters. At the end of the study, echocardiography revealed an increase in thickness and dimensions of left ventricle (LV) and decreased fractional shortening (%FS) in WT+Ang mice. Real time RT-PCR showed that Ang II- infusion resulted in an increase in heart/bodyweight ratio and of cardiac hypertrophy markers ANP and BNP, and profibrotic genes Collagen Type I, Collagen Type II, and TGF-β in WT mice. Electron Spin resonance spectroscopy revealed an increase in total ROS, superoxide and peroxynitrite in the WT+ANG mice when compared to control WT mice. However, these changes were all attenuated in TNF-α (−/−)+Ang mice. Ang II infusion also increased significantly the mRNA expression of gp91Phox, NOX-1, NOX-4 and AT1R in the LV of WT mice, but not in TNF-α (−/−) mice. Interestingly, injection of TNF-α in the TNF-α (−/−) mice, treated with Ang II resulted in increased cardiac hypertrophy and oxidative stress. Conclusions: Findings from the present study suggest that TNF-α plays an important role in the development of cardiac hypertrophy and oxidative stress in Ang II-induced hypertension.


Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Ravi Nistala ◽  
Javad Habibi ◽  
Annayya Aroor ◽  
Melvin R Hayden ◽  
Mona Garro ◽  
...  

Objectives: Obesity is an independent risk factor for development and progression of renal injury. High fructose corn syrup consumption has coincided with the obesity epidemic in the United States. High fructose (60%) diets have been demonstrated to be associated with elevation in BP and worsening insulin resistance along with renal injury via increased hepatic production of uric acid. Recently, DPPIV inhibitors have been shown to improve diabetic changes and sodium excretion, effects that are beyond glycemic control. Therefore, the renal protective benefits of DPPIV inhibition in a clinically relevant Western diet fed mouse model were examined. Methods: Mice fed a high fat/high fructose (WD) diet for 16 weeks and given a DPPIV inhibitor MK0626 in their diet were examined for metabolic parameters, inflammation, kidney renin-angiotensin system (RAS) and oxidative stress. Renal injury was assessed by biochemical, immunohistological and electron microscopy techniques. In vitro , angiotensin II (Ang II) effects on OKP-PTCs were assessed for mechanism. Results: MK0626 ameliorated WD-induced increases in serum uric acid, oxidative stress and RAS. WD induced suppression of IL-10 was reversed by MK0626. There was a tendency to improve HOMA-IR by MK0626 but no effect on BP and body weights. Diet induced DPPIV activation in the plasma and kidney of WD mice was abrogated by MK0626 (~80%). WD mice were characterized by increased proteinuria (~3-fold), mesangial expansion and podocyte effacement and these changes were prevented by MK0626. In addition, the PTC endocytosis protein megalin and basilar canalicular network and mitochondrial ultrastructure abnormalities were reversed by MK0626. WD mice had decreased sodium excretion which was improved by MK0626. Ang II directly increased DPPIV activity and sodium hydrogen exchanger activity in PTCs and decreased megalin protein, which was effectively prevented by MK0626. Conclusion: Thus, WD induced increases in DPPIV activity is associated with elevations in uric acid, renal RAS, inflammation and oxidative stress which may result in renal injury. These results suggest that DPPIV inhibitors prevent WD induced renal injury and offer a novel therapy for diabetic and obesity associated renal disease.


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