Abstract 14287: Ang II-induced Pathological Autophagy is Inhibited by IL-10 via Akt Dependent Inhibition of Beclin 1 in Mice Heart

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Suresh K Verma ◽  
Prasanna Krishnamurthy ◽  
Venkata N Girikipathi ◽  
Tatiana Abramova ◽  
Anna Gumpert ◽  
...  
Keyword(s):  
Heart Failure ◽  
Angiotensin Ii ◽  
Chronic Heart Failure ◽  
Cardiac Function ◽  
Beclin 1 ◽  
Neonatal Rat ◽  
Autophagic Flux ◽  
Physical Interaction ◽  
Ang Ii

Although, autophagy is an essential cellular salvage process to maintain cellular homeostasis, pathological autophagy can lead to cardiac abnormalities and ultimately heart failure. Therefore, a tight regulation on autophagic process would be important to treat chronic heart failure. Previously, we have shown that IL-10 strongly improved cardiac function in chronic heart failure models, but the role of IL-10 in regulation of pathological autophagy is not yet investigated. We tested the hypothesis that IL-10 inhibits angiotensin II-induced pathological autophagy and thus improved cardiac function. Pathological autophagy was induced in wild type (WT) and IL10-knockout mice by angiotensin II infusion. Ang II-induced left ventricular dysfunction and hypertrophic remodeling were accentuated in IL-10 KO mice compared to WT mice. IL-10 KO mice showed exaggerated autophagy with reduced AKT phosphorylation. In neonatal rat ventricular cardiomyocytes, Ang II activated beclin1 and LC3 levels and inhibited AKT/mTORC1 and AKT-Bcl2 signaling. IL-10 inhibited Ang II-induced autophagic marker proteins. Additionally, IL-10 restored Ang II effects on AKT/mTORC1 and AKT-Bcl2 signaling. Both pharmacological/molecular inhibition of AKT via PI3K inhibitor (LY290002) or Akt siRNA, attenuated IL-10 effects on the Ang II-induced pathological autophagy, confirming that IL-10 mediated regulation of pathological autophagy is AKT dependent. Similar results were observed with mTORC1 inhibitor rapamycin. Chloroquine (a lysosome inhibitor) strongly inhibits Ang II-induced autophagic flux. However, chloroquine did not affect IL-10 effects on autophagic flux, suggesting that IL-10 inhibits stress-induced pathological autophagy. Finally, as physical interaction of Bcl2 with beclin 1 is important to inhibit autophagy and IL-10 is strong activator of Bcl2, we performed immunoprecipitation experiment. Immunoprecipitation data suggested that Ang II disrupt the physical interaction of beclin 1 with Bcl2 and IL-10 reestablished this physical interaction to reduce autophagy. Our data give a novel role of IL-10 in regulation of pathological autophagy and thus can act as a potential therapeutic molecule in treatment of chronic heart disease.

Abstract 172: Interleukin-10-mediated Activation of AKT and Bcl2 Inhibits Chronic Angiotensin II-induced Pathological Autophagy

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Suresh K Verma ◽  
Prasanna Krishnamurthy ◽  
Venkata N Girikipathi ◽  
Tatiana Abramova ◽  
Moshin Khan ◽  
...  
Keyword(s):  
Heart Failure ◽  
Angiotensin Ii ◽  
Pressure Overload ◽  
Interleukin 10 ◽  
Left Ventricular ◽  
Beclin 1 ◽  
Neonatal Rat ◽  
Physical Interaction ◽  
Ang Ii

Rationale: Although, autophagy is an essential cellular salvage process to maintain cellular homeostasis, pathological (stress-induced exaggerated/defective) autophagy can lead to cardiac abnormalities and ultimately heart failure. Therefore, a tight regulation of autophagic process would be important to treat chronic heart failure. Previously, we have shown that IL-10 strongly inhibited pressure overload-induced hypertrophy and heart failure, but role of IL-10 in regulation of pathological autophagy is not known. Hypothesis: We tested the hypothesis that IL-10 inhibits angiotensin II-induced pathological autophagy and this process, in part, led to improved cardiac function. Methods and Results: Pathological autophagy was induced in wild type (WT) and IL10-knockout (IL-10 KO) mice by angiotensin II (Ang II for 28 days) infusion. Ang II-induced left ventricular (LV) dysfunction and hypertrophic remodeling were accentuated in IL-10 KO mice compared to WT mice. IL-10 KO mice showed exaggerated autophagy as observed by Electron Microscopy and Western blotting (beclin 1, LC3 II/I and CHOP) with reduced AKT phosphorylation at serine-473. In neonatal rat ventricular cardiomyocytes (NRCM), Ang II treatment enhanced beclin1, LC3 and CHOP protein levels and inhibited AKT and 4EBP1 phosphorylation and Bcl2 levels. Interestingly, IL-10 inhibited Ang II-induced autophagic marker proteins. Additionally, IL-10 restored Ang II-induced suppression of AKT and 4EBP1 phosphrylation and restoration of Bcl2 protein level. Pharmacological inhibition of AKT via PI3K inhibitor (LY290002), reversed IL-10 responses on the Ang II-induced pathological autophagy, confirming that IL-10 mediated inhibition of autophagy is AKT dependent. Finally, as physical interaction of Bcl2 with beclin 1 is important to inhibit autophagy, we performed immunoprecipitation pull-down experiments, which showed Ang II disrupts the physical interaction of beclin 1 with Bcl2 and IL-10 reestablished this physical interaction to reduce autophagy. Conclusion: Our data provides a novel role of IL-10 in regulation of pathological autophagy and thus can act as a potential therapeutic molecule in treatment of chronic heart disease.

Abstract 15532: Altered Ubiquitination and Stability of Protein Inhibitor of Neuronal Nitric Oxide Synthase in the Paraventricular Nucleus of Chronic Heart Failure Rats: Role of Angiotensin II

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Neeru Sharma ◽  
Xuefei Liu ◽  
Hong Zheng ◽  
Kaushik Patel
Keyword(s):  
Nitric Oxide ◽  
Heart Failure ◽  
Angiotensin Ii ◽  
Chronic Heart Failure ◽  
Paraventricular Nucleus ◽  
Neuronal Nitric Oxide Synthase ◽  
Ang Ii ◽  
Protein Inhibitor ◽  
Ubiquitin Proteasome ◽  
Oxide Synthase

Introduction and Hypothesis: Expression of neuronal nitric oxide synthase (nNOS) is decreased in the paraventricular nucleus (PVN) of rats with chronic heart failure (CHF), however the underlying molecular mechanism/s remain unclear. Recently, we demonstrated, Angiotensin II (Ang II) mediated increase in PIN: protein inhibitor of nNOS (0.76±0.10 Sham vs 1.12±0.09* CHF) which is known to down-regulate nNOS through disruption of active dimers (~60% decrease in dimer/monomer ratio) in the PVN of rats with CHF. Functionally impeded monomeric enzyme is degraded by ubiquitin proteasome system. Interestingly, PIN transcript levels remain unchanged in the PVN in CHF (1.00±0.23 Sham vs. 1.1±0.28 CHF). This observation prompted us to elucidate the molecular mechanism for the accumulation of PIN post-transcriptionally in the PVN in CHF Methods and Results: We used coronary artery ligation model of CHF in rats (6-8 weeks past ligation) and neuronal NG108-15 hybrid cell line. PIN translation was inhibited using cyclohexamide (CHX) for 0-4h after 20h of pretreatment with Ang II in NG108 cells. CHX mediated decrease in PIN expression was ameliorated with Ang II (0.19±0.04 vs 0.41±0.06* 4h). Proteasome inhibitor lactacystin (LC) treatment dramatically elevates PIN level suggesting the involvement of proteasome system in PIN regulation. Immunoprecipitation with ubiquitin antibody showed decrease PIN-Ub conjugates in Ang II-treated cells (1.04 ± 0.05 LC vs. 0.62 ± 0.07* LC AngII). In vitro ubiquitination assay in cells transfected with pCMV-(HA-Ub)8 vector revealed reduction of HA-Ub-PIN conjugates after Ang II treatment (9.2 ± 2.2 LC vs. 4.5 ± 0.6* LC Ang II). Furthermore, there was decreased accumulation of PIN-Ub conjugates in the PVN of CHF rats compared to Sham as revealed by immunohistochemistry. Conclusions: Taken together, our studies revealed that PIN is targeted for rapid degradation by the ubiquitin-proteasome pathway and Ang II delays the rate of degradation resulting in accumulation of PIN. We conclude that post-translational accumulation of PIN, mediated by Ang II, leads to a decrease in the dimeric active form of nNOS as well as protein levels of nNOS, which may lead to reduced nitric oxide resulting in over-activation of sympathetic drive during CHF.

scholarly journals Quantitative trait loci associated with angiotensin II and high-salt diet induced acute decompensated heart failure in Balb/CJ mice

2019 ◽  
Vol 51 (7) ◽  
pp. 279-289
Author(s):  
Mediha Becirovic-Agic ◽  
Sofia Jönsson ◽  
Michael Hultström
Keyword(s):  
Heart Failure ◽  
Angiotensin Ii ◽  
Cardiac Function ◽  
Quantitative Trait ◽  
Acute Decompensated Heart Failure ◽  
Decompensated Heart Failure ◽  
Ang Ii ◽  
High Salt Diet ◽  
Salt Diet ◽  
Filial Generation

Genetic background of different mouse strains determines their susceptibility to disease. We have previously shown that Balb/CJ and C57BL/6J mice develop cardiac hypertrophy to the same degree when treated with a combination of angiotensin II and high-salt diet (ANG II+Salt), but only Balb/CJ show impaired cardiac function associated with edema development and substantial mortality. We hypothesized that the different response to ANG II+Salt is due to the different genetic backgrounds of Balb/CJ and C57BL/6J. To address this we performed quantitative trait locus (QTL) mapping of second filial generation (F2) of mice derived from a backcross between Balb/CJ and first filial generation (F1) of mice. Cardiac function was measured with echocardiography, glomerular filtration rate using FITC-inulin clearance, fluid and electrolyte balance in metabolic cages, and blood pressure with tail-cuff at baseline and on the fourth day of treatment with ANG II+Salt. A total of nine QTLs were found to be linked to different phenotypes in ANG II+Salt-treated F2 mice. A QTL on chromosome 3 was linked to cardiac output, and a QTL on chromosome 12 was linked to isovolumic relaxation time. QTLs on chromosome 2 and 3 were linked to urine excretion and sodium excretion. Eight genes located at the different QTLs contained coding nonsynonymous SNPs published in the mouse genome database that differ between Balb/CJ and C57BL/6J. In conclusion, ANG II+Salt-induced acute decompensation in Balb/CJ is genetically linked to several QTLs, indicating a multifaceted phenotype. The present study identified potential candidate genes that may represent important pathways in acute decompensated heart failure.

Abstract 250: Differential Role of Autophagy in Idiopathic versus Ischemic Heart Failure in Humans

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Antoinette Bugyei-Twum ◽  
Krishna K Singh ◽  
Filio Billia ◽  
Kim A Connelly
Keyword(s):  
Heart Failure ◽  
Ischemia Reperfusion ◽  
Fold Increase ◽  
Left Ventricular ◽  
Beclin 1 ◽  
Ischemic Heart ◽  
Autophagic Flux ◽  
Ischemic Heart Failure ◽  
Autophagic Activity

Background: Autophagy is an evolutionary conserved process that plays a key role in a variety of physiological and pathological processes. Despite its beneficial role, excessive/insufficient autophagic activity is known to contribute to the pathogenesis of cardiovascular disorders, including ischemia/reperfusion injury and heart failure. However, the differential role of autophagy in idiopathic versus ischemic heart failure remains unknown. Methods: To investigate the role of autophagy and associated apoptosis in idiopathic versus ischemic heart failure, we obtained LV myocardium biopsies from healthy controls (via 3 commercial sources), and from 10 patients with idiopathic and ischemic end-stage heart failure before the insertion of a left ventricular assist devise. The expression of inducers/markers of autophagy (mTOR, phospho-mTOR, LC3-I/II, p62, Beclin-1, autophagy-related genes ATG4B/ATG5) and apoptosis (Bcl-2 and caspase-3) were assessed at the transcript and protein level using quantitative RT-PCR and Western blotting. Results: Autophagy was activated in both idiopathic and ischemic heart failure in comparison to control, as confirmed by a significant reduction in mTOR expression/activation and a 3.4-fold and 2.2-fold increase in LC3 II/I ratio, respectively. An increase in apoptosis, marked by increased caspase3 and Bcl2 expression, was also observed in both groups in comparison to control. Interestingly, autophagy activity—marked by decreased mTOR expression/activation, increased ATG4B, ATG5, and Beclin-1—was significantly higher in idiopathic heart failure, when compared to ischemic heart failure. While we observed increased autophagic activity in idiopathic heart failure, p62 expression was also significantly increased in this group (2.8-fold increase; p<0.05), demonstrating an impairment of autophagic flux in idiopathic versus ischemic heart failure. Conclusions: For the first time, we provide a direct comparision of autophagy and apoptosis in idiopathic versus ischemic heart failure. Our data, demonstrating an excessive yet insufficient autophagic activity in idiopathic heart failure, suggests a differential role of autophagy apoptosis in idiopathic versus ischemia-related heart failure.

Abstract 152: IL-10 Inhibits Angiotensin II-induced Pathological Autophagy in Myocardium.

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Suresh K Verma ◽  
Prasanna Krishnamurthy ◽  
Tatiana Abramova ◽  
Garikipati Srikanth ◽  
Mohsin Khan ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Fluorescent Protein ◽  
Heart Function ◽  
Cardiac Cells ◽  
Neonatal Rat ◽  
Autophagic Flux ◽  
Protective Effects ◽  
Ang Ii ◽  
Akt Inhibitor

Background: In heart, persistent pressure overload causes pathological autophagy leading to cardiac cell death and heart failure. The role IL-10, a pleiotropic anti-inflammatory cytokine, on pathological autophagy is largely unknown. Here we hypothesized that IL-10 inhibits stress-induced pathological autophagy and therefore attenuates cardiac cells death and improve heart function. Method and Results: Cardiac stress was induced in C57 BL/6 mice by Angiotensin II treatment (Ang II-1.2mg.kg b.wt/day for 28 days) using mini osmotic pumps. Ang II treatment markedly induced autophagy in mice as measured by electron microscopy (autophagosome numbers) and Western blotting (Becline1 and LC3II proteins expression). Interestingly, systemic recombinant mouse IL-10 administration markedly inhibited Ang II-induced autophagy. To further understand the mechanism of IL-10 protection, neonatal rat ventricular myocytes (NRCM) were transfected with monomeric Red Fluorescent Protein-Enhanced Green Fluorescent Protein (mRFP-EGFP) tandem fluorescent-tagged LC3 (tfLC3) adenovirus (to measure autophagic flux) and then treated with AngII (1μM) and/or IL-10 (20ng/mL), in vitro. Ang II treatment significantly increased the numbers of both yellow (merged EGFP and mRFP signals) and red puncta, indicating active formation of both autophagosomes and autolysosomes, however, this flux was strongly inhibited by IL-10. Furthermore, Ang II significantly increased the Beclin1 and LC3II proteins expression, which was markedly reduced by IL-10 as measured by Western blot analysis. In addition, Ang II-inhibited AKT signaling (anti-autophagic signaling component) was strongly enhanced by IL-10. Ang II-induced autophagic signaling was mimicked by AKT inhibitor, suggesting AKT as the downstream target of IL-10 effects. Conclusion: Inhibition of pathological autophagy is a novel mechanism for cardio-protective effects of IL-10.

scholarly journals Effects of ACE inhibition and angiotensin II type 1 receptor blockade on cardiac function and G proteins in rats with chronic heart failure

2001 ◽  
Vol 134 (1) ◽  
pp. 150-160 ◽  
Author(s):  
Hiroyuki Yoshida ◽  
Masaya Takahashi ◽  
Kouichi Tanonaka ◽  
Toshiyuki Maki ◽  
Yoshihisa Nasa ◽  
...  
Keyword(s):  
Heart Failure ◽  
Angiotensin Ii ◽  
Chronic Heart Failure ◽  
Cardiac Function ◽  
G Proteins ◽  
Ace Inhibition ◽  
Receptor Blockade

scholarly journals UBC9-Mediated Sumoylation Favorably Impacts Cardiac Function in Compromised Hearts

2016 ◽  
Vol 118 (12) ◽  
pp. 1894-1905 ◽  
Author(s):  
Manish K. Gupta ◽  
Patrick M. McLendon ◽  
James Gulick ◽  
Jeanne James ◽  
Kamel Khalili ◽  
...  
Keyword(s):  
Cardiac Function ◽  
Protein Quality ◽  
Neonatal Rat ◽  
Autophagic Flux ◽  
Loss Of Function ◽  
Specific Expression ◽  
Cardiac Stress ◽  
Ventricular Cardiomyocytes

Rationale: SUMOylation plays an important role in cardiac function and can be protective against cardiac stress. Recent studies show that SUMOylation is an integral part of the ubiquitin proteasome system, and expression of the small ubiquitin–like modifier (SUMO) E2 enzyme UBC9 improves cardiac protein quality control. However, the precise role of SUMOylation on other protein degradation pathways, particularly autophagy, remains undefined in the heart. Objective: To determine whether SUMOylation affects cardiac autophagy and whether this effect is protective in a mouse model of proteotoxic cardiac stress. Methods and Results: We modulated expression of UBC9, a SUMO E2 ligase, using gain- and loss-of-function in neonatal rat ventricular cardiomyocytes. UBC9 expression seemed to directly alter autophagic flux. To confirm this effect in vivo, we generated transgenic mice overexpressing UBC9 in cardiomyocytes. These mice have an increased level of SUMOylation at baseline and, in confirmation of the data obtained from neonatal rat ventricular cardiomyocytes, demonstrated increased autophagy, suggesting that increased UBC9-mediated SUMOylation is sufficient to upregulate cardiac autophagy. Finally, we tested the protective role of SUMOylation-mediated autophagy by expressing UBC9 in a model of cardiac proteotoxicity, induced by cardiomyocyte-specific expression of a mutant α-B-crystallin, mutant CryAB (CryAB R120G ), which shows impaired autophagy. UBC9 overexpression reduced aggregate formation, decreased fibrosis, reduced hypertrophy, and improved cardiac function and survival. Conclusions: The data showed that increased UBC9-mediated SUMOylation is sufficient to induce relatively high levels of autophagy and may represent a novel strategy for increasing autophagic flux and ameliorating morbidity in proteotoxic cardiac disease.

Measurement of the Renin-Angiotensin System in Heart Failure

2000 ◽  
Vol 1 (3) ◽  
pp. 210-226 ◽  
Author(s):  
Shann Dixon Kim
Keyword(s):  
Heart Failure ◽  
Angiotensin Ii ◽  
Renin Angiotensin System ◽  
Ang Ii ◽  
Angiotensin I ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Advantages And Disadvantages ◽  
Angiotensin I Converting Enzyme

Angiotensin II (ANG II), the effector hormone of the renin-angiotensin system (RAS), has been implicated in the pathophysiology and progression of heart failure. Therefore, the measurement of ANGII has become important to characterize the role of this neurohormone in heart failure. However, because ANG II has been difficult to measure, other components of the RAS have been measured to characterize ANG II production. The RAS components (e.g., renin, angiotensin I–converting enzyme [ACE], angiotensin II) have been measured with a variety of techniques. In this review, RAS physiology and the techniques used to measure the RAS components are discussed. In addition, the advantages and disadvantages of the RAS measurement methods are described.

scholarly journals I-κB Kinase-ε Deficiency Attenuates the Development of Angiotensin II-Induced Myocardial Hypertrophy in Mice

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Yide Cao ◽  
Liangpeng Li ◽  
Yafeng Liu ◽  
Ganyi Chen ◽  
Zhonghao Tao ◽  
...  
Keyword(s):  
Heart Failure ◽  
Angiotensin Ii ◽  
Myocardial Hypertrophy ◽  
Peptide Hormone ◽  
Mitogen Activated Protein Kinase ◽  
Mouse Heart ◽  
Ang Ii ◽  
Extracellular Signal ◽  
Mitogen Activated Protein

I-κB kinase-ε (IKKε) is a member of the IKK complex and a proinflammatory regulator that is active in many diseases. Angiotensin II (Ang II) is a vasoconstricting peptide hormone, and Ang II-induced myocardial hypertrophy is a common cardiovascular disease that can result in heart failure. In this study, we sought to determine the role of IKKε in the development of Ang II-induced myocardial hypertrophy in mice. Wild-type (WT) and IKKε-knockout (IKKε-KO) mice were generated and infused with saline or Ang II for 8 weeks. We found that WT mouse hearts have increased IKKε expression after 8 weeks of Ang II infusion. Our results further indicated that IKKε-KO mice have attenuated myocardial hypertrophy and alleviated heart failure compared with WT mice. Additionally, Ang II-induced expression of proinflammatory and collagen factors was much lower in the IKKε-KO mice than in the WT mice. Apoptosis and pyroptosis were also ameliorated in IKKε-KO mice. Mechanistically, IKKε bound to extracellular signal-regulated kinase (ERK) and the mitogen-activated protein kinase p38, resulting in MAPK/ERK kinase (MEK) phosphorylation, and IKKε deficiency inhibited the phosphorylation of MEK-ERK1/2 and p38 in mouse heart tissues after 8 weeks of Ang II infusion. The findings of our study reveal that IKKε plays an important role in the development of Ang II-induced myocardial hypertrophy and may represent a potential therapeutic target for the management of myocardial hypertrophy.

scholarly journals Effects of Tiaozhi Granule on Regulation of Autophagy Levels in HUVECs

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Ying-Ying Wu ◽  
Chao Chen ◽  
Xiao Yu ◽  
Xiao-Dong Zhao ◽  
Rong-Qi Bao ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Angiotensin Ii ◽  
Physiological Condition ◽  
Pathological Condition ◽  
Umbilical Vein ◽  
Beclin 1 ◽  
Autophagic Flux ◽  
Ang Ii ◽  
Immunofluorescence Analysis ◽  
Umbilical Vein Endothelial Cells

Sera from the rats with Tiaozhi granule treatment were collected. Human umbilical vein endothelial cells (HUVECs) were incubated with different dosage of sera with Tiaozhi granule for 48 hours. Rapamycin or angiotensin II was applied to activate autophagy in HUVECs with or without different dosages of sera of Tiaozhi granule. The mRNA expressions of Atg5, Atg7, Beclin-1, and mammal target of rapamycin (mTOR) were detected by real-time PCR. Autophagic flux markers (protein expression of LC3, Beclin-1, and p62) were examined by western blot analyses. The number of autophagosomes was visualized by immunofluorescence analysis with LC3-II labelling. Results showed that Tiaozhi granule sera increase cell autophagic levels by increase of mRNA of Atg5, Atg7, Beclin-1, and mTOR and increase of autophagic flux and also number of autophagosomes. However, in response to rapamycin or Ang II stimulation, activated autophagic levels were alleviated by Tiaozhi granule sera by reduction of mRNA of Atg5, Atg7, Beclin-1, mTOR, autophagic flux, and also number of autophagosomes. Our present data demonstrate that Tiaozhi granule plays a dual role in response to different cell conditions, which is to increase cell autophagy under physiological condition and to suppress cell excessive autophagy under pathological condition.

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