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 ◽  
...  

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.

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Suresh K Verma ◽  
Prasanna Krishnamurthy ◽  
Venkata N Girikipathi ◽  
Tatiana Abramova ◽  
Anna Gumpert ◽  
...  

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.


Author(s):  
Mortimer Korf-Klingebiel ◽  
Marc R. Reboll ◽  
Felix Polten ◽  
Natalie Weber ◽  
Felix Jäckle ◽  
...  

Background: Inflammation contributes to the pathogenesis of heart failure, but there is limited understanding of inflammation's potential benefits. Inflammatory cells secrete myeloid-derived growth factor (MYDGF) to promote tissue repair after acute myocardial infarction. We hypothesized that MYDGF has a role in cardiac adaptation to persistent pressure overload. Methods: We defined the cellular sources and function of MYDGF in wild-type, Mydgf -deficient ( Mydgf -/- ), and Mydgf bone marrow-chimeric or bone marrow-conditional transgenic mice with pressure overload-induced heart failure after transverse aortic constriction surgery. We measured MYDGF plasma concentrations by targeted liquid chromatography-mass spectrometry. We identified MYDGF signaling targets by phosphoproteomics and substrate-based kinase activity inference. We recorded Ca 2+ transients and sarcomere contractions in isolated cardiomyocytes. Additionally, we explored the therapeutic potential of recombinant MYDGF. Results: MYDGF protein abundance increased in the left ventricular (LV) myocardium and in blood plasma of pressure-overloaded mice. Patients with severe aortic stenosis also had elevated MYDGF plasma concentrations, which declined after transcatheter aortic valve implantation. Monocytes and macrophages emerged as the main MYDGF sources in the pressure-overloaded murine heart. While Mydgf -/- mice had no apparent phenotype at baseline, they developed more severe LV hypertrophy and contractile dysfunction during pressure overload than wild-type mice. Conversely, conditional transgenic overexpression of MYDGF in bone marrow-derived inflammatory cells attenuated pressure overload-induced hypertrophy and dysfunction. Mechanistically, MYDGF inhibited G protein coupled receptor agonist-induced hypertrophy and augmented sarco/endoplasmic reticulum Ca 2+ ATPase 2a (SERCA2a) expression in cultured neonatal rat cardiomyocytes by enhancing PIM1 serine/threonine kinase expression and activity. Along this line, cardiomyocytes from pressure-overloaded Mydgf -/- mice displayed reduced PIM1 and SERCA2a expression, greater hypertrophy, and impaired Ca 2+ cycling and sarcomere function compared to cardiomyocytes from pressure-overloaded wild-type mice. Transplanting Mydgf -/- mice with wild-type bone marrow cells augmented cardiac PIM1 and SERCA2a levels and ameliorated pressure overload-induced hypertrophy and dysfunction. Pressure-overloaded Mydgf -/- mice were similarly rescued by adenoviral Serca2a gene transfer. Treating pressure-overloaded wild-type mice subcutaneously with recombinant MYDGF enhanced SERCA2a expression, attenuated LV hypertrophy and dysfunction, and improved survival. Conclusions: These findings establish a MYDGF-based adaptive crosstalk between inflammatory cells and cardiomyocytes that protects against pressure overload-induced heart failure.


2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Andrea Iorga ◽  
Rangarajan Nadadur ◽  
Salil Sharma ◽  
Jingyuan Li ◽  
Mansoureh Eghbali

Heart failure is generally characterized by increased fibrosis and inflammation, which leads to functional and contractile defects. We have previously shown that short-term estrogen (E2) treatment can rescue pressure overload-induced decompensated heart failure (HF) in mice. Here, we investigate the anti-inflammatory and anti-fibrotic effects of E2 on reversing the adverse remodeling of the left ventricle which occurs during the progression to heart failure. Trans-aortic constriction procedure was used to induce HF. Once the ejection fraction reached ∼30%, one group of mice was sacrificed and the other group was treated with E2 (30 αg/kg/day) for 10 days. In vitro, co-cultured neonatal rat ventricular myocytes and fibroblasts were treated with Angiotensin II (AngII) to simulate cardiac stress, both in the presence or absence of E2. In vivo RT-PCR showed that the transcript levels of the pro-fibrotic markers Collagen I, TGFβ, Fibrosin 1 (FBRS) and Lysil Oxidase (LOX) were significantly upregulated in HF (from 1.00±0.16 to 1.83±0.11 for Collagen 1, 1±0.86 to 4.33±0.59 for TGFβ, 1±0.52 to 3.61±0.22 for FBRS and 1.00±0.33 to 2.88±0.32 for LOX) and were reduced with E2 treatment to levels similar to CTRL. E2 also restored in vitro AngII-induced upregulation of LOX, TGFβ and Collagen 1 (LOX:1±0.23 in CTRL, 6.87±0.26 in AngII and 2.80±1.5 in AngII+E2; TGFβ: 1±0.08 in CTRL, 3.30±0.25 in AngII and 1.59±0.21 in AngII+E2; Collagen 1: 1±0.05 in CTRL.2±0.01 in AngII and 0.65±0.02 (p<0.05, values normalized to CTRL)). Furthermore, the pro-inflammatory interleukins IL-1β and IL-6 were upregulated from 1±0.19 to 1.90±0.09 and 1±0.30 to 5.29±0.77 in the in vivo model of HF, respectively, and reversed to CTRL levels with E2 therapy. In vitro, IL-1β was also significantly increased ∼ 4 fold from 1±0.63 in CTRL to 3.86±0.14 with AngII treatment and restored to 1.29±0.77 with Ang+E2 treatment. Lastly, the anti-inflammatory interleukin IL-10 was downregulated from 1.00±0.17 to 0.49±0.03 in HF and reversed to 0.67±0.09 in vivo with E2 therapy (all values normalized to CTRL). This data strongly suggests that one of the mechanisms for the beneficial action of estrogen on left ventricular heart failure is through reversal of inflammation and fibrosis.


2021 ◽  
Author(s):  
Ding Xiaoli ◽  
Yuan Qingqing ◽  
Qian Haibing

Abstract Background: Myocardial hypertrophy occurs in many cardiovascular diseases. Leonurine (Leo) is commonly used for cardiovascular and cerebrovascular diseases. However, whether it can prevent cardiac hypertrophy is not known. The aim of this study was to investigate the effect and mechanism of Leonurine (Leo) against pressure-overload cardiac hypertrophy induced by abdominal aortic constriction (AAC) in rats. Methods: To answer this question, we prove it in the following way: Cardiac function was evaluated by hemodynamic; the left ventricle enlargement was measured by heart weight index (HWI) and left ventricular mass index (LVWI); myocardial tissue changes and myocardial cell diameter (MD) were determined by Hematoxylin and eosin (HE) staining; theβ-myosin heavy chain(β-MHC)and atrial natriuretic factor (ANF), which are recognized as a marker of cardiac hypertrophy, were determined by Real-time quantitative PCR (qRT-PCR), then another gene phospholipase C (PLC), inositol triphosphate (IP3), which associated with RAS were determined by Western blot(WB). angiotensin II (Ang II), angiotensin II type 1 receptor (AT1R) were determined by ELISA, WB and qRT-PCR methods. Finally, we measured the level of Ca2+ by microplate method and the protooncogene c-fos and c-myc mRNA in left ventricular myocardium by qRT-PCR.Results: Compare with control group, Leonurine can improve systolic dysfunction; inhibit the increase of left cardiac; inhibit myocardial cells were abnormally large and restrain the changes of cardiac histopathology; decrease the expression of β-MHC, ANF, Ang II, AT1R, c-fos and c-myc mRNA and the protein levels of PLC, IP3, AngII and AT1R in left ventricular myocardium, in addition, the content of Ca2+ also decrease. Conclusion: Therefore, Leonurine can inhibit cardiac hypertrophy induced by AAC and its effects may be associated with RAS.


2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Annina Kelloniemi ◽  
Jani Aro ◽  
Elina Koivisto ◽  
Heikki Ruskoaho ◽  
Jaana Rysä

Objectives: Transforming-growth-factor β-stimulated clone 22 (TSC-22) is a leucine zipper protein expressed in many tissues and possessing various transcription-modulating activities. However, its function in the heart remains largely unknown. The aim of the present study was to characterize the cardiac TSC-22 expression. Methods: Acute pressure overload was accomplished in conscious Sprague-Dawley (SD) rats by intravenous infusion of arginine 8 -vasopressin (AVP, 0.05 μg/kg/min) for 4 hours and subcutaneous infusion of angiotensin II (Ang II, 33 μg/kg/h) with and without Ang II receptor type 1 blocker losartan (400 μg/kg/h) by using osmotic minipumps for 2 weeks. Adenovirus-mediated intramyocardial gene transfer of TSC-22 was performed into left ventricle (LV) of SD rats. Experimental myocardial infarction (MI) was produced by ligation of the left anterior descending coronary artery. Cultured neonatal rat ventricular myocytes (NRVM) were treated with endothelin-1 (ET-1, 100 nM). Results: A significant 1.6-fold increase ( P <0.05) in LV TSC-22 mRNA levels was noted already after 1 hour AVP infusion. Moreover, Ang II infusion markedly upregulated TSC-22 expression, LV mRNA levels being highest at 6 hours (11-fold, P <0.001). Simultaneous infusion of losartan completely abolished Ang II-induced increase in TSC-22 mRNA levels. Adenovirus-mediated gene transfer of TSC-22 into LV resulted a 1.9-fold ( P <0.001) increase in TSC-22 mRNA levels, accompanied by upregulated BNP mRNA levels (1.4-fold, P <0.01). In response to experimental MI, TSC-22 mRNA levels were elevated 4.1-fold ( P <0.001) at 1 day and 1.9-fold ( P <0.05) at 4 weeks. In cultured NRVM, ET-1 treatment increased TSC-22 mRNA levels from 1 h to 24 h, the greatest increase being observed at 12 h (2.7-fold, P <0.001). TSC-22 protein levels were upregulated from 4 h to 24 h with the highest increase at 24 h (4.7-fold, P <0.01). Conclusion: These results indicate that TSC-22 expression is rapidly activated in response to pressure overload, MI and in ET-1 treated cultured NRVM. Moreover, adenovirus-mediated overexpression of TSC-22 mRNA was associated with elevated left ventricular BNP mRNA levels.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Susanna Cooper ◽  
Zoe Haines ◽  
Viridiana Alcantara Alonso ◽  
Joshua J Cull ◽  
Feroz Ahmad ◽  
...  

Introduction: Epidermal growth factor (EGF) receptors (EGFRs: ERBB1-4) are activated by a family of ligands (e.g. EGF, Hb-EGF, EREG, TGFa), signaling through ERK1/2 and Akt to promote cell division and cancer. Antibody-based inhibition of ERBB2 in breast cancer can cause heart failure, but the role of other receptors and EGFR ligands in the heart, and potential cardiotoxicity of generic EGFR inhibitors is unclear. Hypothesis: We hypothesize that EGFR ligands play an important role in cardiac adaptation to hypertension, acting through EGFRs to promote adaptive remodelling. Methods & Results: EGF ligand/receptor mRNA expression was assessed in human failing hearts and normal controls (n=12/8). EGFRs were expressed at similar levels, but ligand expression differed with significant up- or downregulation of EGF/Hb-EGF vs EREG/TGFa, respectively, in failing hearts (p<0.05). EGF potently activated ERK1/2 and Akt (assessed by immunoblotting) in neonatal rat cardiomyocytes, leading to hypertrophy (p<0.05, n=4). The anti-cancer drug afatinib inhibits EGFRs. To assess the role of EGF signaling in cardiac adaptation to hypertension in vivo , C57Bl/6J mice (n=6) were treated with 0.8 mg/kg/d angiotensin II (AngII; 7d) ± 0.45 mg/kg/d afatinib. AngII promoted cardiac hypertrophy with increased left ventricular (LV) wall thickness (WT) and decreased LV internal diameter (ID; assessed by echocardiography). Afatinib enhanced AngII-induced hypertrophy with significantly increased WT:ID ratios (1.30-fold and 1.54-fold in diastole and systole, respectively; p<0.05) but inhibited AngII-induced increases in Nppb mRNA expression and cardiomyocyte cross-sectional area (208.80±9.78 vs 161.10±3.87μm 2 ; p<0.05). In contrast, Col1a1 mRNA expression was enhanced by afatinib, along with interstitial and perivascular fibrosis (3.21±0.38 vs 5.61±0.46, 0.98±0.06 vs 1.45±0.18 % area; p<0.05). Conclusion: EGFR signaling is modulated in human heart failure, promotes cardiomyocyte hypertrophy and is required for cardiac adaptation to hypertension. Since EGFR inhibition in hypertension prevents adaptive cardiomyocyte hypertrophy whilst promoting fibrosis, EGFR inhibitors are likely to cause cardiac dysfunction and be cardiotoxic in hypertensive patients.


2014 ◽  
Vol 307 (2) ◽  
pp. H252-H258 ◽  
Author(s):  
Kimberly M. Demos-Davies ◽  
Bradley S. Ferguson ◽  
Maria A. Cavasin ◽  
Jennifer H. Mahaffey ◽  
Sarah M. Williams ◽  
...  

Little is known about the function of the cytoplasmic histone deacetylase HDAC6 in striated muscle. Here, we addressed the role of HDAC6 in cardiac and skeletal muscle remodeling induced by the peptide hormone angiotensin II (ANG II), which plays a central role in blood pressure control, heart failure, and associated skeletal muscle wasting. Comparable with wild-type (WT) mice, HDAC6 null mice developed cardiac hypertrophy and fibrosis in response to ANG II. However, whereas WT mice developed systolic dysfunction upon treatment with ANG II, cardiac function was maintained in HDAC6 null mice treated with ANG II for up to 8 wk. The cardioprotective effect of HDAC6 deletion was mimicked in WT mice treated with the small molecule HDAC6 inhibitor tubastatin A. HDAC6 null mice also exhibited improved left ventricular function in the setting of pressure overload mediated by transverse aortic constriction. HDAC6 inhibition appeared to preserve systolic function, in part, by enhancing cooperativity of myofibrillar force generation. Finally, we show that HDAC6 null mice are resistant to skeletal muscle wasting mediated by chronic ANG-II signaling. These findings define novel roles for HDAC6 in striated muscle and suggest potential for HDAC6-selective inhibitors for the treatment of cardiac dysfunction and muscle wasting in patients with heart failure.


2021 ◽  
Author(s):  
Yuze Zhang ◽  
Xiaoyan Lin ◽  
Yong Chu ◽  
Xiaoming Chen ◽  
Heng Du ◽  
...  

Abstract Background:Cardiac remodeling is one of the major risk factors for heart failure. In patients with type 2 diabetes, sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce the risk of the first hospitalization for heart failure, possibly through glucose-independent mechanisms, but the underlying mechanisms remain largely unknown. This study aimed to shed light on the efficacy of dapagliflozin in reducing cardiac remodeling and potential mechanisms.Methods:Sprague-Dawley (SD) rats, induced by chronic infusion of Angiotensin II (Ang II) at a dose of 520 ng/kg per minute for 4 weeks with ALZET® mini-osmotic pumps, were treated with either SGLT2 inhibitor dapagliflozin (DAPA) or vehicle alone. Echocardiography was performed to determine cardiac structure and function. Cardiac fibroblasts (CFs) were treated with Ang II with or without the indicated concentration of DAPA. The protein levels of collagen and TGF-β1/Smad signaling were measured along with body weight, and blood biochemical indexes.Results:DAPA treatment resulted in the amelioration of left ventricular dysfunction in Ang II-infused SD rats without affecting blood glucose and blood pressure. Myocardial hypertrophy, fibrosis and increased collagen synthesis caused by Ang II infusion were significantly inhibited by DAPA treatment. In vitro, DAPA inhibit the Ang II-induced collagen production of CFs. Immunoblot with heart tissue homogenates from chronic Ang II-infused rats revealed that DAPA inhibited the activation of TGF-β1/Smads signaling.Conclusion:DAPA ameliorates Ang II-induced cardiac remodeling by regulating the TGF-β1/Smad signaling in a glucose-independent manner. DAPA may serve as a novel therapy for pathological cardiac remodeling.


Author(s):  
Bhagya Suresh ◽  
Mathew George ◽  
Lincy Joseph

Cardiovascular (CV) disease is a major cause of morbidity and mortality in the developing and the developed world, and represents a major barrier to sustainable human development. Ischemic heart disease, cerebrovascular disease, cardiomyopathy and heart failure (HF), and hypertension among others represent major forms of CV disease. Heart failure (HF) is among the key contributors to the CV-related health care burden, a uninterrupted concern despite the utilization of clinically tried guideline-directed therapies. The most common cause for HF is reduced left cavum heart muscle perform. ARBs produce equivalent mortality benefits with fewer adverse effects than ACE inhibitors. Angiotensin converting enzyme (ACEI) reduces the combined risk of death or hospitalization, slow progression of HF, and reduced rate of reinfarction. Sacubitril/valsartan could be a first-in-class twin action molecule of the neprilysin (NEP) substance sacubitril (AHU-377) and therefore the angiotensin II (Ang II) sort one (AT1) receptor blocker (ARB) valsartan. The beneficial antihypertensive and HF effects of sacubitril/valsartan are mediated through the inhibition of NEP in catabolizing the natriuretic peptides (NPs) and the blockade of Ang II, AT1 receptor with valsartan. These actions of sacubitril/ valsartan end in general dilation and inflated symptoms and symptoms, resulting in decrease in peripheral tube resistance and plasma volume contraction, all necessary actions for the lowering of BP and improving HF symptoms. Keywords:  cardiovascular disease, left ventricular ejection fraction, angiotensin II receptor blocker, angiotensin converting enzyme, sacubitril/valsartan.


Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Germán E González ◽  
Nour-Eddine Rhaleb ◽  
Xiao- P Yang ◽  
Oscar A Carretero

We previously described that chronic infusion with Angiotensin II (Ang II) increases cardiac Galectin-3 (Gal-3) expression, a carbohydrate-binding lectin present on macrophages. Also, Gal-3 was proposed to be a powerful predictor for mortality in patients with heart failure. Nevertheless, the role of Gal-3 in the pathogenesis of end organ damage (EOD) in hypertension is unknown. Here, we hypothesized that in Ang II-induced hypertension, genetic deletion of Gal-3 prevents innate immunity, EOD, and left ventricular (LV) dysfunction. Male C57 and Gal-3 KO mice were infused with vehicle (V) or Ang II (90 ng/min; s.c.) for 8 weeks and divided into: 1) C57 + V; 2) Gal-3 KO + V; 3) C57 + Ang II and 4) Gal-3 KO + Ang II. Systolic blood pressure (SBP) was measured by plestimography weekly. At 8 week, we evaluated 1) LV ejection fraction (EF) by echocardiography; 2) cardiac hypertrophy by LV weight/tibia length; 3) cardiac fibrosis by picrosirius red staining; 4) infiltrated macrophages by CD68+ staining; 5) ICAM-1 protein expression by Western blot; and 6) serum interleukin (IL)-6 by ELISA. We found that despite a similar increase in SBP and LV hypertrophy in both strains on Ang II, Gal-3 KO mice had better reserved EF and decreased inflammatory and fibrotic responses (see Table). Results: (MEAN ± SEM at 8 w) *p<0.05 C57+Ang II and Gal-3 KO+Ang II vs C57+V; ‡ p<0.05 Gal-3 KO+Ang II vs C57+Ang II. Conclusion: In Ang II-induced hypertension, deletion of Gal-3 prevents EOD and LV systolic dysfunction without altering blood pressure and LV hypertrophy. This study indicates that the deleterious effects of Ang II could be in part mediated by Gal-3, which enhanced inflammation and fibrosis.


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