Abstract 19292: KLF4 Regulates Mitochondrial Homeostasis in the Heart

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Xudong Liao ◽  
Mukesh Jain
Keyword(s):  
Heart Failure ◽  
Mitochondrial Biogenesis ◽  
Transcriptional Control ◽  
Heart Function ◽  
Heart Diseases ◽  
Pressure Overload ◽  
Premature Mortality ◽  
Mitochondrial Homeostasis ◽  
Adult Mice ◽  
Mitochondrial Heterogeneity

Mitochondrial homeostasis is critical for heart function and mitochondrial dysfunction contributes to numerous heart diseases such as heart failure. Our previous work indicates that mice with cardiomyocyte-restricted deficiency of KLF4 develop heart failure precipitously in response to pressure-overload but the underlying mechanisms remain unknown. We hypothesized that KLF4 may regulate mitochondrial function in the heart. Here we show that KLF4 governs mitochondrial biogenesis, metabolic function, dynamics and autophagic clearance. Adult mice with cardiac-specific KLF4 deficiency develop cardiac dysfunction with aging or in response to pressure overload characterized by reduced myocardial ATP levels, elevated ROS, and marked alterations in mitochondrial heterogeneity and alignment. Studies in mitochondria isolated from KLF4-deficient hearts revealed reduced respiration rate likely due to defects in ETC Complex I. Further, embryonic cardiac KLF4 deletion resulted in postnatal premature mortality, impaired mitochondrial biogenesis, and altered mitochondrial maturation. Mechanistically, we show that KLF4 binds to, cooperates with, and is requisite for optimal function of the ERR/PGC-1 transcriptional regulatory module on metabolic and mitochondrial targets. Finally, KLF4 also regulates autophagy through transcriptional control of a broad array of autophagy genes in cardiomyocytes. Collectively, these findings identify KLF4 as a nodal transcriptional regulator of mitochondrial homeostasis.

Abstract 263: A Decline in Kidney-derived Protein Klotho Contributes to Aging-related Heart Failure

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Zhongjie Sun ◽  
Kai Chen
Keyword(s):  
Heart Failure ◽  
Therapeutic Strategy ◽  
Contractile Function ◽  
Heart Function ◽  
Heart Diseases ◽  
Daily Injection ◽  
Aged Mice ◽  
Adult Mice ◽  
Effective Therapeutic Strategy ◽  
Klotho Protein

Background & Objective: The heart function declines in the aged population. At age 80 years, LV contractile function is less than half of what it was at age 20 years. Aging is a recognized risk factor for heart diseases. For instance, the prevalence of heart disease increases with age. The mortality from heart diseases is higher in the aged than in the young population. Klotho is a recently discovered anti-aging gene that is primarily expressed in kidneys. The secreted Klotho is released into blood. The objective of this study is to investigate if a decline serum Klotho levels contributes to aging-related heart failure. Method & Results: The results showed that ejection fraction, stroke volume and cardiac output were decreased in aged mice (24 months) vs. the adult mice (10 months), indicating that aging impairs heart function. The serum level of Klotho was decreased significantly in aged mice. Interestingly, daily injection of recombinant Klotho protein rescued the aging-related decline in heart function. Mutation of Klotho gene ( KL -/- ) resulted in heart failure which was associated with a significant increase in serum phosphate levels (hyperphosphatemia). Low phosphate diet delayed but did not prevent the development of heart failure in male KL -/- mice, suggesting that hyperphosphatemia partially contributes to Klotho deficiency-induced heart failure. Unfortunately, low phosphate diet failed to improve heart failure in female KL -/- mice. Interestingly, administration of estrogen decreased hyperphosphatemia and delayed the development of heart failure in KL -/- although it did not prevent Klotho deficiency-induced heart failure. Therefore, Conclusion: Klotho deficiency contributes to aging-related heart failure. Hyperphosphatemia accelerated the development of Klotho deficiency-induced heart failure. Administration of recombinant Klotho protein is an effective therapeutic strategy for heart aging. (supported by NIH R01 HL118558, AG049780, DK093403).

scholarly journals Agrin promotes coordinated therapeutic processes leading to improved cardiac repair in pigs

2019 ◽  
Author(s):  
Andrea Baehr ◽  
Kfir Baruch Umansky ◽  
Elad Bassat ◽  
Katharina Klett ◽  
Victoria Jurisch ◽  
...  
Keyword(s):  
Heart Failure ◽  
Single Dose ◽  
Ischemia Reperfusion Injury ◽  
Therapeutic Potential ◽  
Heart Function ◽  
Heart Diseases ◽  
Ischemia Reperfusion ◽  
Life Quality ◽  
Cardiac Regeneration ◽  
Adult Mice

AbstractIschemic heart diseases are classified among the leading cause of death and reduced life quality worldwide. Although revascularization strategies significantly reduce mortality after acute myocardial infarction (MI), a significant number of MI patients develop chronic heart failure over time. We have recently reported that a fragment of the extra cellular matrix (ECM) protein Agrin promotes cardiac regeneration following MI in adult mice. Here, we tested the therapeutic potential of Agrin in a preclinical porcine model, comprising either 3 or 28 days (d) reperfusion period. We first demonstrate that local (antegrade) delivery of recombinant human Agrin (rhAgrin) to the infarcted pig heart can target the affected regions in an efficient and clinically-relevant manner. Single dose of rhAgrin resulted in significant improvement in heart function, infarct size, fibrosis and adverse remodeling parameters 28 days post MI. Short-term MI experiment along with complementary murine MI studies revealed myocardial protection, improved angiogenesis, inflammatory suppression and cell cycle re-entry, as Agrin’s mechanisms of action. We conclude that a single dose of Agrin is capable of reducing ischemia reperfusion injury and improving cardiac function, demonstrating that Agrin could serve as a therapy for patients with acute MI and potentially heart failure.

Carvedilol Inhibits Matrix Metalloproteinase-2 Activation in Experimental Autoimmune Myocarditis: Possibilities of Cardioprotective Application

2017 ◽  
Vol 23 (1) ◽  
pp. 89-97 ◽  
Author(s):  
Monika Skrzypiec-Spring ◽  
Katarzyna Haczkiewicz ◽  
Agnieszka Sapa ◽  
Tomasz Piasecki ◽  
Joanna Kwiatkowska ◽  
...  
Keyword(s):  
Heart Failure ◽  
Troponin I ◽  
Heart Function ◽  
Heart Diseases ◽  
Acute Myocarditis ◽  
Study Groups ◽  
Matrix Metalloproteinase 2 ◽  
Autoimmune Myocarditis ◽  
Experimental Autoimmune Myocarditis ◽  
Experimental Autoimmune

Aims: Acute myocarditis is a potentially lethal inflammatory heart disease that frequently precedes the development of dilated cardiomyopathy and subsequent heart failure. At present, there is no effective standardized therapy for acute myocarditis, besides the optimal care of heart failure and arrhythmias in accordance with evidence-based guidelines and specific etiology-driven therapy for infectious myocarditis. Carvedilol has been shown to be cardioprotective by reducing cardiac pro-inflammatory cytokines present in oxidative stress in certain heart diseases. However, effects of carvedilol administration in acute myocarditis with its impact on matrix metalloproteinases’ (MMPs) activation have not been elucidated. Methods and Results: Carvedilol in 3 doses (2, 10, and 30 mg/kg) was given daily to 3 study groups of rats (n = 8) with experimental autoimmune myocarditis by gastric gavage for 3 weeks. In comparison to untreated rats (n = 8) with induced myocarditis, carvedilol significantly prevented the left ventricle enlargement and/or systolic dysfunction depending on the dose in study groups. Performed zymography showed enhanced MMP-2 activity in untreated rats, while carvedilol administration reduced alterations. This was accompanied by prevention of troponin I release and myofilaments degradation in cardiac muscle tissue. Additionally, severe inflammatory cell infiltration was detected in the nontreated group. Carvedilol in all doses tested, had no impact on severity of inflammation. The severity of inflammation did not differ between study groups and in relation to the untreated group. Conclusions: The protective effects of carvedilol on heart function observed in the acute phase of experimental autoimmune myocarditis seem to be associated with its ability to decrease MMP-2 activity and subsequently prevent degradation of myofilaments and release of troponin I while not related to suppression of inflammation.

scholarly journals Agrin Promotes Coordinated Therapeutic Processes Leading to Improved Cardiac Repair in Pigs

Circulation ◽  
2020 ◽  
Vol 142 (9) ◽  
pp. 868-881 ◽  
Author(s):  
Andrea Baehr ◽  
Kfir Baruch Umansky ◽  
Elad Bassat ◽  
Victoria Jurisch ◽  
Katharina Klett ◽  
...  
Keyword(s):  
Heart Failure ◽  
Single Dose ◽  
Matrix Protein ◽  
Ischemia Reperfusion Injury ◽  
Therapeutic Potential ◽  
Heart Function ◽  
Heart Diseases ◽  
Ischemia Reperfusion ◽  
Extracellular Matrix Protein ◽  
Number Of Patients

Background: Ischemic heart diseases are leading causes of death and reduced life quality worldwide. Although revascularization strategies significantly reduce mortality after acute myocardial infarction (MI), a large number of patients with MI develop chronic heart failure over time. We previously reported that a fragment of the extracellular matrix protein agrin promotes cardiac regeneration after MI in adult mice. Methods: To test the therapeutic potential of agrin in a preclinical porcine model, we performed ischemia–reperfusion injuries using balloon occlusion for 60 minutes followed by a 3-, 7-, or 28-day reperfusion period. Results: We demonstrated that local (antegrade) delivery of recombinant human agrin to the infarcted pig heart can target the affected regions in an efficient and clinically relevant manner. A single dose of recombinant human agrin improved heart function, infarct size, fibrosis, and adverse remodeling parameters 28 days after MI. Short-term MI experiments along with complementary murine studies revealed myocardial protection, improved angiogenesis, inflammatory suppression, and cell cycle reentry as agrin’s mechanisms of action. Conclusions: A single dose of agrin is capable of reducing ischemia–reperfusion injury and improving heart function, demonstrating that agrin could serve as a therapy for patients with acute MI and potentially heart failure.

scholarly journals A long noncoding RNA CHAIR protects the heart from pathological stress

2020 ◽  
Vol 134 (13) ◽  
pp. 1843-1857
Author(s):  
Yanxia Qian ◽  
Mingming Zhang ◽  
Ningtian Zhou ◽  
Xiaohan Xu ◽  
Jiahui Zhang ◽  
...  
Keyword(s):  
Heart Failure ◽  
Heart Development ◽  
Noncoding Rna ◽  
Heart Function ◽  
Heart Diseases ◽  
Binding Activity ◽  
Epigenetic Mechanism ◽  
Protein Coding ◽  
Dna Binding Activity ◽  
Heart Failure Progression

Abstract Mammalian genomes have been found to be extensively transcribed. In addition to classic protein coding genes, a large numbers of long noncoding genes (lncRNAs) have been identified, while their functions, especially in heart diseases, remain to be established. We hypothesized that heart failure progression is controlled by tissue-specific lncRNAs. In the present study, we found that the cardiac-enriched lncRNA 4632428C04Rik, named as cardiomyocyte hypertrophic associated inhibitory RNA (CHAIR), is dynamically regulated during heart development, is expressed at low levels in embryonic hearts and accumulated at high levels in adult hearts. More interestingly, the lncRNA was down-regulated during cardiac hypertrophy and failure both in mice and humans. Importantly, loss of lncRNA CHAIR has no effects on normal hearts, whereas it results in accelerated heart function decline, increased hypertrophy, and exacerbated heart failure in response to stress. In contrast, restoring the expression of lncRNA CHAIR rescued the hearts from hypertrophy and failure. DNMT3A was recruited to CHAIR promoter during heart failure to suppress its expression. Reciprocally, CHAIR interacted with DNMT3A to inhibit its DNA-binding activity. Taken together, our data revealed a new cardioprotective lncRNA that represses heart failure through an epigenetic mechanism.

P1614Soluble guanylate cyclase as a therapeutic target in heart failure: myocardial gene expression in response to sGC stimulation in pressure overload

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
J Ruedebusch ◽  
A Benkner ◽  
N Nath ◽  
L Kaderali ◽  
K Klingel ◽  
...  
Keyword(s):  
Gene Expression ◽  
Heart Failure ◽  
Cardiac Hypertrophy ◽  
Expression Pattern ◽  
Heart Function ◽  
Gene Expression Pattern ◽  
Pressure Overload ◽  
Left Ventricular ◽  
Marker Genes ◽  
Cgmp Pathway

Abstract Background Heart Failure (HF) is associated with endothelial dysfunction and reduced bioavailability of NO with insufficient stimulation of sGC and reduced production of cGMP. Therefore, the impairment of the NO-sGC-cGMP pathway results in vasoconstriction, platelet aggregation, inflammation, fibrosis and most importantly maladaptive cardiac hypertrophy. The restoration of the NO-sGC -cGMP pathway is an attractive pharmacological target for HF therapy. Purpose Riociguat is an NO independent stimulator of the sGC that sensitizes the sGC to endogenous NO and directly stimulates sGC to produce cGMP. We therefore hypothesized that Riociguat prevents pathological effects occurring during HF. Methods Pressure overload was induced by transverse aortic constriction (TAC) in 8 weeks old male C57Bl6/N mice. Three weeks after TAC when cardiac hypertrophy has developed either Riociguat (RIO; 3 mg/kg) or a Solvent was administered daily for 5 more weeks (n=12 per group). Animals with sham surgery and same drug regime served as controls. The heart function in all groups was evaluated weekly by small animal echocardiography. Eight weeks after surgery, the transcriptome of the left ventricles (LV) of sham and TAC mice were analysed by RNA Sequencing. Differentially expressed genes (DEG) were categorised using Ingenuity Pathway Analysis (IPA). Results TAC resulted in a steady decrease of left ventricular fractional shortening (FS) in the mice until week 3. When Riociguat treatment commenced, the systolic LV function of the TAC+Rio group recovered significantly whereas the solvent group showed a further decline until week 8 (FS 21.4±3.4% vs. 9.5±2%, p<0.001). Both sham groups (Sham+Sol and Sham+Rio) showed no changes in the heart function over timer. Regarding the hypertrophic response to LV pressure overload, Riociguat treatment attenuated significantly the increase of the left ventricular mass (LVM 208.3±15.8mg vs. 148.9±11.8mg, p<0.001) after TAC. In line with the reduced LVM, histological staining showed a significantly reduced fibrosis and myocyte cross sectional area in the TAC+Rio group compared to TAC+Sol group. Regarding the myocardial transcriptome, the treatment with Riociguat resulted in less changes of gene expression pattern after TAC (TAC+Sol vs. Sham+Sol 3160 DEG; TAC+Rio vs. Sham+Rio 2237 DEG). The expression of heart failure marker genes like ANP (Nppa), BNP (Nppb), β-Myosin Heavy Chain (Myh7) and the Collagens 1 and 3 (Col1a1, Col1a2, Col3a1) were significantly decreased in TAC+Rio, when compared to TAC+Sol. IPA analysis revealed that the activation of biological pathways in response to TAC, like actin cytoskeleton- and Integrin signalling, renin-angiotensin or cardiac hypertrophy signalling was attenuated when Riociguat was administered. Conclusion Riociguat attenuates pressure overload induced LV remodelling resulting in less hypertrophy, improved heart function and less alteration of gene expression pattern.

Abstract 50: Therapeutic Silencing of miRNA-652 Restores Cardiac Function and Attenuates Pathological Remodeling in a Mouse Model of Pressure Overload

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Bianca C Bernardo ◽  
Sally S Nguyen ◽  
Catherine E Winbanks ◽  
Xiao-Ming Gao ◽  
Esther J Boey ◽  
...  
Keyword(s):  
Heart Failure ◽  
Mouse Model ◽  
Cardiac Function ◽  
Cardiac Dysfunction ◽  
Heart Function ◽  
Pressure Overload ◽  
Post Treatment ◽  
Locked Nucleic Acid ◽  
Luciferase Assay ◽  
Sham Operation

Introduction: Targeting microRNAs differentially regulated in settings of stress and protection could represent a new approach for the treatment of heart failure. miR-652 expression increased in hearts of a cardiac stress mouse model and was downregulated in a model of cardiac protection. Aim: To assess the therapeutic potential of silencing miR-652 in a mouse model with established pathological hypertrophy and cardiac dysfunction due to pressure overload. Methods: Mice were subjected to a sham operation (n=10) or transverse aortic constriction (TAC, n=14) for 4 weeks to induce hypertrophy and cardiac dysfunction. Mice were subcutaneously administered a locked nucleic acid (LNA)-antimiR-652 or LNA-control. Cardiac function was assessed by echocardiography before and 8 weeks post treatment, followed by molecular and histological analyses. Results: Expression of miR-652 increased in hearts subjected to pressure overload compared to sham operated mice (2.9 fold, n=3-5, P<0.05), but was silenced in hearts of mice administered LNA-antimiR-652 (95% decrease, n=3-7, P<0.05). In mice subjected to pressure overload, inhibition of miR-652 improved cardiac function (29±1% at 4 weeks post TAC compared to 35±1% post treatment, n=7, P<0.001) and attenuated cardiac hypertrophy. Functional and morphologic improvements in hearts of treated mice were associated with reduced cardiac fibrosis, apoptosis, cardiomyocyte size; decreased B-type natriuretic peptide gene expression; and preserved angiogenesis (all P<0.05, n=4-7/group). Mechanistically, we identified Jagged1, a Notch1 ligand, as a direct target of miR-652 by luciferase assay. Jagged1 and Notch1 mRNA were upregulated in hearts of TAC treated mice (1.2-1.7 fold, n=7, P<0.05). Importantly, chronic knockdown of miR-652 was not associated with any notable toxicity in other tissues. Conclusion: Therapeutic silencing of miR-652 protects the heart against pathological cardiac remodeling and improves heart function via mechanisms that are associated with preserved angiogenesis, decreased fibrosis and upregulation of a miR-652 target, Jagged1. These studies provide the first evidence that targeted inhibition of miR-652 could represent an attractive approach for the treatment of heart failure.

Dysfunctional Insulin Resistant/mTOR Activation Is Involved In The Formation of Pulmonary Hypertension In Pressure Overload-Induced Heart Failure

2021 ◽  
Author(s):  
Xiaojing Wu ◽  
Bo Dong ◽  
Tongxin Ni ◽  
Junhao Hu ◽  
Qi Zhou
Keyword(s):  
Heart Failure ◽  
Insulin Resistance ◽  
Pulmonary Hypertension ◽  
Cardiac Hypertrophy ◽  
Heart Function ◽  
Pressure Overload ◽  
Metabolic Changes ◽  
Heart Catheterization ◽  
Left Heart ◽  
Metabolic Pattern

Abstract Background: Heart failure (HF) usually presents with abnormal changes of metabolisms. Pulmonary hypertension (PH) is a frequent complication of left heart dysfunction. However, the association of serum metabolic changes with PH formation remains unknown. This study analyzed changes of serum metabolomic during the development of PH in a left heart pressure overload model. Methods: Male Sprague-Dawley rats were subjected to transverse aortic constriction (TAC) or sham surgery. Metabolomic analysis was performed on plasma samples of rats at 0 week, 3 weeks and 9 weeks after the surgery. Cardiac remodeling and heart function were determined by echocardiography. Right heart catheterization was performed to assay the mean pulmonary arterial pressure (mPAP). HE staining was performed to observe the remodeling of the myocardium and small pulmonary arteries.Results: The rats developed compensated cardiac hypertrophy with normal mPAP at 3 weeks and PH due to HF (PH-HF) at 9 weeks with distinct metabolic pattern after TAC. Twenty-five metabolites changed in the 9-week group compared with the 3-week group. KEGG analysis suggested abnormal insulin resistance and mTOR activation during the development of PH-HF. Acetylcarnitines related to insulin resistance increased about 3 folds from 4.14 ug/ml at 3 W group to 12.04μg/ml at 9-week group. L-leucine related to mTOR activation increased 1.6-fold with a VIP of 4.08 at 9 W when compared with that of the 3 W group.Conclusions: These results revealed distinct metabolic changes during the development of PH-HF. Dysfunctional insulin resistance and mTOR activation might be involved in the transition from compensated cardiac hypertrophy to PH-HF.

Abstract 1247: Heart Function is Transiently Sustained Despite a Near Loss of SERCA2 Protein in Cardiomyocyte-specific Serca2 null Mice

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Kristin B Andersson ◽  
Alexandra V Finsen ◽  
Ivar Sjaastad ◽  
Yibin Wang ◽  
Ju Chen ◽  
...  
Keyword(s):  
Heart Failure ◽  
Cardiac Output ◽  
Diastolic Pressure ◽  
Heart Function ◽  
Clinical Signs ◽  
Ventricular Myocardium ◽  
Left Ventricular ◽  
Left Ventricular Myocardium ◽  
Lung Weight ◽  
Adult Mice

The SERCA2 Ca 2+ ATPase is of central importance for refilling of the sarcoplasmic reticulum (SR) Ca 2+ store and cardiac contractility. Reduced SERCA2 function is associated with heart failure. We hypothesized that loss of SERCA2 would result in immediate severe myocardial contractile dysfunction and death. Transgenic mice were generated with a Cre-loxP strategy in which tamoxifen induces Serca2 ( Atp2a2 ) gene excision in the cardiomyocytes (SERCA2KO) of adult mice. In SERCA2KO mice, SERCA2 protein was rapidly reduced in left ventricular myocardium with a half-life < 3 days. After 4 weeks, SERCA2 protein was reduced to < 5% of control values. In isolated cardiomyocytes, SERCA2a, SERCA2b, SERCA1 and SERCA3 proteins were not detectable. Strikingly, SERCA2KO mice did not present clinical signs of circulatory failure at 4 weeks. Fractional shortening was preserved, and cardiac output was reduced to 80% of control values. The left atrial diameter, lung weight and left ventricular end-diastolic pressure (LVEDP) were slightly increased in SERCA2KO mice compared with controls, and the maximal rates of pressure development and decline in the left ventricle were affected with a prolongation of the ventricular relaxation time. After seven weeks, SERCA2KO mice developed severe congestive heart failure with dilated chambers, elevated LVEDP and pronounced increases in lung and atrial weights. Cardiac output was reduced to 70% of control values. There were no indications of major cardiomyocyte disarray in the myocardium at the 4 or 7 week timepoints. The abundance of Na + ,Ca 2+ exchanger, L-type Ca 2+ channel 1c and alpha2delta1 subunit proteins and Pmca1 mRNA were all increased at 4 and 7 weeks. The expression of calsequestrin protein and Ryr2 mRNA were unchanged. L-type Ca 2+ channel alpha2delta1 subunit and PMCA1 expression were further enhanced at 7 weeks in SERCA2KO mice. Thus, cardiac function is supported in SERCA2KO mice for several weeks despite the near absence of SERCA2 protein. Alterations in the expression of Ca 2+ transporting proteins suggest that Ca 2+ transients are generated over the plasma membrane rather than the SR. However, the adaptations induced by loss of SERCA2 are not sufficient for long-term support of heart function in adult mice.

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