Stanniocalcin-1 is a naturally occurring L-channel inhibitor in cardiomyocytes: relevance to human heart failure

2003 ◽  
Vol 285 (1) ◽  
pp. H442-H448 ◽  
Author(s):  
David Sheikh-Hamad ◽  
Roger Bick ◽  
Gang-Yi Wu ◽  
Birgitte Mønster Christensen ◽  
Peter Razeghi ◽  
...  

Cardiomyocytes of the failing heart undergo profound phenotypic and structural changes that are accompanied by variations in the genetic program and profile of calcium homeostatic proteins. The underlying mechanisms for these changes remain unclear. Because the mammalian counterpart of the fish calcium-regulating hormone stanniocalcin-1 (STC1) is expressed in the heart, we reasoned that STC1 might play a role in the adaptive-maladaptive processes that lead to the heart failure phenotype. We examined the expression and localization of STC1 in cardiac tissue of patients with advanced heart failure before and after mechanical unloading using a left ventricular assist device (LVAD), and we compared the results with those of normal heart tissue. STC1 protein is markedly upregulated in cardiomyocytes and arterial walls of failing hearts pre-LVAD and is strikingly reduced after LVAD treatment. STC1 is diffusely expressed in cardiomyocytes, although nuclear predominance is apparent. Addition of recombinant STC1 to the medium of cultured rat cardiomyocytes slows their endogenous beating rate and diminishes the rise in intracellular calcium with each contraction. Furthermore, using whole cell patch-clamp studies in cultured rat cardiomyocytes, we find that addition of STC1 to the bath causes reversible inhibition of transmembrane calcium currents through L-channels. Our data suggest differential regulation of myocardial STC1 protein expression in heart failure. In addition, STC1 may regulate calcium currents in cardiomyocytes and may contribute to the alterations in calcium homeostasis of the failing heart.

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Jessica M Bradley ◽  
Craig M Ziblich ◽  
Kazi N Islam ◽  
Amanda M Rushing ◽  
David J Polhemus ◽  
...  

Background: Cardiac fibroblasts are critical mediators of fibrotic remodeling in the failing heart. These maladaptive structural changes can worsen cardiac function accelerating the progression to decompensated heart failure (HF). We investigated the effects of a novel inhibitor of the conversion of normal fibroblast to the myofibroblast phenotype in the setting of pressure overload induced HF. Methods: Male C57BL/6J mice (10 wks) were subjected to transverse aortic constriction (TAC; 27 g needle) and NM922 (NovoMedix, LLC50 mg/kg/d i.p.) or VEH (DMSO + HS-15) was administered daily starting at 6 wks post TAC. Echocardiography was assessed at baseline and for 16 wks post TAC. At the 16 wk endpoint, mice were sacrificed and hearts were collected for biochemical and molecular assessment. Results: NM922 significantly attenuated TAC-induced left ventricular (LV) dilation at 16 wks post TAC (LVEDD: 3.5 ± 0.1 vs. 4.5 ± 0.2 mm, p < 0.01; LVESD: 2.5 ± 0.2 vs. 3.8 ± 0.3 mm, p < 0.01) compared to VEH. NM922 treated mice displayed reduced wall thickening (LVPWd: 1.0 ± 0.03 vs. 1.2 ± 0.05 mm; p < 0.05) at 10 wks post TAC compared to VEH. LV ejection fraction (LVEF) was preserved in NM922 treated mice at 8-16 wks post TAC compared to VEH (*p < 0.05; **p < 0.001) compared to VEH. Treatment with NM922 resulted in reductions in heart (8.5 ± 0.5 vs. 12.0 ± 0.9 mg/mm; p < 0.01) and lung (8.2 ± 0.3 vs. 11.5 ± 0.6 mg/mm; p < 0.0001) weights compared to VEH. Picrosirius Red staining revealed that NM922 reduced cardiac interstitial collagen volume fraction by 50% (p < 0.05 vs. VEH). Circulating BNP levels trended toward lower (p = 0.08) in the NM922 mice when compared to VEH. Conclusion: Chronic treatment with NM922 following the onset of cardiac hypertrophy and HF resulted in attenuated myocardial collagen formation and adverse remodeling with preservation of LVEF. Future studies are aimed at further elucidation of the molecular and cellular mechanisms by which this novel agent protects the failing heart.


2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
B. M. Rocha ◽  
E. M. Toledo ◽  
L. P. S. Barra ◽  
R. Weber dos Santos

Heart failure is a major and costly problem in public health, which, in certain cases, may lead to death. The failing heart undergo a series of electrical and structural changes that provide the underlying basis for disturbances like arrhythmias. Computer models of coupled electrical and mechanical activities of the heart can be used to advance our understanding of the complex feedback mechanisms involved. In this context, there is a lack of studies that consider heart failure remodeling using strongly coupled electromechanics. We present a strongly coupled electromechanical model to study the effects of deformation on a human left ventricle wedge considering normal and hypertrophic heart failure conditions. We demonstrate through a series of simulations that when a strongly coupled electromechanical model is used, deformation results in the thickening of the ventricular wall that in turn increases transmural dispersion of repolarization. These effects were analyzed in both normal and failing heart conditions. We also present transmural electrograms obtained from these simulations. Our results suggest that the waveform of electrograms, particularly the T-wave, is influenced by cardiac contraction on both normal and pathological conditions.


2002 ◽  
Vol 283 (5) ◽  
pp. H1775-H1784 ◽  
Author(s):  
Jonathan R. R. Heyen ◽  
Eileen R. Blasi ◽  
Kristen Nikula ◽  
Ricardo Rocha ◽  
Heather A. Daust ◽  
...  

Heart failure is a complex multifactorial disease resulting in a myriad of progressive changes at the molecular, cellular, and physiological level. To better understand the mechanisms associated with the development of congestive heart failure, a comprehensive examination of the aging lean male spontaneously hypertensive, heart failure-prone rat (SHHF) was conducted. Myocardial function and structural integrity progressively diminished as evidenced by decreased ejection fraction and increased left ventricular volume measured using echocardiography. Functional and structural changes were accompanied by elevations in circulating inflammatory markers, including tumor necrosis factor-α (TNF-α), IL-6, and TNF receptors type 1 and 2. Increased systemic inflammatory marker levels were consistent with age-dependent changes in the expression pattern of genes that contribute to stress, inflammation, and the extracellular matrix in SHHF animals analyzed from age 4 to 18 mo. In summary, the SHHF rat shares many hallmark features of the human disease state and represents a key experimental model for the dissection of complex human heart failure pathophysiology.


2013 ◽  
Vol 115 (10) ◽  
pp. 1572-1580 ◽  
Author(s):  
Vigdis Hillestad ◽  
Frank Kramer ◽  
Stefan Golz ◽  
Andreas Knorr ◽  
Kristin B. Andersson ◽  
...  

In human heart failure (HF), reduced cardiac function has, at least partly, been ascribed to altered calcium homeostasis in cardiomyocytes. The effects of the calcium sensitizer levosimendan on diastolic dysfunction caused by reduced removal of calcium from cytosol in early diastole are not well known. In this study, we investigated the effect of long-term levosimendan treatment in a murine model of HF where the sarco(endo)plasmatic reticulum ATPase ( Serca) gene is specifically disrupted in the cardiomyocytes, leading to reduced removal of cytosolic calcium. After induction of Serca2 gene disruption, these mice develop marked diastolic dysfunction as well as impaired contractility. SERCA2 knockout (SERCA2KO) mice were treated with levosimendan or vehicle from the time of KO induction. At the 7-wk end point, cardiac function was assessed by echocardiography and pressure measurements. Vehicle-treated SERCA2KO mice showed significantly diminished left-ventricular (LV) contractility, as shown by decreased ejection fraction, stroke volume, and cardiac output. LV pressure measurements revealed a marked increase in the time constant (τ) of isovolumetric pressure decay, showing impaired relaxation. Levosimendan treatment significantly improved all three systolic parameters. Moreover, a significant reduction in τ toward normalization indicated improved relaxation. Gene-expression analysis, however, revealed an increase in genes related to production of the ECM in animals treated with levosimendan. In conclusion, long-term levosimendan treatment improves both contractility and relaxation in a heart-failure model with marked diastolic dysfunction due to reduced calcium transients. However, altered gene expression related to fibrosis was observed.


2011 ◽  
Vol 109 (suppl_1) ◽  
Author(s):  
Masamichi Hirose ◽  
Yasuchika Takeishi ◽  
Hisashi Shimojo ◽  
Toshihide Kashihara ◽  
Tsutomu Nakada ◽  
...  

Introduction: Beneficial effects of nicorandil on the treatment of hypertensive heart failure (HF) and ischemic heart disease have been suggested. However, whether nicorandil has inhibitory effects on HF and ventricular arrhythmias caused by the activation of G protein alpha q (Gαq) -coupled receptor (GPCR) signaling pathway still remains unknown. We examined effects of chronic and acute administration of nicorandil on the development of HF and ventricular action potential (VAP) in transgenic mice with transient cardiac expression of activated Gαq (Gαq-TG), respectively. Method and Results: Nicorandil (6 mg/kg/day) or vehicle was chronically administered in Gαq-TG mice for 24 weeks from 8 weeks of age, and then ventricular function, and electrical and structural changes were investigated in the hearts. Chronic nicorandil administration improved the reduction of left ventricular fractional shortening (p < 0.001) in Gαq-TG hearts. During 10 min of electrocardiogram recording, premature ventricular contractions (more than 20 beats/min) were observed in 7 of 10 vehicle-treated Gαq-TG but in none of 10 nicorandil-treated Gαq-TG hearts (p < 0.01). QT interval was significantly shorter in nicorandil-treated Gαq-TG than in vehicle-treated Gαq-TG hearts (p < 0.05). Chronic nicorandil administration improved the increased ventricular interstitial fibrosis (p < 0.05) but not cardiac hypertrophy in Gαq-TG left ventricles. Real time RT-PCR revealed that mRNA expression levels of s sulfonylurea receptor 2B (SUR-2B) were decreased in vehicle-treatd Gαq-TG but not in nicorandil-treated Gαq-TG. In addition, chronic nicorandil increased endotherial nitric oxide syntheses gene expression in Gαq-TG hearts (p < 0.05). Acute nicorandil administration (1 microM) significantly shortened the prolonged VAP duration and reduced the number of PVCs in vehicle treated Gαq-TG hearts. Conclusions: These findings suggest that nicorandil inhibits ventricular electrical and structural remodeling and arrhythmias through the shortening of VAP duration and the increased expression of SUR-2B and eNOS in a mouse model of HF.


2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Cristi L Galindo ◽  
Abigail Murphy ◽  
Michael Hill ◽  
John Cleator ◽  
Ehab Kasasbeh ◽  
...  

Neuregulin-1 (NRG-1) mediates cell-cell interactions and is a critical growth and developmental signaling molecule in the heart. We have been examining whether the recombinant NRG-1 isoform known as glial growth factor 2 (GGF2) has therapeutic potential for heart failure. In rats and swine with experimental myocardial infarction we have found that GGF2 treatment improves myocardial function and limits progressive myocardial remodeling. To understand potential mechanisms for this effect, we compared gene expression in these animals using microarrays. In rats we compared Sham operated, MI treated with vehicle, and MI treated with GGF2 at a single dose. We found that GGF2 treatment was associated with correction of mitochondrial and metabolic genes altered by MI compared to Sham-operated rats. When compared to 9 published datasets of ∼400 samples from rodents and human heart failure, we identified 563 genes associated with heart failure that were also reversed in expression in response to GGF2. Ingenuity pathway analysis demonstrated clusters of genes associated with energy production and cardiovascular tissue development as particularly enriched in GGF2-treated versus untreated MI rats. In swine our analysis was confined to animals with MI +/- GGF2 treatment at two doses. There were 527 genes altered by GGF2 at both doses compared to untreated controls, with a clear GGF2 dose response. Transcripts altered in response to GGF2 treatment were mainly those associated with extracellular matrix structure and function, MAPK signaling, and p53-mediated apoptosis. Electron microscopy of remote infarct left ventricular tissue from swine confirmed extreme morphological differences in mitochondria from GGF2-treated and vehicle-treated control pigs. Most striking was recovery of intercalated discs in response to GGF2, compared to severe disruption of intercalated disc structures in vehicle-treated control animals.


2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Prince Jeyabal ◽  
Rajarajan A Thandavarayan ◽  
Darukeshwara Joladarashi ◽  
Sahana Suresh Babu ◽  
Shashirekha Krishnamurthy ◽  
...  

Diabetic cardiomyopathy is a common complication in patients with diabetes and is associated with underlying chronic inflammation and cardiac cell death, subsequently leading to left ventricular dysfunction and heart failure. ELAV-like protein 1 (ELAVL1, mRNA stabilizing protein) and NLRP3 activation (inflammasome complex protein)-mediated IL-1beta synthesis play a critical role in the progression of heart failure. However, ELAVL1 regulation of pyroptosis (caspase-1-mediated programmed apoptosis) and associated IL-1beta release in cardiomyocytes, especially under diabetic condition, remains elusive. Human diabetic, non-diabetic heart tissues, human ventricular cardiomyocytes and rat cardiomyoblasts exposed to high glucose (HG) were used for our studies. Our data demonstrates that human ventricular cardiomyocytes exposed to high glucose condition showed significant increase in ELAVL1 and NLRP3 expression with a concomitant increase in caspase-1 and IL-1 beta expression. Furthermore, human cardiac tissue from diabetic patients showed increased ELAVL1, caspase-1 and NLRP3 expression as compared to non-diabetic hearts. Intriguingly, ELAVL1 knockdown abrogates TNF-α induced canonical pyroptosis via NLRP3, caspase-1 and IL-1beta suppression. Interestingly, miRNA-9 expression significantly reduces in high glucose treated cardiomyocytes and in human diabetic hearts. Bioinformatics analysis and target validation assays showed that miR-9 directly targets ELAVL1. Inhibition of miR-9 up regulates ELAVL1 expression and activates caspase-1. Alternatively, miR-9 mimics attenuate hyperglycemia-induced ELAVL1 and inhibit cardiomyocyte pyroptosis. To our knowledge, this is the first report to demonstrate the role of miR-9/ELAVL1 in hyperglycemia-induced cardiac pyroptosis. Taken together our study highlights the potential therapeutic implications in preventing cardiomyocyte cell loss in human diabetic failing heart.


2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Marta Szulik ◽  
Miguel Reyes-Mugica ◽  
Daniel F Marker ◽  
Lina Ghaloul-Gonzalez ◽  
Sarah Franklin

The lysine methyltransferase SMYD1 was first identified in mice and shown to be important for embryonic cardiac development. Subsequently, we reported the first analysis of SMYD1 in adult myocardium and demonstrated that cardiomyocyte-specific loss of SMYD1 lead to progressive cardiac hypertrophy and heart failure, and showed that this enzyme is necessary to maintain metabolic homeostasis through transcriptional regulation of mitochondrial energetics in adult mice. While SMYD1 has been the subject of several additional studies in zebrafish and mice, since it was first identified, only in the last few years have human patients been identified with variants in the SMYD1 gene thought to be responsible for their cardiomyopathies. Specifically, two patients have been identified to date, the first patient displaying hypertrophic cardiomyopathy had a de novo heterozygous variant (c.814T>C) and the second patient with left ventricular non-compaction cardiomyopathy and arrhythmias had a truncating heterozygous variant (c.675delA). Here we report a third patient with biventricular heart failure containing a homozygous variant (c.302A>G; p.Asn101S) in the SMYD1 gene which was identified by a whole exome sequencing. Our histopathological analysis of cardiac tissue and skeletal muscle from the proband showed abnormalities in myofibrillar organization in both cardiac and skeletal muscle suggesting that SMYD1 is necessary for sarcomere assembly and organization. In addition, we observe markedly abnormal myocardium with extensive fibrosis and multifocal calcification, and our ultrastructural (EM) analysis revealed presence of abnormal mitochondria with reduced and irregular or lost cristae. Lastly, we have performed structural modeling of SMYD1 containing the p.Asn101Ser variant (N101S) and report how this variant may affect the enzymatic activity of SMYD1 due to its proximity to the substrate binding site. The identification of this novel variant constitutes the third patient with a SMYD1 variant displaying cardiomyopathy and provides insights into the molecular functionality of this protein. In addition, this is the first analysis of tissue from a patient expressing a SMYD1 variant which provides critical insights into the role of SMYD1 in the heart and how loss of function mutations can effect cardiac physiology.


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.


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