Pressure Overload-Induced Heart Failure Is Associated With an Increased Enzymatic O-GlcNAcylation of Calcium Handling Proteins

2010 ◽  
Vol 16 (8) ◽  
pp. S12
Author(s):  
Jorge Suarez ◽  
Mary O. Oyeleye ◽  
Wenlong Han ◽  
Wolfgang H. Dillmann
2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Yao Wu ◽  
Feifei Si ◽  
Xiaojuan Ji ◽  
Kunfeng Jiang ◽  
Sijie Song ◽  
...  

Background. This study was undertaken to determine relative contributions of phosphorylation and oxidation to the increased activity of calcium/calmodulin-stimulated protein kinase II (CaMKII) in juveniles with cardiac myocyte dysfunction due to increased pressure overload. Methods. Juvenile rats underwent abdominal aortic constriction to induce heart failure. Four weeks after surgery, rats were then randomly divided into two groups: one group given valsartan (HF + Val) and the other group given placebo (HF + PBO). Simultaneously, the sham-operated rats were randomly given valsartan (Sham + Val) or placebo (Sham + PBO). After 4 weeks of treatment, Western blot analysis was employed to quantify CaMKII and relative calcium handling proteins (RyR2 and PLN) in all groups. Results. The deteriorated cardiac function was reversed by valsartan treatment. In ventricular muscle cells of group HF + PBO, Thr287 phosphorylation of CaMKII and S2808 phosphorylation of RyR2 and PLN were increased and S16 phosphorylation of PLN was decreased compared to the other groups, while Met281 oxidation was not significantly elevated. In addition, these changes in the expression of calcium handling proteins were ameliorated by valsartan administration. Conclusions. The phosphorylation of Thr286 is associated with the early activation of CaMKII rather than the oxidation of Met281.


2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Robert N Correll ◽  
Sanjeewa A Goonasekera ◽  
Jop H van Berlo ◽  
Adam R Burr ◽  
Federica Accornero ◽  
...  

Stromal interaction molecule 1 (STIM1) is a Ca2+ sensor that partners with Orai1, resulting in store-operated Ca2+ entry (SOCE) that is important for maintaining endoplasmic reticulum (ER) Ca2+ homeostasis. STIM1 is expressed in the heart and upregulated during disease, but its role in disease progression is unclear. In this study we used transgenic mice with STIM1 overexpression in the heart to model the known increase of this protein in response to cardiac disease. We found that STIM1 transgenic myocytes showed elevated Ca2+ entry following store depletion and STIM1 co-localized with the type 2 ryanodine receptor (RyR2) in the sarcoplasmic reticulum (SR). In addition, STIM1 transgenic mice exhibited sudden cardiac death as early as 6 weeks of age, while mice that survived past 12 weeks developed cardiac hypertrophy that progressed to heart failure, pulmonary edema, activation of the fetal gene program, alterations in mitochondrial structure, and reduced ventricular functional performance. When pre-symptomatic STIM1 transgenic mice were subjected to disease stimuli including pressure overload stimulation or neurohumoral agonist infusion, they showed greater pathology compared to control mice. STIM1 elevation also disrupted normal Ca2+ handling in cardiac myocytes, which showed spontaneous Ca2+ transients that could be inhibited by the SOCE blocker SKF-96265, as well as increased diastolic Ca2+ levels and elevated Ca2+ spark frequency. In keeping with this increase in Ca2+ cycling we also found that STIM1 elevation resulted in an increased baseline activity of cardiac nuclear factor of activated T-cells (NFAT) and Ca2+/calmodulin-dependent protein kinase II (CaMKII). This increased CaMKII activity did not, however, translate into additional RyR2 phosphorylation, suggesting that the augmented Ca2+ spark frequency observed was likely due to an elevation in SR Ca2+ load. Our results suggest that increased STIM1 expression elicits augmented Ca2+ entry, SR Ca2+ load and Ca2+ spark frequency, that leads to mitochondrial pathology and the induction of Ca2+ sensitive hypertrophic signaling pathways that contribute to cardiac disease.


2021 ◽  
Author(s):  
Kim Connelly ◽  
Ellen Wu ◽  
Aylin Visram ◽  
Mark K. Friedberg ◽  
Sri Nagarjun Batchu ◽  
...  

Abstract Background— Sodium glucose linked transporter 2 (SGLT2) inhibition not only reduces morbidity and mortality in patients with diagnosed heart failure but also prevents the development of heart failure hospitalization in those at risk. While studies to date have focused on the role of SGLT2 inhibition in left ventricular failure, whether this drug class might be similarly efficacious in the treatment and prevention of right heart failure has not been unexplored. Hypothesis: We hypothesized that SGLT2 inhibition would reduce the structural, functional and molecular responses to pressure overload of the right ventricle. Methods: Thirteen-week-old Fischer F344 rats underwent pulmonary artery banding (PAB) or sham surgery prior to being randomized to receive either the SGLT2 inhibitor: dapagliflozin (0.5mg/kg/day) or vehicle by oral gavage. After six weeks of treatment, animals underwent transthoracic echocardiography and invasive hemodynamic studies. Animals were then terminated, and their hearts harvested for structural and molecular analyses. Results: PAB induced features consistent with a compensatory response to increased right ventricular (RV) afterload with elevated mass, end systolic pressure, collagen content and alteration in calcium handling protein expression (all p<0.05 when compared to sham + vehicle). Dapagliflozin reduced RV mass, including both wet and dry weight as well as normalizing the protein expression of SERCA 2A, AMPkinase and LC3I/II ratio expression (all p<0.05). Significance: Dapagliflozin reduces the structural, functional, and molecular manifestations of right ventricular pressure overload. Whether amelioration of these early changes in the RV may ultimately lead to a reduction in RV failure remains to be determined.


2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Nicholas P Stafford ◽  
Min Zi ◽  
Ludwig Neyses ◽  
Elizabeth J Cartwright

Mutations in ATP2B1 encoding the ubiquitous calcium extrusion pump Plasma Membrane Calcium ATPase 1 (PMCA1) have recently identified it as having the strongest association of any gene to hypertension, yet the role of PMCA1 in the pressure-overloaded heart is not known. To investigate this we generated a novel mouse line carrying cardiomyocyte-specific deletion of PMCA1 (PMCA1 cko ) and challenged them with transverse aortic constriction (TAC) alongside littermate ‘floxed’ controls (PMCA1 f/f ). After two weeks, echocardiographic analysis revealed signs of systolic dysfunction and left ventricular (LV) dilation in PMCA1 cko hearts as evidenced by reduced fractional shortening and increased diastolic diameter (both p<0.05), whilst function in PMCA1 f/f TAC controls remained preserved. This was accompanied by an increase in normalised lung weight in PMCA1 cko mice compared to sham operated and TAC controls (p<0.05) indicative of pulmonary congestion and a progression into LV failure, despite comparable hypertrophic growth amongst the two TAC cohorts. Hemodynamic analysis following LV catheterisation revealed contractility, as measured by left ventricular elastance (E es ), to be increased in controls after TAC (PMCA1 f/f TAC 12.69 ± 1.63 vs sham 7.02 ± 1.11 mmHg/μl, p<0.05), a change which was not reciprocated in knockout hearts (PMCA1 cko TAC 7.70 ± 1.19 vs sham 7.22 ± 1.55 mmHg/μl). To examine whether altered calcium handling could be the underlying cause of the observed phenotype, cardiomyocytes were isolated following one week TAC and loaded with Indo-1, prior to the onset of failure in PMCA1 cko hearts. Compatible with an increase in E es , systolic calcium levels were higher in PMCA1 f/f myocytes following pressure overload compared to sham controls (p<0.05), whilst PMCA1 cko TAC myocytes displayed equivalent peak calcium levels to their respective sham controls. These results suggest that PMCA1 may play a necessary role in enhancing calcium cycling during the early response to pressure overload, and that disrupting this gene may increase the susceptibility to heart failure under these conditions. This may provide first evidence of a novel genetic basis for the development of heart failure in a proportion of hypertensive patients.


2012 ◽  
Vol 18 (9) ◽  
pp. 724-733 ◽  
Author(s):  
Holly R. Middlekauff ◽  
Chris Vigna ◽  
M. Anthony Verity ◽  
Gregg C. Fonarow ◽  
Tamara B. Horwich ◽  
...  

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Laurent Vinet ◽  
Mylène Pezet ◽  
Miresta Prévilon ◽  
Barnabas Gellen ◽  
Celine Dachez ◽  
...  

Alterations in RyR2 function is a hallmark of heart failure (HF). Decreased FKBP12.6 binding to RyR2 has been put forward to explain the diastolic SR Ca 2+ leakage observed in this condition. Previous work in the mouse has shown that cardiac FKBP12.6 overexpression protects against the development of myocardial infarction-induced heart failure. We tested the hypothesis that cardiac FKBP12.6 overexpression protects against transverse aortic constriction (TAC)-induced cardiac remodeling and failure. We used a mouse model of conditional cardiac-specific FKBP12.6 overexpression. Ten weeks after TAC, male transgenic mice (TG) and their wild-type controls (WT) underwent heart catheterization. Hemodynamic and gravimetric data are shown in the table . Ventricular expression of the hypertrophic gene program and calcium handling proteins were assessed by real-time PCR and Western blot, respectively. Ten weeks after TAC, the mortality rate was 23% in WT and 13% in TG (14/60 vs 5/39, ns). The percentage of mice with HF, estimated on the presence of pulmonary oedema, was 42% in WT-TAC and 32% in TG-TAC (15/36 vs 7/22, ns). BNP mRNA level increased 2.8 fold in WT-TAC (p<0.01 vs WT-Shams) and 2.4 fold in TG-TAC (p<0.01 vs TG-Shams). α-skeletal actin mRNA level increased 4.3 fold in WT-TAC (p<0.001 vs WT-Shams) and 3.8 fold in TG-TAC (p<0.001 vs TG-Shams). β-MHC/α-MHC mRNA ratio increased 2.8 fold in WT-TAC (p<0.01 vs WT-Shams) and 4.3 fold in TG-TAC (p<0.05 vs TG-Shams). RyR2 protein level decreased by 58% in WT-TAC and 41% in TG-TAC (p<0.01 and p<0.05 vs sham-operated mice, respectively). SERCA2a protein level decreased by 29% in WT-TAC and 16% in TG-TAC (p<0.01 and p<0.05 vs sham-operated mice, respectively). No statistical difference was found between TG-TAC and WT-TAC for any of these parameters. Conclusion: Cardiac FKBP 12.6 overexpression offers weak protection if any against TAC-induced cardiac remodeling and failure in the mouse.


Circulation ◽  
2001 ◽  
Vol 104 (suppl_1) ◽  
Author(s):  
Christof Stamm ◽  
Ingeborg Friehs ◽  
Douglas B. Cowan ◽  
Adrian M. Moran ◽  
Hung Cao-Danh ◽  
...  

Background Tumor necrosis factor (TNF)-α has been implicated in the pathogenesis of heart failure and ischemia-reperfusion injury. Effects of TNF-α are initiated by membrane receptors coupled to sphingomyelinase signaling and include altered metabolism and calcium cycling, contractile dysfunction, and cell death. We postulate that pressure-overload hypertrophy results in increased myocardial TNF-α expression and that it contributes to decreased contractility in hypertrophied infant hearts subjected to ischemia-reperfusion. Methods and Results Neonatal rabbits underwent aortic banding to induce LV hypertrophy. Myocardial TNF-α protein expression increased progressively with LV hypertrophy. Serum TNF-α was detected only after the onset of heart failure. Before onset of ventricular dilatation and heart failure (determined by serial echocardiograms), hearts from aortic banded and age-matched control rabbits were perfused in the Langendorff mode and subjected to 45 minutes of ischemia and 30 minutes of reperfusion. Postischemic recovery was impaired in hypertrophied hearts, but addition of neutralizing anti-rabbit TNF-α antibody to cardioplegia and perfusate solutions restored postischemic function. This effect was mimicked by treatment with the ceramidase inhibitor N -oleoyl ethanolamine. TNF-α inhibition also was associated with faster postischemic recovery of phosphocreatine, ATP, and pH as assessed by 31 P nuclear magnetic resonance spectroscopy. Intracellular calcium handling, measured by Rhod 2 spectrofluorometry, demonstrated lower diastolic calcium levels and higher systolic calcium transients in anti-TNF-α treated hearts. Conclusions TNF-α is expressed in myocardium during compensated pressure-overload hypertrophy and contributes to postischemic myocardial dysfunction. Inhibition of TNF-α signaling significantly improves postischemic contractile function, myocardial energetics, and intracellular calcium handling.


2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Dogacan Yucel ◽  
Jop H Van Berlo ◽  
Preethy Parthiban

In response to cardiac injury or increased workload, the mammalian heart undergoes ventricular remodeling to maintain cardiac function. Initally, these changes are compensatory, although ultimately, they can lead to death of cardiomyocytes, ventricular dilation, and progression to heart failure. It is critical to understand the underlying mechanisms that regulate this transition, since it could identify new therapeutic targets. The role of the small GTPase Septin4 in the heart, and in regulating cardiac stress response is unknown. Previous research has implicated Septin 4 in regulation of Store Operated Calcium entry, as well as cell death regulation through a splice isoform (ARTS). We performed cardiac pressure overload in wild type controls and Septin 4 knockout (-/-) mice. Importantly, we did not detect differences in cardiac hypertrophy or function at baseline (57% ejection fraction in both groups). Four weeks following transverse aortic constriction (TAC), Septin4-/- mice showed improved cardiac function with higher ejection fraction (51%) compared to controls (40%), while the level of hypertrophy was similar. Furthermore, we detected reduced cleaved caspase-3 staining after TAC in Septin4-/- mice, due to inhibition of cardiomyocyte apoptosis in Septin4 -/- mice. Mechanistically, we detected increases in protein expression of both total and phosphorylated phospholamban and CaMKII in Septin4-/- mice, suggesting alterations in Calcium handling, and indicating compensatory signaling pathways were still active in Septin4-/- mice, while control mice were transitioning to heart failure. In conclusion, genetic deletion of Septin4 prevented cardiomyocyte death and protected mice from heart failure following cardiac pressure overload. Future research will focus on regulation of calcium handling in Septin4-/- mice to determine the exact mechanisms through which Septin4 plays a detrimental role in cardiac remodeling.


2002 ◽  
Vol 92 (4) ◽  
pp. 1524-1530 ◽  
Author(s):  
Lu Lu ◽  
Dan Feng Mei ◽  
An-Guo Gu ◽  
Su Wang ◽  
Benjamin Lentzner ◽  
...  

The cardiac sarcoplasmic reticulum calcium-ATPase (SERCA2a), Na+/Ca2+ exchanger (NCX1), and ryanodine receptor (RyR2) are proteins involved in the regulation of myocyte calcium. We tested whether exercise training (ET) alters those proteins during development of chronic heart failure (CHF). Ten dogs were chronically instrumented to permit hemodynamic measurements. Five dogs underwent 4 wk of cardiac pacing (210 beats/min for 3 wk and 240 beats/min for the 4th wk), whereas five dogs underwent the same pacing regimen plus daily ET (5.1 ± 0.3 km/h, 2 h/day). Paced animals developed CHF characterized by hemodynamic abnormalities and reduced ejection fraction. ET preserved resting hemodynamics and ejection fraction. Left ventricular samples were obtained from all dogs and another five normal dogs for mRNA (Northern analysis, band intensities normalized to glyceraldehyde-3-phosphate dehydrogenase) and protein level (Western analysis, band intensities normalized to tubulin) measurements. In failing hearts, SERCA2a was decreased by 33% ( P < 0.05) and 65% ( P < 0.05) in mRNA and protein level, respectively, compared with normal hearts; there was only an 8.6% reduction in mRNA and a 32% reduction in protein in exercised animals ( P < 0.05 from CHF). mRNA expression of NCX1 increased by 44% in paced-only dogs compared with normal ( P < 0.05) but only by 22% in trained dogs ( P < 0.05 vs. CHF); protein level of NCX1 was elevated in paced-only dogs (71%, P < 0.05) but partially normalized by ET (33%, P < 0.05 from CHF). RyR2 was not altered in any of the dogs. In conclusion, long-term ET may ameliorate cardiac deterioration during development of CHF, in part via normalization of myocardial calcium-handling proteins.


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