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Moderate-Intensity and High-Intensity Interval Exercise Training Offer Equal Cardioprotection, with Different Mechanisms, during the Development of Type 2 Diabetes in Rats. Nutrients 2024; 16:431. [PMID: 38337716 PMCID: PMC10856993 DOI: 10.3390/nu16030431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 01/26/2024] [Accepted: 01/30/2024] [Indexed: 02/12/2024] Open
Abstract
Endurance exercise training is a promising cardioprotective strategy in type 2 diabetes mellitus (T2DM), but the impact of its intensity is not clear. We aimed to investigate whether and how isocaloric moderate-intensity exercise training (MIT) and high-intensity interval exercise training (HIIT) could prevent the adverse cardiac remodeling and dysfunction that develop T2DM in rats. Male rats received a Western diet (WD) to induce T2DM and underwent a sedentary lifestyle (n = 7), MIT (n = 7) or HIIT (n = 8). Insulin resistance was defined as the HOMA-IR value. Cardiac function was assessed with left ventricular (LV) echocardiography and invasive hemodynamics. A qPCR and histology of LV tissue unraveled underlying mechanisms. We found that MIT and HIIT halted T2DM development compared to in sedentary WD rats (p < 0.05). Both interventions prevented increases in LV end-systolic pressure, wall thickness and interstitial collagen content (p < 0.05). In LV tissue, HIIT tended to upregulate the gene expression of an ROS-generating enzyme (NOX4), while both modalities increased proinflammatory macrophage markers and cytokines (CD86, TNF-α, IL-1β; p < 0.05). HIIT promoted antioxidant and dicarbonyl defense systems (SOD2, glyoxalase 1; p < 0.05) whereas MIT elevated anti-inflammatory macrophage marker expression (CD206, CD163; p < 0.01). We conclude that both MIT and HIIT limit WD-induced T2DM with diastolic dysfunction and pathological LV hypertrophy, possibly using different adaptive mechanisms.
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Pyridoxamine Limits Cardiac Dysfunction in a Rat Model of Doxorubicin-Induced Cardiotoxicity. Antioxidants (Basel) 2024; 13:112. [PMID: 38247537 PMCID: PMC10812466 DOI: 10.3390/antiox13010112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 01/10/2024] [Accepted: 01/14/2024] [Indexed: 01/23/2024] Open
Abstract
The use of doxorubicin (DOX) chemotherapy is restricted due to dose-dependent cardiotoxicity. Pyridoxamine (PM) is a vitamin B6 derivative with favorable effects on diverse cardiovascular diseases, suggesting a cardioprotective effect on DOX-induced cardiotoxicity. The cardioprotective nature of PM was investigated in a rat model of DOX-induced cardiotoxicity. Six-week-old female Sprague Dawley rats were treated intravenously with 2 mg/kg DOX or saline (CTRL) weekly for eight weeks. Two other groups received PM via the drinking water next to DOX (DOX+PM) or saline (CTRL+PM). Echocardiography, strain analysis, and hemodynamic measurements were performed to evaluate cardiac function. Fibrotic remodeling, myocardial inflammation, oxidative stress, apoptosis, and ferroptosis were evaluated by various in vitro techniques. PM significantly attenuated DOX-induced left ventricular (LV) dilated cardiomyopathy and limited TGF-β1-related LV fibrotic remodeling and macrophage-driven myocardial inflammation. PM protected against DOX-induced ferroptosis, as evidenced by restored DOX-induced disturbance of redox balance, improved cytosolic and mitochondrial iron regulation, and reduced mitochondrial damage at the gene level. In conclusion, PM attenuated the development of cardiac damage after DOX treatment by reducing myocardial fibrosis, inflammation, and mitochondrial damage and by restoring redox and iron regulation at the gene level, suggesting that PM may be a novel cardioprotective strategy for DOX-induced cardiomyopathy.
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Pyridoxamine Attenuates Doxorubicin-Induced Cardiomyopathy without Affecting Its Antitumor Effect on Rat Mammary Tumor Cells. Cells 2024; 13:120. [PMID: 38247812 PMCID: PMC10814382 DOI: 10.3390/cells13020120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 12/22/2023] [Accepted: 12/30/2023] [Indexed: 01/23/2024] Open
Abstract
Doxorubicin (DOX) is commonly used in cancer treatment but associated with cardiotoxicity. Pyridoxamine (PM), a vitamin B6 derivative, could be a cardioprotectant. This study investigated the effect of PM on DOX cardiotoxicity and DOX antitumor effectiveness. Sprague Dawley rats were treated intravenously with DOX (2 mg/kg/week) or saline over eight weeks. Two other groups received PM via oral intake (1 g/L in water bottles) next to DOX or saline. Echocardiography was performed after eight weeks. PM treatment significantly attenuated the DOX-induced reduction in left ventricular ejection fraction (72 ± 2% vs. 58 ± 3% in DOX; p < 0.001) and increase in left ventricular end-systolic volume (0.24 ± 0.02 µL/cm2 vs. 0.38 ± 0.03 µL/cm2 in DOX; p < 0.0001). Additionally, LA7 tumor cells were exposed to DOX, PM, or DOX and PM for 24 h, 48 h, and 72 h. Cell viability, proliferation, cytotoxicity, and apoptosis were assessed. DOX significantly reduced LA7 cell viability and proliferation (p < 0.0001) and increased cytotoxicity (p < 0.05) and cleaved caspase-3 (p < 0.001). Concomitant PM treatment did not alter the DOX effect on LA7 cells. In conclusion, PM attenuated DOX-induced cardiomyopathy in vivo without affecting the antitumor effect of DOX in vitro, highlighting PM as a promising cardioprotectant for DOX-induced cardiotoxicity.
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Moderate- and High-Intensity Endurance Training Alleviate Diabetes-Induced Cardiac Dysfunction in Rats. Nutrients 2023; 15:3950. [PMID: 37764732 PMCID: PMC10535416 DOI: 10.3390/nu15183950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 09/06/2023] [Accepted: 09/08/2023] [Indexed: 09/29/2023] Open
Abstract
Exercise training is an encouraging approach to treat cardiac dysfunction in type 2 diabetes (T2DM), but the impact of its intensity is not understood. We aim to investigate whether and, if so, how moderate-intensity training (MIT) and high-intensity interval training (HIIT) alleviate adverse cardiac remodeling and dysfunction in rats with T2DM. Male rats received standard chow (n = 10) or Western diet (WD) to induce T2DM. Hereafter, WD rats were subjected to a 12-week sedentary lifestyle (n = 8), running MIT (n = 7) or HIIT (n = 7). Insulin resistance and glucose tolerance were assessed during the oral glucose tolerance test. Plasma advanced glycation end-products (AGEs) were evaluated. Echocardiography and hemodynamic measurements evaluated cardiac function. Underlying cardiac mechanisms were investigated by histology, western blot and colorimetry. We found that MIT and HIIT lowered insulin resistance and blood glucose levels compared to sedentary WD rats. MIT decreased harmful plasma AGE levels. In the heart, MIT and HIIT lowered end-diastolic pressure, left ventricular wall thickness and interstitial collagen deposition. Cardiac citrate synthase activity, mitochondrial oxidative capacity marker, raised after both exercise training modalities. We conclude that MIT and HIIT are effective in alleviating diastolic dysfunction and pathological cardiac remodeling in T2DM, by lowering fibrosis and optimizing mitochondrial capacity.
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Pulmonary hypertension during exercise underlies unexplained exertional dyspnoea in patients with Type 2 diabetes. Eur J Prev Cardiol 2023; 30:37-45. [PMID: 35881689 DOI: 10.1093/eurjpc/zwac153] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 07/16/2022] [Accepted: 07/21/2022] [Indexed: 01/14/2023]
Abstract
AIMS To compare the cardiac function and pulmonary vascular function during exercise between dyspnoeic and non-dyspnoeic patients with Type 2 diabetes mellitus (T2DM). METHODS AND RESULTS Forty-seven T2DM patients with unexplained dyspnoea and 50 asymptomatic T2DM patients underwent exercise echocardiography combined with ergospirometry. Left ventricular (LV) function [stroke volume, cardiac output (CO), LV ejection fraction, systolic annular velocity (s')], estimated LV filling pressures (E/e'), mean pulmonary arterial pressures (mPAPs) and mPAP/COslope were assessed at rest, low- and high-intensity exercise with colloid contrast. Groups had similar patient characteristics, glycemic control, stroke volume, CO, LV ejection fraction, and E/e' (P > 0.05). The dyspnoeic group had significantly lower systolic LV reserve at peak exercise (s') (P = 0.021) with a significant interaction effect (P < 0.001). The dyspnoeic group also had significantly higher mPAP and mPAP/CO at rest and exercise (P < 0.001) with significant interaction for mPAP (P < 0.009) and insignificant for mPAP/CO (P = 0.385). There was no significant difference in mPAP/COslope between groups (P = 0.706). However, about 61% of dyspnoeic vs. 30% of non-dyspnoeic group had mPAP/COslope > 3 (P = 0.009). The mPAP/COslope negatively predicted V̇O2peak in dyspneic group (β = -1.86, 95% CI: -2.75, -0.98; multivariate model R2:0.54). CONCLUSION Pulmonary hypertension and less LV systolic reserve detected by exercise echocardiography with colloid contrast underlie unexplained exertional dyspnoea and reduced exercise capacity in T2DM.
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Acute Exposure to Glycated Proteins Impaired in the Endothelium-Dependent Aortic Relaxation: A Matter of Oxidative Stress. Int J Mol Sci 2022; 23:ijms232314916. [PMID: 36499244 PMCID: PMC9740119 DOI: 10.3390/ijms232314916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 11/03/2022] [Accepted: 11/23/2022] [Indexed: 11/30/2022] Open
Abstract
Chronically increased levels of high molecular weight advanced glycation end products (HMW-AGEs) are known to induce cardiovascular dysfunction. Whether an acute increase in HMW-AGE levels affects vascular function remains unknown. In this study, we examined whether acute exposure to HMW-AGEs disturbs aortic vasomotor function. Aortae were obtained from healthy male rats and were acutely pre-treated with HMW-AGEs in organ baths. Aortic relaxation responses to cumulative doses of acetylcholine (ACh), in the presence or absence of superoxide dismutase (SOD), were measured after precontraction with phenylephrine (PE). Furthermore, levels of 3-nitrotyrosine were evaluated on aortic paraffine sections. In our study, we show that acute exposure to HMW-AGEs significantly decreases the aortic relaxation response to ACh. SOD pre-treatment prevents acute HMW-AGEs-induced impairment by limiting superoxide formation. In conclusion, our data demonstrate that acute exposure to HMW-AGEs causes adverse vascular remodelling, characterised by disturbed vasomotor function due to increased oxidative stress. These results create opportunities for future research regarding the acute role of HMW-AGEs in cardiovascular dysfunction.
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Impact of continuous vs. interval training on oxygen extraction and cardiac function during exercise in type 2 diabetes mellitus. Eur J Appl Physiol 2022; 122:875-887. [PMID: 35038022 DOI: 10.1007/s00421-022-04884-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 12/28/2021] [Indexed: 11/25/2022]
Abstract
PURPOSE Exercise training improves exercise capacity in type 2 diabetes mellitus (T2DM). It remains to be elucidated whether such improvements result from cardiac or peripheral muscular adaptations, and whether these are intensity dependent. METHODS 27 patients with T2DM [without known cardiovascular disease (CVD)] were randomized to high-intensity interval training (HIIT, n = 15) or moderate-intensity endurance training (MIT, n = 12) for 24 weeks (3 sessions/week). Exercise echocardiography was applied to investigate cardiac output (CO) and oxygen (O2) extraction during exercise, while exercise capacity [([Formula: see text] (mL/kg/min)] was examined via cardiopulmonary exercise testing at baseline and after 12 and 24 weeks of exercise training, respectively. Changes in glycaemic control (HbA1c and glucose tolerance), lipid profile and body composition were also evaluated. RESULTS 19 patients completed 24 weeks of HIIT (n = 10, 66 ± 11 years) or MIT (n = 9, 61 ± 5 years). HIIT and MIT similarly improved glucose tolerance (pTime = 0.001, pInteraction > 0.05), [Formula: see text] (mL/kg/min) (pTime = 0.001, pInteraction > 0.05), and exercise performance (Wpeak) (pTime < 0.001, pInteraction > 0.05). O2 extraction increased to a greater extent after 24 weeks of MIT (56.5%, p1 = 0.009, pTime = 0.001, pInteraction = 0.007). CO and left ventricular longitudinal strain (LS) during exercise remained unchanged (pTime > 0.05). A reduction in HbA1c was correlated with absolute changes in LS after 12 weeks of MIT (r = - 0.792, p = 0.019, LS at rest) or HIIT (r = - 0.782, p = 0.038, LS at peak exercise). CONCLUSION In patients with well-controlled T2DM, MIT and HIIT improved exercise capacity, mainly resulting from increments in O2 extraction capacity, rather than changes in cardiac output. In particular, MIT seemed highly effective to generate these peripheral adaptations. TRIAL REGISTRATION NCT03299790, initially released 09/12/2017.
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Combinational Therapy of Cardiac Atrial Appendage Stem Cells and Pyridoxamine: The Road to Cardiac Repair? Int J Mol Sci 2021; 22:ijms22179266. [PMID: 34502175 PMCID: PMC8431115 DOI: 10.3390/ijms22179266] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/24/2021] [Accepted: 08/25/2021] [Indexed: 12/04/2022] Open
Abstract
Myocardial infarction (MI) occurs when the coronary blood supply is interrupted. As a consequence, cardiomyocytes are irreversibly damaged and lost. Unfortunately, current therapies for MI are unable to prevent progression towards heart failure. As the renewal rate of cardiomyocytes is minimal, the optimal treatment should achieve effective cardiac regeneration, possibly with stem cells transplantation. In that context, our research group identified the cardiac atrial appendage stem cells (CASCs) as a new cellular therapy. However, CASCs are transplanted into a hostile environment, with elevated levels of advanced glycation end products (AGEs), which may affect their regenerative potential. In this study, we hypothesize that pyridoxamine (PM), a vitamin B6 derivative, could further enhance the regenerative capacities of CASCs transplanted after MI by reducing AGEs’ formation. Methods and Results: MI was induced in rats by ligation of the left anterior descending artery. Animals were assigned to either no therapy (MI), CASCs transplantation (MI + CASCs), or CASCs transplantation supplemented with PM treatment (MI + CASCs + PM). Four weeks post-surgery, global cardiac function and infarct size were improved upon CASCs transplantation. Interstitial collagen deposition, evaluated on cryosections, was decreased in the MI animals transplanted with CASCs. Contractile properties of resident left ventricular cardiomyocytes were assessed by unloaded cell shortening. CASCs transplantation prevented cardiomyocyte shortening deterioration. Even if PM significantly reduced cardiac levels of AGEs, cardiac outcome was not further improved. Conclusion: Limiting AGEs’ formation with PM during an ischemic injury in vivo did not further enhance the improved cardiac phenotype obtained with CASCs transplantation. Whether AGEs play an important deleterious role in the setting of stem cell therapy after MI warrants further examination.
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Combining stem cells in myocardial infarction: The road to superior repair? Med Res Rev 2021; 42:343-373. [PMID: 34114238 DOI: 10.1002/med.21839] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 05/04/2021] [Accepted: 05/29/2021] [Indexed: 12/25/2022]
Abstract
Myocardial infarction irreversibly destroys millions of cardiomyocytes in the ventricle, making it the leading cause of heart failure worldwide. Over the past two decades, many progenitor and stem cell types were proposed as the ideal candidate to regenerate the heart after injury. The potential of stem cell therapy has been investigated thoroughly in animal and human studies, aiming at cardiac repair by true tissue replacement, by immune modulation, or by the secretion of paracrine factors that stimulate endogenous repair processes. Despite some successful results in animal models, the outcome from clinical trials remains overall disappointing, largely due to the limited stem cell survival and retention after transplantation. Extensive interest was developed regarding the combinational use of stem cells and various priming strategies to improve the efficacy of regenerative cell therapy. In this review, we provide a critical discussion of the different stem cell types investigated in preclinical and clinical studies in the field of cardiac repair. Moreover, we give an update on the potential of stem cell combinations as well as preconditioning and explore the future promises of these novel regenerative strategies.
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Konzo risk factors, determinants and etiopathogenesis: What is new? A systematic review. Neurotoxicology 2021; 85:54-67. [PMID: 33964344 DOI: 10.1016/j.neuro.2021.05.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 05/01/2021] [Accepted: 05/03/2021] [Indexed: 12/13/2022]
Abstract
Konzo is a toxico-nutritional upper motor neuron disease causing a spastic paraparesis in schoolchildren and childbearing women in some African countries. Almost a century since the first description of konzo, its underlying etiopathogenic mechanisms and causative agent remain unknown. This paper aims at refreshing the current knowledge of konzo determinants and pathogenesis in order to enlighten potential new research and management perspectives. Literature research was performed in PubMed and Web of Science databases according to the PRISMA methodology. Available data show that cassava-derived cyanide poisoning and protein malnutrition constitute two well-documented risk factors of konzo. However, observational studies have failed to demonstrate the causal relationship between konzo and cyanide poisoning. Thiocyanate, the current marker of choice of cyanide exposure, may underestimate the actual level of cyanide poisoning in konzo patients as a larger amount of cyanide is detoxified via other unusual pathways in the context of protein malnutrition characterizing these patients. Furthermore, the appearance of konzo may be the consequence of the interplay of several factors including cyanide metabolites, nutritional deficiencies, psycho-emotional and geo-environmental factors, resulting in pathophysiologic phenomena such as excitotoxicity or oxidative stress, responsible for neuronal damage that takes place at sparse cellular and/or subcellular levels.
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Impact of Cardiac Resynchronization Therapy on Global and Cardiac Metabolism and Cardiac Mitochondrial Function. J Card Fail 2021; 27:706-715. [PMID: 33639318 DOI: 10.1016/j.cardfail.2021.02.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/30/2021] [Accepted: 02/03/2021] [Indexed: 10/22/2022]
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Asymptomatic type 2 diabetes mellitus display a reduced myocardial deformation but adequate response during exercise. Eur J Appl Physiol 2021; 121:929-940. [PMID: 33417036 DOI: 10.1007/s00421-020-04557-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 11/07/2020] [Indexed: 01/20/2023]
Abstract
BACKGROUND AND PURPOSE The development of myocardial fibrosis is a major complication of Type 2 diabetes mellitus (T2DM), impairing myocardial deformation and, therefore, cardiac performance. It remains to be established whether abnormalities in longitudinal strain (LS) exaggerate or only occur in well-controlled T2DM, when exposed to exercise and, therefore, cardiac stress. We therefore studied left ventricular LS at rest and during exercise in T2DM patients vs. healthy controls. METHODS AND RESULTS Exercise echocardiography was applied with combined breath-by-breath gas exchange analyses in asymptomatic, well-controlled (HbA1c: 6.9 ± 0.7%) T2DM patients (n = 36) and healthy controls (HC, n = 23). Left ventricular LS was assessed at rest and at peak exercise. Peak oxygen uptake (V̇O2peak) and workload (Wpeak) were similar between groups (p > 0.05). Diastolic (E, e's, E/e') and systolic function (left ventricular ejection fraction) were similar at rest and during exercise between groups (p > 0.05). LS (absolute values) was significantly lower at rest and during exercise in T2DM vs. HC (17.0 ± 2.9% vs. 19.8 ± 2% and 20.8 ± 4.0% vs. 23.3 ± 3.3%, respectively, p < 0.05). The response in myocardial deformation (the change in LS from rest up to peak exercise) was similar between groups (+ 3.8 ± 0.6% vs. + 3.6 ± 0.6%, in T2DM vs. HC, respectively, p > 0.05). Multiple regression revealed that HDL-cholesterol, fasted insulin levels and exercise tolerance accounted for 30.5% of the variance in response of myocardial deformation in the T2DM group (p = 0.002). CONCLUSION Myocardial deformation is reduced in well-controlled T2DM and despite adequate responses, such differences persist during exercise. TRIAL REGISTRATION NCT03299790, initially released 09/12/2017.
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Exercise capacity is related to attenuated responses in oxygen extraction and left ventricular longitudinal strain in asymptomatic type 2 diabetes patients. Eur J Prev Cardiol 2020; 28:1756-1766. [PMID: 33623980 DOI: 10.1093/eurjpc/zwaa007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/09/2020] [Accepted: 07/09/2020] [Indexed: 12/26/2022]
Abstract
AIMS Type 2 diabetes mellitus (T2DM) is associated with reduced exercise capacity and cardiovascular diseases, both increasing morbidity and risk for premature death. As exercise intolerance often relates to cardiac dysfunction, it remains to be elucidated to what extent such an interplay occurs in T2DM patients without overt cardiovascular diseases. Design: Cross-sectional study, NCT03299790. METHODS AND RESULTS Fifty-three T2DM patients underwent exercise echocardiography (semi-supine bicycle) with combined ergospirometry. Cardiac output (CO), left ventricular longitudinal strain (LS), oxygen uptake (O2), and oxygen (O2) extraction were assessed simultaneously at rest, low-intensity exercise, and high-intensity exercise. Glycaemic control and lipid profile were assessed in the fasted state. Participants were assigned according to their exercise capacity being adequate or impaired (EXadequate: O2peak <80% and EXimpaired: O2peak ≥80% of predicted O2peak) to compare O2 extraction, CO, and LS at all stages. Thirty-eight participants (EXimpaired: n = 20 and EXadequate: n = 18) were included in the analyses. Groups were similar regarding HbA1c, age, and sex (P > 0.05). At rest, CO was similar in the EXimpaired group vs. EXadequate group (5.1 ± 1 L/min vs. 4.6 ± 1.4 L/min, P > 0.05) and increased equally during exercise. EXimpaired patients displayed a 30.7% smaller increase in O2 extraction during exercise compared to the EXadequate group (P = 0.016) which resulted in a lower O2 extraction at high-intensity exercise (12.5 ± 2.8 mL/dL vs. 15.3 ± 3.9 mL/dL, P = 0.012). Left ventricular longitudinal strain was similar at rest but increased significantly less in the EXimpaired vs. EXadequate patients (1.9 ± 2.5% vs. 5.9 ± 4.1%, P = 0.004). CONCLUSIONS In asymptomatic T2DM patients, an impaired exercise capacity is associated with an impaired response in oxygen extraction and myocardial deformation (LS). TRIAL REGISTRY Effect of High-intensity Interval Training on Cardiac Function and Regulation of Glycemic Control in Diabetic Cardiomyopathy (https://clinicaltrials.gov/ct2/show/NCT03299790).
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Glycolaldehyde-Derived High-Molecular-Weight Advanced Glycation End-Products Induce Cardiac Dysfunction through Structural and Functional Remodeling of Cardiomyocytes. Cell Physiol Biochem 2020; 54:809-824. [PMID: 32857934 DOI: 10.33594/000000271] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/11/2020] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND/AIMS High-molecular-weight advanced glycation end-products (HMW-AGEs) are abundantly present in our Western diet. There is growing evidence reporting that HMW-AGEs contribute to the development of cardiovascular dysfunction in vivo, next to the well-known low-molecular-weight AGEs. The goal of our study is to assess the ultrastructure and function of cardiomyocytes after chronic exposure to HMW-AGEs. A better understanding of underlying mechanisms is essential to create new opportunities for further research on the specific role of HMW-AGEs in the development and progression of cardiovascular diseases. METHODS Adult male rats were randomly assigned to daily intraperitoneal injection for six weeks with either HMW-AGEs (20 mg/kg/day) or a control solution. Hemodynamic measurements were performed at sacrifice. Single cardiomyocytes from the left ventricle were obtained by enzymatic dissociation through retrograde perfusion of the aorta. Unloaded cell shortening, time to peak and time to 50% relaxation were measured during field stimulation and normalized to diastolic length. L-type Ca2+ current density (ICaL) and steady-state inactivation of ICaL were measured during whole-cell ruptured patch clamp. Myofilament functional properties were measured in membrane-permeabilized cardiomyocytes. Ultrastructural examination of cardiac tissue was performed using electron microscopy. RESULTS Rats injected with HMW-AGEs displayed in vivo cardiac dysfunction, characterized by significant changes in left ventricular peak rate pressure rise and decline accompanied with an increased heart mass. Single cardiomyocytes isolated from the left ventricle revealed concentric hypertrophy, indicated by the increase in cellular width. Unloaded fractional cell shortening was significantly reduced in cells derived from the HMW-AGEs group and was associated with slower kinetics. Peak L-type Ca2+ current density was significantly decreased in the HMW-AGEs group.
L-type Ca2+ channel availability was significantly shifted towards more negative potentials after HMW-AGEs injection. The impact of HMW-AGEs on myofilament function was measured in membrane-permeabilized cardiomyocytes showing a reduction in passive force, maximal Ca2+ activated force and rate of force development. Ultrastructural examination of cardiac tissue demonstrated adverse structural remodeling in HMW-AGEs group characterized by a disruption of the cyto-architecture, a decreased mitochondrial density and altered mitochondrial function. CONCLUSION Our data indicate that HMW-AGEs induce structural and functional cellular remodeling via a different working mechanism as the well-known LMW-AGEs. Results of our research open the door for new strategies targeting HMW-AGEs to improve cardiac outcome.
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Glycolaldehyde-modified proteins cause adverse functional and structural aortic remodeling leading to cardiac pressure overload. Sci Rep 2020; 10:12220. [PMID: 32699285 PMCID: PMC7376068 DOI: 10.1038/s41598-020-68974-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 07/06/2020] [Indexed: 02/07/2023] Open
Abstract
Growing evidence supports the role of advanced glycation end products (AGEs) in the development of diabetic vascular complications and cardiovascular diseases (CVDs). We have shown that high-molecular-weight AGEs (HMW-AGEs), present in our Western diet, impair cardiac function. Whether HMW-AGEs affect vascular function remains unknown. In this study, we aimed to investigate the impact of chronic HMW-AGEs exposure on vascular function and structure. Adult male Sprague Dawley rats were daily injected with HMW-AGEs or control solution for 6 weeks. HMW-AGEs animals showed intracardiac pressure overload, characterized by increased systolic and mean pressures. The contraction response to PE was increased in aortic rings from the HMW-AGEs group. Relaxation in response to ACh, but not SNP, was impaired by HMW-AGEs. This was associated with reduced plasma cyclic GMP levels. SOD restored ACh-induced relaxation of HMW-AGEs animals to control levels, accompanied by a reduced half-maximal effective dose (EC50). Finally, collagen deposition and intima-media thickness of the aortic vessel wall were increased with HMW-AGEs. Our data demonstrate that chronic HMW-AGEs exposure causes adverse vascular remodelling. This is characterised by disturbed vasomotor function due to increased oxidative stress and structural changes in the aorta, suggesting an important contribution of HMW-AGEs in the development of CVDs.
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Effect of Exercise Intervention on Cardiac Function in Type 2 Diabetes Mellitus: A Systematic Review. Sports Med 2020; 49:255-268. [PMID: 30357657 DOI: 10.1007/s40279-018-1003-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND The effect of exercise on cardiac function/structure in type 2 diabetes mellitus (T2DM) with or without diabetic cardiomyopathy (DCM) is not yet completely understood. To date, results of studies have been controversial with variable outcomes due to the variety of exercise modalities. OBJECTIVES The aim of the present review was to examine the impact of exercise intervention, and different types of exercise, on cardiac function and structure in T2DM through a systematic literature review, combining both pre-clinical and clinical studies. METHODS A systematic literature search was performed on PubMed, Web of Science, and PEDro to identify studies up to 2 April 2018. Articles were included when well-defined exercise protocols were provided, and cardiac function in T2DM patients or validated animal models was examined. RESULTS In diabetic animals, improvements in both diastolic and systolic function through exercise therapy were mainly attributed to reduced collagen deposition. In T2DM patients, improvements were observed in diastolic function, but not consistently in systolic function, after endurance (and combined resistance) exercise training. Different exercise intervention modalities and exercise types seemed equally effective in improving cardiac structure and function. CONCLUSION Exercise training elicits significant improvements in diastolic function and beneficial remodeling in T2DM and DCM animal models, but not necessarily improvements in systolic function and left ventricular structure, regardless of exercise type. Therefore, exercise intervention should be a cornerstone in the treatment of T2DM patients not only to improve glycemic control but also to specifically enhance cardiac function.
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Acute exposure to glycated proteins reduces cardiomyocyte contractile capacity. Exp Physiol 2019; 104:997-1003. [PMID: 30997698 DOI: 10.1113/ep087127] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 04/11/2019] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? Does acute exposure to high molecular weight advanced glycation end products (HMW-AGEs) alter cardiomyocyte contractile function? What is the main finding and its importance? Ventricular cardiomyocytes display reduced Ca2+ influx, resulting in reduced contractile capacity, after acute exposure to HMW-AGEs, independent of activation of their receptor. Given that HMW-AGEs are abundantly present in our Western diet, a better understanding of underlying mechanisms, especially in patients already displaying altered cardiac function, should be gained for these compounds. ABSTRACT Sustained elevated levels of high molecular weight advanced glycation end products (HMW-AGEs) are known to promote cardiac dysfunction. Recent data suggest that acutely elevated levels of AGEs occur in situations of increased oxidative stress. Whether this increase might have detrimental effects on cardiac function remains unknown. In this study, we investigated whether acute exposure to HMW-AGEs affects cardiomyocyte function via activation of their receptor (RAGE) signalling pathway. Single cardiomyocytes from the left ventricle of adult male rats were obtained by enzymatic dissociation through retrograde perfusion of the aorta. Functional experiments were performed in cardiomyocytes pre-incubated with or without an anti-RAGE antibody. Unloaded cell shortening and L-type Ca2+ current amplitude were evaluated in the presence or absence of HMW-AGEs (200 μg ml-1 ). Expression of RAGE, c-Jun N-terminal kinase (JNK) and phosphorylated JNK (pJNK) were assessed by western blot. Experiments were performed at room temperature. After 4 min application of HMW-AGEs, unloaded cell shortening was significantly reduced. This impaired contractile function was related to reduced Ca2+ influx. These alterations were also observed in cardiomyocytes pre-incubated with anti-RAGE antibody. Our study demonstrates that acute exposure to elevated levels of HMW-AGEs leads to direct and irreversible cardiomyocyte dysfunction, independent of RAGE activation.
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High intensity training improves cardiac function in healthy rats. Sci Rep 2019; 9:5612. [PMID: 30948751 PMCID: PMC6449502 DOI: 10.1038/s41598-019-42023-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 03/11/2019] [Indexed: 02/08/2023] Open
Abstract
Exercise training is a low cost and safe approach for reducing the risk of cardiovascular disease development. Currently, moderate-intensity training (MIT) is the most preferred exercise type. However, high-intensity interval training (HIIT) is gaining interest especially among athletes and healthy individuals. In this study, we examined cardiac remodeling resulting from MIT and HIIT in healthy rats. Healthy male Sprague-Dawley rats were randomly assigned to MIT or HIIT for 13 weeks. Animals kept sedentary (SED) were used as control. Cardiac function was evaluated with echocardiography and hemodynamic measurements. Heart tissue was stained for capillary density and fibrosis. After 13 weeks of training, only HIIT induced beneficial cardiac hypertrophy. Overall global cardiac parameters (such as ejection fraction, cardiac output and volumes) were improved similarly between both training modalities. At tissue level, collagen content was significantly and similarly reduced in both exercise groups. Finally, only HIIT increased significantly capillary density. Our data indicate that even if very different in design, HIIT and MIT appear to be equally effective in improving cardiac function in healthy rats. Furthermore, HIIT provides additional benefits through improved capillary density and should therefore be considered as a preferred training modality for athletes and for patients.
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Autologous cardiac progenitor transplantation for myocardial repair: A step towards personalized medicine. Meta Gene 2018. [DOI: 10.1016/j.mgene.2018.05.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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Western diet given to healthy rats mimics the human phenotype of diabetic cardiomyopathy. J Nutr Biochem 2018; 61:140-146. [PMID: 30245335 DOI: 10.1016/j.jnutbio.2018.08.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 07/04/2018] [Accepted: 08/15/2018] [Indexed: 01/20/2023]
Abstract
Diabetes mellitus (DM) is a major problem worldwide. Within this patient group, cardiovascular diseases are the biggest cause of morbidity and mortality. Diabetic cardiomyopathy (DCM) is defined as diabetes-associated structural and functional changes in the myocardium, not directly attributable to other confounding factors such as coronary artery disease or hypertension. Pathophysiology of DCM remains unclear due to a lack of adequate animal models reflecting the current pandemic of diabetes, associated with a high increased sugar intake and the 'Western' lifestyle. The aim of this study was to develop an animal model mimicking this 'Western' lifestyle causing a human-like phenotype of DCM. Twenty-four Sprague-Dawley rats were randomly assigned into a normal or a 'Western' diet group for 18 weeks. Glucose and insulin levels were measured with an OGTT. Heart function was assessed by echocardiography and hemodynamic measurements in vivo. Cardiac fibrosis and inflammation were investigated in vitro. 'Western' diet given to healthy rats for 18 weeks induced hyperglycemia together with increased AGEs levels, insulin levels and hypertriglyceridemia. Heart function was altered with increased end-diastolic pressure, left ventricle hypertrophy. Changes in vivo were associated with increased collagen deposition and increased PAI-1 levels in the heart. High-sugar diet or 'Western' diet causes T2DM and the hallmarks of DCM in rats, reflecting the phenotype of the disease seen in patients. Using this new model of T2DM with DCM might open new insight in understanding the pathophysiology of DCM and on a long term, test targeted therapies for T2DM with DCM patients.
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Impact of glycated proteins on cardiomyocyte function. J Mol Cell Cardiol 2018. [DOI: 10.1016/j.yjmcc.2018.05.054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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P1463The origin of diabetes: high-sugar diet to induce diabetic cardiomyopathy in rats. Eur Heart J 2017. [DOI: 10.1093/eurheartj/ehx502.p1463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Advanced glycation end products (AGEs) and cardiovascular dysfunction: focus on high molecular weight AGEs. Amino Acids 2017; 49:1535-1541. [DOI: 10.1007/s00726-017-2464-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 07/07/2017] [Indexed: 12/27/2022]
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From Bone Marrow to Cardiac Atrial Appendage Stem Cells for Cardiac Repair: A Review. Curr Med Chem 2017; 23:2421-38. [PMID: 27222265 DOI: 10.2174/0929867323666160525114735] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Revised: 05/14/2016] [Accepted: 05/24/2016] [Indexed: 11/22/2022]
Abstract
Traditionally the heart is considered a terminally differentiated organ. However, at the beginning of this century increased mitotic activity was reported in ischemic and idiopathic dilated cardiomyopathy hearts, compared to healthy controls, underscoring the potential of regeneration after injury. Due to the presence of adult stem cells in bone marrow and their purported ability to differentiate into other cell lineages, this cell population was soon estimated to be the most suited candidate for cardiac regeneration. Clinical trials with autologous bone marrow-derived mononuclear cells, using either an intracoronary or direct intramyocardial injection approach consistently showed only minor improvement in global left ventricular ejection fraction. This was explained by their limited cardiomyogenic differentiation potential. To obtain more convincing improvement in cardiac function, based on true myocardial regeneration, the focus of research has shifted towards resident cardiac progenitor cells. Several isolation procedures have been described: the c-kit surface marker was the first to be used, however experimental research has clearly shown that c-kit+ cells only marginally contribute to regeneration post myocardial infarction. Sphere formation was used to isolate the so-called cardiosphere derived cells (CDC), and also in this cell population cardiomyogenic differentiation is a rare event. Recently a new type of stem cells derived from atrial tissue (cardiac atrial stem cells - CASCs) was identified, based on the presence of the enzyme aldehyde dehydrogenase (ALDH). Those cells significantly improve both regional and global LV ejection fraction, based on substantial engraftment and consistent differentiation into mature cardiomyocytes (98%).
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Reduced mitochondrial respiration in the ischemic as well as in the remote nonischemic region in postmyocardial infarction remodeling. Am J Physiol Heart Circ Physiol 2016; 311:H1075-H1090. [PMID: 27614227 DOI: 10.1152/ajpheart.00945.2015] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 08/07/2016] [Indexed: 11/22/2022]
Abstract
Scarring and remodeling of the left ventricle (LV) after myocardial infarction (MI) results in ischemic cardiomyopathy with reduced contractile function. Regional differences related to persisting ischemia may exist. We investigated the hypothesis that mitochondrial function and structure is altered in the myocardium adjacent to MI with reduced perfusion (MIadjacent) and less so in the remote, nonischemic myocardium (MIremote). We used a pig model of chronic coronary stenosis and MI (n = 13). Functional and perfusion MR imaging 6 wk after intervention showed reduced ejection fraction and increased global wall stress compared with sham-operated animals (Sham; n = 14). Regional strain in MIadjacent was reduced with reduced contractile reserve; in MIremote strain was also reduced but responsive to dobutamine and perfusion was normal compared with Sham. Capillary density was unchanged. Cardiac myocytes isolated from both regions had reduced basal and maximal oxygen consumption rate, as well as through complex I and II, but complex IV activity was unchanged. Reduced respiration was not associated with detectable reduction of mitochondrial density. There was no significant change in AMPK or glucose transporter expression levels, but glycogen content was significantly increased in both MIadjacent and MIremote Glycogen accumulation was predominantly perinuclear; mitochondria in this area were smaller but only in MIadjacent where also subsarcolemmal mitochondria were smaller. In conclusion, after MI reduction of mitochondrial respiration and glycogen accumulation occur in all LV regions suggesting that reduced perfusion does not lead to additional specific changes and that increased hemodynamic load is the major driver for changes in mitochondrial function.
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Poster session 3Cell growth, differentiation and stem cells - Heart511The role of the endocannabinoid system in modelling muscular dystrophy cardiac disease with induced pluripotent stem cells.512An emerging role of T lymphocytes in cardiac regenerative processes in heart failure due to dilated cardiomyopathy513Canonical wnt signaling reverses the ‘aged/senescent’ human endogenous cardiac stem cell phenotype514Hippo signalling modulates survival of human induced pluripotent stem cell-derived cardiomyocytes515Biocompatibility of mesenchymal stem cells with a spider silk matrix and its potential use as scaffold for cardiac tissue regeneration516A snapshot of genome-wide transcription in human induced pluripotent stem cell-derived hepatocyte-like cells (iPSC-HLCs)517Can NOS/sGC/cGK1 pathway trigger the differentiation and maturation of mouse embryonic stem cells (ESCs)?518Introduction of external Ik1 to human-induced pluripotent stem cell-derived cardiomyocytes via Ik1-expressing HEK293519Cell therapy of the heart studied using adult myocardial slices in vitro520Enhancement of the paracrine potential of human adipose derived stem cells when cultured as spheroid bodies521Mechanosensitivity of cardiomyocyte progenitor cells: the strain response in 2D and 3D environments522The effect of the vascular-like network on the maturation of the human induced pluripotent stem cell derived cardiomyocytes.Transcriptional control and RNA species - Heart525Gene expression regulation in heart failure: from pathobiology to bioinformatics526Human transcriptome in idiopathic dilated cardiomyopathy - a novel high throughput screening527A high-throghput approach unveils putative miRNA-mediated mitochondria-targeted cardioprotective circuits activated by T3 in the post ischemia reperfusion setting528The effect of uraemia on the expression of miR-212/132 and the calcineurin pathway in the rat heartCytokines and cellular inflammation - Heart531Lack of growth differentiation factor 15 aggravates adverse cardiac remodeling upon pressure-overload in mice532Blocking heteromerization of platelet chemokines ccl5 and cxcl4 reduces inflammation and preserves heart function after myocardial infarction533Is there an association between low-dose aspirin use and clinical outcome in HFPEF? Implications of modulating monocyte function and inflammatory mediator release534N-terminal truncated intracellular matrix metalloproteinase-2 expression in diabetic heart.535Expression of CD39 and CD73 on peripheral T-cell subsets in calcific aortic stenosis536Mast cells in the atrial myocardium of patients with atrial fibrillation: a comparison with patients in sinus rhythm539Characteristics of the inflammatory response in patients with coronary artery disease and arterial hypertension540Pro-inflammatory cytokines as cardiovascular events predictors in rheumatoid arthritis and asymptomatic atherosclerosis541Characterization of FVB/N murinic bone marrow-derived macrophage polarization into M1 and M2 phenotypes542The biological expression and thoracic anterior pain syndromeSignal transduction - Heart545The association of heat shock protein 90 and TGFbeta receptor I is involved in collagen production during cardiac remodelling in aortic-banded mice546Loss of the inhibitory GalphaO protein in the rostral ventrolateral medulla of the brainstem leads to abnormalities in cardiovascular reflexes and altered ventricular excitablitiy547Selenoprotein P regulates pressure overload-induced cardiac remodeling548Study of adenylyl cyclase activity in erythrocyte membranes in patients with chronic heart failure549Direct thrombin inhibitors inhibit atrial myocardium hypertrophy in a rat model of heart failure and atrial remodeling550Tissue factor / FVIIa transactivates the IGF-1R by a Src-dependent phosphorylation of caveolin-1551Notch signaling is differently altered in endothelial and smooth muscle cells of ascending aortic aneurysm patients552Frizzled 5 expression is essential for endothelial proliferation and migration553Modulation of vascular function and ROS production by novel synthetic benzopyran analogues in diabetes mellitusExtracellular matrix and fibrosis - Heart556Cardiac fibroblasts as inflammatory supporter cells trigger cardiac inflammation in heart failure557A role for galectin-3 in calcific aortic valve stenosis558Omega-3 polyunsaturated fatty acids- can they decrease risk for ventricular fibrillation?559Serum levels of elastin derived peptides and circulating elastin-antielastin immune complexes in sera of patients with coronary artery disease560Endocardial fibroelastosis is secondary to hemodynamic alterations in the chick model of hypoplastic left heart syndrome561Dynamics of serum levels of matrix metalloproteinases in primary anterior STEMI patients564Deletion of the alpha-7 nicotinic acetylcholine receptor changes the vascular remodeling induced by transverse aortic constriction in mice.565Extracellular matrix remodelling in response to venous hypertension: proteomics of human varicose veinsIon channels, ion exchangers and cellular electrophysiology - Heart568Microtubule-associated protein RP/EB family member 1 modulates sodium channel trafficking and cardiac conduction569Investigation of electrophysiological abnormalities in a rabbit athlete's heart model570Upregulation of expression of multiple genes in the atrioventricular node of streptozotocin-induced diabetic rat571miR-1 as a regulator of sinoatrial rhythm in endurance training adaptation572Selective sodium-calcium exchanger inhibition reduces myocardial dysfunction associated with hypokalaemia and ventricular fibrillation573Effect of racemic and levo-methadone on action potential of human ventricular cardiomyocytes574Acute temperature effects on the chick embryonic heart functionVasculogenesis, angiogenesis and arteriogenesis577Clinical improvement and enhanced collateral vessel growth after monocyte transplantation in mice578The role of HIF-1 alpha, VEGF and obstructive sleep apnoea in the development of coronary collateral circulation579Initiating cardiac repair with a trans-coronary sinus catheter intervention in an ischemia/reperfusion porcine animal model580Early adaptation of pre-existing collaterals after acute arteriolar and venular microocclusion: an in vivo study in chick chorioallantoic membraneEndothelium583EDH-type responses to the activator of potassium KCa2.3 and KCa3.1 channels SKA-31 in the small mesenteric artery from spontaneously hypertensive rats584The peculiarities of endothelial dysfunction in patients with chronic renocardial syndrome585Endothelial dysfunction, atherosclerosis of the carotid arteries and level of leptin in patient with coronary heart disease in combination with hepatic steatosis depend from body mass index.586Role of non-coding RNAs in thoracic aortic aneurysm associated with bicuspid aortic valve587Cigarette smoke extract abrogates atheroprotective effects of high laminar flow on endothelial function588The prognostic value of anti-connective tissue antibodies in coronary heart disease and asymptomatic atherosclerosis589Novel potential properties of bioactive peptides from spanish dry-cured ham on the endothelium.Lipids592Intermediate density lipoprotein is associated with monocyte subset distribution in patients with stable atherosclerosis593The characteristics of dyslipidemia in rheumatoid arthritisAtherosclerosis596Macrophages differentiated in vitro are heterogeneous: morphological and functional profile in patients with coronary artery disease597Palmitoylethanolamide promotes anti-inflammatory phenotype of macrophages and attenuates plaque formation in ApoE-/- mice598Amiodarone versus esmolol in the perioperative period: an in vitro study of coronary artery bypass grafts599BMPRII signaling of fibrocytes, a mesenchymal progenitor cell population, is increased in STEMI and dyslipidemia600The characteristics of atherogenesis and systemic inflammation in rheumatoid arthritis601Role of adenosine-to-inosine RNA editing in human atherosclerosis602Presence of bacterial DNA in thrombus aspirates of patients with myocardial infarction603Novel E-selectin binding polymers reduce atherosclerotic lesions in ApoE(-/-) mice604Differential expression of the plasminogen receptor Plg-RKT in monocyte and macrophage subsets - possible functional consequences in atherogenesis605Apelin-13 treatment enhances the stability of atherosclerotic plaques606Mast cells are increased in the media of coronary lesions in patients with myocardial infarction and favor atherosclerotic plaque instability607Association of neutrophil to lymphocyte ratio with presence of isolated coronary artery ectasiaCalcium fluxes and excitation-contraction coupling610The coxsackie- and adenovirus receptor (CAR) regulates calcium homeostasis in the developing heart611HMW-AGEs application acutely reduces ICaL in adult cardiomyocytes612Measuring electrical conductibility of cardiac T-tubular systems613Postnatal development of cardiac excitation-contraction coupling in rats614Role of altered Ca2+ homeostasis during adverse cardiac remodeling after ischemia/reperfusion615Experimental study of sarcoplasmic reticulum dysfunction and energetic metabolism in failing myocardium associated with diabetes mellitusHibernation, stunning and preconditioning618Volatile anesthetic preconditioning attenuates ischemic-reperfusion injury in type II diabetic patients undergoing on-pump heart surgery619The effect of early and delayed phase of remote ischemic preconditioning on ischemia-reperfusion injury in the isolated hearts of healthy and diabetic rats620Post-conditioning with 1668-thioate leads to attenuation of the inflammatory response and remodeling with less fibrosis and better left ventricular function in a murine model of myocardial infarction621Maturation-related changes in response to ischemia-reperfusion injury and in effects of classical ischemic preconditioning and remote preconditioningMitochondria and energetics624Phase changes in myocardial mitochondrial respiration caused by hypoxic preconditioning or periodic hypoxic training625Desmin mutations depress mitochondrial metabolism626Methylene blue modulates mitochondrial function and monoamine oxidases-related ROS production in diabetic rat hearts627Doxorubicin modulates the real-time oxygen consumption rate of freshly isolated adult rat and human ventricular cardiomyocytesCardiomyopathies and fibrosis630Effects of genetic or pharmacologic inhibition of the ubiquitin/proteasome system on myocardial proteostasis and cardiac function631Suppression of Wnt signalling in a desmoglein-2 transgenic mouse model for arrhythmogenic cardiomyopathy632Cold-induced cardiac hypertrophy is reversed after thermo-neutral deacclimatization633CD45 is a sensitive marker to diagnose lymphocytic myocarditis in endomyocardial biopsies of living patients and in autopsies634Atrial epicardial adipose tissue derives from epicardial progenitors635Caloric restriction ameliorates cardiac function, sympathetic cardiac innervation and beta-adrenergic receptor signaling in an experimental model of post-ischemic heart failure636High fat diet improves cardiac remodelling and function after extensive myocardial infarction in mice637Epigenetic therapy reduces cardiac hypertrophy in murine models of heart failure638Imbalance of the VHL/HIF signaling in WT1+ Epicardial Progenitors results in coronary vascular defects, fibrosis and cardiac hypertrophy639Diastolic dysfunction is the first stage of the developing heart failure640Colchicine aggravates coxsackievirus B3 infection in miceArterial and pulmonary hypertension642Osteopontin as a marker of pulmonary hypertension in patients with coronary heart disease combined with chronic obstructive pulmonary disease643Myocardial dynamic stiffness is increased in experimental pulmonary hypertension partly due to incomplete relaxation644Hypotensive effect of quercetin is possibly mediated by down-regulation of immunotroteasome subunits in aorta of spontaneously hypertensive rats645Urocortin-2 improves right ventricular function and attenuates experimental pulmonary arterial hypertension646A preclinical evaluation of the anti-hypertensive properties of an aqueous extract of Agathosma (Buchu)Biomarkers648The adiponectin level in hypertensive females with rheumatoid arthritis and its relationship with subclinical atherosclerosis649Markers for identification of renal dysfunction in the patients with chronic heart failure650cardio-hepatic syndromes in chronic heart failure: North Africa profile651To study other biomarkers that assess during myocardial infarction652Interconnections of apelin levels with parameters of lipid metabolism in hypertension patients653Plasma proteomics in hypertension: prediction and follow-up of albuminuria during chronic renin-angiotensin system suppression654Soluble RAGE levels in plasma of patients with cerebrovascular events. Cardiovasc Res 2016. [DOI: 10.1093/cvr/cvw150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Cross-linking versus RAGE: How do high molecular weight advanced glycation products induce cardiac dysfunction? Int J Cardiol 2016; 210:100-8. [DOI: 10.1016/j.ijcard.2016.02.095] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 02/11/2016] [Accepted: 02/14/2016] [Indexed: 02/05/2023]
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Poster session 5The imaging examinationP1097Correlation between visual and quantitative assessment of left ventricle: intra- and inter-observer agreementP1099Incremental prognostic value of late gadolinium-enhanced by cardiac magnetic resonance in patients with heart failureAnatomy and physiology of the heart and great vesselsP1100Left ventricular geometry and diastolic performance in erectile dysfunction patients; a topic of differential arterial stiffness influenceAssessment of diameters, volumes and massP1101Impact of the percutaneous closure of atrial septal defect on the right heart "remodeling"P1102Left Ventricular Mass Indexation in Infants, Children and Adolescents: a Simplified Approach for the Identification of Left Ventricular Hypertrophy in Clinical PracticeP1103Impact of trabecules while quantifying cardiac magnetic resonance exams in patients with systemic right ventricleP1104Detection of subclinical atherosclerosis by carotid intima-media thickness: correlation with leukocytes telomere shorteningAssessments of haemodynamicsP1105Flow redirection towards the left ventricular outflow tract: vortex formation is not affected by variations in atrio-ventricular delayAssessment of systolic functionP1106Reproducibility and feasibility of cardiac MRI feature tracking in Fabry diseaseP1107Normal left ventricular strain values by two-dimensional strain echocardiography; result of normal (normal echocardiographic dimensions and functions in korean people) studyP1108Test-retest repeatability of global strain following st-elevation myocardial infarction - a comparison of tagging and feature trackingP1109Cardiotoxicity induced by tyrosine kinase inhibitors in patients with gastrointestinal stromal tumors (GIST)P1110Finite strain ellipses for the analysis of left ventricular principal strain directions using 3d speckle tracking echocardiographyP1111Antihypertensive therapy reduces time to peak longitudinal strainP1112Right ventricular systolic function as a marker of prognosis after inferior myocardial infarction - 5-year follow-upP1113Is artery pulmonary dilatation related with right but also early left ventricle dysfunction in pulmonary artery hypertension?P1114Right ventricular mechanics changes according to pressure overload increasing, a 2D-speckle tracking echocardiographic evaluationAssessment of diastolic functionP1115Paired comparison of left atrial strain from P-wave to P-wave and R-wave to R-waveP1116Diagnostic role of Tissue Doppler Imaging echocardiographic criteria in obese heart failure with preserved ejection fraction patientsP1117Evaluation of diastolic function of right ventricle in idiopathic pulmonary arterial hypertensionP1118Severity and predictors of diastolic dysfunction in a non-hypertensive non-ischemic cohort of Egyptian patients with documented systemic autoimmune disease; pilot reportP1119correlation between ST segment shift and cardiac diastolic function in patients with acute myocardial infarctionIschemic heart diseaseP1120Computed tomography coronary angiography verSus sTRess cArdiac magneTic rEsonance for the manaGement of sYmptomatic revascularized patients: a cost effectiveness study (STRATEGY study)P1121Utility of transmural myocardial mechanic for early infarct size prediction after primary percutaneous coronary intervention in STEMI patientsP1122Progressive Improvements of the echocardiographic deformation parameters in ST Elevation Myocardial Infarction after five years follow-upP1123Long-term prognostic value of left ventricular dyssynchrony as assessed by cardiac magnetic resonance feature-tracking imaging after a first st-segment elevation myocardial infarctionP1124Differences in mitral annulus remodeling in acute anterior ST elevation and acute inferior ST elevation myocardial infarctionP1125Reduction of microvascular injury using a novel theragnostic ultrasound strategy: a first in men feasibility and safety studyP1126Impact of focused echocardiography in clinical decision of patient presented with st elevation myocardial infarction underwent primary angioplastyHeart valve DiseasesP1127Aortic valve area calculation in aortic stenosis: a comparison among conventional and 3D-transesophageal echocardiography and computed tomographyP1128Myocardial fibrosis and microRNA-21 expression in patients with severe aortic valve stenosis and preserved ejection fraction: a 2D speckle tracking echocardiography, tissutal and plasmatic studyP1129Quantification of calcium amount in a new experimental model: a comparison between calibrated integrated backscatter of ultrasound and computed tomographyP1130Altered diffusion capacity in aortic stenosis: role of the right heartP1131Osteoprotegerin predicts all-cause mortality in calcific aortic stenosis patients with preserved left ventricle ejection fraction in long term observationP1132Mitral regurgitation as a risk factor for pulmonary hypertension in patients with aortic stenosisP1133The relationship between the level of plasma B-type natriuretic peptide and mitral stenosisP1134Aortic regurgitation, left ventricle mechanics and vascular load: a single centre 2d derived-speckle tracking studyP1135Feasibility and reproducibility issues limit the usefulness of quantitative colour Doppler parameters in the assessment of chronic aortic and mitral regurgitation severityP1136Predictors of postoperative outcome in degenerative mitral regurgitationP1137Left ventricular mechanical dyssynchrony in patients with severe mitral regurgitation of rheumatic etiology; three dimensional echocardiography studyP1138Functional mitral regurgitation and left atrial dysfunction concur in determining pulmonary hypertension and functional status in subjects with left ventricular systolic dysfunctionP11393D echocardiography allows more effective quantitative assessment of the severity of functional tricuspid regurgitation than conventional 2D/Doppler echocardiographyP1140Prosthetic valve thrombosis: still a severe disease? 10-years experience in a university hospitalP1141Validity of echocardiography in the hospital course of patients with feverP1142Do baseline 3DTEE characteristics of mitral valve apparatus predict long term result in patients undergoing percutaneous valve repair for degenerative regurgitation?P1143Influence of baseline aortic regurgitation on mitral regurgitation change after transcatheter aortic valve replacement for aortic stenosisP1144Prevalence of echocardiography detected significant valvular regurge in subclinical rheumatic carditis in assiut childrenCardiomyopathiesP1145Can we early detect left ventricular systolic dysfunction in patients with Duchenne muscular dystrophy using global longitudinal strain assessment?P1146Prevalence of isolated papillary muscle hypertrophy in young competitive athletesP1147Troponin release after exercise in patients with hypertrophic cardiomyopathy: associations with clinical and mr imaging characteristicsP1148Atrial fibrillation in hypertrophic cardiomyopathy: can we score the risk?P1149Impact of hypertrophy on multiple layer longitudinal deformation in hypertrophy cardiomyopathy and cardiac amyloidosis compared to controlsP1150Functional evaluation in hypertrophic cardiomyopathy combining cardiopulmonary exercise testing combined with exercise-echocardiographyP1151Refinement of the old diagnostic criteria of left ventricular noncompaction cardiomyopathy (LVNC) based on cardiac magnetic resonance (CMR)P1152Differences of clinical characteristics and outcomes between acute myocarditis with preserved and reduced left ventricular systolic functionP1153Value of longitudinal strain for distinguishing left ventricular non-compaction from idiopathic dilated cardiomyopathyP1154Speed of recovery of left ventricular function is not related to the prognosis of Takotsubo cardiomyopathy. A Portuguese multicentre studyP1155Predictors of in-hospital left ventricular systolic function recovery after admission with takotsubo cardiomyopathy. Portuguese multicentre studyP1156Mid-ventricular takotsubo detected by initial echocardiogram associates with recurrence of takotsubo cardiomyopathy - a portuguese multicentre studySystemic diseases and other conditionsP1157Relations between left ventricle remodelling and expression of angiotensin 2 AT2R1 geneP1158Impact of renal denervation on long-term blood pressure variability and surrogate markers of target organ damage in individuals with drug-resistant arterial hypertensionP1159Greater improvement of coronary artery function, left ventricular deformation and twisting by IL12/23 compared to TNF-a inhibition in psoriasisP1160Advanced glycation end products play a role in adverse LV remodeling following MIP1161Incidence of subclinical myocardial dysfunction in patients with systemic sclerosis and normal left ventricular systolic and diastolic functionP1162Left atrial remodeling and dysfunction occur early in patients with systemic sclerosis and normal left ventricular functionP1163Intrinsic vortex formation : a unique performance indicatorP1164P-wave morphology is unaffected by training-induced biatrial dilatation: a prospective, longitudinal study in healthy athletesP1165Usefulness of transthoracic echocardiography in diagnosis of young patients with ischemic strokeP1166Primary cardiac lymphoma: role of echocardiography in the clinical managementP1167Abnormal echocardiographic findings in cancer patients before chemotherapyMasses, tumors and sources of embolismP1168Three-dimensional transesophageal echocardiography of the left atrial appendage reduces rate of postpone electrical cardioversionP1169Detection of ventricular thrombus by cmr after reperfused st-segment elevation myocardial infarction correlated with echocardiographyP1170Clinical and transthoracic echocardiographic predictors of left atrial appendage thrombus in patients with atrial fibrillationStress echocardiographyP1171Pharmacological stress echocardiography complications: a 4-year single center experienceP1172Myocardial functional and perfusion reserve in type I diabetesP1173Feasibility of incorporating 3D Dobutamine stress echocardiography into routine clinical practiceP1174Right ventricular isovolumic acceleration at rest and during exercise in children after heart transplantP1175Right ventricular systolic and diastolic response to exercise in children after heart transplant -a bicycle exercise studyP1176Determinants of functional capacity in heart failure patients with reduced ejection fractionP1177Handgrip stress echocardiography with emotional component compared to conventional isometric exercise in coronary artery disease diagnosisP1178The relationship between resting transthoracic echocardiography and exercise capacity in patients with paroxysmal atrial fibrillationP1179Correlation between NT-proBNP and selected echocardiography parameters at rest and after exercise in patients with functional ischemic mitral regurgitation qualified for cardiosurgical treatmentReal-time three-dimensional TEEP1180Vena contracta area for severity grading in functional and degenerative mitral regurgitation: A study based on transesophageal 3D colour Doppler in 419 patientsP1181Proximal flow convergence by 3D echocardiography in the evaluation of mitral valve area in rheumatic mitral stenosisP1182Quantification of valve dimensions by transesophageal 3D echocardiography in patients with functional and degenerative mitral regurgitationTissue Doppler and speckle trackingP1183Automatic calculation of left ventricular volume changes over a cardiac cycle from echocardiography images by nonlinear dimensionality reductionP1184Effect of the mitral valve repairs on the left ventricular blood flow formationP1185Quantification of left atrial strain using cardiovascular magnetic resonance. a comparison between hypertrophic cardiomyopathy and healthy controlsP1186The role of early systolic lengthening in patients with non-ST elevation acute coronary syndrome and its relation to syntax scoreP1187Different standard two dimensional strain methods to quantity left ventricular mechanicsP1188Atrial function and electrocardiography caracteristics in sportsmen with or without paroxysmal atrial fibrillationP1189Right ventricular outflow premature contractions induce regional left ventricular dysfunctionP1190Ultrasound guided venous access for pacemaker and defibrillators. Randomized TrialP1191Atrial function analysis correlates with symptoms and quality of life of heart failure patientsP1192The use of tissue doppler echocardiography in myocardial iron overload in patients with thalassaemia majorP1193Independent association between pulse pressure and left ventricular global longitudinal strainP1194Global and regional longitudinal strain identifies the presence of coronary artery disease in patients with suspected reduction of coronary flow reserve and absence of wall motion abnormalitiesP1195Prognostic value of invasive and noninvasive parameters of right ventricular function in patients with pulmonary arterial hypertension receiving specific vasodilator therapyP1196Myocardial deformation analysis to improve arrhythmic risk stratificationP1197Quantitative assessment of regional systolic and diastolic function parameters for detecting prior transient ischemia in normokinetic segmentsP1198Left atrial function in patients with corrected tetralogy of Fallot - a three-dimensional speckle-tracking echocardiographic studyP1199Left atrial ejection force correlates with left atrial strain and volume-based functional properties as assessed by three-dimensional speckle tracking echocardiographyP1200Acute angulation of the aortic arch late after the arterial switch operation for transposition of the great arteries: impact on cardiac mechanicsP1201Circumferential deformation of the ascending thoracic aorta in hypertensive patients by three-dimensional speckle tracking echocardiographyCardiac Magnetic ResonanceP1202The incremental value of cardiac magnetic resonance on diagnosis myocardial infarction and non-obstructed coronary arteriesP1204Reference ranges of global and regional myocardial T1 values derived from MOLLI and shMOLLI at 3TComputed Tomography & Nuclear CardiologyP1205Deformation of the left atrial appendage after percutaneous closure with the Amplatzer cardiac plugP1206Prognostic impact of non-obstructive coronary artery disease on coronary computed tomographic angiography: A single-center study. Eur Heart J Cardiovasc Imaging 2015. [DOI: 10.1093/ehjci/jev275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Possibilities and limitations for co-transplantation of cardiac atrial appendage stem cells and mesenchymal stem cells for myocardial repair. Int J Cardiol 2015; 203:1155-6. [PMID: 26549562 DOI: 10.1016/j.ijcard.2015.10.141] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 10/18/2015] [Indexed: 11/19/2022]
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On the interpretation of second harmonic generation intensity profiles of striated muscle. JOURNAL OF BIOMEDICAL OPTICS 2015; 20:86010. [PMID: 26277989 DOI: 10.1117/1.jbo.20.8.086010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 07/21/2015] [Indexed: 06/04/2023]
Abstract
Recently, a supramolecular model was developed for predicting striated skeletal muscle intensity profiles obtained by label-free second harmonic generation (SHG) microscopy. This model allows for a quantitative determination of the length of the thick filament antiparallel range or M-band (M ), and results in M=0.12 μm for single-band intensity profiles when fixing the A-band length (A ) to A=1.6 μm , a value originating from electron microscopy (EM) observations. Using simulations and experimental data sets, we showed that the objective numerical aperture (NA) and the refractive index (RI) mismatch (Δn=n 2ω −n ω ) between the illumination wave (ω ) and the second harmonic wave (2ω ) severely affect the simulated sarcomere intensity profiles. Therefore, our recovered filament lengths did not match with those observed by EM. For an RI mismatch of Δn=0.02 and a moderate illumination NA of 0.8, analysis of single-band SHG intensity profiles with freely adjustable A- and M-band sizes yielded A=1.40±0.04 μm and M=0.07±0.05 μm for skeletal muscle. These lower than expected values were rationalized in terms of the myosin density distribution along the myosin thick filament axis. Our data provided new and practical insights for the application of the supramolecular model to study SHG intensity profiles in striated muscl
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Abstract
In cardiac myocytes, Ca(2+) release from the sarcoplasmic reticulum (SR) Ca(2+) store through the opening of ryanodine receptors (RyRs) is the major source of Ca(2+) for activation of myofilaments and contraction. Over the past 20 years, tools have become available to study this release process in detail, allowing new insights into the regulation of SR Ca(2+) release and RyR function. To assess these processes, we recommend and here review a systematic approach that evaluates the essential transport mechanisms and Ca(2+) fluxes in isolated single cardiac myocytes by using fluorescent Ca(2+) indicators and whole-cell recording of membrane voltage and ionic currents under voltage clamp. The approach includes an assessment of the L-type Ca(2+) current as a trigger for opening of RyRs and release of SR Ca(2+), of the SR Ca(2+) content, of intrinsic properties of RyRs, and of Ca(2+)-removal systems.
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Abstract
This protocol describes the measurement of Ca(2+) sparks in intact myocytes by using a Ca(2+)-sensitive dye and imaging using laser scanning confocal microscopy. It takes advantage of spontaneous Ca(2+)-release events-sparks-using them as a measure of the activity of ryanodine receptors (RyRs). Two methodologies are described: One requires that cardiomyocytes be stimulated, preferably under voltage clamp by depolarizing pulses, until steady-state is reached, and then stimulation is stopped and Ca(2+) sparks are recorded. The second requires that cells be permeabilized and bathed in a solution to load the cell with Ca(2+) sufficient to elicit Ca(2+) sparks, but not Ca(2+) waves. These are then analyzed offline to quantify spark frequency and morphology. The advantages and disadvantages of each approach are discussed.
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Abstract
The decline of an intracellular calcium ([Ca(2+)]i) transient during a single excitation-contraction coupling (ECC) cycle reflects the combined activity of the sarcoplasmic reticulum Ca(2+)-ATPase (SERCA) pump and the sarcolemmal Na(+)-Ca(2+) exchanger (NCX), along with minor contributions of the plasma membrane Ca(2+)-ATPase and mitochondrial Ca(2+) uniporter, in removing Ca(2+) from the cytosol. A traditional approach for assessing the individual components is to fit the decline of the [Ca(2+)]i transient evoked during electrical stimulation with an exponential. This reflects mostly the SERCA-dependent rate of uptake, which can be properly deduced after correcting for a component of NCX removal. As NCX function is an important determinant of the membrane potential as well as the Ca(2+) balance, we present here several detailed protocols for assessing NCX function. As the reversal potential and the amplitudes of the current are highly dependent on the prevailing concentrations of Na(+) and Ca(2+), we show how NCX function can be assessed under highly controlled conditions, with Ca(2+) and Na(+) clamped, as well as under more physiological conditions, with freely changing Ca(2+) and Na(+).
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Basic methods for monitoring intracellular Ca2+ in cardiac myocytes using Fluo-3. Cold Spring Harb Protoc 2015; 2015:392-397. [PMID: 25834257 DOI: 10.1101/pdb.prot076950] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In cardiac myocytes, the physiological increase of intracellular calcium, the [Ca(2+)]i transient, elicited during excitation-contraction coupling typically reaches a peak amplitude of up to 1 µm, from a resting value of ∼100 nm, within 50-100 msec, depending on the species. Various conditions will affect the amplitude and rise time of the [Ca(2+)]i transient and, depending on the nature of the Ca(2+) signals under study, a variety of different probes are available for monitoring changes in intracellular Ca(2+). In this protocol, we focus on Fluo-3, which exists in the cytosol in its salt form K5Fluo-3. This form is practically nonfluorescent in the absence of Ca(2+), but the fluorescence increases dramatically on Ca(2+) binding. Although Fluo-3 is a single excitation-emission dye, it has a number of advantages for investigators, including an ideal dissociation constant (Kd) value and high quantum yield, meaning that it can be used at low concentrations that introduce minimal buffering. Here, we describe the basic setup and methodology for recording the global cytosolic [Ca(2+)]i transient with this probe during simultaneous patch-clamp and whole-cell recording of membrane voltage or of ionic currents under voltage clamp.
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Measuring sarcoplasmic reticulum Ca2+ content, fractional release, and Ca2+ buffering in cardiac myocytes. Cold Spring Harb Protoc 2015; 2015:403-7. [PMID: 25834259 DOI: 10.1101/pdb.prot076976] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Here, we describe a protocol for the reliable measurement of the amount of Ca(2+) in the sarcoplasmic reticulum (SR) Ca(2+) store of cardiac myocytes. The whole-cell patch-clamp method is used to provide controlled loading of the SR during conditioning depolarizing pulses, followed by rapid application of a high dose of caffeine to release all SR Ca(2+) and to prevent Ca(2+) reuptake by the SR. Simultaneous measurement of membrane currents records Ca(2+) extruded through the Na(+)-Ca(2+) exchanger. The integral of the caffeine-induced Na(+)-Ca(2+) exchange current is then used as a measure of the SR Ca(2+). Derived measurements include the Ca(2+) buffering capacity and measurement of fractional release as an indicator of coupling gain. Caveats, advantages, and disadvantages of this method and alternative methods are discussed.
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Characterizing the trigger for sarcoplasmic reticulum Ca2+ release in cardiac myocytes. Cold Spring Harb Protoc 2015; 2015:398-402. [PMID: 25834258 DOI: 10.1101/pdb.prot076968] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Here, we describe a method for characterizing the L-type Ca(2+) current, ICaL, which is a major trigger for Ca(2+) release from the sarcoplasmic reticulum (SR). The protocol includes measuring ICaL amplitude and voltage dependence and the elicited SR Ca(2+) release. The procedure for measuring ICaL activity is performed using solutions (internal and external) and voltage control such that other ionic currents are eliminated. The resultant relationship between the Ca(2+) current and the associated internal [Ca(2+)]i transient is a first approach for evaluating coupling gain. We discuss which parameters are most appropriate for this analysis and how an evaluation of gain needs to be further explored by measuring the SR Ca(2+) content.
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Exercise improves cardiac function and attenuates insulin resistance in Dahl salt-sensitive rats. Int J Cardiol 2015; 186:154-60. [PMID: 25828108 DOI: 10.1016/j.ijcard.2015.03.094] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 03/07/2015] [Indexed: 02/04/2023]
Abstract
BACKGROUND The development of heart failure (HF) secondary to hypertension is a complex process related to a series of physiological and molecular factors including glucose dysregulation. The overall objective of this study was to investigate whether exercise training could improve cardiac function and insulin resistance in a rat model of hypertensive HF. METHODS Seven week old Dahl salt-sensitive rats received either 8% NaCl (n = 30) or 0.3% NaCl (n = 18) diet. After a 5-week diet, animals were randomly assigned to exercise training (treadmill running at 18 m/min, 5% inclination for 60 min, 5 days/week) or kept sedentary for 6 additional weeks. 2D echocardiography was used to calculate left ventricular (LV) dimensions, volumes and global functional parameters. LV global deformation parameters were measured with speckle tracking echocardiography. Insulin resistance was assessed using 1h oral glucose tolerance testing. RESULTS High salt diet led to cardiac hypertrophy and HF, characterized by increased wall thicknesses and LV volumes as well as reduced deformation parameters. In addition, high salt diet was associated with the development of insulin resistance. Exercise training improved cardiac function, reduced the extent of interstitial fibrosis and reduced insulin levels 60 min post-glucose administration. CONCLUSIONS Even if not fully reversed, exercise training in HF animals improved cardiac function and insulin resistance. Adjusted modalities of exercise training might offer new insights not only as a preventive strategy, but also as a treatment for HF patients.
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Poster session 4: Friday 5 December 2014, 08:30-12:30 * Location: Poster area. Eur Heart J Cardiovasc Imaging 2014. [DOI: 10.1093/ehjci/jeu256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Young Investigator Award session - Basic Science: Thursday 4 December 2014, 10:00-11:00 * Location: Agora. Eur Heart J Cardiovasc Imaging 2014. [DOI: 10.1093/ehjci/jeu250] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Melusin protects from cardiac rupture and improves functional remodelling after myocardial infarction. Cardiovasc Res 2013; 101:97-107. [DOI: 10.1093/cvr/cvt235] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Abstract
Aims
Melusin is a muscle-specific chaperone protein whose expression is required for a compensatory hypertrophy response to pressure overload. Here, we evaluated the consequences of melusin overexpression in the setting of myocardial infarction (MI) using a comprehensive multicentre approach.
Methods and results
Mice overexpressing melusin in the heart (TG) and wild-type controls (WT) were subjected to permanent LAD ligation and both the acute response (Day 3) and subsequent remodelling (2 weeks) were examined. Mortality in wild-type mice was significant between Days 3 and 7, primarily due to cardiac rupture, but melusin's overexpression strongly reduced mortality (43.2% in wild-type vs. 27.3% in melusin-TG, P = 0.005). At Day 3 after MI, a time point preceding the mortality peak, TG hearts had increased heat shock protein 70 expression, increased ERK1/2 signalling, reduced cardiomyocyte hyper-contractility and inflammatory cell infiltrates, and increased matricellular protein expression in the infarcted area.
At 2 weeks after MI, melusin overexpression conferred a favourable adaptive remodelling characterized by reduced left ventricle dilatation and better preserved contractility in the presence of a comparable degree of hypertrophy. Adaptive remodelling in melusin TG mice was characterized by reduced apoptosis and fibrosis as well as increased cardiomyocyte contractility.
Conclusions
Consistent with its function as a chaperone protein, melusin overexpression exerts a dual protective action following MI reducing an array of maladaptive processes. In the early phase after MI, reduced inflammation and myocyte remodelling protect against cardiac rupture. Chronically, reduced myocyte loss and matrix remodelling, with preserved myocyte contractility, confer adaptive LV remodelling.
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Selective modulation of coupled ryanodine receptors during microdomain activation of calcium/calmodulin-dependent kinase II in the dyadic cleft. Circ Res 2013; 113:1242-52. [PMID: 24081880 DOI: 10.1161/circresaha.113.301896] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RATIONALE In ventricular myocytes of large mammals with low T-tubule density, a significant number of ryanodine receptors (RyRs) are not coupled to the sarcolemma; cardiac remodeling increases noncoupled RyRs. OBJECTIVE Our aim was to test the hypothesis that coupled and noncoupled RyRs have distinct microdomain-dependent modulation. METHODS AND RESULTS We studied single myocytes from pig left ventricle. The T-tubule network was analyzed in 3-dimension (3D) to measure distance to membrane of release sites. The rising phase of the Ca(2+) transient was correlated with proximity to the membrane (confocal imaging, whole-cell voltage-clamp, K5fluo-4 as Ca(2+) indicator). Ca(2+) sparks after stimulation were thus identified as resulting from coupled or noncoupled RyRs. We used high-frequency stimulation as a known activator of Ca(2+)/calmodulin-dependent kinase II. Spark frequency increased significantly more in coupled than in noncoupled RyRs. This specific modulation of coupled RyRs was abolished by the Ca(2+)/calmodulin-dependent kinase II blockers autocamtide-2-related inhibitory peptide and KN-93, but not by KN-92. Colocalization of Ca(2+)/calmodulin-dependent kinase II and RyR was not detectably different for coupled and noncoupled sites, but the F-actin disruptor cytochalasin D prevented the specific modulation of coupled RyRs. NADPH oxidase 2 inhibition by diphenyleneiodonium or apocynin, or global reactive oxygen species scavenging, also prevented coupled RyR modulation. During stimulated Ca(2+) transients, frequency-dependent increase of the rate of Ca(2+) rise was seen in coupled RyR regions only and abolished by autocamtide-2-related inhibitory peptide. After myocardial infarction, selective modulation of coupled RyR was lost. CONCLUSIONS Coupled RyRs have a distinct modulation by Ca(2+)/calmodulin-dependent kinase II and reactive oxygen species, dependent on an intact cytoskeleton and consistent with a local Ca(2+)/reactive oxygen species microdomain, and subject to modification with disease.
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Exercise training limits cardiac impairment induced by high-salt diet. Eur Heart J 2013. [DOI: 10.1093/eurheartj/eht310.p5809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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ACE-inhibition, but not weight reduction restores cardiomyocyte response to β-adrenergic stimulation in the metabolic syndrome. BMC Cardiovasc Disord 2013; 13:51. [PMID: 23848952 PMCID: PMC3729821 DOI: 10.1186/1471-2261-13-51] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2013] [Accepted: 07/10/2013] [Indexed: 11/30/2022] Open
Abstract
Background Diabetic cardiomyopathy is characterized by systolic and early diastolic ventricular dysfunction. In the metabolic syndrome (MS), ventricular stiffness is additionally increased in a later stage. It is unknown whether this is related to intrinsic cardiomyocyte dysfunction, extrinsic factors influencing cardiomyocyte contractility and/or cardiac function, or a combination of both. A first aim was to study cardiomyocyte contractility and Ca2+ handling in vitro in a mouse model of MS. A second aim was to investigate whether in vivo hypocaloric diet or ACE-inhibition (ACE-I) improved cardiomyocyte contractility in vitro, contractile reserve and Ca2+ handling. Methods This study was performed in LDL-receptor (LDLR−/−) and leptin-deficient (ob/ob), double knock-out mice (DKO), featuring obesity, type II diabetes, atherogenic dyslipidemia and hypertension. Single knock-out LDLR−/−, ob/ob and wild type mice were used as controls. Cellular contractility, Ca2+ handling and their response to in vivo treatment with diet or ACE-I were studied in isolated cardiomyocytes at baseline, during β-adrenergic stimulation or increased extracellular Ca2+, using field stimulation and patch-clamp. Results In untreated conditions, prolongation of contraction-relaxation cycle and altered Ca2+ handling are observed in MS. Response to increased extracellular Ca2+ and β-adrenergic stimulation is impaired and could not be rescued by weight loss. ACE-I restored impaired response to β-adrenergic stimulation in MS, but not the decreased response to increased extracellular Ca2+. Conclusions Cardiomyocyte contractility and β-adrenergic response are impaired in MS, due to alterations in cellular Ca2+ handling. ACE-I, but not weight loss, is able to restore cardiomyocyte response to β-adrenergic stimulation in MS.
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Combined Na(+)/Ca(2+) exchanger and L-type calcium channel block as a potential strategy to suppress arrhythmias and maintain ventricular function. Circ Arrhythm Electrophysiol 2013; 6:371-9. [PMID: 23515266 DOI: 10.1161/circep.113.000322] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND L-type calcium channel (LTCC) and Na(+)/Ca(2+) exchanger (NCX) have been implicated in repolarization-dependent arrhythmias, but also modulate calcium and contractility. Although LTCC inhibition is negative inotropic, NCX inhibition has the opposite effect. Combined block may, therefore, offer an advantage for hemodynamics and antiarrhythmic efficiency, particularly in diseased hearts. In a model of proarrhythmia, the dog with chronic atrioventricular block, we investigated whether combined inhibition of NCX and LTCC with SEA-0400 is effective against dofetilide-induced torsade de pointes arrhythmias (TdP), while maintaining calcium homeostasis and hemodynamics. METHODS AND RESULTS Left ventricular pressure (LVP) and ECG were monitored during infusion of SEA-0400 and verapamil in anesthetized dogs. Different doses were tested against dofetilide-induced TdP in chronic atrioventricular block dogs. In ventricular myocytes, effects of SEA-0400 were tested on action potentials, calcium transients, and early afterdepolarizations. In cardiomyocytes, SEA-0400 (1 μmol/L) blocked 66±3% of outward NCX, 50±2% of inward NCX, and 33±9% of LTCC current. SEA-0400 had no effect on systolic calcium, but slowed relaxation, despite action potential shortening, and increased diastolic calcium. SEA-0400 stabilized dofetilide-induced lability of repolarization and suppressed early afterdepolarizations. In vivo, SEA-0400 (0.4 and 0.8 mg/kg) had no effect on left ventricular pressure and suppressed dofetilide-induced TdPs dose dependently. Verapamil (0.3 mg/kg) also inhibited TdP, but caused a 15±8% drop of left ventricular pressure. A lower dose of verapamil without effects on left ventricular pressure (0.06 mg/kg) was not antiarrhythmic. CONCLUSIONS In chronic atrioventricular block dogs, SEA-0400 treatment is effective against TdP. Unlike specific inhibition of LTCC, combined NCX and LTCC inhibition has no negative effects on cardiac hemodynamics.
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T-tubule remodelling and ryanodine receptor organization modulate sodium-calcium exchange. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 961:375-83. [PMID: 23224896 DOI: 10.1007/978-1-4614-4756-6_32] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The Na(+)/Ca(2+) exchanger (NCX) is a key regulator of intracellular Ca(2+) in cardiac myocytes, predominantly contributing to Ca(2+) removal during the diastolic relaxation process but also modulating excitation-contraction coupling. NCX is preferentially located in the T-tubules and can be close to or within the dyad, where L-type Ca(2+) channels face ryanodine receptors (RyRs), the Ca(2+) release channels of the sarcoplasmic reticulum. However, especially in larger animals, not all RyRs are in dyads or adjacent to T-tubules, and a substantial fraction of Ca(2+) release from the sarcoplasmic reticulum thus occurs at distance from NCX. This chapter deals with the functional consequences of NCX location and how NCX can modulate diastolic and systolic Ca(2+) events. The loss of T-tubules and the effects on RyR function and NCX modulation are explored, as well as quantitative measurement of local Ca(2+) gradients at the level of the dyadic space.
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Abstract
Reducing the open probability of the ryanodine receptor (RyR) has been proposed to have beneficial effects in heart failure. We investigated whether conditional FKBP12.6 overexpression at the time of myocardial infarction (MI) could improve cardiac remodelling and cell Ca(2+) handling. Wild-type (WT) mice and mice overexpressing FKBP12.6 (Tg) were studied on average 7.5 ± 0.2 weeks after MI and compared with sham-operated mice for in vivo, myocyte function and remodelling. At baseline, unloaded cell shortening in Tg was not different from WT. The [Ca(2+)](i) transient amplitude was similar, but sarcoplasmic reticulum (SR) Ca(2+) content was larger in Tg, suggesting reduced fractional release. Spontaneous spark frequency was similar despite the increased SR Ca(2+) content, consistent with a reduced RyR channel open probability in Tg. After MI, left ventricular dilatation and myocyte hypertrophy were present in both groups, but more pronounced in Tg. Cell shortening amplitude was unchanged with MI in WT, but increased with MI in Tg. The amplitude of the [Ca(2+)](i) transient was not affected by MI in either genotype, but time to peak was increased; this was most pronounced in Tg. The SR Ca(2+) content and Na(+)- Ca(2+) exchanger function were not affected by MI. Spontaneous spark frequency was increased significantly after MI in Tg, and larger than in WT (at 4 Hz, 2.6 ± 0.4 sparks (100 μm)(-1) s(-1) in Tg MI versus 1.6 ± 0.2 sparks (100 μm)(-1) s(-1) in WT MI; P < 0.05). We conclude that FKPB12.6 overexpression can effectively reduce RyR open probability with maintained cardiomyocyte contraction. However, this approach appears insufficient to prevent and reduce post-MI remodelling, indicating that additional pathways may need to be targeted.
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Phospholamban ablation in hearts expressing the high affinity SERCA2b isoform normalizes global Ca²⁺ homeostasis but not Ca²⁺-dependent hypertrophic signaling. Am J Physiol Heart Circ Physiol 2012; 302:H2574-82. [PMID: 22505640 DOI: 10.1152/ajpheart.01166.2011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cardiomyocytes from failing hearts exhibit reduced levels of the sarcoplasmic reticulum (SR) Ca(2+)-ATPase (SERCA) and/or increased activity of the endogenous SERCA inhibitor phospholamban. The resulting reduction in the Ca(2+) affinity of SERCA impairs SR Ca(2+) cycling in this condition. We have previously investigated the physiological impact of increasing the Ca(2+) affinity of SERCA by substituting SERCA2a with the higher affinity SERCA2b pump. When phospholamban was also ablated, these double knockouts (DKO) exhibited a dramatic reduction in total SERCA levels, severe hypertrophy, and diastolic dysfunction. We presently examined the role of cardiomyocyte Ca(2+) homeostasis in both functional and structural remodeling in these hearts. Despite the low SERCA levels in DKO, we observed near-normal Ca(2+) homeostasis with rapid Ca(2+) reuptake even at high Ca(2+) loads and stimulation frequencies. Well-preserved global Ca(2+) homeostasis in DKO was paradoxically associated with marked activation of the Ca(2+)-dependent nuclear factor of activated T-cell-calcineurin pathway known to trigger hypertrophy. No activation of the MAP kinase signaling pathway was detected. These findings suggest that local changes in Ca(2+) homeostasis may play an important signaling role in DKO, perhaps due to reduced microdomain Ca(2+) buffering by SERCA2b. Furthermore, alterations in global Ca(2+) homeostasis can also not explain impaired in vivo diastolic function in DKO. Taken together, our results suggest that normalizing global cardiomyocyte Ca(2+) homeostasis does not necessarily protect against hypertrophy and heart failure development and that excessively increasing SERCA Ca(2+) affinity may be detrimental.
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Treatment of male mice with estrogen for the study of contractile dysfunction. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.1139.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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