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Cardiac mechanics

Carlos Fernandez-Patron, Zamaneh Kassiri, Dickson Leung
Matrix metalloproteinase-2 (MMP-2) is a 72-kDa zinc- and calcium-dependent endopeptidase with intracellular and extracellular functions ranging from the modulation of extracellular matrix remodeling to cell growth and migration, angiogenesis, inflammation, and metabolism. An upregulation of MMP-2 activity has the potential to deregulate lipid metabolism through the cleavage of numerous metabolic mediators including plasma lipoproteins and cell surface receptors of lipoproteins. Paradoxically, MMP-2 deficiency induces inflammation and deregulates metabolism...
September 15, 2016: Comprehensive Physiology
Salma Ayoub, Giovanni Ferrari, Robert C Gorman, Joseph H Gorman, Frederick J Schoen, Michael S Sacks
Heart valves control unidirectional blood flow within the heart during the cardiac cycle. They have a remarkable ability to withstand the demanding mechanical environment of the heart, achieving lifetime durability by processes involving the ongoing remodeling of the extracellular matrix. The focus of this review is on heart valve functional physiology, with insights into the link between disease-induced alterations in valve geometry, tissue stress, and the subsequent cell mechanobiological responses and tissue remodeling...
September 15, 2016: Comprehensive Physiology
Heinrich Taegtmeyer, Truong Lam, Giovanni Davogustto
The heart is a biological pump that converts chemical to mechanical energy. This process of energy conversion is highly regulated to the extent that energy substrate metabolism matches energy use for contraction on a beat-to-beat basis. The biochemistry of cardiac metabolism includes the biochemistry of energy transfer, metabolic regulation, and transcriptional, translational as well as posttranslational control of enzymatic activities. Pathways of energy substrate metabolism in the heart are complex and dynamic, but all of them conform to the First Law of Thermodynamics...
September 15, 2016: Comprehensive Physiology
Jeffrey L Ardell, John Andrew Armour
Cardiac control is mediated via a series of reflex control networks involving somata in the (i) intrinsic cardiac ganglia (heart), (ii) intrathoracic extracardiac ganglia (stellate, middle cervical), (iii) superior cervical ganglia, (iv) spinal cord, (v) brainstem, and (vi) higher centers. Each of these processing centers contains afferent, efferent, and local circuit neurons, which interact locally and in an interdependent fashion with the other levels to coordinate regional cardiac electrical and mechanical indices on a beat-to-beat basis...
September 15, 2016: Comprehensive Physiology
Laura Denise Mendes da Silva, Mariana Gatto, Mariana Miziara de Abreu Teodoro, Marjorie de Assis Golim, Érika Alessandra Pelisson Nunes da Costa, Francilene Capel Tavares Carvalho, Daniela Ramos Rodrigues, Paulo Câmara Marques Pereira, Ângela Maria Victoriano de Campos Soares, Sueli Aparecida Calvi
Chagas disease (CD), caused by the protozoan Trypanosoma cruzi is a serious public health issue. Its evolution involves an acute stage, characterized by no specific symptoms, and the chronic stage during most individuals are asymptomatic, but about 30 to 40% of them become symptomatic presenting the cardiac or digestive disease. Host immune response mechanisms involved in symptomatic or asymptomatic chronic disease are not fully understood. The pro-inflammatory cytokines are crucial in host resistance. However, a fine control of this inflammatory process, by action of anti-inflammatory cytokines, is necessary to avoid tissue injury...
October 26, 2016: Scandinavian Journal of Immunology
Jan Marro, Catherine Pfefferli, Anne-Sophie de Preux Charles, Thomas Bise, Anna Jaźwińska
Zebrafish heart regeneration depends on cardiac cell proliferation, epicardium activation and transient reparative tissue deposition. The contribution and the regulation of specific collagen types during the regenerative process, however, remain poorly characterized. Here, we identified that the non-fibrillar type XII collagen, which serves as a matrix-bridging component, is expressed in the epicardium of the zebrafish heart, and is boosted after cryoinjury-induced ventricular damage. During heart regeneration, an intense deposition of Collagen XII covers the outer epicardial cap and the interstitial reparative tissue...
2016: PloS One
Pendar Farahani
Evidence from literature illustrates that from a pathophysiological perspective, sulfonylureas (SU) may impact the heart three ways: directly by intrinsic properties from a pharmacological receptor perspective, indirectly by adverse effects related to hypoglycemia, and obesity. From a pharmacologlogical receptor perspective, SU can bind to ATP-sensitive potassium channels in cardiomyocytes. Channel binding by SU in cardiac tissue may prevent ischemia myocardial protective mechanisms. From a pathophysiological perspective, obesity is associated with cardiac issues such as pulmonary hypertension, left ventricular hypertrophy, arrhythmia, and atrial fibrillation...
September 13, 2016: Journal of Population Therapeutics and Clinical Pharmacology
J-J Liu, Y Lu, N-N Ping, X Li, Y-X Lin, C F Li
Oxidative stress plays an important role in pressure overload-induced cardiac remodeling. The purpose of this study was to determine whether apocynin, a nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor, attenuates pressure overload-induced cardiac remodeling in rats. After abdominal aorta constriction, the surviving rats were randomly divided into four groups: sham group, abdominal aorta constriction group, apocynin group, captopril group. Left ventricular pathological changes were studied using Masson's trichrome staining...
October 26, 2016: Physiological Research
Jenna Scotcher, Oleksandra Prysyazhna, Andrii Boguslavskyi, Kornel Kistamas, Natasha Hadgraft, Eva D Martin, Jenny Worthington, Olena Rudyk, Pedro Rodriguez Cutillas, Friederike Cuello, Michael J Shattock, Michael S Marber, Maria R Conte, Adam Greenstein, David J Greensmith, Luigi Venetucci, John F Timms, Philip Eaton
The Frank-Starling mechanism allows the amount of blood entering the heart from the veins to be precisely matched with the amount pumped out to the arterial circulation. As the heart fills with blood during diastole, the myocardium is stretched and oxidants are produced. Here we show that protein kinase G Iα (PKGIα) is oxidant-activated during stretch and this form of the kinase selectively phosphorylates cardiac phospholamban Ser16-a site important for diastolic relaxation. We find that hearts of Cys42Ser PKGIα knock-in (KI) mice, which are resistant to PKGIα oxidation, have diastolic dysfunction and a diminished ability to couple ventricular filling with cardiac output on a beat-to-beat basis...
October 26, 2016: Nature Communications
Esma R Isenovic, Aleksandra Jovanovic, Emina Sudar Milovanovic, Sudar Milovanovic, Samantha J Pitt, Alan J Stewart, Sonja Zafirovic, Julijana Stanimirovic, Djordje Radak
Overexpression of inducible nitric oxide synthase (iNOS) is a key link between high-fat (HF) diet induced obesity and cardiovascular disease. Oestradiol has cardioprotective effects that may be mediated through reduction of iNOS activity/expression. In the present study, female Wistar rats were fed a standard diet or a HF diet (42% fat) for 10 weeks. iNOS gene and protein expressions were measured in heart tissue. HF-fed rats exhibited a significant increase in cardiac iNOS mRNA by 695% (p<0.05), iNOS protein level by 248% (p<0...
October 25, 2016: Current Vascular Pharmacology
Tang-Meng Guo, Li-Li Huang, Kai Liu, Li Ke, Zhi-Jian Luo, Yun-Qiao Li, Xing-Lin Chen, Bei Cheng
BACKGROUND: Pentraxin 3 (PTX3) is expressed in the heart under inflammatory conditions and plays an important role in atherogenesis. Patients with increased PTX3 levels may suffer from higher rates of cardiac events. Regulation of specific genes by promoter methylation is important in atherogenesis. The factors influencing PTX3 levels and the association between epigenetics and PTX3 levels have not been investigated. METHODS: Blood samples were collected from 64 patients admitted to the Department of Cardiology, 35 who had coronary artery disease (CAD), and 29 who were CAD-free...
August 2016: Journal of Geriatric Cardiology: JGC
Fenfen Ma, Wenwen Li, Xinghui Li, Ba Hieu Tran, Rinkiko Suguro, Ruijuan Guan, Cuilan Hou, Huijuan Wang, Aijie Zhang, Yichun Zhu, YiZhun Zhu
Extracorporeal pulsed electromagnetic field (PEMF) has shown the ability to regenerate tissue by promoting cell proliferation. Here, we investigated for the first time whether PEMF treatment could improve the myocardial ischemia/reperfusion (I/R) injury and uncovered its underlying mechanisms. In our study, we demonstrated for the first time that extracorporeal pulsed electromagnetic field(PEMF)has a novel effect on myocardial ischemia/reperfusion(I/R)injury. The number and function of circulating endothelial progenitor cells were increased in PEMF treating rats...
October 25, 2016: Bioscience Reports
Shu-Ching Huang, Anyu Zhou, Dan T Nguyen, Henry S Zhang, Edward J Benz
Protein 4.1R (4.1R) isoforms are expressed in both cardiac and skeletal muscle. 4.1R is a component of the contractile apparatus. It is also associated with dystrophin at the sarcolemma in skeletal myofibers. However, the expression and function of 4.1R during myogenesis have not been characterized. We now report that 4.1R expression increases during C2C12 myoblast differentiation into myotubes. Depletion of 4.1R impairs skeletal muscle differentiation, and is accompanied by a decrease in the levels of myosin heavy and light chains and caveolin-3...
October 25, 2016: Journal of Biological Chemistry
Jonathan M Behar, Simon Claridge, Tom Jackson, Ben Sieniewicz, Bradley Porter, Jessica Webb, Ronak Rajani, Stamatis Kapetanakis, Gerald Carr-White, Christopher A Rinaldi
Cardiac resynchronization therapy (CRT) is an effective pacemaker delivered treatment for selected patients with heart failure with the target of restoring electro-mechanical synchrony. Imaging techniques using echocardiography have as yet failed to find a metric of dyssynchrony to predict CRT response. Current guidelines are thus unchanged in recommending prolonged QRS duration, severe systolic function and refractory heart failure symptoms as criteria for CRT implantation. Evolving strain imaging techniques in 3D echocardiography, cardiac MRI and CT may however, overcome limitations of older methods and yield more powerful CRT response predictors...
October 26, 2016: Expert Review of Cardiovascular Therapy
Kuan-Ho Lin, Chien-Liang Liu, Wei-Wen Kuo, Catherine Reena Paul, Wei-Kung Chen, Su-Ying Wen, Cecilia Hsuan Day, Hsi-Chin Wu, Vijaya Padma Viswanadha, Chih-Yang Huang
Cardiac trauma has been recognized as a complication associated with blunt chest trauma involving coronary artery injury, myocardium contusion and myocardial rupture. Secondary cardiac injuries after trauma supposed to be a critical factor in trauma patients, but the mechanism is not fully explored. Overproduction of TNF-alpha had been reported in multiple trauma animals, this induces oxidative stress resulting in cardiac apoptosis. Apoptosis gradually increases after trauma and reaches to a maximum level in 12 h time...
2016: PloS One
Seema Patel
Cardiac glycosides, the cardiotonic steroids such as digitalis have been in use as heart ailment remedy since ages. They manipulate the renin-angiotensin axis to improve cardiac output. However; their safety and efficacy have come under scrutiny in recent times, as poisoning and accidental mortalities have been observed. In order to better understand and exploit them as cardiac ionotropes, studies are being pursued using different cardiac glycosides such as digitoxin, digoxin, ouabain, oleandrin etc. Several cardiac glycosides as peruvoside have shown promise in cancer control, especially ovary cancer and leukemia...
October 22, 2016: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
Zipu Yu, Yu Zou, Jingya Fan, Chengchen Li, Liang Ma
Notch signaling is involved in the early process of differentiation to determine the fate of stem cells. However, the precise role of Notch in human bone marrow‑derived mesenchymal stem cells (hBMSCs) remains unclear. The present study aimed to investigate the involvement of Notch signalling during the course of hBMSC differentiation into cardiomyocytes using hBMSCs, with multilineage differentiation ability, isolated and purified from human bone marrow. Flow cytometric analysis revealed that CD29, CD44 and CD90 were highly expressed on the surface of cells in their fifth passage, whereas detection of CD34, CD45, CD54 and HLA‑DR was negative...
October 19, 2016: Molecular Medicine Reports
Maria Clara Alencar, Flavio F Arbex, Aline Souza, Adriana Mazzuco, Priscila A Sperandio, Alcides Rocha, Daniel M Hirai, Frederico Mancuso, Danilo C Berton, Audrey Borghi-Silva, Dirceu Almeida, Denis E OʼDonnel, J Alberto Neder
PURPOSE: To investigate whether the opposite effects of heart failure (HF) and chronic obstructive pulmonary disease (COPD) on exercise ventilatory inefficiency (minute ventilation [(Equation is included in full-text article.)E]-carbon dioxide output [(Equation is included in full-text article.)CO2] relationship) would negatively impact its prognostic relevance. METHODS: After treatment optimization and an incremental cardiopulmonary exercise test, 30 male patients with HF-COPD (forced expiratory volume in 1 second [FEV1] = 57% ± 17% predicted, ejection fraction = 35% ± 6%) were prospectively followed up during 412 ± 261 days for major cardiac events...
November 2016: Journal of Cardiopulmonary Rehabilitation and Prevention
S Cacanyiova, A Berenyiova, F Kristek, M Drobna, K Ondrias, M Grman
The aorta plays an important role in blood pressure control so the early determination of its vasoactive properties could predict pathological changes in hypertension. The aim of study was to compare vasoactive properties and geometry of thoracic aorta (TA) and the participation of two vasoactive transmitters, nitric oxide (NO) and hydrogen sulphide (H2S), in TA tone regulation in young Wistar rats (WR) and spontaneously hypertensive rats (SHR). Four-weeks-old WR and SHR were used. Systolic blood pressure (sBP) was measured by plethysmography...
August 2016: Journal of Physiology and Pharmacology: An Official Journal of the Polish Physiological Society
Min Xie, Yan Yu, Rui Kang, Shan Zhu, Liangchun Yang, Ling Zeng, Xiaofang Sun, Minghua Yang, Timothy R Billiar, Haichao Wang, Lizhi Cao, Jianxin Jiang, Daolin Tang
Sepsis, severe sepsis and septic shock are the main cause of mortality in non-cardiac intensive care units. Immunometabolism has been linked to sepsis; however, the precise mechanism by which metabolic reprogramming regulates the inflammatory response is unclear. Here we show that aerobic glycolysis contributes to sepsis by modulating inflammasome activation in macrophages. PKM2-mediated glycolysis promotes inflammasome activation by modulating EIF2AK2 phosphorylation in macrophages. Pharmacological and genetic inhibition of PKM2 or EIF2AK2 attenuates NLRP3 and AIM2 inflammasomes activation, and consequently suppresses the release of IL-1β, IL-18 and HMGB1 by macrophages...
October 25, 2016: Nature Communications
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