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Your search keyword '"Beauchamp, Philippe"' showing total 18 results
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18 results on '"Beauchamp, Philippe"'

8. Development and characterization of a scaffold-free 3D spheroid model of iPSC-derived human cardiomyocytes

Author

Suter, Thomas, Zuppinger, Christian, Moritz, Wolfgang, Anson, Blake, Ullrich, Nina, Agarkova, Irina, Beauchamp, Philippe, and Jens, Kelm

Subjects
610 Medicine & health
Abstract

Purpose: Cardiomyocytes are terminally differentiated cells in the adult heart and ischemia and cardiotoxic compounds can lead to cell death and irreversible decline of cardiac function. As testing platforms, isolated organs and primary cells from rodents have been the standard in research and toxicology, but there is a need for better models that more faithfully recapitulate native human biology. Hence, a new in vitro model comprising the advantages of 3D cell culture and the availability of induced pluripotent stem cells (iPSC) from human origin was developed and characterized. Methods: Human cardiomyocytes (CMs) derived from induced pluripotent stem cells (iPSCs) were studied in standard 2D culture and as cardiac microtissues (MTs) formed in hanging drops. 2D cultures were examined using immunofluorescence microscopy and Western blotting while the cardiac MTs were subjected to immunofluorescence, contractility, and pharmacological investigations. Results: iPSC-derived CMs in 2D culture showed well-formed myofibrils, cell-cell contacts positive for connexin-43, and other typical cardiac proteins. The cells reacted to pro-hypertrophic growth factors with a substantial increase in myofibrils and sarcomeric proteins. In hanging drop cultures, iPSC-derived cardiomyocytes formed spheroidal MTs within 4 days showing a homogeneous tissue structure with well-developed myofibrils extending throughout the whole spheroid without a necrotic core. MTs showed spontaneous contractions for more than 4 weeks that were recorded by optical motion tracking, sensitive to temperature, and responsive to electrical pacing. Contractile pharmacology was tested with several agents known to modulate cardiac rate and viability. Calcium-transients underlay the contractile activity and were also responsive to electrical stimulation, caffeine-induced Ca2+-release, extracellular calcium levels. Conclusions: 3D culture using iPSC-derived human cardiomyocytes provides an organoid human-based cellular platform that is free of necrosis and recapitulates vital cardiac functionality, thereby providing new and promising relevant model for the evaluation and development of new therapies and detection of cardiotoxicity.

Published
2015
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9. Del Nido cardioplegia in the setting of minimally invasive aortic valve surgery

Author

Vistarini, Nicola, primary, Laliberté, Eric, additional, Beauchamp, Philippe, additional, Bouhout, Ismail, additional, Lamarche, Yoan, additional, Cartier, Raymond, additional, Carrier, Michel, additional, Perrault, Louis, additional, Bouchard, Denis, additional, El-Hamamsy, Ismaïl, additional, Pellerin, Michel, additional, and Demers, Philippe, additional

Published
2016
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14. Real time simulation for the study on smart grid

Author

Guo, Feng, primary, Herrera, Luis, additional, Murawski, Robert, additional, Inoa, Ernesto, additional, Wang, Chih-Lun, additional, Huang, Yi, additional, Ekici, Eylem, additional, Wang, Jin, additional, and Beauchamp, Philippe, additional

Published
2011
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18. Endothelial protective effects of preconditioning

Author

Laude, Karine, Beauchamp, Philippe, Thuillez, Christian, and Richard, Vincent

Subjects
*ISCHEMIA, *ENDOTHELIUM, *NITRIC oxide
Abstract

The consequences of cardiac ischemia–reperfusion are not limited to myocytes but also extend to the coronary endothelium, where they are characterized by decreased nitric oxide (NO)-dependent relaxations. Given the essential role of the endothelium and NO in the regulation of vascular tone as well as platelet and leukocyte function, protection of coronary endothelial cells is an important therapeutic target. In this context, several studies have shown that both early and delayed preconditioning may prevent endothelial dysfunction after index ischemia–reperfusion. This endothelial protection most likely results from the inhibitory effects of preconditioning on expression of endothelial adhesion molecules, resulting in reduced neutrophil–endothelial interactions. The mechanisms of early endothelial preconditioning resemble those described at the level of the myocytes, and may involve mediators such as adenosine, bradykinin, NO and free radicals, together with activation of protein kinase C and opening of ATP-sensitive potassium channels. With regard to delayed preconditioning, recent studies have shown that both NO and free radicals are involved as triggers of this second window of endothelial protection. The complex interactions between these two radical species ultimately lead to a delayed increase in NO production, most likely responsible for the decreased adhesion of neutrophils to endothelial cells. Further identification of the triggers and mediators of this endothelial protection will allow the development of new therapeutic agents targeting both the myocardium and the coronary vasculature. [Copyright &y& Elsevier]

Published
2002
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