Carbachol-induced reverse transformation of Chinese hamster ovary cells transfected with and expressing the m5 muscarinic acetylcholine receptor

AbstractReverse transformation was induced in Chinese hamster ovary (CHO) cells transfected with and stably expressing the m5 subtype of the muscarinic acetylcholine receptor when stimulated with the muscarinic agonist, carbachol. Atropine, a muscarinic antagonist, blocked the carbachol-stimulated reverse transformation. CHO cells not transfected with the muscarinic receptor did not change with added carbachol. PMA induced reverse transformation without increasing cAMP accumulation in CHO cells. Carbachol, prostaglandin E2, and cholecystokinin increased cAMP accumulation but only carbachol caused reverse transformation. Carbachol-stimulated cAMP accumulation occurred at a higher concentration (EC50 10 μM) than did carbachol-stimulated reverse transformation (EC50 63 nM). Muscarinic m5 acetylcholine receptor transfected into CHO cells can induce reverse transformation which may be independent of cAMP

Automated Video-Based Analysis of Contractility and Calcium Flux in Human-Induced Pluripotent Stem Cell-Derived Cardiomyocytes Cultured over Different Spatial Scales

Contractile motion is the simplest metric of cardiomyocyte health in vitro, but unbiased quantification is challenging. We describe a rapid automated method, requiring only standard video microscopy, to analyze the contractility of human-induced pluripotent stem cell-derived cardiomyocytes (iPS-CM). New algorithms for generating and filtering motion vectors combined with a newly developed isogenic iPSC line harboring genetically encoded calcium indicator, GCaMP6f, allow simultaneous user-independent measurement and analysis of the coupling between calcium flux and contractility. The relative performance of these algorithms, in terms of improving signal to noise, was tested. Applying these algorithms allowed analysis of contractility in iPS-CM cultured over multiple spatial scales from single cells to three-dimensional constructs. This open source software was validated with analysis of isoproterenol response in these cells, and can be applied in future studies comparing the drug responsiveness of iPS-CM cultured in different microenvironments in the context of tissue engineering

Automated Video-Based Analysis of Contractility and Calcium Flux in Human-Induced Pluripotent Stem Cell-Derived Cardiomyocytes Cultured over Different Spatial Scales

Contractile motion is the simplest metric of cardiomyocyte health in vitro, but unbiased quantification is challenging. We describe a rapid automated method, requiring only standard video microscopy, to analyze the contractility of human-induced pluripotent stem cell-derived cardiomyocytes (iPS-CM). New algorithms for generating and filtering motion vectors combined with a newly developed isogenic iPSC line harboring genetically encoded calcium indicator, GCaMP6f, allow simultaneous user-independent measurement and analysis of the coupling between calcium flux and contractility. The relative performance of these algorithms, in terms of improving signal to noise, was tested. Applying these algorithms allowed analysis of contractility in iPS-CM cultured over multiple spatial scales from single cells to three-dimensional constructs. This open source software was validated with analysis of isoproterenol response in these cells, and can be applied in future studies comparing the drug responsiveness of iPS-CM cultured in different microenvironments in the context of tissue engineering

Miniaturized iPS-Cell-Derived Cardiac Muscles for Physiologically Relevant Drug Response Analyses.

Tissue engineering approaches have the potential to increase the physiologic relevance of human iPS-derived cells, such as cardiomyocytes (iPS-CM). However, forming Engineered Heart Muscle (EHM) typically requires >1 million cells per tissue. Existing miniaturization strategies involve complex approaches not amenable to mass production, limiting the ability to use EHM for iPS-based disease modeling and drug screening. Micro-scale cardiospheres are easily produced, but do not facilitate assembly of elongated muscle or direct force measurements. Here we describe an approach that combines features of EHM and cardiospheres: Micro-Heart Muscle (μHM) arrays, in which elongated muscle fibers are formed in an easily fabricated template, with as few as 2,000 iPS-CM per individual tissue. Within μHM, iPS-CM exhibit uniaxial contractility and alignment, robust sarcomere assembly, and reduced variability and hypersensitivity in drug responsiveness, compared to monolayers with the same cellular composition. μHM mounted onto standard force measurement apparatus exhibited a robust Frank-Starling response to external stretch, and a dose-dependent inotropic response to the β-adrenergic agonist isoproterenol. Based on the ease of fabrication, the potential for mass production and the small number of cells required to form μHM, this system provides a potentially powerful tool to study cardiomyocyte maturation, disease and cardiotoxicology in vitro

Miniaturized iPS-Cell-Derived Cardiac Muscles for Physiologically Relevant Drug Response Analyses

Tissue engineering approaches have the potential to increase the physiologic relevance of human iPS-derived cells, such as cardiomyocytes (iPS-CM). However, forming Engineered Heart Muscle (EHM) typically requires >1 million cells per tissue. Existing miniaturization strategies involve complex approaches not amenable to mass production, limiting the ability to use EHM for iPS-based disease modeling and drug screening. Micro-scale cardiospheres are easily produced, but do not facilitate assembly of elongated muscle or direct force measurements. Here we describe an approach that combines features of EHM and cardiospheres: Micro-Heart Muscle (μHM) arrays, in which elongated muscle fibers are formed in an easily fabricated template, with as few as 2,000 iPS-CM per individual tissue. Within μHM, iPS-CM exhibit uniaxial contractility and alignment, robust sarcomere assembly, and reduced variability and hypersensitivity in drug responsiveness, compared to monolayers with the same cellular composition. μHM mounted onto standard force measurement apparatus exhibited a robust Frank-Starling response to external stretch, and a dose-dependent inotropic response to the β-adrenergic agonist isoproterenol. Based on the ease of fabrication, the potential for mass production and the small number of cells required to form μHM, this system provides a potentially powerful tool to study cardiomyocyte maturation, disease and cardiotoxicology in vitro

Liberal Government and the Practical History of Anthropology

This paper explores the implications of Foucault's perspective of liberal government for approaches to the practical history of anthropology. It also draws on assemblage theory to consider the changing relations between field, museum and university in relation to a range of early twentieth-century anthropological practices. These focus mainly on the development of the Boasian paradigm in the USA during the inter-war years and on the anthropological practices clustered around the Musée de l'Homme in the 1930s. Key steps in the argument focus on the role of what Foucault called "transactional realities" in mediating the practical applications of anthropology in colonial contexts and in "anthropology at home" projects. Special consideration is also given to the increasingly archival properties of anthropological collections in the early twentieth century and the consequences of this for anthropology's relations to practices of governing

Science de l'Homme et domination rationnelle : Savoir ethnologique et politique indigène en Afrique coloniale française

International audienceThis paper explores the uses of the Weberian notion of «rational domination» as a tool for analysing the relationships between efforts by the Colonial State at controlling native populations and the development of a specific form of scientific rationality, taking these populations as objects: anthropological knowledge. Focusing on French colonial Africa, it argues that the aspects of instrumentation (with the production of instruments of identification and understanding) and of legitimization play an essential part in the emergence of a knowledge on native societies and cultures, firstly within the administration, but also in metropolitan scientific institutions. Support for the development of the science of man takes place within the framework of projects or «rationalization» of colonial domination that draw together scientists and reformers attached to the Colonial School, aiming at professionalizing the role of «colonial administrator», redefining it as a «specialist of natives».L'article explore la notion wébérienne de «domination rationnelle» comme outil pour analyser les rapports entre les efforts de gestion des populations indigènes par l'État colonial, et le développement d'une forme spécifique de rationalité scientifique, prenant pour objet ces populations: les savoirs anthropologiques. En s'appuyant sur le cas de l'Afrique coloniale française, on s'efforce de montrer comment les dimensions d'instrumentation (avec la production d'instruments d'identification et de compréhension) et de légitimation sont essentielles dans l'émergence de savoirs sur les sociétés et les cultures indigènes, d'abord au sein des appareils administratifs, mais aussi dans les institutions savantes métropolitaines. L'appui au développement de la science de l'homme se fait dans le cadre de projets de «rationalisation» de la colonisation qui rapprochent des savants et des réformateurs liés à l'École coloniale, voulant redéfinir la profession d'administrateur colonial comme «spécialiste des indigènes»