From bench to imagingRole of molecular imaging in defining and denying death…
Introduction
In 1992 Fadok et al1 established the essentials for a unique apoptosis detection method by demonstrating that apoptotic cells externalize phosphatidylserine (PS), a plasma membrane phospholipid, at their surface. Reutelingsperger and colleagues2 discovered that annexin A5 binds to PS that is exposed by cells undergoing apoptosis. The high-affinity binding capacities of annexin A5 provide us with an excellent tool by which to detect apoptotic cells. Today, annexin A5 is globally used as a rapid way to detect apoptotic cells in vitro as well as in vivo. The first attempts to detect apoptosis in vivo were performed by van den Eijnde et al,3 who demonstrated detection of apoptosis in the developing embryo by direct injection of biotinylated annexin A5 in the heart. In this review we will discuss the use of annexin A5 in the detection of apoptosis in cardiovascular diseases, such as acute myocardial infarction and atherosclerotic plaque instability. We will focus on the detection of cardiac apoptosis induced by ischemia and reperfusion and discuss the possibilities for reversal of apoptosis to salvage myocardial cells and to preserve cardiac function.
Section snippets
Apoptosis in general
Apoptosis is a mode of programmed cell death, which results from a molecular program based on a well-organized biochemistry. Apoptosis is used by multicellular organisms to regulate their cell number and to remove unwanted and dysfunctional cells. Strict regulation of cell number through apoptosis is an essential process in the normal development and homeostasis of the healthy adult. Dysregulation of apoptosis is a major determinant in the etiology and progression of a variety of diseases, such
Molecular imaging in general
Molecular imaging is a swiftly developing technique that aims to visualize the biology and physiology of disease in organisms in a repetitive and noninvasive way.5 In conventional imaging, such as magnetic resonance imaging and computed tomography, the anatomic consequences of a disease are visualized, such as the size and localization of a tumor. The limited spatial resolution of conventional imaging techniques does not allow the visualization of the anatomic consequences of a disease below a
Acknowledgements
The authors have indicated they have no financial conflicts of interest.
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