Optical characterization of arterial apoptosis

Apoptosis is a biological hallmark of both acute and chronic vascular pathology. It contributes to erosion and rupturing of atherosclerotic plaques, causing stroke and myocardial infarction, and plays an important role in post-angioplastic remodeling. Therefore, apoptosis is intensively studied in both explanatory and interventional vascular studies. Real-time molecular imaging of vascular processes, such as apoptosis, promises to improve our understanding and control over vascular micropathology, and could accelerate the development of novel therapies. Annexin A5 binds to apoptotic cells and is a well-established molecular imaging tool for detecting cell death in vivo. Here we describe a relatively straightforward approach to visualizing cell death in a murine carotid artery injury model using fluorescently tagged annexin A5. Our methods allow investigators to monitor gross apoptotic burden in real-time, as well as to assess in detail the apoptotic cell population and localization.