Imaging Myocardial Ischemia and Reperfusion Injury via Cy5.5-Annexin V

Abstract

Aim The aim of this article is to present the results of an imaging study of myocardial apoptosis induced by ischemia/reperfusion injury. Methods Twenty nude mice were randomly divided into an experimental group (10 mice) and control group (10 mice). In the experimental group, myocardial apoptosis was induced by ligation of the left anterior descending coronary artery (LAD) for 30 min. This was followed by reperfusion for 90 min. In the control group, the heart was exposed for the same length of time as in the experimental group. Cy5. 5-annexin V (25 μg) was injected into both sets of mice after the onset of reperfusion. At 90 min post-injection, the mice were imaged. The region of interest (ROI) was obtained, and the fluorescence intensity of the ROI was quantified. The animals were sacrificed, and myocardial apoptosis was assayed by TUNEL assay. Results Fluorescence intensity in the ischemia/reperfusion hearts was significantly higher than that in the control group (P<0.05). In the TUNEL assay, more apoptotic cells were observed in the experimental group than in the control group, correlating with imaging results. Conclusion Fluorescence imaging of Cy5.5-annexin V in a mouse model of myocardial ischemia/reperfusion can be used in vivo as a noninvasive means of detecting ischemia/reperfusion-induced apoptotic cells in the heart.

Prognostic Value of Normal Perfusion but Impaired Left Ventricular Function in the Diabetic Heart on Quantitative Gated Myocardial Perfusion SPECT

“…Myocardial perfusion single-photon emission computed tomography (SPECT) is well-known to provide ischemic, metabolic, and prognostic information in not only research but clinical data of general and specific conditions, especially diabetes, even though new image modalities such as fluorine-18 fluorodeoxyglucose positron emission tomography (F-18 FDG PET)/magnetic resonance imaging (MRI) and optical imaging studies are widely investigated [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. Information on perfusion such as the greater degree, extent and reversibility of perfusion defect on SPECT, are related directly to patient's adverse outcome.…”

Relationship between Apoptosis Imaging and Radioiodine Therapy in Tumor Cells with Different Sodium Iodide Symporter Gene Expression

“…10 Although annexin V has been widely used for apoptosis imaging in clinical circumstances, annexin V, which targets phosphatidylserine in the inner leaflet of cell membrane, has many disadvantages in terms of a lack of specificity for apoptotic cells to nonapoptotic cells, slow removal from the body, and a low signal to background ratio for in vivo practice. 11,12 ApoFlamma (BioActs, Seoul, Korea) is a new apoptosistargeting peptide 1, named ApoPep-1, with six amino acids (CQRPQR) conjugated to a fluorescent dye ( Figure S1, online version only). ApoPep-1 targets apoptotic cells by binding to histone H1 exposed on the surface of apoptotic cells but does not compete with annexin V ( Figure S2, online version only).…”

“…10 Although annexin V has been widely used for apoptosis imaging in clinical circumstances, annexin V, which targets phosphatidylserine in the inner leaflet of cell membrane, has many disadvantages in terms of a lack of specificity for apoptotic cells to nonapoptotic cells, slow removal from the body, and a low signal to background ratio for in vivo practice. 11,12…”