Excerpt

Just recently, inflammatory processes after myocardial infarction (MI) as an important additional factor for cardiac remodeling have come to the fore. As a consequence, there is an urgent unmet clinical need for tracers targeting specifically non-pathogen-driven, inflammatory processes in the heart. Here, we present the potential of a novel PET tracer targeting the expression of the chemokine receptor 4 (CXCR4) on inflammatory cells after acute MI. CXCR4 belongs to the family of G-protein-coupled receptors and is involved in biological processes such as the entry of HIV-1, the development of metastasis and several inflammatory conditions. The CXCR4 receptor is expressed only at low levels on the surface of circulating lymphocytes, macrophages, and neutrophils, but is highly upregulated when these cells infiltrate inflamed tissues. In addition, CXCR4 expression is strongly increased on the cell surface under hypoxic conditions via the stimulation of HIF (hypoxia-inducible factor). Therefore, the CXCR4 receptor represents an attractive molecular target to identify the presence of activated inflammatory cells located in the post-ischemic myocardium. …