Fig. 3: ⁸⁹Zr-mA1 as a probe for monitoring inflammation in the LAD-ligated mouse model of myocardial infarction.

A Schematic overview of the experimental design. B Representative PET/CT images of infarcted animals scanned 24 h after tracer injection. Arrow indicates infarcted region. C PET-based quantification of ⁸⁹Zr-mA1 uptake in the myocardium 24 h post tracer injection (n = 4). D ⁸⁹Zr-mA1 uptake in the myocardium measured by ex vivo gamma counting (n = 4–5). Control: tissue from C57BL/6 mice. E Autoradiographs showing tracer distribution in the myocardium of infarcted mice 24 h p.i. Images show whole heart followed by a representative sectioned slice of ~1 mm thick. Corresponding TTC-stained tissues are also shown. F Autoradiography (left) and qualitative histology of the infarcted myocardium showing H&E staining (top right) and regions of macrophage accumulation as determined by Mac-3 staining (bottom). Scale bars represent 1 mm in the main figure and 20 μm in the magnification. G Mice were injected with ^natZr-mA1 two days after myocardial infarction. Twenty-four hours after injection, mice were euthanized and CyTOF performed on the infarct zone (n = 3). t-SNE plot of viable leukocytes in the infarct, color-coded for ^natZr-mA1 uptake and the expression of various myeloid cell markers. H Quantification of cell subsets in the infarct as a percentage of the total number of viable cells. I Percentage of ^natZr-positive cells within each subset. J Relative abundance of ^natZr-positive cell subsets in the infarct (right). Control: healthy myocardium of non-infarcted animals, DC dendritic cells, remote remote myocardium. *P < 0.05.