Positron Emission Tomography Imaging of Macrophages in Atherosclerosis with ¹⁸F-GE-180, a Radiotracer for Translocator Protein (TSPO)

Figure 3

Ex vivo autoradiography of aortic sections in LDLR^–/–ApoB^100/100 mice. Longitudinally cut aortic arch stained with hematoxylin-eosin (a, d) shows large atherosclerotic plaques in the inner curvature of the arch and its all branches. Scale bar is 1 mm. AA = aortic arch, B = brachiocephalic trunk, LC = left common carotid artery, LS = left subclavian artery, L = lumen, and W = lesion-free vessel wall. Macrophage immunostainings (b, e) show areas of high (arrowhead) and low (black arrow) macrophage infiltration in the plaques. Lesion-free vessel wall is indicated with a red arrow. (c) Autoradiography shows high ¹⁸F-GE-180 count density (red colour) in the macrophage-rich areas in plaques as well as in the lesion-free vessel wall. Plaque areas with low macrophage infiltration show low count density (blue to green). (f) Autoradiography in mice preinjected with nonradioactive GE-180 shows similar level of count density in lesion-free vessel wall and all plaque areas. (g) Quantitative results of the autoradiography. ANOVA with Tukey’s correction were used in assessing differences between analysed areas within each mouse group. Asterisk indicates statistically significant difference to nonblocked LDLR^−/−ApoB^100/100 mice in Student’s t-test.

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