@article {Bascu{\~n}ana977, author = {Pablo Bascu{\~n}ana and Annika Hess and Tobias Borchert and Yong Wang and Kai C. Wollert and Frank M. Bengel and James T. Thackeray}, title = {11C-Methionine PET Identifies Astroglia Involvement in Heart{\textendash}Brain Inflammation Networking After Acute Myocardial Infarction}, volume = {61}, number = {7}, pages = {977--980}, year = {2020}, doi = {10.2967/jnumed.119.236885}, publisher = {Society of Nuclear Medicine}, abstract = {Acute myocardial infarction (MI) triggers a local and systemic inflammatory response. We recently showed microglia involvement using translocator protein imaging. Here, we evaluated whether 11C-methionine provides further insight into heart{\textendash}brain inflammation networking. Methods: Male C57BL/6 mice underwent permanent coronary artery ligation followed by 11C-methionine PET at 3 and 7 d (n = 3). In subgroups, leukocyte homing was blocked by integrin antibodies (n = 5). The cellular substrate for PET signal was identified using brain section immunostaining. Results: 11C-methionine uptake (percentage injected dose/cm3) peaked in the MI region on day 3 (5.9 {\textpm} 0.9 vs. 2.4 {\textpm} 0.5), decreasing to the control level by day 7 (4.3 {\textpm} 0.6). Brain uptake was proportional to cardiac uptake (r = 0.47, P \< 0.05), peaking also on day 3 (2.9 {\textpm} 0.4 vs. 2.4 {\textpm} 0.3) and returning to baseline on day 7 (2.3 {\textpm} 0.4). Integrin blockade reduced uptake at every time point. Immunostaining on day 3 revealed colocalization of the l-type amino acid transporter, with glial fibrillary acidic protein{\textendash}positive astrocytes but not CD68-positive microglia. Conclusion: PET imaging with 11C-methionine specifically identifies an astrocyte component, enabling further dissection of the heart{\textendash}brain axis in post-MI inflammation.}, issn = {0161-5505}, URL = {https://jnm.snmjournals.org/content/61/7/977}, eprint = {https://jnm.snmjournals.org/content/61/7/977.full.pdf}, journal = {Journal of Nuclear Medicine} }