Abstract
Acute myocardial infarction (MI) triggers a local and systemic inflammatory response. We recently showed microglia involvement using TSPO imaging. Here, we evaluate whether 11C-methionine provides further insights into heart-brain inflammation networking. Methods: Male Bl6N mice underwent permanent coronary artery ligation followed by 11C-methionine PET at 3 and 7 days (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 peaked in the MI region at d3 (5.9±0.9vs 2.4±0.5 %ID/cc), decreasing to control level by d7 (4.3±0.6 %ID/cc). Brain uptake was proportional to cardiac uptake (r=0.47,p<0.05), peaking also at d3 (2.9±0.4vs 2.4±0.3 %ID/cc) and returning to baseline at d7 (2.3±0.4 %ID/cc). Integrin blockade reduced uptake at every time point. Immunostaining at d3 revealed co-localization of the L-type amino acid transporter with GFAP-positive astrocytes but not CD68-positive microglia. Conclusion: PET imaging with 11C-methionine specifically identifies an astrocyte component, enabling further dissection of the heart-brain axis in post MI inflammation.
- Animal Imaging
- Cardiology (basic/technical)
- PET
- astroglia
- inflammation
- methionine
- myocardial infarction
- positron emission tomgoraphy
- Copyright © 2019 by the Society of Nuclear Medicine and Molecular Imaging, Inc.