Skip to main content
. 2020 Jul 23;10(20):9315–9331. doi: 10.7150/thno.46875

Figure 1.

Figure 1

[18F]CB251 as a TSPO-targeting radioactive ligand. (A) Various TSPO ligands and the structure of TSPO-targeting radioactive ligands. CB251 is compared with known TSPO ligands, such as PK11195, PBR28, fm-PBR-d2, and GE-180. [18F]fmPBR28-d2 is fluoromethyl-PBR28-d2 (ref. 24, 30). Ki of ligands for TSPO from refs. 47a, 50b, 31c, and 24d. (B) Competitive inhibition assay of PK11195, fmPBR28-d2, and CB251 with [3H]PK11195 on membrane proteins. HAB indicates high affinity ligand binding phenotype (wild type TSPO); LAB indicates low affinity ligand binding phenotype (A147T mutant) isolated from 293FT cells expressing polymorphic TSPOs. CPM indicates count per minute. The ratio of IC50 LAB/HAB represents the sensitivity of TSPO polymorphism; a value close to 1 indicates less sensitive to TSPO polymorphism. (C) In vitro cellular uptake of CB251 in 293FT cells expressing polymorphic TSPO was compared with TSPO ligands. (D) PET scan images of 293FT cells expressing polymorphic TSPOs (E) Representative PET/MR images of mice bearing 293FT cells with polymorphic TSPOs (N=2 for each treatment).