Positron emission tomography (PET) imaging of Colony Stimulating Factor 1 Receptor (CSF1R) is a new strategy for quantifying both neuroinflammation and inflammation in the periphery since CSF1R is expressed on microglia and macrophages. AZ683 has high affinity for CSF1R (Ki = 8 nM; IC50 = 6 nM) and >250-fold selectivity over 95 other kinases. In this paper, we report the radiosynthesis of [11C]AZ683 and initial evaluation of its use in CSF1R PET. [11C]AZ683 was synthesized by 11C-methylation of the desmethyl precursor with [11C]MeOTf in 3.0% non-corrected activity yield (based upon [11C]MeOTf), >99% radiochemical purity and high molar activity. Preliminary PET imaging with [11C]AZ683 revealed low brain uptake in rodents and nonhuman primates, suggesting that imaging neuroinflammation could be challenging but that the radiopharmaceutical could still be useful for peripheral imaging of inflammation.
集落刺激因子 1 受体(CSF1R)的正电子发射断层扫描(PET)成像是量化神经炎症和外周炎症的一种新策略,因为 CSF1R 在小胶质细胞和巨噬细胞上表达。AZ683 对 CSF1R 具有高亲和力(Ki = 8 nM;IC50 = 6 nM),其选择性是其他 95 种激酶的 250 倍。本文报告了[11C]AZ683的放射合成及其在CSF1R PET中应用的初步评估。[11C]AZ683是通过[11C]MeOTf对去甲基前体进行11C-甲基化合成的,非校正活性收率为3.0%(基于[11C]MeOTf),放射化学纯度为99%,摩尔活性高。[11C]AZ683的初步正电子发射计算机断层成像显示,啮齿动物和非人灵长类动物的脑摄取率较低,这表明神经炎症成像可能具有挑战性,但该放射性药物仍可用于炎症的外周成像。