Highly Selective Drug-Derived Fluorescent Probes for the Cannabinoid Receptor Type 1 (CB₁R)

The cannabinoid receptor type 1 (CB1R) is pivotal within the endocannabinoid system regulating various signaling cascades with effects in appetite regulation, pain perception, memory formation, and thermoregulation. Still, understanding of CB1R’s cellular signaling, distribution, and expression dynamics is very fragmentary. Real-time visualization of CB1R is crucial for addressing these questions. Selective drug-like CB1R ligands with a defined pharmacological profile were investigated for the construction of CB1R fluorescent probes using a reverse design-approach. A modular design concept with a diethyl glycine-based building block as the centerpiece allowed for the straightforward synthesis of novel probe candidates. Validated by computational docking studies, radioligand binding, and cAMP assay, this systematic approach allowed for the identification of novel pyrrole-based CB1R fluorescent probes. Application in fluorescence-based target-engagement studies and live cell imaging exemplify the great versatility of the tailored CB1R probes for investigating CB1R localization, trafficking, pharmacology, and its pathological implications.1型大麻素受体（cannabinoid receptor type 1）是内源性大麻素系统的核心调控因子，可介导多种信号级联反应，参与食欲调节、疼痛感知、记忆形成及体温调节过程。但目前学界对CB1R的细胞信号传导、组织分布及表达动态的认知仍较为零散。实时可视化CB1R是解答上述科学问题的关键手段。 本研究采用反向设计策略，对具备明确药理学特性的选择性类药物CB1R配体进行筛选，以构建CB1R荧光探针。基于二乙基甘氨酸结构单元的模块化设计理念，可实现新型探针候选化合物的便捷合成。经计算机分子对接研究、放射性配体结合实验及环磷酸腺苷（cAMP）检测实验验证，该系统性研发策略成功筛选得到新型吡咯类CB1R荧光探针。 通过基于荧光的靶点结合实验与活细胞成像的应用验证，这类定制化CB1R探针展现出优异的通用性，可用于研究CB1R的定位、转运过程、药理学特性及其病理相关意义。