美国加州大学Christina K. Kim团队近期取得重要工作进展，他们研究开发了对体内细胞活动历史进行快速生化标记的方法。相关研究成果2024年8月5日在线发表于《自然—方法学》杂志上。

据介绍，细胞内钙（Ca²⁺）是整个生物学中普遍存在于细胞信号。虽然现有的荧光传感器和报告器可以检测到Ca²⁺水平升高的活化细胞，但这些方法需要植入物将光传递到深层组织，从而排除了它们在行为自由的动物中的非侵入性使用。

研究人员设计了一种酶催化的方法，可以在体内快速地用升高的Ca²⁺对细胞进行生化标记。Ca²⁺激活的分裂TurboID（CaST）在10分钟内用外源递送的生物素分子标记激活的细胞。酶信号随着Ca²⁺浓度和生物素标记时间的增加而增加，表明CaST是总Ca²⁺活性的时间门控积分器。

此外，与需要数小时才能产生信号的转录报告子相比，CaST读出可以在活性标记后立即进行。这些能力使研究人员能够将CaST应用于标记由裸盖菇素激活的前额叶皮层神经元，并将CaST信号与裸盖菇素诱导的无束缚小鼠头部抽搐反应相关联。

附：英文原文

Title: Rapid, biochemical tagging of cellular activity history in vivo

Author: Zhang, Run, Anguiano, Maribel, Aarrestad, Isak K., Lin, Sophia, Chandra, Joshua, Vadde, Sruti S., Olson, David E., Kim, Christina K.

Issue&Volume: 2024-08-05

Abstract: Intracellular calcium (Ca2+) is ubiquitous to cell signaling across biology. While existing fluorescent sensors and reporters can detect activated cells with elevated Ca2+ levels, these approaches require implants to deliver light to deep tissue, precluding their noninvasive use in freely behaving animals. Here we engineered an enzyme-catalyzed approach that rapidly and biochemically tags cells with elevated Ca2+ in vivo. Ca2+-activated split-TurboID (CaST) labels activated cells within 10min with an exogenously delivered biotin molecule. The enzymatic signal increases with Ca2+ concentration and biotin labeling time, demonstrating that CaST is a time-gated integrator of total Ca2+ activity. Furthermore, the CaST readout can be performed immediately after activity labeling, in contrast to transcriptional reporters that require hours to produce signal. These capabilities allowed us to apply CaST to tag prefrontal cortex neurons activated by psilocybin, and to correlate the CaST signal with psilocybin-induced head-twitch responses in untethered mice.

DOI: 10.1038/s41592-024-02375-7

Source: https://www.nature.com/articles/s41592-024-02375-7