Cysteine (Cys) as a crucial precursor for intracellular glutathione (GSH) synthesis, plays an important role in the redox regulation in ferroptosis, Therefore, evaluating intracellular Cys levels is worthy to better understand ferroptosis-related physiological process. In this work, we constructed a novel NIR coumarin-derived fluorescent probe (NCDFP-Cys) based on a dual-ICT system, the NCDFP-Cys can show fluorescence turn-on response at 717 nm toward Cys over other amino acids, and possess large Stokes shift (Δλ = 167 nm), low detection limit, hypotoxicity. More significantly, NCDFP-Cys has been utilized to monitor the intracellular Cys fluctuation in pancreatic cancer cells during ferroptosis induced by Erastin and RSL3 respectively, and revealing the difference of Cys levels changes in different activator-triggered ferroptosis pathways.

中文翻译：

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基于 DAD 型的近红外荧光探针用于监测铁死亡过程中胰腺癌细胞中的半胱氨酸水平

半胱氨酸（Cys）作为细胞内谷胱甘肽（GSH）合成的重要前体，在铁死亡的氧化还原调节中发挥着重要作用，因此，评估细胞内Cys水平有助于更好地了解铁死亡相关的生理过程。在这项工作中，我们构建了一种基于双ICT系统的新型近红外香豆素衍生荧光探针（NCDFP-Cys），NCDFP-Cys可以在717 nm处对Cys表现出优于其他氨基酸的荧光开启响应，并且具有斯托克斯位移大（Δλ = 167 nm），检测限低，毒性低。更重要的是，NCDFP-Cys已分别用于监测Erastin和RSL3诱导的铁死亡过程中胰腺癌细胞的细胞内Cys波动，并揭示不同激活剂触发的铁死亡途径中Cys水平变化的差异。