Center of Excellence for Environmental Safety and Biological Effects, Beijing Key Laboratory for Green Catalysis and Separation, Department of Chemistry, Beijing University of Technology, 100124, Beijing, PR China.
Large-scale Instruments and Equipments Sharing Platform, Beijing University of Technology, 100124, Beijing, PR China.
Anal Chim Acta. 2024 Dec 15;1332:343372. doi: 10.1016/j.aca.2024.343372. Epub 2024 Oct 24.
Inflammatory bowel disease (IBD) is a prevalent inflammatory disorder, and the abnormal expression of nitric oxide (NO) produced by biocatalysis of iNOS enzyme in mitochondria is directly associated with the occurrence and progression of IBD. Activatable fluorescent probes offer promising tools for early diagnosis of IBD, however, inadequate biodistribution and limited targeting properties of these probes in vivo severely impede accurate diagnosis of IBD and real-time evaluation of inflammatory levels in situ. Therefore, it is necessary to design a highly efficient fluorescent probe towards NO to overcome inadequate biodistribution and achieve accurate diagnosis and evaluation of IBD in situ.
We designed a highly efficient mitochondria-targeted "turn-on" NIR fluorescent probe Cy-OMe which has excellent targeting properties and imaging ability. The response mechanism is probe Cy-OMe rapidly undergoes N-nitrosation reaction resulting in "turn-on" NIR fluorescence signal when exposed to NO. Cy-OMe exhibits high sensitivity and specificity in detecting NO content in vitro, owing to its large Stokes shift. Furthermore, the probe Cy-OMe not only efficiently targets mitochondria but also enables precise assessment of fluctuations in endogenous NO concertation across various cell types. Importantly, by virtue of large Stokes shift and excellent mitochondrial targeting ability, Cy-OMe has the capability to specifically evaluate dynamic fluctuations of NO in lipopolysaccharide (LPS)-stimulated IBD mouse models in situ and Cy-OMe was achieved high-contrast imaging and precision diagnosis of intestinal inflammation diseases.
Cy-OMe can accurately assess fluctuations in NO levels and show high signal fidelity in the diseased intestine region, which has prospects in the non-invasive diagnosis of intestinal inflammation in vivo. At the same time, it is expected to serve as a potential diagnose platform for investigating the physiological processes underlying NO-related inflammatory diseases and promoting understanding of the pathological functions of NO across diverse inflammatory diseases.
炎症性肠病（IBD）是一种常见的炎症性疾病，线粒体中诱导型一氧化氮合酶（iNOS）产生的生物催化物一氧化氮（NO）的异常表达与 IBD 的发生和发展直接相关。可激活的荧光探针为 IBD 的早期诊断提供了有前景的工具，然而，这些探针在体内的生物分布不足和有限的靶向特性严重阻碍了 IBD 的准确诊断和对原位炎症水平的实时评估。因此，有必要设计一种针对 NO 的高效荧光探针来克服生物分布不足，实现 IBD 的准确诊断和原位评估。
我们设计了一种高效的线粒体靶向“开启”近红外荧光探针 Cy-OMe，它具有出色的靶向特性和成像能力。其响应机制是探针 Cy-OMe 快速经历 N-亚硝化反应，当暴露于 NO 时会导致“开启”近红外荧光信号。Cy-OMe 具有大的斯托克斯位移，在体外对 NO 含量的检测具有高灵敏度和特异性。此外，该探针不仅能够高效靶向线粒体，还能够精确评估各种细胞类型中内源性 NO 浓度的波动。重要的是，由于大的斯托克斯位移和优异的线粒体靶向能力，Cy-OMe 能够特异性地评估脂多糖（LPS）刺激的 IBD 小鼠模型中原位 NO 动态波动，并且 Cy-OMe 实现了对肠道炎症疾病的高对比度成像和精确诊断。
Cy-OMe 可以准确评估 NO 水平的波动，并在患病肠道区域显示出高信号保真度，这有望实现体内肠道炎症的非侵入性诊断。同时，它有望成为研究与 NO 相关的炎症性疾病的生理过程和促进对不同炎症性疾病中 NO 的病理功能的理解的潜在诊断平台。
