Evaluating toxicity and decoding the underlying mechanisms of active compounds are crucial for drug development. In this study, we present an innovative, integrated approach that combines air flow-assisted desorption electrospray ionization mass spectrometry imaging (AFADESI-MSI), time-of-flight secondary ion mass spectrometry (ToF-SIMS), and spatial metabolomics to comprehensively investigate the nephrotoxicity and underlying mechanisms of nitidine chloride (NC), a promising anti-tumor drug candidate. Our quantitive AFADESI-MSI analysis unveiled the region specific of accumulation of NC in the kidney, particularly within the inner cortex (IC) region, following single and repeated dose of NC. High spatial resolution ToF-SIMS analysis further allowed us to precisely map the localization of NC within the renal tubule. Employing spatial metabolomics based on AFADESI-MSI, we identified over 70 discriminating endogenous metabolites associated with chronic NC exposure. These findings suggest the renal tubule as the primary target of NC toxicity and implicate renal transporters (organic cation transporters, multidrug and toxin extrusion, organic cation transporter 2), metabolic enzymes (protein arginine N-methyltransferase, nitric oxide synthase), mitochondria, oxidative stress, and inflammation in NC-induced nephrotoxicity. This study offers novel insights into NC-induced renal damage, representing a crucial step towards devising strategies to mitigate renal damage caused by this compound.

中文翻译：

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双质谱成像和空间代谢组学研究氯化两面针碱的代谢和肾毒性

评估活性化合物的毒性并解读其潜在机制对于药物开发至关重要。在这项研究中，我们提出了一种创新的集成方法，结合了气流辅助解吸电喷雾电离质谱成像（AFADESI-MSI）、飞行时间二次离子质谱（ToF-SIMS）和空间代谢组学来全面研究氯化两面针碱（NC）的肾毒性和潜在机制，一种有前途的抗肿瘤候选药物。我们的定量 AFADESI-MSI 分析揭示了单次和重复剂量 NC 后 NC 在肾脏中积累的区域特异性，特别是在内皮层 (IC) 区域。高空间分辨率 ToF-SIMS 分析进一步使我们能够精确绘制 NC 在肾小管内的定位。采用基于 AFADESI-MSI 的空间代谢组学，我们鉴定了 70 多种与慢性 NC 暴露相关的有区别的内源代谢物。这些发现表明肾小管是 NC 毒性的主要目标，并涉及肾脏转运蛋白（有机阳离子转运蛋白、多药和毒素挤出、有机阳离子转运蛋白 2）、代谢酶（蛋白精氨酸 N-甲基转移酶、一氧化氮合酶）、线粒体、氧化NC 诱导的肾毒性中的应激和炎症。这项研究为 NC 引起的肾损伤提供了新的见解，代表着朝着制定减轻该化合物引起的肾损伤的策略迈出了关键的一步。