Kidney-Targeted Near-Infrared Fluorescence Probe Reveals That SO₂ Is a Biomarker for Cisplatin-Induced Acute Kidney Injury

Abstract

With the widespread use of drugs, drug-induced acute kidney injury (AKI) has become an increasingly serious health concern worldwide. Currently, early diagnosis of drug-induced AKI remains challenging because of the lack of effective biomarkers and noninvasive imaging tools. SO 2 plays important physiological roles in living systems and is an important antioxidant for maintaining redox homeostasis. However, the relationship between SO 2 (in water as SO 3 2– /HSO 3 – ) and drug-induced AKI remains largely unknown. Herein, we report the highly sensitive near-infrared fluorescence probe DSMN, which for the first time reveals the relationship between SO 2 and drug-induced AKI. The probe responds to SO 3 2– /HSO 3 – selectively and rapidly (within seconds) and shows a significant turn-on fluorescence at 710 nm with a large Stokes shift (125 nm). With these properties, the probe was successfully applied to detect SO 2 in living cells and mice. Importantly, the probe can selectively target the kidneys, allowing for the detection of changes in the SO 2 concentration in the kidneys. Based on this, DSMN was successfully used to detect cisplatin-induced AKI and revealed an increase in the SO 2 levels. The results indicate that SO 2 is a new biomarker for AKI and that DSMN is a powerful tool for studying and diagnosing drug-induced AKI.