A CE-Activated Fluorescent Probe for Unraveling Mitochondria–Lipid Droplet Interactions and Multiplex Visualization of Acute Alcoholic Liver Injury

Acute alcoholic liver injury (AALI) represents a crucial early phase in the development of alcoholic liver disease (ALD), which is closely associated with mitochondrial dysfunction, abnormal accumulation of lipid droplets (LDs), and carboxylesterase (CE) activity reduction. However, existing detection methods struggle to achieve multitarget and real-time dynamic monitoring of AALI, severely limiting the research on AALI mechanisms and the development of therapeutic strategies. Here, we proposed a novel near-infrared multifunctional fluorescent probe ZZD. ZZD exhibited a fast response and high selectivity to CEs and enabled simultaneous dual-organelle imaging of mitochondria and LDs. Under starvation and oleic acid treatment, the increasing contacts between mitochondria and LDs in HepG2 cells can be clearly observed by using ZZD imaging in two-color channels, and dynamic tracking of the two organelles was visualized in real-time without cross-talk. In AALI cell models, key pathological features including mitochondrial damage, LD accumulation, and CE activity reduction were captured, and the therapeutic effects of silymarin (SILY) and andrographolide (AG) were evaluated by ZZD. Moreover, fluorescence imaging performed on the AALI mouse model by ZZD indicated aggravated hepatic damage of mice, and the inhibitory effects of SILY and AG on AALI progression were disclosed by monitoring changes in CE activity and lipid levels. Therefore, ZZD, as a powerful tool to detect CEs and unravel the interactions between mitochondria and LDs, holds great potential in the research of the AALI mechanism and the development of therapeutic treatments.