Fluorogenic probes for intracellular copper detection and the study of cuproptosis.

Copper is an essential trace element involved in key biological processes, including cellular respiration, antioxidant defense, and enzymatic activity. Intracellular copper homeostasis is regulated through coordinated uptake, trafficking, storage, and excretion mechanisms. Disruption of this balance can result in copper overload, leading to cuproptosis-a recently characterized, copper-dependent form of regulated cell death marked by aggregation of lipoylated mitochondrial proteins, disruption of the tricarboxylic acid cycle, and proteotoxic stress. Cuproptosis has been implicated in the pathogenesis of neurodegenerative diseases, cancer, and metabolic disorders. Accurate monitoring of intracellular copper dynamics is therefore critical for understanding disease mechanisms. In this chapter, we describe the use of fluorogenic probes for detecting intracellular copper ions in cultured cells, providing practical guidelines for their application.