Development of a Golgi-targeted fluorescent chemosensor for detecting ferrous ions overload under Golgi stress

Ferrous ion (Fe²⁺) is a crucial metal ion in the body and participates in the diseases related to oxidation and reduction. Golgi apparatus is the main subcellular organelle of Fe²⁺ transport in cells, and the stability of its structure is related to the Fe²⁺ at an appropriate concentration. In this work, a turn-on type Golgi-targeting fluorescent chemosensor Gol-Cou-Fe²⁺ was rationally designed for sensitive and selective detection of Fe²⁺. Gol-Cou-Fe²⁺ showed excellent capacity of detecting exogenous and endogenous Fe²⁺ in HUVEC and HepG2 cells. It was used to capture the up-regulated Fe²⁺ level during the hypoxia. Moreover, the fluorescence of sensor was enhanced over time under Golgi stress combining with the reduce of Golgi matrix protein GM130. However, elimination of Fe²⁺ or addition of nitric oxide (NO) would restore the fluorescence intensity of Gol-Cou-Fe²⁺ and the expression of GM130 in HUVEC. Thus, development of chemosensor Gol-Cou-Fe²⁺ provides a new window for tracking Golgi Fe²⁺ and elucidating Golgi stress-related diseases.