Golgi apparatus-targeting fluorescent probe for the imaging of superoxide anion (O2•−) in living cells during ferroptosis

Ferroptosis is an emerging iron-dependent oxidative cell death type, and recently has been demonstrated to show close relation with Golgi apparatus (GA). Exploring the fluctuation of superoxide anion (O2•−) level in GA during ferroptosis is of great significance to profoundly study the biological functions of GA in ferroptosis. Here, we present a GA-targeting probe (N-GA) to monitor cellular O2•− during ferroptosis. N-GA employed a triflate group and a tetradecanoic amide unit as the recognition site for O2•− and GA-targeting unit, respectively. After the response of N-GA to O2•−, the triflate unit of N-GA converted into hydroxyl group with strong electron-donating ability, generating bright green fluorescence under UV light. N-GA exhibited excellent sensitivity and selectivity towards O2•−. Fluorescence imaging results showed that N-GA could be applied as a GA-targeting probe to monitor cellular O2•−. The stimulation of cells with PMA and rotenone could result in the massive generation of endogenous O2•− in GA. Erastin-induced ferroptosis can markedly induce the increase of O2•− level in GA. Similar to Fer-1 and DFO, dihydrolipoic acid (DHLA) and rutin were demonstrated to inhibit the enormous production of O2•− in GA of the living cells during ferroptosis.