Assessing ferroptosis in Parkinson’s disease model by monitoring lipid peroxyl radical with an ER-targeted fluorescent probe

Abstract

Ferroptosis, driven by uncontrolled membrane lipid peroxidation, is closely related to the pathology of Parkinson’s disease (PD) and is considered a promising therapeutic target for PD. Lipid peroxyl radical (LOO•) is indispensable for the continuation and amplification of the lipid peroxidation process. Thus, fluorescent probes that can real-time monitor LOO• production in neural cells are highly desirable for understanding the role of ferroptosis in PD. Given that membrane lipid peroxidation is initially accumulated in endoplasmic reticulum (ER) during ferroptosis, we report herein the fabrication of the first ER-targeted fluorescent probes ER-Nap-LP1 and ER-Nap-LP2, for selective detection of LOO•. In vitro experiments demonstrate that both probes exhibit high selectivity and good fluorescence turn-on response to multiple forms of LOO•, of which ER-Nap-LP2 shows faster response and longer excitation/emission wavelength toward LOO•. ER-Nap-LP2 has been effectively employed to track both exogenous and endogenous LOO• in PC12 cells and zebrafish. Furthermore, with the aid of ER-Nap-LP2, we found that ER LOO• is dramatically upregulated in rotenone-induced PD model. Pretreating the cells with ferroptosis inhibitors could eliminate excessively generated LOO•, further rescuing PC12 cells from rotenone-induced cell death, indicating the therapeutic value of ferroptosis inhibitors in PD. Overall, these results demonstrate that ER-Nap-LP2 is a promising imaging tool to evaluate ferroptosis, which will facilitate the development of novel therapeutic strategies for PD.