LMTK2 inhibits Ab25-35-elicited ferroptosis, oxidative stress and apoptotic damage in PC12 cells through activating Nrf2/ARE signalling pathway

Alzheimer’s disease (AD), the most common contributor to dementia, is a growing global health problem. This study aimed to investigate the role of lemur tyrosine kinase 2 (LMTK2) in AD as well as its relevant mechanism. To establish an in vitro cell model, PC12 cells were challenged with 20 µmol/l Ab_25-35 for 24 h. RT-qPCR and western blot examined LMTK2 mRNA and protein expressions. With the application of CCK-8, TUNEL, iron colorimetric assay kit and DCFH-DA, the viability, apoptosis, Fe²⁺ and ROS content in PC12 cells were assessed. Besides, the expressions of oxidative stress-, apoptosis-, ferroptosis- and Nrf2/ARE signalling-related proteins were evaluated with western blot. Moreover, commercial kits examined SOD, MDA and CAT contents. The results manifested that LMTK2 expression was noticeably downregulated in Ab_25-35-treated PC12 cells. Notably, LMTK2 overexpression exhibited inhibitory effects on oxidative stress, apoptosis and ferroptosis in PC12 cells exposed to Ab_25-35. The upregulated Nrf2, NQO1 and HO-1 expressions in LMTK2 overexpressed-PC12 cells with Ab_25-35 induction revealed that LMTK2 overexpression could activate the Nrf2/ARE signalling pathway. What is more, a series of cellular experiments further testified that ML385, a specific Nrf2 inhibitor, partly hindered the protective role of LMTK2 overexpression against Ab_25-35-triggered oxidative stress, apoptosis and ferroptosis in PC12 cells. In conclusion, LMTK2 overexpression alleviated the ferroptosis, oxidant damage and apoptosis in PC12 cells exposed to Ab_25-35 through the activation of the Nrf2/ARE signalling pathway, indicating the potential target of LMTK2 in the treatment of AD.