Teneligliptin, a DPP4 Inhibitor Protects Dopaminergic Neurons in PD Models via Inhibiting of Oxidative Stress and Ferroptosis

Parkinson's disease is a progressive neurodegenerative disorder with pathological hallmarks of loss of nigrostriatal dopaminergic neurons. Oxidative stress is one of the pivotal molecular pathways involved. Ferroptosis, a novel form of cell death, is closely associated with oxidative stress and presents a new potential therapeutic target for PD. Amounting reports showed that dipeptidyl peptidase-4 (DPP4) inhibitors, may hold potential for PD treatment. In this study, we found that Teneligliptin, a DPP4 inhibitor, when pretreated in SH-SY5Y cells, alleviated MPP + -induced cellular damage, including enhancing cell viability and modulating the Bax/Bcl-2 ratio. Furthermore, Teneligliptin not only inhibited the accumulation of reactive oxygen species (ROS), prevented the decline of mitochondrial membrane potential, decreased malondialdehyde (MDA) levels, restored glutathione (GSH) and superoxide dismutase (SOD) contents, but also lowered ferrous ion levels. At the same time, Teneligliptin restored antioxidant defenses by inhibiting DPP4 to enhance p62-mediated Keap1 degradation, thereby activating the Nrf2 signaling pathway. This upregulated downstream target including HO-1 and xCT, maintaining glutathione peroxidase 4 (GPX4) expression. Finally, Teneligliptin improved behavioral performance and protected dopaminergic neurons in MPTP-induced PD mouse. Taken together, our findings of Teneligliptin as a promising candidate for the treatment of PD warrant further study.