Sitagliptin rescues memory deficits in Parkinsonian rats via upregulating BDNF to prevent neuron and dendritic spine loss.

OBJECTIVES: Parkinson's disease (PD) is a neurodegenerative disease with high morbidity among adults worldwide that causes tremendous trouble to people's lives. The purpose of this study was to investigate the impact of sitagliptin on PD and its potential mechanism.

METHODS: First, the memory of rats in each group was evaluated with the Morris water maze (MWM) test and the passive avoidance test. Then, both brain-derived neurotrophic factor (BDNF) protein and mRNA levels were detected by ELISA and qPCR assays, respectively. Then, rapid Golgi impregnation was used to observe the density of dendritic spines in the hippocampal CA1 area. Finally, k252a, an antagonist of Trk receptors, was used to block the binding of BDNF with its receptors, and the effects of sitagliptin on PD improvement were detected.

RESULTS: Our study showed that sitagliptin improved memory deficits in PD rats. Meanwhile, the expression level of BDNF and tyrosine hydroxylase (TH) was upregulated, and the density of dendritic spine was increased by sitagliptin administration. Moreover, K252a administration blocked the positive effects of sitagliptin on memory in PD rats.

DISCUSSION: Sitagliptin rescued the memory deficits, which was achieved by upregulating BDNF to prevent neuronal death and dendritic spine loss. Our findings indicate that sitagliptin might be a promising potential drug for PD treatment in the future.