Abstract: Objective To investigate the effect of DJ-1 protein expression on neurotransmitters levels in the hippocampus of depression rats. Methods Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) was used to detect the apoptosis in hippocampus. Enzyme linked immunosorbent assay was used to determine the levels of tumor necrosis factor-α ( TNF-α) and interleukin 6 (IL-6) in serum, and the levels of 5-hydroxytryptamine (5-HT), 5-hydroxyindoleacetic acid (5-HIAA) and dopamine (DA) in hippocampus. Western blotting assay was used to detect the expression levels of DJ-1, PI3K, AKT, phosphorylated PI3K (p-PI3K), phosphorylated AKT ( p-AKT), Bcl-2 and Bcl-2 associated X protein ( Bax) in the hippocampus ofrats. Results Overexpression of DJ-1 significantly reduced the cell apoptosis rate in hippocampusand the levels of TNF-α and IL-6 in serum and the expression level of Bax in hippocampus, and upregulated the levels of 5-HT, 5-HIAA and DA in hippocampus and the expression levels of p-PI3K, p-AKT and Bcl-2 in hippocampus. However, the PI3K inhibitor LY294002 could partially reversethe protective effect of DJ-1 overexpression on neurons. Conclusion Overexpression of DJ-1 couldsignificantly inhibit inflammatory stress in the hippocampus of depression rats, reduce the apoptosis rate of neurons in the hippocampus, upregulate the levels of 5-HT, 5-HIAA and DA in the hippocampus, the mechanism may be related to the activation of PI3K / AKT signaling pathway.

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