Hippocampal Proteomic Analysis Reveals Potential Antidepressant Protein Targets of Abdominal Massage Therapy in a Rat Chronic Unpredictable Mild Stress Model of Depression

Background: Major depressive disorder (MDD) is a highly prevalent and complex psychiatric disease concomitant with severe impairment in social functioning. Abdominal massage therapy (AMT), also known as Zhenfu (ZF), is an ancient and effective form of complementary and alternative medicine in China. Applied to the patient's abdomen, the fundamental technique of AMT uses rapid vibrations created by the hand which can be used to treat multiple diseases. This study aims to evaluate the antidepressant effects of AMT.Methods: In this study, 30 rats were randomly divided into three groups: the control group, the model group, and the abdominal massage therapy group. We first established a rat model of chronic unpredictable mild stress (CUMS) and observed the changes in depression-like behaviors. Then, Tandem Mass Tags (TMT)-based quantitative proteomics analysis was conducted to investigate the differentially expressed proteins in the hippocampus between CUMS and AMT rats to excavate potential antidepressant protein targets. Finally, we validated molecules of interest and detected proteins using parallel reaction monitoring (PRM) to further determine the related mechanisms. The expression of p11/Anxa2/Ahnak in the hippocampus was also measured by western blot and immunohistochemistry analysis.Results: Our study revealed the presence of depression-like behaviors in rats subjected to CUMS. In the TMT proteomic analysis, 78 differentially expressed proteins were identified: 55 were upregulated and 23 were downregulated. Functional analysis revealed that these proteins participate in Acute myeloid leukemia, the Toll-like receptor signaling pathway, Glycolysis/Gluconeogenesis, interleukin 17 (IL-17) signaling pathway and Metabolism of xenobiotics by cytochrome P450. Further independent analysis using PRM revealed that identified changes in Acss1, Tagln2, Serpina6, Cmbl, Serpinh1, Ampd3, Gstm7, Anxa2, AABR07034632.1, Apoa1, Ahnak that were distinctly correlated to CUMS and AMT groups. The expression of p11/Anxa2/Ahnak in the hippocampus was significantly downregulated in the CUMS rats (p < 0.01, p < 0.01, p < 0.01). AMT could significantly normalize these alternations with evident curative effects (p < 0.01, p < 0.01, p < 0.01). Conclusions: In summary, the current study explored the antidepressant-like effects of AMT in rats subjected to 21 consecutive days of CUMS. The results of TMT proteomic analysis demonstrated that AMT could ameliorate the symptoms of depression by modulating multiple molecular targets. Our results also provide new insights to further explore alternative therapeutic approaches for the treatment of depression.