Transcriptome analysis of rats with chronic unpredictable mild stress treated with electroacupuncture

Abstract

Background

Depression remains one of the most prevalent psychiatric disorders, with many patients not responding adequately to available treatments. Electroacupuncture (EA), a nonpharmacologic therapy, holds great promise for alleviating depressive symptoms. In this study, RNA sequencing (RNA-Seq) was used to identify genome-wide alterations in the hippocampus of rats after chronic unpredictable mild stress (CUMS) and EA treatments to further elucidate the mechanism by which EA ameliorates depression to provide a basis for the clinical application of EA in stress-related diseases.

Methods

The sucrose preference test (SPT), open field test (OFT), and forced swimming test (FST) were used to investigate the ability of EA at Baihui (GV20) and Taichong acupoints (LR3) to improve depression-like behavior in rats subjected to CUMS. Subsequently, RNA-Seq analysis revealed transcriptomic profiles of the hippocampus of rats subjected to CUMS in which EA ameliorated depressive behavior. Finally, the expression profiles of major differentially expressed genes were tested by real-time quantitative polymerase chain reaction (qRT-PCR) to determine the accuracy of the RNA-Seq results.

Results

Rats subjected to CUMS exhibited depressive-like behaviors, such as decreased sucrose consumption in the SPT (p < .001), decreased time in the central area of the OFT (p < .001), and increased immobility in the FST (p < .01). Importantly, rats subjected to CUMS and treated with EA showed increased sucrose consumption (p < .001), increased time spent in the central area of the OFT (p < .001) and decreased immobility in the FST (p < .01). Sixty-three genes that were differentially expressed following CUMS were altered by EA; most of these were associated with immune pathways. Compared with those in the control group, the expression levels of Colla2 (p < .001), Col3a1 (p < .001), Psmb9 (p < .01), and Tap1 (p < .01) in the hippocampus of rats subjected to CUMS were lower. The changes in the expression of these genes were reversed by EA treatment.

Conclusion

EA at GV20 and LR3 attenuated CUMS-induced depression-like behaviors by regulating the expression of specific genes such as Colla2, Col3a1, Psmb9, and Tap1.