Non-specific physiological background effects of acupuncture revealed by proteomic analysis in normal rats

Abstract

Background: The total effects of adequate real acupuncture treatment consist of pathologic-specific and non-specific physiological effects. The latter may be the fundamental component of the therapeutic effects of acupuncture. This study investigated the physiological background effects of acupuncture in normal rats treated with acupuncture.

Methods: Manual acupuncture was performed on normal rats at experienced acupoints, GV14 (Dazhui), BL12 (Fengmen) and BL13 (Feishu), once every other day for two weeks. The proteomic profile of rat lung tissue was examined using 2-DE/MS-based proteomic techniques. Gene Ontology (GO) enrichment and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway were analyzed for differentially expressed proteins using the WebGestalt toolkit.

Results: In total, 25 differentially expressed protein spots were detected in the 2-DE gels. Among these spots, 24 corresponded to 20 unique proteins that were successfully identified using mass spectrometry. Subsequent GO and KEGG pathway analyses demonstrated that these altered proteins were mainly involved in biological processes, such as 'protein stabilization', 'glycolysis/gluconeogenesis' and 'response to stimulus'.

Conclusions: Our study indicated the non-specific background effects of acupuncture at acupoints GV14, BL12 and BL13 likely maintained internal homeostasis via regulation of the local stimulus response, energy metabolism, and biomolecule function balance, which may be important contributors to the therapeutic effects of acupuncture.

Figure 1

Rats on the suspended shelf. For the convenient manipulation of the acupuncture points on the back, rats were placed on the suspended shelf (50 × 45 mm, approximately 50 cm high from the ground), which calmed the rats and allowed them to stand still without anesthesia.

Figure 2

The identified proteins were analyzed according to Gene Ontology (GO) enrichment using WebGestalt (WEB-based GEne SeT AnaLysis Toolkit). (A) Directed Acyclic Graph (DAG) of the enriched GO categories under Biological Process. Each node shows the name of the GO category, the number of gene/proteins in the category and the P value indicating the significance of enrichment. (B) and (C) GO classification from the Biological Process and Molecular Function ontology enrichment. The number of proteins enriched in each GO term is shown at the right side of the bars.