[Using bioinformatics tools to explore cellular biological mechanisms of "Triple Energizer Acupuncture Method" in treating senile dementia]

Abstract

Objective: To observe the effect of needling "Danzhong" (CV17), "Zhongwan"(CV12), "Qihai" (CV6), "Xuehai"(SP10)and "Zusanli"(ST36) (Triple Energizer Acupuncture Method) on the learning-memory ability and profile of hippocampal differentially-expressed genes and proteins of SAMP8 mice (rapid aging mice), so as to explore its underlying mechanisms in improving Alzheimer's disease (AD)．.

Methods: A total of 60 SAMP8 were used as the dementia model and randomly divided into blank control, acupoint and non-acupoint groups (n＝20 per group). The 5 acupuncture points and non-acupoints (subcostal region) on the bilateral sides were needled with filiform needles and manipulated manually for 30 s at each one，once daily, 6 times a week for 4 weeks. The Morris water maze tests (location navigation tests and space probing trials) were used to evaluate the mouse's learning-memory ability. The hippocampal tissue was extracted to detect differentially expressed genes and proteins related to acupuncture intervention by gene chip and isobaric tags for relative and absolute quantitation (iTRAQ) techniques as well as bioinformatic analysis, separately. The information is analyzed through bioinformatics database tools. Finally, immunofluorescence staining was used to verify theresults of microarray analysis.

Results: Compared with mice of the control and non-acupoint groups, the escape latency of location navigation task of Morris water maze tests on 4^th and 5^th day of training was significantly shortened in mice of the acupoint group, and the duration of stay in the original safe-platform quadrant was significantly increased in the acupoint group (P<0.05). Gene microarray displayed that in comparison with the control group, 898 differentially expressed genes were up-regulated, 418 genes were down-regulated in the hippocampus of acupoint group. The iTRAQ analysis indicated that in the acupoint and non-acupoint groups, 286 and 299 differentially expressed proteins were up-regulated, 319 and 179 proteins down-regulated, respectively. Of the 34 terms containing 47 proteins up-regulated by acupoint needling, including intermediate filament, keratin filament, myelin sheath, postsynaptic density, neuron projection were related with neurite and cytoskele-ton. While in the non-acupoint group, of the 24 terms were listed by the system, only the myelin sheath involving 11 differentially expressed proteins functions in activities of neurite and cytoskeleton. Immunofluorescence staining of the hippocampal tissue showed that the high-density distribution areas of neurons and neurite fibers were characterized by decentralization and disordering, with the highlighted areas being mainly near the cell body parts in control mice, but in mice of the acupoint group, the highlighted areas at the neurite were relatively dense, the morphology of hippocampal cells was complete, the fiber structure was clear, dense and orderly, and the neurites were closely arranged and in order, indicating an improvement of the distribution and arrangement of nerve fibers after acupuncture. The height of neurite highlight area of the acupoint group was significantly higher than that of the non-acupoint group (P<0.05)．.

Conclusion: The "Triple Energizer Acupuncture" of acupoints is able to improve the learning-memory ability in SAMP8, which may be related to its effects in regulating the expression and function of hippocampal genes and proteins related to neurite and cytoskeleton.

Keywords: Alzheimer’s disease; Bioinformatics; Cytoskeleton; Neurite protuberance; Senescence accelerated mice prone 8.