Neuroprotective changes in degeneration-related gene expression in the substantia nigra following acupuncture in an MPTP mouse model of Parkinsonism: Microarray analysis
OBJECTIVES To find new biomarkers by stimulating acupuncture point GB34 (Yangneungcheon) which has neuroprotective effect on the mouse model of Parkinson's disease, analysis of cDNA microarray on mRNAs of the substantia nigra was performed. METHODS Male C57BL/6 mice were divided into two groups: 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated mice (MPTP group, n=3); 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine and acupuncture (GB34)-treated mice (MPTP + ACU group, n=3). The mice received an intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (30 mg/kg) once daily for 3 consecutive days. Manual acupuncture was performed 2 hours after every injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. The total RNA in the substantia nigra of each mouse was isolated on 3 days after the last 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine injection. Agilent mouse whole genome 44K chip was used for microarray analysis and the hybridization image was analysed by GenePix Pro 6.0. Data normalization and analysis were performed using GeneSpring GX 7.3.1 program. RESULTS The acupuncture stimulation revealed 799 genes (424 up- and 375 down-regulated) of which expression levels were changed more than two-folds in the MPTP + ACU group, compared to the MPTP group. The genes selected were classified into several categories based on their functions using DAVID Bioinformatics Resources 2008 (http://david.abcc.ncifcrf.gov/) and KEGG PATHWAY Database (http://www.genome.jp/kegg/pathway.html). DISCUSSION Biomarkers in response to acupuncture stimulation to GB34 were identified in a mouse model for Parkinson's disease. These biomarkers might provide a promising clue for understanding the neuroprotective effect of acupuncture in Parkinson's disease.