Schisandrone has strong activities of anti-oxidation, effectively scavenges hydroxyl radical and superoxide anion, and has protective effects on cells under active oxygen stress state. Neurofibrillary tangles in neurons is composed of abnormal phosphorylation Tau protein and positively correlated with severity of Alzheimer disease.OBJECTIVE:
To explore the effect of schisandrone on tau protein phosphorylation in the process of differentiation of APP transgenic mouse neural stem cells into neural cells.DESIGN, TIME AND SETTING:
The cytological in vitro controlled study was performed at the Experimental Center for Medicine, Zhengzhou University from July 2006 to October 2008.MATERIALS:
A total of 30 APP gene mutation mice were purchased from Heredity Animal Center, Peking Union Medical College. Schisandrone was supplied by Medicine Institute, Henan Institute of Traditional Chinese Medicine.METHODS:
DNA was extracted from tails of newborn transgenic mouse to check for APP gene by PCR. APP positive mice were considered as APP+, and APP negative mice as APP−. Brain tissues were obtained from the hippocampus of APP+ mice and APP− mice. Neural stem cells were separated from above-mentioned brain tissues, and were cultured and induced to differentiate into neural cells in vitro. The differentiated cells from APP positive mice (APP+) were divided into 2 groups: APP+ cell control group and schisandrone group, and cells from APP negative transgenic mice were assigned as APP− cell control group. Cells in the schisandrone group were treaded with 50 μ mol/L schisandrone for 24 hours. Cells in the APP+ and APP− cell control groups were incubated in phosphate buffered saline for 24 hours.MAIN OUTCOME MEASURES:
Western blotting and Immunofluorence staining were used to detect the level of Tau protein phosphorylation with 262, 396 site of tau in APP+ cells and APP− cells.RESULTS:
Compared with the APP+ cell control group, cell fluorescence intensity became weak in the schisandrone group. Phosphorylation levels of Tau[Ps262] and Tau[Ps396] were reduced, especially at Tau[Ps396] site. Phosphorylation levels of Tau[Ps262] and Tau[Ps396] were low in the APP− cell control group.CONCLUSION:
In the process of differentiation of APP transgenic mouse neural stem cells, schisandrone can significantly decrease phosphorylation levels of Tau protein at 396, 262 sites, and relieve neuronal injury, but the phosphorylation level does not reach a negative cell level.