The Effect Of PTEN Lipid Phosphatase Inhibitor On The Over-phosphorylated Tau In The Cell Model Of Experimental Alzheimer's Disease

Objectives:In order to analyze whether the activity of PTEN lipid phosphatase could alleviate the formation of AD, we choosed the specific inhibitor of PTEN lipid phosphatase, BPV (pic), to explore the intensity and time effect of the inhibitor on the over-phosphorylated tau in the cell model of Alzheimer's disease. In so doing, we can improve our understanding about the pathogenesis of AD. And thus, it would provide us a novel pharmaceutical target toward AD.Methods:(1) SH-SY5Y cells were treated with 40nmol/L OA and 40μmol/L abeta. The cells morphological change, the levels of tau [pSer396] change and levels of PTEN change were choosed as the pivot indictors to determine the formation of AD cell model. (2) We inhibited PTEN lipid phosphatase with different concentrations of BPV (pic) and detect the tau protein alteration via Western blot. (3) We inhibited PTEN lipid phosphatase with 90nmol/L BPV (pic) and detected the tau protein alteration via Western blot.Results:1, The effect of PTEN lipid phosphatase activity to the OA-induced SH-SY5Y cell model:①SH-SY5Y cells were cultured with 40nmol/L OA for 0h, 3h, 6h, 12h, 18h, 24h, 36h, 48h. We found the cells would be deteriorated with time ?dependence. We alsod found the levels of phosphorylated tau at site Ser396 would be increased after the exposure for 12h, and reached peak at 18h, and then decline; PTEN protein would be increased after the exposure for 3h, and reached peak at 6h, and then decreased. Those data could determine the establishment of the AD cell model.②We inhibited PTEN lipid phosphates activity with different concentrations of BPV(pic) and found the levels of phosphorlyted tau at site Ser396 decreased with the increasing dose of BPV(pic); Phophorylated Akt at site Ser473 also increased with the increasing dose of BPV (pic); PTEN protein did not change. Those data show that the BPV (pic) would decrease the level of phosphorylated tau via mediate the activity of PTEN lipid phosphatase.③we inhibited PTEN lipid phosphates activity with 90nmol/L BPV(pic) and levels of phosphorylated tau increase 18h, reached at 24h, and then decline. Comparing with model, we found that the time of AD formation has been postponed and the time of PTEN protein alteration was not different. Therefore, these data suggest that 90nmol/L BPV (pic) would postpone the formation of AD.2, The effect of PTEN lipid phosphatase activity to the Aβ25~35-induced SH-SY5Y cell model:①SH-SY5Y cells were cultured with 40umol/L Aβ25~35 for 0h, 3h, 6h, 12h, 18h, 24h, 36h, 48h. We found the cells would be deteriorated with time dependence. We also found the levels of phosphorylated tau at site Ser396 would be increased after the exposure for 6h, and reached peak at 12h, and then decline; PTEN protein would be increased after the exposure for 3h, and reached peak at 6h, and then decreased. Those data could determine the establishment of the AD cell model.②We inhibited PTEN lipid phosphates activity with different concentrations of BPV(pic) and found the levels of phosphorlyted tau at site Ser396 decreased with the increasing dose of BPV(pic); Phophorylated Akt at site Ser473 also increased with the increasing dose of BPV (pic); PTEN protein did not change. Those data show that the BPV (pic) would decrease the level of phosphorylated tau via mediate the activity of PTEN lipid phosphatase.③We inhibited PTEN lipid phosphates activity with 90nmol/L BPV(pic) and levels of phosphorylated tau increase 6h, reached at12 and18h, and then decline. Comparing with model, we found that the time of AD formation has been postponed and the time of PTEN protein alteration was not different. Therefore, these data suggest that 90nmol/L BPV (pic) would postpone the formation of ADConclusions:1, Inhibiting PTEN lipid phosphatase could reduce the level of phosphorylated tau in OA-induced SH-SY5Y AD-like model.2, Inhibiting PTEN lipid phosphatase could alleviate the level of phosphorylated tau in Aβ25~35-induced SH-SY5Y AD-like model.3, The abnormal increased activity of PTEN lipid phosphatsase would accelerate the formation of AD. And, PTEN may expect to be a novel pharmaceutical target towards AD.