Neuroprotective effect of astrocyte protein phosphatase 2A up-regulation on APP/PS1 double transgenic mice

AIM: To investigate the protective effects of astrocyte protein phosphatase 2A(PP2A) up-regulation on APP/PS1 double transgenic mice.METHODS: An eGFP-wtPP2A lentivirus with glial fiber acidic protein promoter was constructed to specifically increase PP2A expression in the astrocytes. The mice were divided into wild -type mice+vector virus group(Con), APP/PS1 transgenic mice+vector virus group(APP/PS1) and APP/PS1 transgenic mice+eGFP-wtPP2A lentivirus group(PP2A) by lateral ventricular injection of the lentivirus. Four weeks after injection of the virus, the immunofluorescence of brain slices were used to detect the level of β-amyloid protein(Aβ). Golgi staining was used to detect the changes of dendritic spine density and morphology. Electron microscopy was applied to detect the thickness of postsynaptic density(PSD). The Morris water maze test was applied to examine the learning and memory abilities of the mice.RESULTS: Up-regulation of PP2A in the astrocytes attenuated Aβ level increasing in APP/PS1 group. Up-regulation of PP2A in the astrocytes significantly attenuated both decreases in the dendritic spine density and the percentage of mushroom-like dendritic spines in the hippocampal CA3 region of APP/PS1 mice. Up-regulation of PP2A in the astrocytes significantly attenuated the reduced thickness of PSD in APP/PS1 group. Up-regulation of PP2A in the astrocytes attenuated the escape latency extending in APP/PS1 group.CONCLUSION: Up-regulation of PP2A in the astrocytes reduces AD-like pathological changes, and attenuates synaptic impairment, synaptic plasticity deficits and cognitive impairment in the APP/PS1 double transgenic mice.