The Protective Effects Of AFGF And TAT-aFGF On Neurites Of Cortical Neurons Damaged By ADDLs In Rats

Objective:The aim of our research was to establish an Alzheimer's disease model in vitro induced by ?-amyloid oligomers(A?-derived diffusible ligands, ADDLs) in DIV6 primary cortical neurons from new born SD rats, and to investigate the neuroprotection effect and preliminary mechanism of a FGF and TAT-ha FGF14-154 in primary cortical neurons.Methods:(1) ADDLs was prepared and identified, DIV6 primary cortical neurons from new born SD rats were exposed to a series concentrations of ADDLs( 125, 250,500,1000 n M), the optimal concentration of ADDLs to established AD model was selected by MTT and immunofluorescence of MAP2.(2) Cortical neurons were pre-treated for 2hrs by different concentrations of aFGF or TAT-a FGF, co-incubated with optimal concentration of 250 n M ADDLs and for24 hrs. Optimal concentration of a FGF or TAT-a FGF were determined by MTT and immunofluorescence of MAP2.(3) Cells were treated with the optimal concentration of 1000 ng/mL aFGF or TATa FGF and 250 n M ADDLs as above, proteins in PI3K/AKT and MEK/ERK signaling pathway and synapse-associated proteins(MAP2 and PSD95) were deteced by western blotting. PI3 K inhibitor LY294002 or ERK1/2 inhibitor PD98059 was used 30 min before all the treatments, cell viability and related proteins expression were detected by MTT and western blotting to determine activation of the two pathway.Result:MTT and immunofluorescence shown that, to induce an AD model, ADDLs optimal concentration was 250 n M, which the cell viability was reduced to 66.3%; The optimal concentration of a FGF and TAT-a FGF antagonistic to ADDLs were both1000 ng/m L. The proteins in two pathway and synapse-associated proteins shown:(1) In PI3K/AKT pathway, the phosphorylation of PI3 K, AKT, GSK3?, CREB and the expression of MAP2 and PSD95 were significantly increased by a FGF or TAT-a FGF for 24 hrstreatments.Afterincubated with PI3Kinhibitor( LY294002),this up-regulation were suppressed, at the same time the viability of cells were reduced to 62.0% and 61.8%.(2) In MEK/ERK pathway, the phosphorylation of ERK1/2, GSK3?, CREB and the expression of MAP2 and PSD95 were significantly increased by a FGF or TATa FGF for 24 hrs treatments. After incubated with ERK1/2 inhibitor(PD98059),this up-regulation were suppressed, and the viability of cells were reduced to61.4% and 62.8%.Conclution:The aFGF and TAT- aFGF can significantly increase the phosphorylation level of CREB, and expression of synapse-associated proteins(MAP2 and PSD95) via PI3K/AKT/GSK3? and ERK signaling pathway, antagonize the synaptic damage of cortical neurons caused by ADDLs, and exhibit a neuroprotective effect.