Abstract: Objective To investigate the effect of β-amyloid peptide 1-42( Aβ1-42) on neurite outgrowth, microtubule structure and expression of T514 phosphorated collapsin response mediator protein 2 (CRMP2) in SH-SY5Y cells. Methords Making cells model by adding aggregated Aβ1-42 in the culture medium of all-trans retinoic acid induced neuroblastoma cells SH-SY5Y. MTT methord was employed to identify the viability of SH-SY5Y cells. Cytochemistry was used to measure neurite length of induced SH-SY5Y cells. The intracellular microtubule structure and distribution of T514 phosphorated CRMP-2 was detected by immunofluorescence . Westen blot was used to detect the influence of Aβ1-42 on total expression of T514 phosphorated CRMP-2 . Results The viability of SH-SY5Y showed significant decrease in response to 24h aggregated Aβ1-42 exposure at 0.1 and 1μmol/L (p<0.01). Neurites measurement showed that 1μmol/L aggregated Aβ1-42 lead to obvious neutrite retraction (p<0.05). Immunofluorescence showed the CRMP2 immuno-positive expression was higher in both experimental groups (0.1 and 1μmol/L ) (p<0.01) . Westen blot showed the totle expression of T514 phosphorated CRMP-2 in both experimental groups (0.1 and 1μmol/L ) maintain significant higher level compared with control (p<0.01). Conclusion Aβ1-42 can increase intracellular expression of T514 phosphorated CRMP-2 and have a negtive effect on microtubule structure and neurite outgrowth.

Key words: β-amyloid protein , SH-SY5Y, all-trans retinonic acid