Abstract:

Objective    To investigate the inhibitory effects of neprilysin(NEP) on SK-N-SH cell apoptosis induced by neurotoxic amyloid beta peptide(Aβ25-35). Methods    The adenovirus vector carrying NEP was transfected into human embryonic kidney 293 cells by using LipofectaminTM 2000 and the adenovirus expressing exogenous genes was generated. Then the person nerve metrocyte lump cell SK-N-SH cells induced by Aβ25-35 were infected. Cell survival rate was measured by MTT. Cell apoptosis rate and  level of intracellular ROS were measured by flow cytometry. Expressions of the apoptosisassociated genes bax and bcl-2 in cells were detected by RT-PCR and Western blot. Results    MTT and flow cytometry indicated that expression of NEP reduced  cell apoptosis rate and  level of intracellular ROS induced by Aβ25-35.RT-PCR and Western blot showed that the inhibitory effect of NEP on Aβ25-35-induced apoptosis might be exerted by reducing the expression level of bax and the level of intracellular ROS. Conclusion    Expression of NEP may exert  a neuro-protective effect on SH-N-SK cells induced by neurotoxic Aβ25-35, which might be associated with apoptosis-associated genes.

Key words: Endopeptidases; Adenoviruses, human; Amyloid betaprotein; Apoptosis; Alzheimer disease