The protection of APP17-mer peptide against neuronal apoptosis induced by A?_(25-35) / 中国药理学通报

ABSTRACT

AIM To examine the effects of the APP17-mer peptide against A? 25-35 -induced apoptosis and gain some insight into the neuroprotective mechanism of the APP17-mer peptide. METHODS Protective effects of APP17-mer peptide against A? 25-35 -induced apoptosis in SH-SY5Y cell was proved by cell morphology, LM-PCR DNA ladder assay and FCM assay. The antiapoptotic mechanism of APP17-mer peptide was investigated using the MTT assay to measure mitochondrial energy redox state, using the fluorescent probe DCF-DA?Rhodamine 123 to measure relative levels of cellular peroxides and mitochondrial membrane potential and using Western blot for AIF and NF-?B to detect the expression of AIF and NF-?B. RESULTS Damage of cell morphology was ameliorated by pretreating with APP17-mer peptide. The apoptotic rate of the SH-SY5Y cells exposed to A? 25-35 in the presence of APP17-mer peptide decreased from 63.75% to 28.25%. Exposure of SH-SY5Y to A? 25-35 for 48 h resulted in an increase in DCF-DA fluorescence,a decrease in Rhodamine 123 fluorescence and MTT reduction, the results were weakened by pre-incubating with APP17-mer peptide for 30 minutes. Treatment of cells with APP17-mer peptide resulted in a significant attenuation in the expression of AIF and a strong increase in the expression of NF-?B. CONCLUSION APP17-mer is protective against cell apoptosis induced by A? 25-35 by provoking and sustaining upregulation of a key antiapoptotic transcription factor NF-?B, by suppressing oxyradical production and by preserving mitochondrial function and inhibiting the release of apoptotic protein from mitochondria.