Abstract: Objective To investigate the role of hypoxia on the expression of miR-124 and BACE1. Methods Cultured SH-SY5Y cells were divided into blank control group, oxygen-glucose deprivation (OGD) group, Aβ1-42 group and overexpression or inhibition of miR-124 group. Real-time quantitative PCR was performed to analyze the expression of miR-124 level. The level of BACE1 was examined by Western blot. Results After OGD for 48h, the expression level of miR-124 decreased significantly to 46.9% of the control group (P<0.05), while the expression level of BACE1 was increased by 36% compared with the control group (P<0.01). After transfection of 48h, miR-124 level of miR-124 mimic group was increased by 245 folds as compared with control (P<0.01) and by 219 folds as compared with miR-124 mimic control (P<0.01); BACE1 level was decreased by 29% compared with control (P<0.05) and by 25% compared with miR-124 mimic control (P<0.05); miR-124 level of miR-124 inhibitor group was decreased to 45.4% of control (P<0.05), 48% of miR-124 inhibitor control (P<0.05), BACE1 level was increased by 21% compared with control (P<0.05), 40.3% compared with miR-124 inhibitor control (P<0.01). miR-124 level was decreased by 52% compared with control (P<0.05) and the level of BACE1 level was increased by 51% after Aβ1-42 treatment for 24h (P<0.05). Conclusion Hypoxia could increase the expression of BACE1 through the down-regulation of miR-124 which plays a role in the early pathogenesis of Alzheimer disease.

Key words: hypoxia, miR-124, β-Amyloid(Aβ), β-Amyloid precursor protein cleavage enzyme 1（BACE1）