The effect of aquaporin 4 regulated by microRNA-320a on a cell model of Alzheimer′s disease / 中华物理医学与康复杂志

ABSTRACT

Objective:To explore the effect of aquaporin 4 (AQP4) regulated by miR-320a on a cell model of Alzheimer′s disease.Methods:A rat adrenal pheochromocytoma cell line (PC12) was induced into neurons using nerve growth factor (NGF). The morphology of the PC12 cells and the neurons was observed, and ubiquitin carboxy terminal hydrolase L1 (Uch-L1) and neurofilament protein (NFP) were detected. Levels of microtubule-associated protein (MAP2) and AQP4 target genes were related to the mRNA expression of NFP to determine the neuron-inducing effect. The neurons were then randomly divided into a control group (given no treatment), an miR-320a mimic transfection group (cultured by adding 50nmol/L miR-320a as a mimic agent), an miR-320a inhibitor group (cultured by adding 50nmol/L miR-320a as an inhibitor), an Aβ treatment group (cultured by adding Aβ), an Aβ+ miR-320a mimic group (cultured by adding both 50nmol/L miR-320a and Aβ), and an Aβ+ miR-320a inhibitor group (also cultured by adding Aβ, but with 50nmol/L miR-320a as an inhibitor). Cell activity was measured by the CCK8 method. Reverse-transcription polymerase chain reactions were used to detect the relative expression of the target gene miR-320a, AQP4, B-cell bcl2-associated X (Bax), and B-cell bcl-2 (Bcl-2) mRNA. Western blotting was employed to detect the relative expression of AQP4, Bax and Bcl-2 proteins.Results:After PC12 was induced by 50μg/L NGF, the expression of Uch-L1 genes in the induced neuron was significantly down-regulated compared with the PC12. The expressions of NFP, MAP2 and AQP4 genes were significantly up-regulated, and the relative expressions of MAP2 and AQP4 proteins increased significantly. Compared with the control group, the apoptosis and cell activity of neurons in the treatment group increased, the mRNA and protein expressions of miR-320a, AQP4, bcl-2, AQP4 and Bcl-2 decreased significantly, and the mRNA and protein expressions of Bax increased significantly. Compared with the Aβ-treated group, the cell activity of the Aβ+ Mir-320a mimic group increased significantly, the mRNA and protein expressions of miR-320a, AQP4 and Bcl-2 increased significantly, and the mRNA and protein expressions of Bax decreased significantly. Compared with the Aβ+ miR-320a mimic group, the cell activity of the Aβ+ miR-320a inhibitor group decreased significantly, the mRNA and protein expressions of miR-320a, AQP4 and Bcl-2 decreased significantly, and the mRNA and protein expressions of Bax increased significantly.Conclusion:miR-320a can up-regulate AQP4 expression in a cell model of Alzheimer′s disease, reduce apoptosis and increase the cell survival rate.