LncRNA Rpph1 protects amyloid-β induced neuronal injury in SK-N-SH cells via miR-122/Wnt1 axis

Abstract

Objective: To investigate the role of lncRNA Rpph1 on amyloid-β induced neuronal injury in SK-N-SH cells and underlying mechanism.

Methods: In vitro Alzheimer’s disease (AD) model was established using the SK-N-SH cells treated with Aβ_25-35 peptide. APPswe/PS1ΔE9 double transgenic mice were used as AD animal model. Rpph1 was over-expressed and miR-122 was inhibited or overexpressed in SK-N-SH cells via transfection with pcDNA3.1-oe Rpph1 vector, miR-122 inhibitor or miR-122 mimic, respectively. Cell viabilities and apoptosis were evaluated using MTT or flow cytometry assay, respectively. Quantitative real-time PCR (RT-qPCR) was used to determine expression of Rpph1 and miR-122. Western blotting was used to determine the expression of apoptosis related proteins as well as Wnt/β-catenin signaling related proteins. Dual luciferase reporter assay was conducted to confirm the binding of miR-122 with predictive binding site in 3’ UTR of Rpph1 and Wnt1.

Results: Both lncRNA Rpph1 and miR-122 were up-regulated in AD mouse. Either over-expression of Rpph1 or inhibition of miR-122 restored the cell viability or decreased cell apoptosis rate in Aβ induced SK-N-SH cells. Overexpression of miR-122 inhibited the cell viability while did not influence the Aβ level in SK-N-SH cells. Furthermore, over-expression of Rpph1, as well as inhibition of miR-122, elevated Bcl-2, c-myc, Survivin and decreased Bax expression via activating Wnt/β-catenin signaling. Dual luciferase reporter assay showed that miR-122 could directly target to 3’UTR of Rpph1 and Wnt1.

Conclusion: Both lncRNA Rpph1 and miR-122 were up-regulated in AD mouse and Rpph1 activated Wnt/β-catenin signaling to ameliorate amyloid-β induced neuronal apoptosis in SK-N-SH cells via direct targeting miR-122.

Keywords:

• LncRNA Rpph1
• miR-122
• amyloid-β induced neuronal injury
• apoptosis
• Wnt/β-catenin signaling

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (No.81401083) and the Science and Technology Joint Fund Project of Guizhou Provincial Science and Technology Department and Guizhou Provincial People’s Hospital (grant no. Qian Ke He LH [2014]7022).