AGE/RAGE promotes thecalcification of human aortic smooth muscle cells via the Wnt/β-catenin axis.

Objective: The present study aims to investigate whether RAGE promotes the calcification of human arterial smooth muscle cells (HASMCs) and determine the relationshipbetween RAGE and the Wnt/β-catenin signaling pathway in this process.

Method: In this study,there were four groups, namelythe blank control group, the non-transfection group, the empty vector group, and the RAGE transfection group.Cells were co-cultured with 10 mmol/L β-glycerophosphoric acid, pyruvate and 20 mg/L AGE. The expression of osteogenic proteins in each group before and after the intervention wasdetected using Western blotting. Short interfering RNA (siRNA) targeting β-catenin was used toinhibitthe expression of β-catenin. HASMCs cultured under normal conditions were usedas the blank control.

Results: (1) High RAGE expression was successfully induced in HASMCs according to the results of GFP detection, flow cytometry and Western blotting. (2) Compared with the blank control group, non-transfection group and empty vector group, RAGE transfection enhanced the calcification of cells when incubated with calcification medium plus AGE. (3) The expression of RAGE, β-catenin, OPG and Cbfa1 proteins in the blank control group, empty vector group and RAGE transfection group wasnot significantly enhanced after intervention. However, expression of the proteins in the RAGE transfection group was much higher than those of the other groups. (4) Compared with the RAGE transfection group and control siRNA group, the cells transfected with β-catenin siRNA and cultured with interventional drugs showed significant inhibition of the expression of the downstream Cbfa1 and OPG genes.

Conclusion: Increased expression of RAGE promoted calcification in HASMCs and up regulated the β-catenin, OPG and Cbfa1 genes. RAGE may activate the downstream genes via the Wntβ-catenin pathway, thereby promoting HASMC differentiation into osteogenic cells and calcification.