The Role and Mechanism of α-Klotho in the Calcification of Rat Aortic Vascular Smooth Muscle Cells

Abstract EN

Objective.

To investigate the role and possible mechanism of α-Klotho in the calcification and the osteogenic transition of cultured VSMCs.

Methods.

VSMCs were cultured in vitro and divided into 5 groups, each using a different medium: (1) control; (2) β-GP; (3) β-GP + Klotho; (4) β-GP + LiCl; (5) β-GP + Klotho + LiCl.

Calcium deposits were visualized using Alizarin Red S staining.

The calcium concentrations were determined by the o-cresolphthalein complexone method.

BMP2, Runx2 and β-catenin levels were estimated by western blotting, and the level of α-SMA was determined by using immunofluorescence at day 12.

Results.

β-GP induced an increase in the expression of BMP2, Runx2, and β-catenin.

The calcium content increased, and the expression of α-SMA decreased.

Alizarin Red S staining was positive under the high phosphorus conditions.

BMP2, Runx2, and β-catenin levels and the calcium content decreased when the cells were cultured with rmKlotho; however, the levels of each were upregulated after treatment with the LiCl.

Conclusions.

Klotho can ameliorate the calcification and osteogenic transition of VSMCs induced by β-GP.

The mechanism of Klotho in preventing calcification in VSMCs may be partially mediated by the inhibition of the Wnt/β-catenin signaling pathway.