Figure 7.

Anti-Calcification Effect of miR-27a-3p Is Blocked by Atf3

(A) Effect of miR-27a-3p mimic on Atf3 transcript amount. The Pi-induced increase as well as the basal level of Atf3 mRNA were significantly attenuated by transfection of miR-27a-3p mimic. (B) miR-27a-3p mimic-induced reduction of calcium deposition in the presence of Pi was completely blocked when Atf3 was overexpressed. (C and D) Changes in mRNA levels of Runx2 (C) and Alp (D). (E and F) miR-27a-3p mimic-induced reduction of Runx2 protein amount was recovered by co-transfection of pcDNA6-Atf3-myc. Quantitative results of (E) was shown in (F). (G and H) miR-27a-3p inhibitor-induced increase in Runx2 protein amount was blocked by simultaneous transfection of Atf3 siRNA. Quantitative results of (G) are shown in (H). (I) Diagram. Pi reduces the expression of miR-27a-3p, which results in the activation of ATF3, a novel pro-calcific mediator. Error bars indicate SD. ∗p < 0.05, ∗∗p < 0.01, ^@@p < 0.01. NS, not significant.