Figure 14.

RIG-I effector MAVS supports osteogenic differentiation and noncanonical Wnt/NFAT signaling in aortic VSM. Primary aortic VSM cells were prepared from WT and MAVS^−/− mice and analyzed for protein expression, osteogenic differentiation, and mineralization as indicated. A, Western blot analysis confirms absence of MAVS, with concomitant down-regulation of OPN expression. B, although Wnt5b treatment increases nuclear NFATc4 protein accumulation in WT cells, stimulation is markedly reduced in MAVS^−/− VSM cells. Runx2 protein accumulation is unaltered. NFATc4 is significantly reduced in MAVS^−/− nuclei (p < 0.05 all comparisons). C, osteogenic mRNA accumulation is reduced in cultures of MAVS^−/− aortic VSM cells. D, alkaline phosphatase enzyme activity is reduced in MAVS^−/− VSM cultured under mineralizing conditions. E, Alizarin red staining with digital image analysis (94) confirms significant reduction in VSM calcification with MAVS deficiency. F, aortic calcium accrual is significantly reduced in male MAVS^−/−;LDLR^−/− mice fed arteriosclerotic high-fat diets for 12 weeks as compared with male LDLR^−/− controls. Systemic inflammation as indicated by serum haptoglobin (supporting data S12) and aortic sinus atheroma lesion areas (supporting data S13) were not reduced. See text for details. *, **, #, p ≤ 0.05, ≤ 0.01, and ≤ 0.001 versus corresponding controls.