Figure 3. IDG-CM6 cementocytes mineralize in culture.
IDG-CM6 cementocytes and IDG-SW3 osteocytes were cultured up to 42 days under mineralizing conditions (inclusion of 50 μg/ml ascorbic acid and 4 mM β-glycerophosphate). (A, C) Dmp1-driven GFP expression increases over time and shows a similar profile in IDG-CM6 and IDG-SW3 cells, however, cementocytes are slower to achieve peak GFP expression (day 35 vs. day 21 in IDG-SW3 cells). (B, D) By alizarin red staining, a detectable increase in mineral deposition by IDG-CM6 is observed by day 7, whereas IDG-SW3 cells initiate mineralization by day 14. Both cementocyte and osteocyte cultures became heavily mineralized over 42 days. (E) Alkaline phosphatase activity (ALP) activity increases in both cells over days 3-14, coincident with increased mineral deposition. In C-E, data are presented as mean ± SD. Two-way ANOVA and Bonferroni post-hoc test were used to indicate inter- and intragroup statistical significance, * p < 0.05; ns = not significant (p > 0.05).