Figure 6.

PMCA inhibitors decrease mineralization levels. (A,C) HOB cells were cultured for 28 days in mineralization medium with PMCA inhibitors (each lower column), 10 μM CE (A), or 100 μM caloxin 1b1 (C), or without them (each upper column in (A,C)) at pH 7.4. Alizarin red (left columns; red indicative of calcium deposition) and von Kossa (right columns; black indicative of phosphate and calcium deposition) staining. (B,D) Mineralization levels with (gray columns) and without (open columns) PCMA inhibitors 10 μM CE (B) or 100 μM caloxin 1b1 (D), assessed by Alizarin red (upper columns), and von Kossa (lower columns) staining. Each column in (B,D) denotes the mean ± SE from 8 and 12 experiments, respectively. The mineralization levels in the absence of CE (as controls in (B)) were 1.15 ± 0.03 I/I₀ with Alizarin red staining and 1.08 ± 0.02 I/I₀ units with von Kossa staining. The mineralization levels with CE (gray bars in (B)) were 1.00 ± 0.01 I/I₀ units with Alizarin red staining and 1.01 ± 0.01 I/I₀ units with von Kossa staining. The mineralization levels without caloxin 1b1 (as controls in (D)) were 1.34 ± 0.02 I/I₀ units with Alizarin red staining and 1.11 ± 0.01 I/I₀ units with von Kossa staining. The mineralization levels with caloxin 1b1 (gray bars in (D)) were 1.18 ± 0.04 I/I₀ units with Alizarin red staining and 1.07 ± 0.01 I/I₀ with von Kossa staining. Statistically significant differences (in (B,D)) between columns (shown by solid lines) are indicated by asterisks. * P < 0.05.