Fig. 3.

Cx43 overexpression is associated with higher levels of OCN mRNA expression (A), suggesting that increased GJIC results in an enhanced capacity of cells to undergo osteogenic differentiation. Increased cell-cell communication also increases the production of osteoinductive soluble factors (D and E). Overexpression of Cx43 also had significant effects on OCN expression when comparing 2D to 3D cultures (B). OCN mRNA expression was significantly greater in 2D for cells that did not overexpress Cx43, while cells that overexpressed Cx43 exhibited no significant difference in level of OCN expression between 2D and 3D cultures. Analysis of the surface versus core of the scaffolds (C) suggests that increased GJIC in the interior regions of a tissue equivalent can enhance the magnitude and reduce spatial gradients in differentiation. Significant increases are indicated by * versus Cx43Δ7, ** vs. BMSC, *** vs. Cx43, # vs. BMP-7. Horizontal bars indicate pairs that are significantly different.