Fig. 4

Collagen type I (COL1) expression, regulation, and interactions in COL-XFM and XFM cultures on D10 and D20. a Immunohistostaining of both confluent/monolayered and overconfluent/multilayered XFM cultures on D10 and D20, respectively. The single channels (COL1 and DAPI) are shown in gray; all nuclei in the merged images are shown in magenta (DAPI); scale bars, 100 μm. b Immunoblotting and quantification of COL1 protein expression in the cultures described in a. β-actin was used as a loading control to normalize protein expression of COL1; **p < 0.01; N.S., no significant difference. c RT-PCR was used to measure gene expression of COL1 in COL-XFM and XFM cells in the absence (Hypo) or presence (YC-1) of a HIF-1α inhibitor YC-1 during cobalt chloride-induced hypoxia. d Western blot and quantification of integrin α2 and α11 subunits (ITGA2 and ITGA11) in both types of multilayered XFM cultures on D20. β-actin was used as a loading control to normalize the expression of ITGA2 and ITGA11. **p < 0.01