Figure 5.

Fibronectin up-regulates bcl-xL in the second stage. TER119⁻ progenitor cells were cultured overnight on uncoated surfaces in the presence of Epo and were dissociated and serum starved for 1 h before being transferred to fresh fibronectin or control surfaces in Epo-free media. bcl-xL expression was assayed at 30 min via Western blotting. (A) Representative Western blot indicating the up-regulation of bcl-xL on fibronectin and the equivalent expression of actin as a loading control. The anti-actin and anti–bcl-xL antibodies were raised in different hosts, thereby allowing the visualization of both proteins on the same membrane. (B) Quantification of five identical experiments. Integrated fluorescence intensity on the control substrate was normalized to that on fibronectin, indicating a statistically significant decrease in the absence of fibronectin. *, P ≤ 0.01. Error bars represent the SD.