Fig. 5

Id1 signals through the *pJnk pathway in HMVECs and EPCs. HMVECs and EPCs were cultured in 6-well plates and stimulated at different time intervals with human recombinant Id1. The cell lysate was collected and western blot analysis was performed. The results are shown as fold increase from the nonstimulated (NS), which was arbitrarily set at 1. The upper band represents phosphorylated signaling molecule (*p) and the lower band represents total signaling molecule. Using these bands, the amount of phosphorylated signaling molecule was quantified for each respective blot and results pooled. Upregulation (↑) of *pJnk and *pP38 was statistically significant in EPCs and upregulation of *pJnk was statistically significant in HMVECs. Upregulation of *pJnk plateaued at 5 min in EPCs and later in HMVECs at 30 min. Other signaling molecules were tested but results were not significant (data not shown, n = number of experimental replicates; the delta symbol with slash represents no change. EPC endothelial progenitor cell, HMVEC human dermal microvascular endothelial cell, Id1 inhibitor of DNA binding 1, NS nonstimulated