RCAS1 induces apoptosis of ECFCs.
Day 7 ECFCs (5 × 105cells/mL) were incubated with or without nRCAS1 (40 μg/mL) in the presence of rhEPO and rhSCF, and viability, colony-forming capacity, and apoptosis were measured at the indicated times. (A) Viability of ECFCs with (■) or without (○) nRCAS1 was determined by trypan blue exclusion, using a hemocytometer. (B) Plasma clot assays for colony-forming capacity of day 7 ECFCs after incubation in liquid media with (▪) or without (■) nRCAS1. After incubation for indicated periods, the cells were transferred for plasma clot assays and incubations were carried out for another 7 days. The number of colonies was measured after benzidine staining. (C) After liquid culture for 36 hours with (right panel) or without (left panel) nRCAS1, apoptotic cells were detected by measuring membrane redistribution of phosphatidylserine, using annexin V–FITC, and staining with PI. Figure 2C shows representative data from 10 independent experiments.
