Endothelial cell surface SDF-1 regulates specific cell transmigration under static conditions. (A) BL-41 and BC-1 cell migration across HUVEC monolayers in the presence or absence of SDF-1 in the lower chamber of transwells. HUVEC monolayers were either untreated or treated with heparinase III (Hep III) or chondroitinase (Chon). The results reflect the mean (± SEM) number of cells transmigrated to the lower chamber over 4 hours from 3 replicate wells per condition. Representative experiment of 5 performed. (B) BC-1 cell migration across HDMEC monolayers in the presence or absence of SDF-1 in the lower and upper chamber of transwells. The results reflect the mean (± SEM) number of cells transmigrated to the lower chamber over 4 hours from 3 replicate wells per condition. Representative experiment of 3 performed. (C) Surface SDF-1 expression in early (passage 4) and late (passage 18) passage HUVECs detected by flow cytometry. (D) BL-41 and BC-1 cell transmigration as a function of HUVEC passage in culture. Early (passage 4) or late (passage 18) passage HUVECs were used to generate monolayers separating the upper and lower chambers of transwells. Medium alone or with SDF-1 was placed in the lower chamber. The results reflect the mean (± SEM) number of cells transmigrated to the lower chamber from 9 replicate wells per condition. Representative experiment of 3 performed is shown.