Figure 5.

CMV-infected HUVECs increase expression of ALK5 and reduce ALK1. A: Surface expression of ALK1, endoglin, and ALK5 was analyzed by flow cytometric analysis at 7 days after infection in the absence or presence of viral DNA polymerase inhibitors. Typical histograms from control (cont.) and infected (inf.) HUVECs are shown. Shaded areas represent expression of specific proteins. Lines represent isotype control. Numbers represent mean fluorescence intensity. The experiments were repeated at least four times. B: Cell lysates from control (cont.) or infected (inf.) HUVECs at 3 and 10 days after infection were fractionated by 10% SDS-PAGE and blotted on nitrocellulose. Filters were incubated with antibodies to ALK1, endoglin, ALK5, and Grb2 (loading control). C: Surface expression of ALK1, endoglin, and ALK5 was analyzed by flow cytometric analysis at 7 days of culture with conditioned medium (CM) from infected HUVECs. Relative surface expression as expressed by mean fluorescence intensity was normalized for control HUVECs in the same experiment. Results are the mean (±SE) from three to seven experiments. Asterisks indicate relative expression level of receptors in HUVECs cultured with conditioned medium as compared with controls (*P < 0.05, **P < 0.01).