Endothelial Cells Group Research Articles

Effects of cytomegalovirus infection on growth factor production in endothelial cells and fibroblasts.

To determine whether cytomegalovirus (CMV) infection alters growth factor production from endothelial cells (EC) or fibroblasts, we infected human umbilical vein EC with CMV VHL/E, a strain of CMV with affinity for human EC, and we infected human foreskin fibroblasts with CMV AD169. CMV caused cytopathic effect and positive CMV staining by immunofluorescence within 5 d, effects not seen in cells infected with UV-irradiated CMV or in uninfected (control) cells. The supernatants from the EC were assayed for platelet-derived growth factor (PDGF)-like protein using a radioreceptor inhibition assay, and EC and fibroblasts were assayed for basic fibroblast growth factor (bFGF) by Western blot analysis. There were no significant differences in PDGF production between groups of EC: CMV-infected EC, 13.5 +/- 2.6; UV-irradiated infected EC, 12.1 +/- 3.6; control EC, 12.9 +/- 1.7 fmol/10(6) EC (mean +/- SD, n = 10, p = NS). There were also no significant differences in bFGF production between CMV-infected EC, UV-irradiated infected EC, and control EC as evidenced by similar intensity of migration of bFGF as a single band at approximately 18 kD (n = 5). In contrast, CMV infection of fibroblasts induced a shift in production of bFGF to higher molecular weight forms migrating at 24 and 26 kD molecular mass. alpha-Interferon failed to alter bFGF production. We conclude that CMV VHL/E infection of EC does not directly alter PDGF or bFGF production from EC. However, CMV infection of cultured human fibroblasts qualitatively alters bFGF by inducing a shift to higher molecular weight forms.

Biocompatibility of hemoglobin solutions. I. Reactions of vascular endothelial cells to pure and impure hemoglobins.

Hemoglobin (Hb) solutions can cause vasoconstriction and activation of intravascular coagulation. Because the endothelium plays a major role in the regulation of vascular tone and hemostasis, a study was conducted of human umbilical vein endothelial cells (EC) incubated with various Hbs. Cell injury was evaluated by electron microscopy and the release of lactic dehydrogenase, H2O2, and procoagulant "tissue factor." Cell reaction was assessed by the measurement of 6-keto-prostaglandin F (PGF)1 alpha (metabolite of prostacyclin) and thromboxane B2 (metabolite of thromboxane A2). Incubation with unmodified bovine hemoglobin for 24 h caused no cell injury and a reaction characterized by 48.4 +/- 8.2% increase in 6-keto-PGF1 alpha production, accompanied by 40.2 +/- 9.4% reduction in thromboxane (Tx)B2 (compared with a control group of EC incubated with saline solution). Incubation with a nonpure Hb solution (Hb plus red blood cell membrane aminophospholipids; a-PLs) caused cell injury with significant release of tissue factor, plus a reaction characterized by 97.5 +/- 12.5% increase in TxB2 production accompanied by 25.3 +/- 3% reduction in 6-keto-PGF1 alpha. A second nonpure Hb [Hb plus bacterial environmental endotoxin (E)] caused cell injury, the release of tissue factor, and increased production of both prostaglandins, with greater release of TxB2 (197 +/- 17%) than of 6-keto-PGF1 alpha (112 +/- 8.3%). These data indicate that the endothelium reacts differently to pure and nonpure hemoglobins. The biocompatibility of Hb solutions, with regard to vasoconstriction and activation of intravascular coagulation, depends on the absence of stromal a-PLs and bacterial E.