Upregulation of functionally active vascular endothelial growth factor by human cytomegalovirus.
Human cytomegalovirus (HCMV) infection is known to modulate host gene expression and has been linked to the pathogenesis of vasculopathies; however, relevant pathomechanisms are still unclear. It was shown that HCMV infection leads to upregulation of vascular endothelial growth factor (VEGF) expression in human foreskin fibroblasts and coronary artery smooth muscle cells (SMC). Activation of VEGF transcription by HCMV infection was confirmed by transient-expression experiments, which revealed that a short promoter fragment, pLuc135 (-85 to +50), is sufficient for activation. Site-directed mutagenesis of Sp1-recognition sites within this fragment abolished the upregulation of transcription. Functional VEGF protein is released into the culture supernatant of infected SMC. Incubation of endothelial cells with supernatants from HCMV-infected SMC cultures induced upregulation of VEGF receptor-2 expression on endothelial cells, as well as a significant upregulation of DNA synthesis, implicating cell proliferation. The mean incline of DNA synthesis at 48 and 72 h post-infection was 148 and 197 %, respectively. Addition of neutralizing antibodies against VEGF completely abolished this effect. Supernatants from SMC cultures incubated with UV-inactivated virus induced a comparable effect. This virus-induced paracrine effect may represent a molecular mechanism for HCMV-induced pathogenesis, such as inflammatory vasculopathies, by inducing a proatherogenic phenotype in SMC.
Reinhardt
Barbara
B
Abteilung Virologie, Universitätsklinikum Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany.
Schaarschmidt
Peter
P
Roche Diagnostics GmbH, Nonnenwald 2, 82372 Penzberg, Germany.
Bossert
Andrea
A
Abteilung Virologie, Universitätsklinikum Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany.
Lüske
Anke
A
Abteilung Virologie, Universitätsklinikum Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany.
Finkenzeller
Günter
G
Department of Plastic Surgery, University Hospital Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany.
Mertens
Thomas
T
Abteilung Virologie, Universitätsklinikum Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany.
Michel
Detlef
D
Abteilung Virologie, Universitätsklinikum Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany.
D002478:Cells, Cultured; D003587:Cytomegalovirus / Q000502:physiology*; D042783:Endothelial Cells / Q000378:metabolism / Q000821:virology; D005347:Fibroblasts / Q000378:metabolism / Q000821:virology; D006801:Humans; D016297:Mutagenesis, Site-Directed; D019899:Paracrine Communication; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D011956:Receptors, Cell Surface; D016329:Sp1 Transcription Factor / Q000235:genetics; D015854:Up-Regulation; D042461:Vascular Endothelial Growth Factor A / Q000032:analysis / Q000235:genetics / Q000378:metabolism*
D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D016329:Sp1 Transcription Factor; D042461:Vascular Endothelial Growth Factor A