Heat shock proteins and other components of cellular machinery for protein synthesis are up-regulated in vascular endothelial cell growth factor-activated human endothelial cells

Cellular communication network factor 2 (CCN2, also known as CTGF), is a modular and matricellular protein and a well-known angiogenic factor in physiological and pathological angiogenesis. However, its roles in lymphangiogenesis and intracellular signaling in lymphatic endothelial cells (LECs) remain unclear. Here, we investigated CCN2 signaling in LECs and its effects on lymphangiogenesis. In primary cultured LECs, gene expressions of lymphatic endothelial markers lymphatic vessel endothelial hyaluronan receptor 1 (Lyve1), Podoplanin and prospero homeobox 1 (Prox1) and lymphangiogenic factors vascular endothelial cell growth factor c (Vegfc), vascular endothelial cell growth factor d (Vegfd) and fms-related tyrosine kinase 4 (Flt4, also known as Vegfr3) were upregulated by CCN2. Subsequently, we found that CCN2 induced phospho-ERK and that was decreased by suppression of integrin v. CCN2 slightly decreased the growth of LECs due to enhancement of the interaction of ERK and dual specific protein phosphatase 6 (DUSP6), and knockdown of DUSP6 increased CCN2-induced phospho-ERK levels. In in vivo Matrigel plug assays, the number of Podoplanin-positive vessels was increased by exogenous CCN2, and phospho-ERK-positive LEC and DUSP6-positive LEC were detected in CCN2 plugs. These results suggest that CCN2-related lymphangiogenesis is regulated by DUSP6, which enables negative modulation of ERK-signaling.

Download Full-text

Vascular Endothelial Cell Growth Factor–Induced Tissue Factor Expression in Endothelial Cells Is Mediated by EGR-1

Blood ◽

10.1182/blood.v93.11.3811 ◽

1999 ◽

Vol 93 (11) ◽

pp. 3811-3823 ◽

Cited By ~ 140

Author(s):

Diana Mechtcheriakova ◽

Alexander Wlachos ◽

Harry Holzmüller ◽

Bernd R. Binder ◽

Erhard Hofer

Keyword(s):

Endothelial Cells ◽

Endothelial Cell ◽

Growth Factor ◽

Cell Growth ◽

Tissue Factor ◽

Vascular Endothelial Cell ◽

Vascular Endothelial ◽

Endothelial Cell Growth Factor ◽

Inflammatory Stimuli ◽

Endothelial Cell Growth

Abstract Vascular endothelial cell growth factor (VEGF) is a major regulator of angiogenesis. We report here that treatment of endothelial cells with VEGF leads to upregulation of tissue factor mRNA and protein expression on the cell surface. Reporter gene studies show that transcriptional activation of the tissue factor gene by VEGF is mediated by a GC-rich promoter element containing overlapping binding sites for Sp1 and EGR-1. As shown by immunofluorescence and electrophoretic mobility shift assays, upon VEGF treatment EGR-1 rapidly accumulates in the nucleus and binds to its respective recognition site in the tissue factor promoter. Sp1 occupies this element in unstimulated cells and seems to be partially displaced by increasing amounts of EGR-1. Transfection of endothelial cells with an EGR-1 expression plasmid mimics the upregulation of tissue factor transcription observed after VEGF treatment. In contrast, NFκB, the major transcription factor involved in tissue factor upregulation by inflammatory stimuli, is not activated by VEGF. These data show that VEGF induces a response in endothelial cells largely distinct from inflammatory stimuli, and suggest that EGR-1 is a major mediator of the activation of the tissue factor and possibly other VEGF-responsive genes.

Download Full-text

Vascular Endothelial Cell Growth Factor–Induced Tissue Factor Expression in Endothelial Cells Is Mediated by EGR-1

Blood ◽

10.1182/blood.v93.11.3811.411k40_3811_3823 ◽

1999 ◽

Vol 93 (11) ◽

pp. 3811-3823 ◽

Cited By ~ 4

Author(s):

Diana Mechtcheriakova ◽

Alexander Wlachos ◽

Harry Holzmüller ◽

Bernd R. Binder ◽

Erhard Hofer

Keyword(s):

Endothelial Cells ◽

Endothelial Cell ◽

Growth Factor ◽

Cell Growth ◽

Tissue Factor ◽

Vascular Endothelial Cell ◽

Vascular Endothelial ◽

Endothelial Cell Growth Factor ◽

Inflammatory Stimuli ◽

Endothelial Cell Growth

Vascular endothelial cell growth factor (VEGF) is a major regulator of angiogenesis. We report here that treatment of endothelial cells with VEGF leads to upregulation of tissue factor mRNA and protein expression on the cell surface. Reporter gene studies show that transcriptional activation of the tissue factor gene by VEGF is mediated by a GC-rich promoter element containing overlapping binding sites for Sp1 and EGR-1. As shown by immunofluorescence and electrophoretic mobility shift assays, upon VEGF treatment EGR-1 rapidly accumulates in the nucleus and binds to its respective recognition site in the tissue factor promoter. Sp1 occupies this element in unstimulated cells and seems to be partially displaced by increasing amounts of EGR-1. Transfection of endothelial cells with an EGR-1 expression plasmid mimics the upregulation of tissue factor transcription observed after VEGF treatment. In contrast, NFκB, the major transcription factor involved in tissue factor upregulation by inflammatory stimuli, is not activated by VEGF. These data show that VEGF induces a response in endothelial cells largely distinct from inflammatory stimuli, and suggest that EGR-1 is a major mediator of the activation of the tissue factor and possibly other VEGF-responsive genes.

Download Full-text