Background: Angiogenesis has a key role in numerous disease processes. One of the most important angiogenic factors is vascular endothelial growth factor (VEGF-A), whereas thrombospondin-1 (TSP-1) is a major antiangiogenic factor. Recent studies have shown that VEGF-A as well as TSP-1 is regulated by transforming growth factor-beta1 (TGF-beta1), but the mechanism remains unclear.

Methods: We examined the role of TGF-beta1 and its signaling pathways in mediating expression of these two molecules. Rat proximal tubular cells (NRK52E) were stimulated with TGF-beta1 to induce VEGF-A and TSP-1 synthesis. To clarify roles of receptor-activated Smads (R-Smads), we blocked Smad signaling using overexpression of the inhibitory Smad, Smad7, and by using fibroblasts from wild-type or knockout mice. To confirm the antiantigenic role of Smads, soluble Flt-1 regulation in response to TGF-beta1 was also examined. In addition, the effect of conditioned media from NRK52E and Smad knockout cells was examined on endothelial cell proliferation.

Results: Induction of VEGF-A and TSP-1 by TGF-beta1 in NRK52E cells was associated with activation of pathway-restricted R-Smads (Smad2 and 3) and blocking these Smads by overexpression of Smad7 blocked their induction. By using of Smad knockout cells, Smad3 was shown to have a key role in the stimulation of VEGF-A expression whereas Smad2 was critical for TSP-1 expression. Consistent with the hypothesis that Smad2 has an antiangiogenic function, we also demonstrated that Smad2, but not Smad3, mediated the expression of VEGF-A antagonist, soluble VEGF-A receptor sFlt-1, in response to TGF-beta1. Conditioned media from NRK52E, which was stimulated by TGF-beta1 for 24 hours, did not induce endothelial cell proliferation. However, conditioned media from Smad2 knockout induced endothelial cell proliferation, whereas endothelial cell proliferation was inhibited by Smad3 knockout-derived conditioned media.

Conclusion: R-Smads have distinct roles in mediating the expression of pro- and antiangiogenic growth factors in response to TGF-beta1.

Download full-text PDF

Source
http://dx.doi.org/10.1111/j.1523-1755.2004.00780.xDOI Listing

Publication Analysis

Top Keywords

endothelial cell
16
response tgf-beta1
12
conditioned media
12
cell proliferation
12
key role
8
tgf-beta1
8
mediating expression
8
nrk52e stimulated
8
stimulated tgf-beta1
8
vegf-a tsp-1
8

Similar Publications

Pulmonary arterial hypertension (PAH) is a syndrome characterized by increased pulmonary vascular resistance and elevated pulmonary artery pressure, ultimately leading to right heart failure and even death. Increasing evidence implicates the fat mass and obesity-associated protein (FTO) in various metabolic and inflammatory pathways; however, its role in pulmonary endothelial function and PAH remains largely unexplored. In this study, we examined the effects of endothelial cell-specific FTO knockout on PAH development.

View Article and Find Full Text PDF

Optimal embryonic development depends upon cell-signaling molecules released by the maternal reproductive tract called embryokines. Identity of specific embryokines that enhance competence of the embryo for sustained survival is largely lacking. The current objective was to evaluate effects of three putative embryokines in cattle on embryonic development to the blastocyst stage.

View Article and Find Full Text PDF

This study presents T-1-NBAB, a new compound derived from the natural xanthine alkaloid theobromine, aimed at inhibiting VEGFR-2, a crucial protein in angiogenesis. T-1-NBAB's potential to interacts with and inhibit the VEGFR-2 was indicated using in silico techniques like molecular docking, MD simulations, MM-GBSA, PLIP, essential dynamics, and bi-dimensional projection experiments. DFT experiments was utilized also to study the structural and electrostatic properties of T-1-NBAB.

View Article and Find Full Text PDF

Chemigenetic Ca2+ indicators report elevated Ca2+ levels in endothelial Weibel-Palade bodies.

PLoS One

January 2025

Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, University of Muenster, Muenster, Germany.

Weibel-Palade bodies (WPB) are secretory organelles exclusively found in endothelial cells and among other cargo proteins, contain the hemostatic von-Willebrand factor (VWF). Stimulation of endothelial cells results in exocytosis of WPB and release of their cargo into the vascular lumen, where VWF unfurls into long strings of up to 1000 µm and recruits platelets to sites of vascular injury, thereby mediating a crucial step in the hemostatic response. The function of VWF is strongly correlated to its structure; in order to fulfill its task in the vascular lumen, VWF has to undergo a complex packing/processing after translation into the ER.

View Article and Find Full Text PDF

Background: This study tested the hypothesis that extracorporeal shockwave therapy (ECSWT) effectively rescues critical limb ischemia (CLI) in mice through the upregulation of GPR120, which protects against inflammation and angiogenesis to restore blood flow in the ischemic area.

Methods And Results: Compared with the control, ECSWT-induced GPR120-mediated anti-inflammatory effects significantly suppressed the expression of inflammatory signaling biomarkers (TAK1/MAPK family/NF-κB/IL-1β/IL-6/TNF-α/MCP-1) in HUVECs, and these effects were abolished by silencing GPR120 or by the GPR120 antagonist AH7614 (all P < 0.001).

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!