Abstract
Sprouty1 (Spry1) is a conserved antagonist of FGF signaling. The goal of this study was to further explore the downstream mechanisms governing Spry1 inhibition of endothelial cell proliferation. Up-regulation of Spry1 in HUVECs inhibited tube formation on Matrigel (n = 6, P < 0.001). This was associated with decreased proliferation as measured by BrdU incorporation (n = 6, P < 0.001) and increased protein expression of the cyclin-dependent kinase inhibitor 1A (CDKN1A), p21 and cyclin-dependent kinase inhibitor 1B (CDKN1B), p27. A transcriptional analysis using a targeted human angiogenesis array following up-regulation of Spry1 demonstrated a >2-fold increase in an anti-angiogenic factor, serpin peptidase inhibitor, clad F (Serpinf1), and a >2-fold decrease in pro-angiogenic factors fms-related tyrosine kinase 1 (FLT1), angiopoietin2 (Ang-2), and placental growth factor (PGF) (n = 2). To define upstream mechanisms that may regulate endogenous Spry1, we performed a search for responsive elements upstream of the promoter region. This search resulted in the identification of multiple degenerate hypoxia responsive elements. Exposure to hypoxia resulted in a significant increase in Spry1 expression (n = 8, P < 0.01). These findings shed new light on downstream signaling pathways associated with Spry1 anti-proliferative responses, and provide new evidence that hypoxia stimulates Spry1 expression.
Original language | English (US) |
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Pages (from-to) | 255-261 |
Number of pages | 7 |
Journal | Molecular and cellular biochemistry |
Volume | 338 |
Issue number | 1-2 |
DOIs | |
State | Published - May 2010 |
Bibliographical note
Funding Information:Acknowledgments This work was supported by a grant-in-aid from the American Heart Association (JH, 06555827) and NIH grants RO1 HL65301 and P20 RR15555 to RF. We thank Dr. Vercellotti’s lab at the University of Minnesota for providing HUVECs, Dr. Clohisy’s lab at the University of Minnesota for help with resources and Jenny Springsteen and the facilities staff under her direction in the Lillehei Heart Institute, and Ken Stern for his help in the preparation of this manuscript. Finally, we thank Dr. Lorrie Kirshenbaum at the University of Manitoba for his helpful discussions with this project.
Keywords
- Endothelial cell
- HIF
- HUVEC
- Hypoxia
- Serpinf1