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Circ Res. 2016 Jan 8;118(1):38-47. doi: 10.1161/CIRCRESAHA.115.307408. Epub 2015 Oct 15.

VEGF-Induced Expression of miR-17-92 Cluster in Endothelial Cells Is Mediated by ERK/ELK1 Activation and Regulates Angiogenesis.

Author information

1
From the Vascular Biology and Therapeutics Program (A.C.-J., M.Y.L., E.A., M.F.-F., M.S., J.Y., C.F.-H., W.C.S., Y.S.), Section of Comparative Medicine (A.C.-J., E.A., M.F.-F., M.S., M.Q.R., C.F.-H., Y.S.), Departments of Pathology (A.C.-J., E.A., M.F.-F., M.S., C.F.-H., Y.S.); Pharmacology (M.Y.L., S.L.-E., W.C.S.), and Internal Medicine, Section of Cardiovascular Medicine (J.Y.), Yale University School of Medicine, New Haven, CT; and Department of Medicine, New York University School of Medicine (C.S.).
2
From the Vascular Biology and Therapeutics Program (A.C.-J., M.Y.L., E.A., M.F.-F., M.S., J.Y., C.F.-H., W.C.S., Y.S.), Section of Comparative Medicine (A.C.-J., E.A., M.F.-F., M.S., M.Q.R., C.F.-H., Y.S.), Departments of Pathology (A.C.-J., E.A., M.F.-F., M.S., C.F.-H., Y.S.); Pharmacology (M.Y.L., S.L.-E., W.C.S.), and Internal Medicine, Section of Cardiovascular Medicine (J.Y.), Yale University School of Medicine, New Haven, CT; and Department of Medicine, New York University School of Medicine (C.S.). yajaira.suarez@yale.edu.

Abstract

RATIONALE:

Several lines of evidence indicate that the regulation of microRNA (miRNA) levels by different stimuli may contribute to the modulation of stimulus-induced responses. The miR-17-92 cluster has been linked to tumor development and angiogenesis, but its role in vascular endothelial growth factor-induced endothelial cell (EC) functions is unclear and its regulation is unknown.

OBJECTIVE:

The purpose of this study was to elucidate the mechanism by which VEGF regulates the expression of miR-17-92 cluster in ECs and determine its contribution to the regulation of endothelial angiogenic functions, both in vitro and in vivo. This was done by analyzing the effect of postnatal inactivation of miR-17-92 cluster in the endothelium (miR-17-92 iEC-KO mice) on developmental retinal angiogenesis, VEGF-induced ear angiogenesis, and tumor angiogenesis.

METHODS AND RESULTS:

Here, we show that Erk/Elk1 activation on VEGF stimulation of ECs is responsible for Elk-1-mediated transcription activation (chromatin immunoprecipitation analysis) of the miR-17-92 cluster. Furthermore, we demonstrate that VEGF-mediated upregulation of the miR-17-92 cluster in vitro is necessary for EC proliferation and angiogenic sprouting. Finally, we provide genetic evidence that miR-17-92 iEC-KO mice have blunted physiological retinal angiogenesis during development and diminished VEGF-induced ear angiogenesis and tumor angiogenesis. Computational analysis and rescue experiments show that PTEN (phosphatase and tensin homolog) is a target of the miR-17-92 cluster and is a crucial mediator of miR-17-92-induced EC proliferation. However, the angiogenic transcriptional program is reduced when miR-17-92 is inhibited.

CONCLUSIONS:

Taken together, our results indicate that VEGF-induced miR-17-92 cluster expression contributes to the angiogenic switch of ECs and participates in the regulation of angiogenesis.

KEYWORDS:

cell proliferation; endothelial cells; microRNAs; transcription activation; vascular endothelial growth factor A

PMID:
26472816
PMCID:
PMC4703066
DOI:
10.1161/CIRCRESAHA.115.307408
[Indexed for MEDLINE]
Free PMC Article

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