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Skuli N, Majmundar AJ, Krock BL, Mesquita RC, Mathew LK, Quinn ZL, Runge A, Liu L, Kim MN, Liang J, Schenkel S, Yodh AG, Keith B, Simon MC. Endothelial HIF-2α regulates murine pathological angiogenesis and revascularization processes. J Clin Invest 2012; 122:1427-43. [PMID: 22426208 PMCID: PMC3314446 DOI: 10.1172/jci57322] [Citation(s) in RCA: 141] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Accepted: 02/03/2012] [Indexed: 12/12/2022] Open
Abstract
Localized tissue hypoxia is a consequence of vascular compromise or rapid cellular proliferation and is a potent inducer of compensatory angiogenesis. The oxygen-responsive transcriptional regulator hypoxia-inducible factor 2α (HIF-2α) is highly expressed in vascular ECs and, along with HIF-1α, activates expression of target genes whose products modulate vascular functions and angiogenesis. However, the mechanisms by which HIF-2α regulates EC function and tissue perfusion under physiological and pathological conditions are poorly understood. Using mice in which Hif2a was specifically deleted in ECs, we demonstrate here that HIF-2α expression is required for angiogenic responses during hindlimb ischemia and for the growth of autochthonous skin tumors. EC-specific Hif2a deletion resulted in increased vessel formation in both models; however, these vessels failed to undergo proper arteriogenesis, resulting in poor perfusion. Analysis of cultured HIF-2α-deficient ECs revealed cell-autonomous increases in migration, invasion, and morphogenetic activity, which correlated with HIF-2α-dependent expression of specific angiogenic factors, including delta-like ligand 4 (Dll4), a Notch ligand, and angiopoietin 2. By stimulating Dll4 signaling in cultured ECs or restoring Dll4 expression in ischemic muscle tissue, we rescued most of the HIF-2α-dependent EC phenotypes in vitro and in vivo, emphasizing the critical role of Dll4/Notch signaling as a downstream target of HIF-2α in ECs. These results indicate that HIF-1α and HIF-2α fulfill complementary, but largely nonoverlapping, essential functions in pathophysiological angiogenesis.
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MESH Headings
- Adaptor Proteins, Signal Transducing
- Angiopoietin-2/genetics
- Angiopoietin-2/physiology
- Animals
- Basic Helix-Loop-Helix Transcription Factors/deficiency
- Basic Helix-Loop-Helix Transcription Factors/genetics
- Basic Helix-Loop-Helix Transcription Factors/physiology
- Calcium-Binding Proteins
- Cell Hypoxia
- Cell Movement
- Cells, Cultured/cytology
- Collateral Circulation/physiology
- Endothelial Cells/metabolism
- Hindlimb/blood supply
- Hypoxia-Inducible Factor 1, alpha Subunit/deficiency
- Hypoxia-Inducible Factor 1, alpha Subunit/genetics
- Hypoxia-Inducible Factor 1, alpha Subunit/physiology
- Intracellular Signaling Peptides and Proteins/genetics
- Intracellular Signaling Peptides and Proteins/physiology
- Ischemia/physiopathology
- Membrane Proteins/genetics
- Membrane Proteins/physiology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Transgenic
- Neovascularization, Pathologic/physiopathology
- Neovascularization, Physiologic/physiology
- Receptors, Notch/physiology
- Recombinant Fusion Proteins/physiology
- Recovery of Function
- Skin Neoplasms/blood supply
- Skin Neoplasms/chemically induced
- Wound Healing/physiology
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Affiliation(s)
- Nicolas Skuli
- Howard Hughes Medical Institute,
Abramson Family Cancer Research Institute,
School of Medicine,
Department of Physics and Astronomy,
Department of Cancer Biology, and
Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Amar J. Majmundar
- Howard Hughes Medical Institute,
Abramson Family Cancer Research Institute,
School of Medicine,
Department of Physics and Astronomy,
Department of Cancer Biology, and
Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Bryan L. Krock
- Howard Hughes Medical Institute,
Abramson Family Cancer Research Institute,
School of Medicine,
Department of Physics and Astronomy,
Department of Cancer Biology, and
Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Rickson C. Mesquita
- Howard Hughes Medical Institute,
Abramson Family Cancer Research Institute,
School of Medicine,
Department of Physics and Astronomy,
Department of Cancer Biology, and
Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Lijoy K. Mathew
- Howard Hughes Medical Institute,
Abramson Family Cancer Research Institute,
School of Medicine,
Department of Physics and Astronomy,
Department of Cancer Biology, and
Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Zachary L. Quinn
- Howard Hughes Medical Institute,
Abramson Family Cancer Research Institute,
School of Medicine,
Department of Physics and Astronomy,
Department of Cancer Biology, and
Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Anja Runge
- Howard Hughes Medical Institute,
Abramson Family Cancer Research Institute,
School of Medicine,
Department of Physics and Astronomy,
Department of Cancer Biology, and
Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Liping Liu
- Howard Hughes Medical Institute,
Abramson Family Cancer Research Institute,
School of Medicine,
Department of Physics and Astronomy,
Department of Cancer Biology, and
Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Meeri N. Kim
- Howard Hughes Medical Institute,
Abramson Family Cancer Research Institute,
School of Medicine,
Department of Physics and Astronomy,
Department of Cancer Biology, and
Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jiaming Liang
- Howard Hughes Medical Institute,
Abramson Family Cancer Research Institute,
School of Medicine,
Department of Physics and Astronomy,
Department of Cancer Biology, and
Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Steven Schenkel
- Howard Hughes Medical Institute,
Abramson Family Cancer Research Institute,
School of Medicine,
Department of Physics and Astronomy,
Department of Cancer Biology, and
Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Arjun G. Yodh
- Howard Hughes Medical Institute,
Abramson Family Cancer Research Institute,
School of Medicine,
Department of Physics and Astronomy,
Department of Cancer Biology, and
Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Brian Keith
- Howard Hughes Medical Institute,
Abramson Family Cancer Research Institute,
School of Medicine,
Department of Physics and Astronomy,
Department of Cancer Biology, and
Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - M. Celeste Simon
- Howard Hughes Medical Institute,
Abramson Family Cancer Research Institute,
School of Medicine,
Department of Physics and Astronomy,
Department of Cancer Biology, and
Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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