Abstract
Akt kinases control essential cellular functions, including proliferation, apoptosis, metabolism and transcription, and have been proposed as promising targets for treatment of angiogenesis-dependent pathologies, such as cancer and ischemic injury. But their precise roles in neovascularization remain elusive. Here we show that Akt1 is the predominant isoform in vascular cells and describe the unexpected consequences of Akt1 knockout on vascular integrity and pathological angiogenesis. Angiogenic responses in three distinct in vivo models were enhanced in Akt1−/− mice; these enhanced responses were associated with impairment of blood vessel maturation and increased vascular permeability. Although impaired vascular maturation in Akt1−/− mice may be attributed to reduced activation of endothelial nitric oxide synthase (eNOS), the major phenotypic changes in vascular permeability and angiogenesis were linked to reduced expression of two endogenous vascular regulators, thrombospondins 1 (TSP-1) and 2 (TSP-2). Re-expression of TSP-1 and TSP-2 in mice transplanted with wild-type bone marrow corrected the angiogenic abnormalities in Akt1−/− mice. These findings establish a crucial role of an Akt-thrombospondin axis in angiogenesis.
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References
Risau, W. Mechanisms of angiogenesis. Nature 386, 671–674 (1997).
Folkman, J. Angiogenesis in cancer, vascular, rheumatoid and other disease. Nat. Med. 1, 27–31 (1995).
Carmeliet, P. Angiogenesis in health and disease. Nat. Med. 9, 653–660 (2003).
Jiang, B.H., Zheng, J.Z., Aoki, M. & Vogt, P.K. Phosphatidylinositol 3-kinase signaling mediates angiogenesis and expression of vascular endothelial growth factor in endothelial cells. Proc. Natl. Acad. Sci. USA 97, 1749–1753 (2000).
Kandel, E.S. & Hay, N. The regulation and activities of the multifunctional serine/threonine kinase Akt/PKB. Exp. Cell Res. 253, 210–229 (1999).
Chen, W.S. et al. Growth retardation and increased apoptosis in mice with homozygous disruption of the Akt1 gene. Genes Dev. 15, 2203–2208 (2001).
Peng, X.D. et al. Dwarfism, impaired skin development, skeletal muscle atrophy, delayed bone development, and impeded adipogenesis in mice lacking Akt1 and Akt2. Genes Dev. 17, 1352–1365 (2003).
O'neill, B.T. & Abel, E.D. Akt1 in the cardiovascular system: friend or foe? J. Clin. Invest. 115, 2059–2064 (2005).
Shiojima, I. et al. Disruption of coordinated cardiac hypertrophy and angiogenesis contributes to the transition to heart failure. J. Clin. Invest. 115, 2108–2118 (2005).
Byzova, T.V. et al. A mechanism for modulation of cellular responses to VEGF: activation of the integrins. Mol. Cell 6, 851–860 (2000).
Ruoslahti, E. & Engvall, E. Integrins and vascular extracellular matrix assembly. J. Clin. Invest. 99, 1149–1152 (1997).
Carmeliet, P. et al. Synergism between vascular endothelial growth factor and placental growth factor contributes to angiogenesis and plasma extravasation in pathological conditions. Nat. Med. 7, 575–583 (2001).
Byzova, T.V. et al. Adenovirus encoding vascular endothelial growth factor-D induces tissue-specific vascular patterns in vivo. Blood 99, 4434–4442 (2002).
Tammela, T., Enholm, B., Alitalo, K. & Paavonen, K. The biology of vascular endothelial growth factors. Cardiovasc. Res. 65, 550–563 (2005).
Thurston, G. et al. Leakage-resistant blood vessels in mice transgenically overexpressing angiopoietin-1. Science 286, 2511–2514 (1999).
Agah, A., Kyriakides, T.R., Lawler, J. & Bornstein, P. The lack of thrombospondin-1 (TSP1) dictates the course of wound healing in double-TSP1/TSP2-null mice. Am. J. Pathol. 161, 831–839 (2002).
Bornstein, P. Thrombospondins as matricellular modulators of cell function. J. Clin. Invest. 107, 929–934 (2001).
Chen, J. et al. Impaired platelet responses to thrombin and collagen in AKT-1 deficient mice. Blood 104, 1703–1710 (2004).
Ackah, E. et al. Akt1/protein kinase Balpha is critical for ischemic and VEGF-mediated angiogenesis. J. Clin. Invest. 115, 2119–2127 (2005).
Mazure, N.M., Chen, E.Y., Laderoute, K.R. & Giaccia, A.J. Induction of vascular endothelial growth factor by hypoxia is modulated by a phosphatidylinositol 3-kinase/Akt signaling pathway in Ha-ras-transformed cells through a hypoxia inducible factor-1 transcriptional element. Blood 90, 3322–3331 (1997).
Arsham, A.M., Plas, D.R., Thompson, C.B. & Simon, M.C. Akt and hypoxia-inducible factor-1 independently enhance tumor growth and angiogenesis. Cancer Res. 64, 3500–3507 (2004).
Yu, J. et al. Endothelial nitric oxide synthase is critical for ischemic remodeling, mural cell recruitment, and blood flow reserve. Proc. Natl. Acad. Sci. USA 102, 10999–11004 (2005).
van Hinsbergh, V.W., Collen, A. & Koolwijk, P. Role of fibrin matrix in angiogenesis. Ann. NY Acad. Sci. 936, 426–437 (2001).
Aicher, A. et al. Essential role of endothelial nitric oxide synthase for mobilization of stem and progenitor cells. Nat. Med. 9, 1370–1376 (2003).
Hotary, K.B. et al. Membrane type I matrix metalloproteinase usurps tumor growth control imposed by the three-dimensional extracellular matrix. Cell 114, 33–45 (2003).
Puolakkainen, P.A., Brekken, R.A., Muneer, S. & Sage, E.H. Enhanced growth of pancreatic tumors in SPARC-null mice is associated with decreased deposition of extracellular matrix and reduced tumor cell apoptosis. Mol. Cancer Res. 2, 215–224 (2004).
Visse, R. & Nagase, H. Matrix metalloproteinases and tissue inhibitors of metalloproteinases: structure, function, and biochemistry. Circ. Res. 92, 827–839 (2003).
Simantov, R. & Silverstein, R.L. CD36: a critical anti-angiogenic receptor. Front. Biosci. 8, s874–s882 (2003).
Rodriguez-Manzaneque, J.C. et al. Thrombospondin-1 suppresses spontaneous tumor growth and inhibits activation of matrix metalloproteinase-9 and mobilization of vascular endothelial growth factor. Proc. Natl. Acad. Sci. USA 98, 12485–12490 (2001).
Armstrong, L.C. et al. Thrombospondin 2 inhibits microvascular endothelial cell proliferation by a caspase-independent mechanism. Mol. Biol. Cell 13, 1893–1905 (2002).
Lange-Asschenfeldt, B. et al. Increased and prolonged inflammation and angiogenesis in delayed-type hypersensitivity reactions elicited in the skin of thrombospondin-2–deficient mice. Blood 99, 538–545 (2002).
Bornstein, P., Agah, A. & Kyriakides, T.R. The role of thrombospondins 1 and 2 in the regulation of cell-matrix interactions, collagen fibril formation, and the response to injury. Int. J. Biochem. Cell Biol. 36, 1115–1125 (2004).
Shiojima, I. & Walsh, K. Role of Akt signaling in vascular homeostasis and angiogenesis. Circ. Res. 90, 1243–1250 (2002).
Sun, J.F. et al. Microvascular patterning is controlled by fine-tuning the Akt signal. Proc. Natl. Acad. Sci. USA 102, 128–133 (2005).
Nagoshi, T. et al. PI3K rescues the detrimental effects of chronic Akt activation in the heart during ischemia/reperfusion injury. J. Clin. Invest. 115, 2128–2138 (2005).
Reynolds, L.E. et al. Enhanced pathological angiogenesis in mice lacking beta3 integrin or beta3 and beta5 integrins. Nat. Med. 8, 27–34 (2002).
Dong, Q.G. et al. A general strategy for isolation of endothelial cells from murine tissues. Characterization of two endothelial cell lines from the murine lung and subcutaneous sponge implants. Arterioscler. Thromb. Vasc. Biol. 17, 1599–1604 (1997).
Byzova, T.V., Kim, W., Midura, R.J. & Plow, E.F. Activation of integrin alpha(V)beta(3) regulates cell adhesion and migration to bone sialoprotein. Exp. Cell Res. 254, 299–308 (2000).
De, S. et al. Molecular pathway for cancer metastasis to bone. J. Biol. Chem. 278, 39044–39050 (2003).
Narizhneva, N.V. et al. Thrombospondin-1 up-regulates expression of cell adhesion molecules and promotes monocyte binding to endothelium. FASEB J. 19, 1158–1160 (2005).
De, S. et al. VEGF-integrin interplay controls tumor growth and vascularization. Proc. Natl. Acad. Sci. USA 102, 7589–7594 (2005).
Takahashi, T. et al. Ischemia- and cytokine-induced mobilization of bone marrow-derived endothelial progenitor cells for neovascularization. Nat. Med. 5, 434–438 (1999).
Han, E.D., MacFarlane, R.C., Mulligan, A.N., Scafidi, J. & Davis, A.E., III. Increased vascular permeability in C1 inhibitor-deficient mice mediated by the bradykinin type 2 receptor. J. Clin. Invest. 109, 1057–1063 (2002).
Stockton, R.A., Schaefer, E. & Schwartz, M.A. p21-activated kinase regulates endothelial permeability through modulation of contractility. J. Biol. Chem. 279, 46621–46630 (2004).
Soula-Rothhut, M. et al. The tumor suppressor PTEN inhibits EGF-induced TSP-1 and TIMP-1 expression in FTC-133 thyroid carcinoma cells. Exp. Cell Res. 304, 187–201 (2005).
Acknowledgements
We acknowledge support from the US National Institutes of Health (HL071625 and DK060933 to T.V.B. and CA90764 to N.H). We thank J. Li for his help in statistical analysis, J. Drazba, A. Vasantji and Imaging Core, Cleveland Clinic Foundation for the help in tissue processing and image analysis and L. Mavrakis and S. Bundy for supply of HUVEC, harvested through Birthing Services Department at the Cleveland Clinic Foundation and Perinatal Clinical Research Center at the MetroHealth Hospital.
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Supplementary information
Supplementary Fig. 1
Akt1 is the major Akt isoform in vascular cells. (PDF 279 kb)
Supplementary Fig. 2
Characteristics of vasculature in Akt1 null mice. (PDF 339 kb)
Supplementary Fig. 3
Absence of Akt1 results in impaired collagen matrix organization. (PDF 165 kb)
Supplementary Fig. 4
Tumor vasculature and TSP-1 expression are inversely related. (PDF 267 kb)
Supplementary Fig. 5
Basal levels of eNOS phosphorylation is reduced in Akt1−/− endothelial cells (EC). (PDF 69 kb)
Supplementary Fig. 6
Reduced vascular maturation in eNOS null mice. (PDF 274 kb)
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Chen, J., Somanath, P., Razorenova, O. et al. Akt1 regulates pathological angiogenesis, vascular maturation and permeability in vivo. Nat Med 11, 1188–1196 (2005). https://doi.org/10.1038/nm1307
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DOI: https://doi.org/10.1038/nm1307
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