VEGF Regulation of Hepatic Erythropoietin Synthesis

Summary

Principal Investigator: Calvin Kuo
Affiliation: Stanford University
Country: USA
Abstract: DESCRIPTION (provided by applicant): Erythropolesis, the production of red blood cells (RBCs), is regulated by an intricate network of signals involving the hormone erythropoietin (Epo), and sensing of hypoxia through inhibition of both HIF-1alpha proline hydroxylation and its subsequent interaction with the Von Hippel-Lindau (VHL) protein. Either insufficient or excess erythropoiesis produces disease in humans, with too few RBCs resulting in anemia, and too many RBCs resulting in polycythemia vera. The treatment of anemia alone consumes significant economic resources, with the necessity for either blood transfusions or Epo treatment. We have developed adenoviruses which express soluble ectodomains of the Flkl and Fltl receptors for Vascular Endothelial Growth Factor (VEGF). Single injections in mice of these adenoviruses produce high levels of circulating soluble Flk1 and Flt1 ectodomains which persist for >3-4 weeks, potently suppressing tumor growth and angiogenesis, and producing stringent conditional inactivation of-VEGF in adult animals. Surprisingly, adenoviral expression of Flk1 or Flt1 ectodomains (soluble VEGF receptors, or sVEGFRs) in normal mice strongly stimulates erythropoiesis, with increase in hematocrit increasing from baseline 45% to new levels of 55-75 %. Circulating erythropoietin levels are elevated in parallel;however, the Epo originates from the liver as in embryonic development, not the usual site of synthesis in the kidney. This data implicates VEGF as an unsuspected repressor of hepatic Epo synthesis, and this grant application is focused on determining the underlying moIecular mechanisms. In Aim 1, experiments will expand upon preliminary data implicating perturbation of hepatocyte--endothelial cross-talk in the sVEGFR induction of hepatic Epo. Adenoviral and transgenic expression of Cre recombinase will be used to test the effects of specific inhibition of hepatocyte-produced VEGF on hepatocyte Epo expression. Conversely, co-culture experiments manipulating VEGF will be used to test the effects of endothelial cells on hepatocyte Epo production. Aim 2 will define the specific factors mediating the transcriptional regulation of Epo by VEGF and VEGF blockade. Candidate factors (HIF proteins, HNF4, RXRalpha, GATA factors) will be directly tested by chromatin immunoprecipitation assays and functionally by adenoviral and transgenic expression of Cre to delete floxed alleles of relevant candidates. Additionally, novel factors will be sought by unbiased approaches of DNAse1 footprinting and hypersensitivity assays. The therapeutic implications of the ability to reactivate hepatic Epo synthesis are substantial. These studies should also yield significant insight into the action of VEGF as an unsuspected upstream regulator of RBC homeostasis, into the regulation of hepatic Epo production which is strongly repressed post-natally, and indicate the potential utility of alterations in erythropoiesis as surrogate markers for or a desirable consequence of stringent VEGF blockade.
Funding Period: 2009-07-01 - 2011-06-30
more information: NIH RePORT

Top Publications

  1. pmc Vascular endothelial growth factor: biology and therapeutic applications
    Quoc T Ho
    Division of Hematology, Stanford University School of Medicine, 269 Campus Drive, Stanford, CA 94305, USA
    Int J Biochem Cell Biol 39:1349-57. 2007
  2. pmc A liver Hif-2α-Irs2 pathway sensitizes hepatic insulin signaling and is modulated by Vegf inhibition
    Kevin Wei
    1 Division of Hematology, Stanford University School of Medicine, Stanford, California, USA 2
    Nat Med 19:1331-7. 2013
  3. pmc Cross-talk between hypoxia and insulin signaling through Phd3 regulates hepatic glucose and lipid metabolism and ameliorates diabetes
    Cullen M Taniguchi
    Division of Radiation and Cancer Biology, Department of Radiation Oncology, Center for Clinical Sciences Research, Stanford, California, USA
    Nat Med 19:1325-30. 2013
  4. doi Maintenance bevacizumab is associated with increased hemoglobin in patients with advanced, nonsquamous, non-small cell lung cancer
    Jonathan W Riess
    Division of Hematology, Department of Medicine, Stanford University School of Medicine, CA, USA
    Cancer Invest 30:231-5. 2012
  5. pmc Targeting endothelium-pericyte cross talk by inhibiting VEGF receptor signaling attenuates kidney microvascular rarefaction and fibrosis
    Shuei Liong Lin
    Renal Division, Department of Medicine, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan
    Am J Pathol 178:911-23. 2011
  6. pmc Essential regulation of CNS angiogenesis by the orphan G protein-coupled receptor GPR124
    Frank Kuhnert
    Department of Medicine, Hematology Division, Stanford University, Stanford, CA 94305, USA
    Science 330:985-9. 2010
  7. pmc VEGF signaling has distinct spatiotemporal roles during heart valve development
    Kryn Stankunas
    Division of Cardiovascular Medicine, Department of Medicine, Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
    Dev Biol 347:325-36. 2010
  8. pmc Angiopoietin/Tie2 signaling transforms capillaries into venules primed for leukocyte trafficking in airway inflammation
    Jonas Fuxe
    Department of Anatomy, University of California San Francisco, San Francisco, CA 94143 0452, USA
    Am J Pathol 176:2009-18. 2010
  9. ncbi Increased hemoglobin associated with VEGF inhibitors in advanced renal cell carcinoma
    Lauren C Harshman
    Stanford University School of Medicine, California 94305, USA
    Cancer Invest 27:851-6. 2009
  10. pmc Endochondral ossification is required for haematopoietic stem-cell niche formation
    Charles K F Chan
    Department of Pathology, Developmental Biology and Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, California, USA
    Nature 457:490-4. 2009

Scientific Experts

  • Jonathan W Riess
  • Charles K F Chan
  • Calvin J Kuo
  • Frank Kuhnert
  • Kevin Wei
  • Jenny Yuan
  • Cullen M Taniguchi
  • Kryn Stankunas
  • Betty Y Y Tam
  • Lisa M McGinnis
  • Amato J Giaccia
  • Gavin Thurston
  • Shuei Liong Lin
  • Jonas Fuxe
  • Jacquelyn J Maher
  • Michael R Mancuso
  • Donald M McDonald
  • Lauren C Harshman
  • Quoc T Ho
  • Richard C Mulligan
  • Nihar R Nayak
  • Lori C Morton
  • Keith Anderson
  • David Kuo
  • Edward L LaGory
  • Etienne Lefai
  • Fabienne Rajas
  • Anh N Diep
  • Adam J Krieg
  • Gilles Mithieux
  • Elizabeth C Finger
  • Mario Vallon
  • Justin P Annes
  • Owen P McGuinness
  • Stanley J Wiegand
  • Stephanie M Piecewicz
  • Kimberly X Mulligan
  • M Celeste Simon
  • Colleen Wu
  • Kwan Dun Wu
  • Tun Jun Tsai
  • Jeremy S Duffield
  • Yung Ming Chen
  • Fan Chi Chang
  • Ching Fang Wu
  • Vin Cent Wu
  • Wen Chih Chiang
  • Claudia Schrimpf
  • Yi Ting Chen
  • William L Young
  • Sarah C Heilshorn
  • Sebastien P Tabruyn
  • Amir Shamloo
  • Calvin Kuo
  • Erin Lashnits
  • Gene K Ma
  • Mareike Florek
  • Peter Baluk
  • Ching Pin Chang
  • Hua Su
  • Shaun O'Brien
  • Marcus Fruttiger
  • Vir Choksi
  • Frank J Kuhnert
  • Hsiao Ting Wang
  • Bryan Y Wong
  • Nicholas J Vogelzang
  • Sandy Srinivas
  • Jessica Hampton
  • Chang Zheng Chen
  • Tomoichiro Asano
  • Barbara Sennino
  • Angeline Jocson
  • John T Gray
  • Grace Wu
  • Randall S Johnson
  • Shelly Jiang
  • Joceyln Holash
  • Frans A Kuypers
  • Cecile Chartier
  • Colleen Hefner
  • Jana Hoffman
  • Uma Sundram
  • Jeng Shin Lee
  • George D Yancopoulos
  • Joseph A Garcia
  • Lisa Ma
  • Stanley L Schrier
  • John S Rudge
  • Nihar R Niyak

Detail Information

Publications14

  1. pmc Vascular endothelial growth factor: biology and therapeutic applications
    Quoc T Ho
    Division of Hematology, Stanford University School of Medicine, 269 Campus Drive, Stanford, CA 94305, USA
    Int J Biochem Cell Biol 39:1349-57. 2007
    ....
  2. pmc A liver Hif-2α-Irs2 pathway sensitizes hepatic insulin signaling and is modulated by Vegf inhibition
    Kevin Wei
    1 Division of Hematology, Stanford University School of Medicine, Stanford, California, USA 2
    Nat Med 19:1331-7. 2013
    ..These studies also indicate distinct roles in hepatic metabolism for Hif-1α, which promotes glycolysis, and Hif-2α, which suppresses gluconeogenesis, and suggest new treatment approaches for type 2 diabetes mellitus. ..
  3. pmc Cross-talk between hypoxia and insulin signaling through Phd3 regulates hepatic glucose and lipid metabolism and ameliorates diabetes
    Cullen M Taniguchi
    Division of Radiation and Cancer Biology, Department of Radiation Oncology, Center for Clinical Sciences Research, Stanford, California, USA
    Nat Med 19:1325-30. 2013
    ..Thus, isoform-specific inhibition of Phd3 could be exploited to treat type 2 diabetes without the toxicity that could occur with chronic inhibition of multiple Phd isoforms. ..
  4. doi Maintenance bevacizumab is associated with increased hemoglobin in patients with advanced, nonsquamous, non-small cell lung cancer
    Jonathan W Riess
    Division of Hematology, Department of Medicine, Stanford University School of Medicine, CA, USA
    Cancer Invest 30:231-5. 2012
    ..268 days, p =.38.) Maintenance bevacizumab is associated with increased hemoglobin in advanced, nonsquamous, NSCLC patients...
  5. pmc Targeting endothelium-pericyte cross talk by inhibiting VEGF receptor signaling attenuates kidney microvascular rarefaction and fibrosis
    Shuei Liong Lin
    Renal Division, Department of Medicine, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan
    Am J Pathol 178:911-23. 2011
    ..These findings link fibrogenesis inextricably with microvascular rarefaction for the first time, add new significance to fibrogenesis, and identify novel therapeutic targets...
  6. pmc Essential regulation of CNS angiogenesis by the orphan G protein-coupled receptor GPR124
    Frank Kuhnert
    Department of Medicine, Hematology Division, Stanford University, Stanford, CA 94305, USA
    Science 330:985-9. 2010
    ..Further, the functional tropism of GPR124 marks this receptor as a therapeutic target for CNS-related vascular pathologies...
  7. pmc VEGF signaling has distinct spatiotemporal roles during heart valve development
    Kryn Stankunas
    Division of Cardiovascular Medicine, Department of Medicine, Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
    Dev Biol 347:325-36. 2010
    ..Thus, VEGF roles in the developing valves are dynamic, transitioning from a differentiation role directed by VEGFR1 in the OFT to a morphogenetic role through VEGFR2 primarily in the AVC-derived valves...
  8. pmc Angiopoietin/Tie2 signaling transforms capillaries into venules primed for leukocyte trafficking in airway inflammation
    Jonas Fuxe
    Department of Anatomy, University of California San Francisco, San Francisco, CA 94143 0452, USA
    Am J Pathol 176:2009-18. 2010
    ..pulmonis-infected mouse airways. Together, these findings suggest that blockade of the Ang/Tie2 pathway may represent a therapeutic approach in airway inflammation...
  9. ncbi Increased hemoglobin associated with VEGF inhibitors in advanced renal cell carcinoma
    Lauren C Harshman
    Stanford University School of Medicine, California 94305, USA
    Cancer Invest 27:851-6. 2009
    ..2 months with rises > 15%. This study identifies increased hemoglobin as a possible consequence of VEGF inhibitors. The correlation with longer PFS suggests that rise in hemoglobin may be a surrogate biomarker of efficacy...
  10. pmc Endochondral ossification is required for haematopoietic stem-cell niche formation
    Charles K F Chan
    Department of Pathology, Developmental Biology and Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, California, USA
    Nature 457:490-4. 2009
    ..Collectively, our data implicate endochondral ossification, bone formation that proceeds through a cartilage intermediate, as a requirement for adult HSC niche formation...
  11. doi Attribution of vascular phenotypes of the murine Egfl7 locus to the microRNA miR-126
    Frank Kuhnert
    Division of Hematology, Department of Medicine, Stanford University School of Medicine, CCSR 1155, 269 Campus Drive, Stanford, CA 94305, USA
    Development 135:3989-93. 2008
    ....
  12. pmc Soluble receptor-mediated selective inhibition of VEGFR and PDGFRbeta signaling during physiologic and tumor angiogenesis
    Frank Kuhnert
    Division of Hematology, Stanford University School of Medicine, Stanford, CA 94305, USA
    Proc Natl Acad Sci U S A 105:10185-90. 2008
    ..These studies using highly specific soluble receptors suggest that additivity between VEGFR and PDGFRbeta inhibition depends on the strength of VEGF blockade and appears minimal under conditions of maximal VEGF antagonism...
  13. ncbi Recombinant adenovirus as a methodology for exploration of physiologic functions of growth factor pathways
    Kevin Wei
    Division of Hematology, Stanford University School of Medicine, 269 Campus Dr, CCSR 1155, Stanford, CA 94305, USA
    J Mol Med (Berl) 86:161-9. 2008
    ..Finally, we discuss the potential physiological and therapeutic relevance of our findings...
  14. ncbi VEGF modulates erythropoiesis through regulation of adult hepatic erythropoietin synthesis
    Betty Y Y Tam
    Division of Hematology, Stanford University School of Medicine, 269 Campus Drive, CCSR 1155, Stanford, California, 94305, USA
    Nat Med 12:793-800. 2006
    ....