Targeted knockdown of insulin-like growth factor binding protein-2 disrupts cardiovascular development in zebrafish embryos

Mol Endocrinol. 2005 Apr;19(4):1024-34. doi: 10.1210/me.2004-0392. Epub 2004 Dec 23.


IGF binding protein-2 (IGFBP-2) is an evolutionarily conserved protein that binds IGFs and modulates their biological activities. Although the actions of IGFBP-2 have been well studied in vitro, we have a poor understanding of its in vivo functions, particularly during early development. Using the transparent zebrafish embryo as a model, we show that IGFBP-2 mRNA is expressed in lens epithelium and cranial boundary regions during early embryonic development and becomes localized to the liver by the completion of embryogenesis. Targeted knock-down of IGFBP-2 by antisense morpholino-modified oligonucleotides resulted in delayed development, reduced body growth, reduced IGF-I mRNA levels, and disruptions to cardiovascular development, including reduced blood cell number, reduced blood circulation, cardiac dysfunction, and brain ventricle edema. Detailed examination of vascular tissues, using a stable transgenic line of zebrafish expressing green fluorescent protein in vascular endothelial cells, revealed specific angiogenic (vessel sprouting) defects in IGFBP-2 knockdown embryos, with effects being localized in regions associated with IGFBP-2 mRNA expression. These findings suggest that IGFBP-2 is required for general embryonic development and growth and plays a local role in regulating vascular development in a model vertebrate organism.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Cardiovascular Abnormalities / genetics
  • Cardiovascular System / embryology*
  • Down-Regulation
  • Embryo, Nonmammalian / abnormalities
  • Embryo, Nonmammalian / metabolism
  • Embryonic Development
  • Gene Expression / drug effects
  • Gene Targeting
  • Hematopoiesis / genetics
  • Hematopoiesis / physiology
  • Insulin-Like Growth Factor Binding Protein 2 / genetics
  • Insulin-Like Growth Factor Binding Protein 2 / physiology*
  • Insulin-Like Growth Factor I / genetics
  • Oligodeoxyribonucleotides, Antisense / genetics
  • Oligodeoxyribonucleotides, Antisense / pharmacology
  • RNA, Messenger / analysis
  • RNA, Messenger / metabolism
  • Zebrafish / embryology*
  • Zebrafish / genetics


  • Insulin-Like Growth Factor Binding Protein 2
  • Oligodeoxyribonucleotides, Antisense
  • RNA, Messenger
  • Insulin-Like Growth Factor I