Novel genetic approach for in vivo vascular imaging in mice

Circ Res. 2012 Mar 30;110(7):938-47. doi: 10.1161/CIRCRESAHA.111.254375. Epub 2012 Feb 28.

Abstract

Rationale: The formation and maintenance of a functional vasculature is essential for normal embryonic development, and genetic changes that affect the vasculature underlie pathogenesis in many human diseases. In vivo imaging in mouse models is required to understand the full complexity of mammalian vascular formation, which is a dynamic and 3-dimensional process. Optical microscopy of genetically expressed fluorescent reporter proteins offers high resolution but limited depth of penetration in vivo. Conversely, there are a plethora of molecular probes for alternative in vivo vascular imaging modalities, but few options for genetic control of contrast enhancement.

Objective: To develop a reporter system for multimodal imaging of genetic processes involved in mammalian vascular biology.

Methods and results: To approach this problem, we developed an optimal tagging system based on Biotag-BirA technology. In the resulting Biotag reporter system, coexpression of 2 interacting proteins results in biotin labeling of cell membranes, thus enabling multimodal imaging with "avidinated" probes. To assess this approach for in vivo imaging, we generated transgenic mice that expressed the Biotag-BirA transgene from a minimal Tie2 promoter. A variety of imaging methods were used to show the utility of this approach for quantitative analysis in embryonic and adult models of vascular development, using intravascular injection of avidinated probes for near infrared, ultrasound, and magnetic resonance imaging.

Conclusions: The present results demonstrate the versatility of the Biotag system for studies of vascular biology in genetically engineered mice, providing a robust approach for multimodal in vivo imaging of genetic processes in the vasculature.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Biomarkers / metabolism
  • Biotechnology / methods
  • Biotin / genetics
  • Biotin / metabolism
  • Blood Vessels / cytology*
  • Blood Vessels / embryology*
  • Blood Vessels / metabolism
  • Embryo, Mammalian / blood supply*
  • Embryo, Mammalian / embryology*
  • Embryo, Mammalian / metabolism
  • Embryonic Development / genetics*
  • Female
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • HEK293 Cells
  • Humans
  • Magnetic Resonance Imaging / methods*
  • Mice
  • Mice, Transgenic
  • Models, Animal
  • Platelet Endothelial Cell Adhesion Molecule-1 / genetics
  • Platelet Endothelial Cell Adhesion Molecule-1 / metabolism
  • Pregnancy
  • Receptor Protein-Tyrosine Kinases / genetics
  • Receptor Protein-Tyrosine Kinases / metabolism
  • Receptor, TIE-2

Substances

  • Biomarkers
  • Platelet Endothelial Cell Adhesion Molecule-1
  • Green Fluorescent Proteins
  • Biotin
  • Receptor Protein-Tyrosine Kinases
  • Receptor, TIE-2
  • Tek protein, mouse