Transgenic mice for cGMP imaging

Circ Res. 2013 Aug 2;113(4):365-71. doi: 10.1161/CIRCRESAHA.113.301063. Epub 2013 Jun 25.


Rationale: Cyclic GMP (cGMP) is an important intracellular signaling molecule in the cardiovascular system, but its spatiotemporal dynamics in vivo is largely unknown.

Objective: To generate and characterize transgenic mice expressing the fluorescence resonance energy transfer-based ratiometric cGMP sensor, cGMP indicator with an EC50 of 500 nmol/L (cGi500), in cardiovascular tissues.

Methods and results: Mouse lines with smooth muscle-specific or ubiquitous expression of cGi500 were generated by random transgenesis using an SM22α promoter fragment or by targeted integration of a Cre recombinase-activatable expression cassette driven by the cytomegalovirus early enhancer/chicken β-actin/β-globin promoter into the Rosa26 locus, respectively. Primary smooth muscle cells isolated from aorta, bladder, and colon of cGi500 mice showed strong sensor fluorescence. Basal cGMP concentrations were < 100 nmol/L, whereas stimulation with cGMP-elevating agents such as 2-(N,N-diethylamino)-diazenolate-2-oxide diethylammonium salt (DEA/NO) or the natriuretic peptides, atrial natriuretic peptide, and C-type natriuretic peptide evoked fluorescence resonance energy transfer changes corresponding to cGMP peak concentrations of ≈ 3 µmol/L. However, different types of smooth muscle cells had different sensitivities of their cGMP responses to DEA/NO, atrial natriuretic peptide, and C-type natriuretic peptide. Robust nitric oxide-induced cGMP transients with peak concentrations of ≈ 1 to > 3 µmol/L could also be monitored in blood vessels of the isolated retina and in the cremaster microcirculation of anesthetized mice. Moreover, with the use of a dorsal skinfold chamber model and multiphoton fluorescence resonance energy transfer microscopy, nitric oxide-stimulated vascular cGMP signals associated with vasodilation were detected in vivo in an acutely untouched preparation.

Conclusions: These cGi500 transgenic mice permit the visualization of cardiovascular cGMP signals in live cells, tissues, and mice under normal and pathological conditions or during pharmacotherapy with cGMP-elevating drugs.

Keywords: biosensing techniques; cyclic GMP; fluorescence resonance energy transfer; microscopy, fluorescence, multiphoton; muscle, smooth; vasodilation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biosensing Techniques / methods
  • Cardiovascular System / chemistry*
  • Cyclic GMP / analysis*
  • Cyclic GMP / genetics*
  • Fluorescence Resonance Energy Transfer / methods*
  • Mice
  • Mice, Transgenic / genetics*
  • Microscopy, Fluorescence, Multiphoton / methods
  • Models, Animal
  • Muscle, Smooth / chemistry
  • Muscle, Smooth, Vascular / chemistry
  • Signal Transduction / genetics*


  • Cyclic GMP