In vivo imaging of immuno-spin trapped radicals with molecular magnetic resonance imaging in a diabetic mouse model.

RHEAL A TOWNER; NATALIYA SMITH; SAUNDERS D; HENDERSON M; DOWNUM K; LUPU F; SILASI-MANSAR R; RAMIREZ, DC; GOMEZ MEJIBA, SE; BONINI MG; EHENSHAFT M; MASON, RP

DIABETES

AMER DIABETES ASSOC

Año: 2012 p. 2405 - 2413

0012-1797

Diabetes. 2012 Oct;61(10):2405-13. Epub 2012 Jun 14. In vivo imaging of immuno-spin trapped radicals with molecular magnetic resonance imaging in a diabetic mouse model. Towner RA1, Smith N, Saunders D, Henderson M, Downum K, Lupu F, Silasi-Mansat R, Ramirez DC, Gomez-Mejiba SE, Bonini MG, Ehrenshaft M, Mason RP. Author information 1Advanced Magnetic Resonance Center, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, USA. rheal-towner@omrf.org Abstract Oxidative stress plays a major role in diabetes. In vivo levels of membrane-bound radicals (MBRs) in a streptozotocin-induced diabetic mouse model were uniquely detected by combining molecular magnetic resonance imaging (mMRI) and immunotrapping techniques. An anti-DMPO (5,5-dimethyl-1-pyrroline N-oxide) antibody (Ab) covalently bound to an albumin (BSA)-Gd (gadolinium)-DTPA (diethylene triamine penta acetic acid)-biotin MRI contrast agent (anti-DMPO probe), and mMRI, were used to detect in vivo levels of DMPO-MBR adducts in kidneys, livers, and lungs of diabetic mice, after DMPO administration. Magnetic resonance signal intensities, which increase in the presence of a Gd-based molecular probe, were significantly higher within the livers, kidneys, and lungs of diabetic animals administered the anti-DMPO probe compared with controls. Fluorescence images validated the location of the anti-DMPO probe in excised tissues via conjugation of streptavidin-Cy3, which targeted the probe biotin moiety, and immunohistochemistry was used to validate the presence of DMPO adducts in diabetic mouse livers. This is the first report of noninvasively imaging in vivo levels of MBRs within any disease model. This method can be specifically applied toward diabetes models for in vivo assessment of free radical levels, providing an avenue to more fully understand the role of free radicals in diabetes.