lacZ as a genetic reporter for real-time MRI.
Molecular imaging based on MRI is currently hampered by the lack of genetic reporters for in vivo imaging. We determined that the commercially available substrate S-Gal can be used to detect genetically engineered beta-galactosidase expressing cells by MRI. The effect and specificity of the reaction between beta-galactosidase and S-Gal on MRI contrast were determined both in vitro and in vivo. beta-galactosidase activity in the presence of S-Gal resulted in enhanced T(2) and T*(2) MR-contrast, which was amplified with increasing magnetic field strengths (4.7-17.6 T) in phantom studies. Using both lacZ(+) transgenic animals and lacZ(+) tissue transplants, we were able to detect labeled cells in live animals in real time. Similar to phantom studies, detection of the labeled cells/tissues in vivo was enhanced at high magnetic fields. These results demonstrate that the genetic reporter, lacZ, can be used as an in vivo marker gene using high-field-strength MRI.
Program in Stem Cell Biology and Regenerative Medicine, University of Florida, Gainesville, Florida 32610, USA.
Niclas E
NE
Bengtsson
Gary
G
Brown
Edward W
EW
Scott
Glenn A
GA
Walter
D000818:Animals; D001853:Bone Marrow / Q000502:physiology*; D003199:Computer Systems; D017930:Genes, Reporter / Q000235:genetics; D007763:Lac Operon / Q000235:genetics*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051379:Mice; D008810:Mice, Inbred C57BL; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism*
D001616:beta-Galactosidase