Program in Stem Cell Biology and Regenerative Medicine, University of Florida, Gainesville, Florida 32610, USA.
Magn Reson Med. 2010 Mar;63(3):745-53. doi: 10.1002/mrm.22235.
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.
基于 MRI 的分子成像目前受到缺乏用于体内成像的遗传报告基因的限制。我们确定，市售的底物 S-Gal 可用于通过 MRI 检测表达基因工程β-半乳糖苷酶的细胞。在体外表征和体内实验中，确定了β-半乳糖苷酶与 S-Gal 之间的反应对 MRI 对比的影响和特异性。在 S-Gal 存在的情况下，β-半乳糖苷酶活性导致 T(2)和 T*(2)MR 对比增强，在磁共振体模研究中，随着磁场强度的增加（4.7-17.6T）而放大。利用 lacZ(+)转基因动物和 lacZ(+)组织移植，我们能够实时检测活体动物中的标记细胞。与磁共振体模研究相似，在高磁场下增强了对标记细胞/组织的检测。这些结果表明，遗传报告基因 lacZ 可以用作高场强 MRI 的体内标记基因。
