Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot, Israel.
Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel.
Nat Biotechnol. 2022 Jul;40(7):1143-1149. doi: 10.1038/s41587-021-01162-5. Epub 2022 Jan 31.
Imaging of gene-expression patterns in live animals is difficult to achieve with fluorescent proteins because tissues are opaque to visible light. Imaging of transgene expression with magnetic resonance imaging (MRI), which penetrates to deep tissues, has been limited by single reporter visualization capabilities. Moreover, the low-throughput capacity of MRI limits large-scale mutagenesis strategies to improve existing reporters. Here we develop an MRI system, called GeneREFORM, comprising orthogonal reporters for two-color imaging of transgene expression in deep tissues. Starting from two promiscuous deoxyribonucleoside kinases, we computationally designed highly active, orthogonal enzymes ('reporter genes') that specifically phosphorylate two MRI-detectable synthetic deoxyribonucleosides ('reporter probes'). Systemically administered reporter probes exclusively accumulate in cells expressing the designed reporter genes, and their distribution is displayed as pseudo-colored MRI maps based on dynamic proton exchange for noninvasive visualization of transgene expression. We envision that future extensions of GeneREFORM will pave the way to multiplexed deep-tissue mapping of gene expression in live animals.
在活体动物中对基因表达模式进行成像非常困难，因为组织对可见光不透明。磁共振成像（MRI）可以穿透深层组织，但对转基因表达的成像受到单一报告基因可视化能力的限制。此外，MRI 的低通量能力限制了大规模诱变策略来改进现有报告基因。在这里，我们开发了一种称为 GeneREFORM 的 MRI 系统，它由两种用于深层组织中转基因表达双色成像的正交报告基因组成。从两种混杂的脱氧核苷激酶开始，我们通过计算设计了高度活跃的正交酶（“报告基因”），这些酶专门磷酸化两种可 MRI 检测的合成脱氧核苷（“报告探针”）。系统给药的报告探针仅在表达设计的报告基因的细胞中积累，并且根据质子动态交换将其分布显示为伪彩色 MRI 图谱，从而可以非侵入性地可视化转基因表达。我们设想 GeneREFORM 的未来扩展将为活体动物中基因表达的多色深层组织图谱铺平道路。
