A dual-gene reporter-amplifier architecture for enhancing the sensitivity of molecular MRI by water exchange.
A dual-gene reporter-amplifier architecture for enhancing the sensitivity of molecular MRI by water exchange.
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一种双基因报告放大器架构，用于通过水交换增强分子 MRI 的灵敏度。
DOI：
10.1101/2024.01.22.576672
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发表时间：
2024
期刊：
影响因子：
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通讯作者：
Mukherjee,Arnab
中科院分区：
文献类型：
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作者：
Huang,Yimeng;Chen,Xinyue;Zhu,Ziyue;Mukherjee,Arnab
开发用于磁共振成像（MRI）的遗传报告基因对于研究体内生物功能至关重要。 然而，目前的MRI报告分子具有低灵敏度，使得与组织背景形成显著对比具有挑战性，特别是当只有一小部分细胞表达报告分子时。为了克服这一局限性，我们开发了一种方法，通过将化学发生学对比机制与生物物理方法相结合来增强分子MRI的灵敏度，以通过包含有机阴离子转运多肽Oatp1b3和水通道Aqp1的双基因构建体的共表达来增加水扩散。我们首先表明，Aqp1的表达放大了MRI对比度在培养的细胞工程表达Oatp1b3。我们证明，对比放大是由Aqp1驱动的水交换增加引起的，与交换限制条件相比，这为Oatp1b3表达细胞内化的钆离子提供了更大的水池。我们进一步表明，我们的方法允许使用比无Aqp1情况低约10倍的钆浓度来检测细胞。最后，我们证明了我们的方法能够对含有低比例Oatp1b3标记细胞的混合细胞培养物进行成像，这些细胞在单独Oatp1b3表达的基础上无法检测到。
The development of genetic reporters for magnetic resonance imaging (MRI) is essential for investigating biological functions in vivo. However, current MRI reporters have low sensitivity, making it challenging to create significant contrast against the tissue background, especially when only a small fraction of cells express the reporter. To overcome this limitation, we developed an approach for amplifying the sensitivity of molecular MRI by combining a chemogenetic contrast mechanism with a biophysical approach to increase water diffusion through the co‐expression of a dual‐gene construct comprising an organic anion transporting polypeptide, Oatp1b3, and a water channel, Aqp1. We first show that the expression of Aqp1 amplifies MRI contrast in cultured cells engineered to express Oatp1b3. We demonstrate that the contrast amplification is caused by Aqp1‐driven increase in water exchange, which provides the gadolinium ions internalized by Oatp1b3‐expressing cells with access to a larger water pool compared with exchange‐limited conditions. We further show that our methodology allows cells to be detected using approximately 10‐fold lower concentrations of gadolinium than that in the Aqp1‐free scenario. Finally, we show that our approach enables the imaging of mixed‐cell cultures containing a low fraction of Oatp1b3‐labeled cells that are undetectable on the basis of Oatp1b3 expression alone.