Abstract：
Here, we propose for the first time the evaluation of magnetosensitive clMagR/clCry4 as a magnetic resonance imaging (MRI) reporter gene that imparts sensitivity to endogenous contrast in eukaryotic organisms. Using a lentiviral vector, we introduced clMagR/clCry4 into C57BL/6 mice-derived bone marrow mesenchymal stem cells (mBMSCs), which could specifically bind with iron, significantly affected MRI transverse relaxation, and generated readily detectable contrast without adverse effects in vivo. Specifically, clMagR/clCry4 makes mBMSCs beneficial for enhancing the sensitivity of MRI-R2 for iron-bearing granules, in which cells recruit exogenous iron and convert these stores into an MRI-detectable contrast; this is not achievable with control cells. Additionally, Prussian blue staining was performed together with ultrathin cell slices to provide direct evidence of natural iron-bearing granules being detectable on MRI. Hence, it was inferred that the sensitivity of MRI detection should be correlated with clMagR/clCry4 and exogenous iron. Taken together, the clMagR/clCry4 has great potential as an MRI reporter gene. STATEMENT OF SIGNIFICANCE: In this study, we propose the evaluation of magnetosensitive clMagR/clCry4 as an MRI reporter gene, imparting detection sensitivity to eukaryotic mBMSCs for endogenous contrast. At this point, the clMagR and clCry4 were located within the cytoplasm and possibly influence each other. The clMagR/clCry4 makes mBMSCs beneficial for enhancing the sensitivity of MRI-R2 for iron-bearing granules, in which protein could specifically bind with iron and convert these stores into MRI-detectable contrast; this is not achieved by control cells. The viewpoint was speculated that the clMagR/clCry4 and exogenous iron were complementary to each other. Additionally, Prussian blue staining was performed together with TEM observations to provide direct evidence that the iron-bearing granules were sensitive to MRI.
摘要：
这里,我们首次提出评估磁敏clMagR/clCry4作为磁共振成像（MRI）报告基因，可赋予真核生物对内源性对比的敏感性。使用慢病毒载体，我们将clMagR/clCry4引入C57BL/6小鼠来源的骨髓间充质干细胞（mBMSCs），可以与铁特异性结合，显著影响MRI横向松弛，并且在体内产生容易检测到的对比度而没有不利影响。具体来说,clMagR/clCry4使mBMSCs有利于增强MRI-R2对铁颗粒的敏感性,其中细胞募集外源性铁并将这些储存转化为MRI可检测的造影剂;这对于对照细胞是无法实现的。此外,与TEM一起进行普鲁士蓝染色以提供在MRI上可检测到天然铁颗粒的直接证据。因此，推断MRI检测的敏感性应与clMagR/clCry4和外源性铁相关。一起来看,clMagR/clCry4作为MRI报告基因具有巨大的潜力。重要声明：：在这项研究中，我们建议评估磁敏clMagR/clCry4作为MRI报告基因，赋予真核mBMSCs内源性对比的检测灵敏度。在这一点上,clMagR和clCry4位于细胞质内，可能相互影响。clMagR/clCry4使mBMSCs有利于增强MRI-R2对天然铁颗粒的敏感性,其中蛋白质可以与铁特异性结合，并将这些储存转化为MRI可检测的造影剂；这不是由对照细胞实现的。该观点推测clMagR/clCry4与外源铁互补。此外,普鲁士蓝染色与TEM观察一起进行,以提供铁颗粒对MRI敏感的直接证据。
