PDF(Pubmed)
Abstract：
Quantitative susceptibility mapping (QSM) is an MRI modality used to non-invasively measure iron content in the brain. Iron exhibits a specific anatomically varying pattern of accumulation in the brain across individuals. The highest regions of accumulation are the deep grey nuclei, where iron is stored in paramagnetic molecule ferritin. This form of iron is considered to be what largely contributes to the signal measured by QSM in the deep grey nuclei. It is also known that QSM is affected by diamagnetic myelin contents. Here, we investigate spatial gene expression of iron and myelin related genes, as measured by the Allen Human Brain Atlas, in relation to QSM images of age-matched subjects. We performed multiple linear regressions between gene expression and the average QSM signal within 34 distinct deep grey nuclei regions. Our results show a positive correlation (p < .05, corrected) between expression of ferritin and the QSM signal in deep grey nuclei regions. We repeated the analysis for other genes that encode proteins thought to be involved in the transport and storage of iron in the brain, as well as myelination. In addition to ferritin, our findings demonstrate a positive correlation (p < .05, corrected) between the expression of ferroportin, transferrin, divalent metal transporter 1, several gene markers of myelinating oligodendrocytes, and the QSM signal in deep grey nuclei regions. Our results suggest that the QSM signal reflects both the storage and active transport of iron in the deep grey nuclei regions of the brain.
摘要：
定量磁化率图（QSM）是一种MRI模式，用于非侵入性地测量大脑中的铁含量。铁在个体的大脑中表现出特定的解剖学变化的积累模式。积累的最高区域是深灰色核，铁储存在顺磁性分子铁蛋白中。这种形式的铁被认为是对QSM在深灰色核中测量的信号有很大贡献的。还已知QSM受抗磁性髓鞘含量的影响。这里,我们研究了铁和髓鞘相关基因的空间基因表达，根据艾伦人脑地图集的测量，与年龄匹配受试者的QSM图像有关。我们在34个不同的深灰核区域内的基因表达和平均QSM信号之间进行了多重线性回归。我们的结果显示在深灰核区域中铁蛋白的表达和QSM信号之间的正相关(p<.05,校正)。我们重复了对其他编码蛋白质的基因的分析，这些蛋白质被认为与铁在大脑中的运输和储存有关，以及髓鞘形成。除了铁蛋白,我们的研究结果证明了一个正相关（p<0.05，校正）之间的表达，转铁蛋白,二价金属转运蛋白1，髓鞘少突胶质细胞的几个基因标记，和深灰核区域的QSM信号。我们的结果表明，QSM信号反映了大脑深灰核区域中铁的储存和主动运输。
