Nishie Akihiro, Yoshimitsu Kengo, Nakayama Tomohiro, Hatakenaka Masamitsu, Irie Hiroyuki, Shioyama Yoshiyuki, Matsuura Shuji, Nishihara Yunosuke, Kobayashi Koji, Honda Hiroshi
Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku Fukuoka, 812-8582, Japan.
Comput Med Imaging Graph. 2007 Dec;31(8):638-42. doi: 10.1016/j.compmedimag.2007.07.004. Epub 2007 Sep 21.
The aim is to evaluate if a difference in activity of monocytic cells can be described on superparamagnetic iron oxide (SPIO)-magnetic resonance imaging (MRI) in vitro when a low concentration of SPIO is administered. Human monocytic cells were stimulated with phorbol 12-myristate 13-acetate (PMA) or left non-stimulated for 24 h and then treated with SPIO with a final concentration of 7.2 microg Fe/ml for 48 h. They were collected, and an MRI phantom was prepared by suspending them in 4% gelatin and scanned using gradient-echo T2*-weighted and spin-echo T2-weighted imaging with two different echo times. The signal intensity and T2*/T2 relaxation times of each layer were also assessed. The number and degree of intracellular filling of cells positively stained with Berlin blue were evaluated microscopically. In addition, the heme oxygenase-1 expression in non-stimulated monocytic cells or monocytic cells stimulated with PMA was evaluated using semiquantitative reverse transcription and polymerase chain reaction. The signal reduction of cells stimulated with PMA was 3.9- to 5.0-fold and 2.7- to 3.1-fold greater than that of non-stimulated cells on the T2*- and T2-weighted images, respectively. These signal reductions were also visually confirmed. Estimated T2*/T2 relaxation times of cells stimulated with PMA and non-stimulated cells were 31.3/137.8 and 122.8/182.6 ms, respectively. Cells positively stained with Berlin blue were observed in 4.5% and 25.3% of non-stimulated cells and those stimulated with PMA, respectively (p<0.05). The intracellular filling in cells stimulated with PMA was significantly larger than that in non-stimulated cells (p<0.05). The expression of the heme oxygenase-1 gene in monocytic cells stimulated with PMA was 2.9-fold greater than that in non-stimulated monocytic cells. SPIO-MRI can visually describe a difference in activity of monocytic cells in vitro when a low concentration of SPIO is administered.
目的是评估当给予低浓度超顺磁性氧化铁（SPIO）时，体外超顺磁性氧化铁磁共振成像（MRI）能否描述单核细胞活性的差异。用佛波酯12 -肉豆蔻酸酯13 -乙酸酯（PMA）刺激人单核细胞或不刺激24小时，然后用终浓度为7.2微克铁/毫升的SPIO处理48小时。收集细胞，将其悬浮于4%明胶中制备MRI模型，并使用梯度回波T2 *加权和自旋回波T2加权成像（两种不同回波时间）进行扫描。还评估了每层的信号强度和T2 */T2弛豫时间。用柏林蓝阳性染色的细胞的数量和细胞内填充程度通过显微镜进行评估。此外，使用半定量逆转录和聚合酶链反应评估未刺激的单核细胞或经PMA刺激的单核细胞中血红素加氧酶-1的表达。在T2 *加权和T2加权图像上，经PMA刺激的细胞的信号降低分别比未刺激细胞大3.9至5.0倍和2.7至3.1倍。这些信号降低也通过视觉得到证实。经PMA刺激的细胞和未刺激细胞的估计T2 */T2弛豫时间分别为31.3/137.8和122.8/182.6毫秒。未刺激细胞和经PMA刺激的细胞中分别有4.5%和25.3%观察到用柏林蓝阳性染色的细胞（p<0.05）。经PMA刺激的细胞中的细胞内填充明显大于未刺激细胞（p<0.05）。经PMA刺激的单核细胞中血红素加氧酶-1基因的表达比未刺激的单核细胞高2.9倍。当给予低浓度SPIO时，SPIO - MRI能够在体外直观地描述单核细胞活性的差异。
