Sawada J, Kikuchi Y, Shibutani M, Mitsumori K, Inoue K, Kasahara T
Division of Biochemistry and Immunochemistry, National Institute of Health Sciences, Tokyo, Japan.
Biol Signals. 1994 May-Jun;3(3):157-68. doi: 10.1159/000109539.
Immunohistochemical staining of human and rat brains for metallothionein (MT) using a monoclonal anti-MT antibody (MT45) revealed that protoplasmic astrocytes, which are densely localized in the gray matter, contain high levels of MT. Human U373MG astrocytoma cells were stimulated with interleukin (IL)-1 or heavy metals to produce MT. When expression of MT in U373MG cells was analyzed by Northern blotting or indirect immunofluorescence using the MT45 antibody, it was found that IL-1 (> or = 10 U/ml), CdCl2 (50 microM) and high concentrations of ZnCl2 (500 microM) induced marked biosynthesis of MT.IL-6 (up to 3,000 U/ml) and lower concentrations of ZnCl2 (10-50 microM), however, showed little inducing activity. Hippocampal astrocytes in primary culture produced a relatively high basal level of MT. The MT level increased in response to addition of IL-1 (> or = 10 U/ml), ZnCl2 (50 microM) and CdCl2 (5 microM). However, the increase induced by IL-6 (1,000 U/ml) was not very marked. The in vivo induction of MT in the brain by cytokines is not fully understood. However, our data and other indirect evidence suggest that IL-1 may be a potent stimulator of MT induction in astrocytes. Furthermore, the astrocytoma cell line, U373MG, is a suitable in vitro system to analyze the expression of MT in astrocytes.
使用单克隆抗金属硫蛋白（MT）抗体（MT45）对人和大鼠大脑进行金属硫蛋白（MT）的免疫组织化学染色显示，密集分布于灰质中的原浆型星形胶质细胞含有高水平的MT。用人白细胞介素（IL）-1或重金属刺激人U373MG星形胶质瘤细胞以产生MT。当使用MT45抗体通过Northern印迹法或间接免疫荧光分析U373MG细胞中MT的表达时，发现IL-1（≥10 U/ml）、CdCl2（50 μM）和高浓度的ZnCl2（500 μM）可诱导MT的显著生物合成。然而，IL-6（高达3000 U/ml）和较低浓度的ZnCl2（10 - 50 μM）诱导活性很小。原代培养的海马星形胶质细胞产生相对较高的基础水平的MT。MT水平在添加IL-1（≥10 U/ml）、ZnCl2（50 μM）和CdCl2（5 μM）后升高。然而，IL-6（1000 U/ml）诱导的增加并不十分明显。细胞因子在脑内对MT的体内诱导作用尚未完全了解。然而，我们的数据和其他间接证据表明，IL-1可能是星形胶质细胞中MT诱导的有效刺激物。此外，星形胶质瘤细胞系U373MG是分析星形胶质细胞中MT表达的合适体外系统。
