RESEARCH ON THE PATHOGENESIS AND PATHOPHYSIOLOGY OF HEREDITARY CERULOPLASMIN DEFICIENCY (ACERULOPLASMINEMIA)

铜蓝蛋白血症是一种常染色体隐性遗传病，由铜蓝蛋白（CP）基因突变引起。我们对5例本病患者的脑组织进行了组织病理学和免疫组织化学检查。在大脑中，基底节区（尤其是尾状核和壳核）受到的影响最为严重，在基底节区可以观察到大量的铁沉积和广泛的神经元损失。铁超载在星形胶质细胞中比在神经元中更为突出。星形胶质细胞明显变形，球状结构与铁沉积程度成正比。球状结构与抗胶质纤维酸性蛋白和抗s -100抗体有明显反应，但与神经标记蛋白（如神经丝和突触素）抗体无明显反应。因此，它们可能起源于星形胶质细胞。变形的星形胶质细胞和球状结构也对抗4-羟基壬烯醛抗体反应积极。这些发现表明星形胶质细胞的形态变化与铁超载和随后的氧化应激密切相关。为了阐明CP在铁代谢中的功能参与，我们制造了CP缺陷（CP^<-/->）小鼠。小鼠表现出明显的肝脏铁超载和轻度的小细胞贫血和低色素贫血，但它们在包括大脑在内的任何其他器官中都没有表现出铁超载。我们用TaqMan RT-PCR检测了十二指肠和肝脏中铁代谢基因的表达水平。CP^<-/->小鼠十二指肠中二价金属转运蛋白1 （DMT1）、铁转运蛋白1 （FPN1）和hephaestin （HEPH）基因均未上调。这一结果与Harris等先前的铁动力学研究一致，该研究显示CP^<-/->和CP^<+/+>小鼠的肠道铁吸收率没有差异。结合携带HEPH基因突变的性联性贫血（sla）小鼠表现出十二指肠铁吸收缺陷和严重缺铁性贫血的事实，我们的数据表明CP对肠道铁吸收的重要性低于HEPH。在肝脏中，CP^<-/->小鼠的DMT1和转铁蛋白受体（TFR和TFR2）的基因表达未增加，表明CP^<-/->小鼠的肝细胞中没有激活任何已知的铁摄取途径。这一结果支持了CP主要从肝脏细胞中释放铁的假设。少

Aceruloplasminemia is an autosomal recessive disorder of iron metabolism caused by mutations in the ceruloplasmin (CP) gene. We scrutinized the brains of 5 patients with this disease histopathologically and immunohistochemically. In the brain, the basal ganglia (especially the caudate nucleus and putamen) were most severely affected, where heavy iron deposition and extensive loss of neurons were observed. Iron overload was more prominent in astrocytes than in neurons. Markedly deformed astrocytes and spheroid-like globular structures were seen in proportion to the degree of iron deposition. Globular structures clearly reacted with anti-glial fibrillary acidic protein and anti-S-100 antibodies, but not with antibodies for neuronal marker proteins, such as neurofilament and synaptophysin. Therefore, they presumably originated from astrocytes. Deformed astrocytes and globular structures also reacted positively to anti-4-hydroxynonenal antibody. These findings indicate that morphological c … More hanges of astrocytes are closely linked to iron overload and subsequent oxidative stress.In order to elucidate the functional involvement of CP in iron metabolism, we generated CP-deficient (CP^<-/->) mice. The mice showed a marked iron overload in the liver and mild microcytic and hypochromic anemia, but they did not exhibit iron overload in any other organs including the brain. We examined expression levels of the iron-metabolism genes in the duodenum and liver with TaqMan RT-PCR. The divalent metal transporter 1 (DMT1), ferroportin 1 (FPN1), and hephaestin (HEPH) genes were not up-regulated in the duodenum from CP^<-/-> mice. This result is compatible with a previous ferrokinetic study by Harris et al., which showed no difference in the rate of intestinal iron absorption between CP^<-/-> and CP^<+/+> mice. Together with the fact that sex-linked anemia (sla) mice, which carry a mutation in the HEPH gene, show defective iron absorption in the duodenum and severe iron deficiency anemia, our data suggest that CP is less important than HEPH for intestinal iron absorption. In the liver, CP^<-/-> mice showed no increase of gene expression for DMT1 and transferrin receptors (TFR and TFR2), suggesting that any known pathway of iron uptake is not activated in hepatocytes in CP^<-/-> mice. This result supports the hypothesis that CP mainly acts to release iron from cells in the liver. Less