Kawashima R, Mochida S, Matsui A, YouLuTuZ Y, Ishikawa K, Toshima K, Yamanobe F, Inao M, Ikeda H, Ohno A, Nagoshi S, Uede T, Fujiwara K
Third Department of Internal Medicine, Saitama Medical School, 38 Morohongo, Moroyama-cho, Iruma-gun, Saitama, 350-0495, Japan.
Biochem Biophys Res Commun. 1999 Mar 24;256(3):527-31. doi: 10.1006/bbrc.1999.0372.
Activated Kupffer cells and macrophages accumulate in necrotic areas in the liver. Osteopontin, an extracellular matrix with RGD sequence, has been shown to act as a chemokine that can induce monocyte migration. The possibility that osteopontin can play a role in infiltration of both cells into hepatic necrotic areas was investigated in rats. Northern blot analysis revealed that osteopontin mRNA expression was minimal in Kupffer cells and hepatocytes immediately after isolation from normal rats, but slight in hepatic stellate cells assumed nearly quiescent in function after 3 days of culture on plastic dishes. When rat received carbon tetrachloride, liver necrosis developed between 1 and 3 days following the intoxication. In these rats, osteopontin mRNA expression assessed by quantitative competitive RT-PCR was increased in the liver later than 1 day with its peak at 2 days following the intoxication. Kupffer cells and hepatic macrophages and hepatic stellate cells isolated from such liver showed marked expression of osteopontin mRNA on Northern blotting. Immunohistochemical examination disclosed that osteopontin was stained in macrophages including Kupffer cells and stellate cells in the necrotic areas. On electron microscopy, osteopontin stains were present in the Golgi apparatus in these cells. Recombinant human osteopontin promoted migration of Kupffer cells isolated from normal rats and cultured in a Transwell cell culture chamber in a dose-related manner. We conclude that activated Kupffer cells and hepatic macrophages and stellate cells express osteopontin. These cells might contribute to the infiltration of Kupffer cells and macrophages into hepatic necrotic areas by expressing osteopontin.
活化的库普弗细胞和巨噬细胞在肝脏坏死区域积聚。骨桥蛋白是一种具有RGD序列的细胞外基质，已被证明可作为一种趋化因子，诱导单核细胞迁移。本研究在大鼠中探讨了骨桥蛋白在这两种细胞浸润至肝脏坏死区域过程中发挥作用的可能性。Northern印迹分析显示，从正常大鼠分离后，库普弗细胞和肝细胞中骨桥蛋白mRNA表达极低，但在塑料培养皿上培养3天后功能接近静止的肝星状细胞中表达轻微。当大鼠接受四氯化碳时，中毒后1至3天出现肝坏死。在这些大鼠中，通过定量竞争性RT-PCR评估的骨桥蛋白mRNA表达在中毒后1天以上在肝脏中增加，在2天时达到峰值。从这种肝脏分离的库普弗细胞、肝巨噬细胞和肝星状细胞在Northern印迹上显示出骨桥蛋白mRNA的显著表达。免疫组织化学检查显示，骨桥蛋白在坏死区域的包括库普弗细胞和星状细胞在内的巨噬细胞中染色。电子显微镜检查发现，这些细胞的高尔基体中有骨桥蛋白染色。重组人骨桥蛋白以剂量相关的方式促进从正常大鼠分离并在Transwell细胞培养室中培养的库普弗细胞的迁移。我们得出结论，活化的库普弗细胞、肝巨噬细胞和星状细胞表达骨桥蛋白。这些细胞可能通过表达骨桥蛋白促进库普弗细胞和巨噬细胞浸润至肝脏坏死区域。
