ORIGIN AND ISOLATION OF LIVER PROGENITOR CELLS

描述（申请人提供）： 最近的研究已经认识到成人器官中存在干细胞。 然而，肝干细胞尚未被鉴定和分离。下 在某些情况下，当肝细胞增殖受损时， 细胞，也称为卵圆细胞，出现在肝脏中，增殖并开始 沿着肝细胞或胆管谱系分化。最近的研究也 显示骨髓细胞或纯化的造血干细胞能够 在肝脏中分化成肝细胞和胆汁上皮细胞。我们 工作假设是肝祖细胞/卵圆细胞是两者的后代， 肝脏和造血干细胞。因为生物医学的伟大 这些细胞的重要性，我们的长期目标是分离这些细胞， 细胞，在适当的条件下体外扩增它们，并将它们用于 动物模型中患病肝脏的再增殖和治疗。实现 为了实现这一目标，确定其起源地至关重要， 它们来源于肝脏、骨髓或这两种器官。到 确定祖细胞/卵圆细胞是否来源于骨髓，遗传上 标记的骨髓细胞将被移植到致死辐射的 受体及其D-半乳糖胺和 将监测反曲马新/部分肝切除术损伤模型。使用已知 卵圆细胞标记物，我们将能够确定是否有一些 移植的细胞表现得像肝祖细胞， 沿着肝细胞/胆管谱系分化。如果肝祖细胞 是骨髓细胞的后代，这将是非常重要的，以确定 通过设计适当的细胞标记物的组合， 在造血祖细胞亚群中独特表达， 然后用这组标记物从骨髓中分离出它们。以下 同样的策略，我们将设计一个标记的组合， 肝脏中祖细胞的鉴定。标记板将 代表在造血祖细胞中表达的细胞表面标志物， 成肝细胞、胆管上皮细胞和肝细胞。这些的组合 将设计仅在肝祖细胞/卵圆细胞中表达的标志物。 这组标记物将用于分离肝祖细胞 从肝脏。

DESCRIPTION (Provided by Applicant): Recent research has recognized the existence of stem cells in adult organs. However, liver stem cells have not yet been identified and isolated. Under certain conditions, when hepatocyte proliferation is impaired, liver progenitor cells, also termed oval cells, emerge in the liver, proliferate and commence differentiationalong hepatocyticor bile duct lineages. Recent studies have also shown that bone marrow cells or purified hematopoietic stem cells are capable of differentiating in the liver into hepatocytes and bile epithelial cells. Our working hypothesis is that liver progenitor/oval cells are progeny of both liver and hematopoietic stem cells. Because of the great biomedical significance of these cells, our long-term objectives are to isolate these cells, expand them in vitro under appropriate conditions and use them for repopulation and treatment of the diseased liver in animal models. To achieve this goal, it is of great importance to identify their site of origin, whether they originate from the liver, from bone marrow or both of these organs. To determine whether progenitor/oval cells originate from bone marrow, genetically marked bone marrow cells will be transplanted into lethally irradiated recipients and their appearance and distribution in D-galactosamine and retrorsine/partial hepatectomy injury models will be monitored. Using known oval cell markers, we will be able to determine whether some of the transplanted cells behave like liver progenitor cells and commence differentiation along hepatocytic/bile duct lineages. If liver progenitor cells are progeny of bone marrow cells, it will be extremely important to identify their precursors by designing a combination of appropriate cell markers uniquely expressed in a subset of hematopoietic progenitor cells and the oval cells and use this panel of markers to isolate them from bone marrow. Following the same strategy, we will design a combination of markers for the identification of progenitor cells in the liver. The panel of markers will represent cell surface markers expressed in hematopoietic progenitor cells, hepatoblasts, biliary epithelial cells and hepatocytes. A combination of these markers will be designed that is expressed only in liver progenitor/oval cells. This panel of markers will be then used for isolation of liver progenitor cells from the liver.