Division of Hepatology, Xijing Hospital of Digestive Diseases, Fourth Military Medical University, Xi'an, Shannxi Province, China.
Cytotherapy. 2010 Dec;12(8):1022-34. doi: 10.3109/14653249.2010.515578. Epub 2010 Sep 20.
Circulating monocytes have been exploited as an important progenitor cell resource for hepatocytes in vitro and are instrumental in the removal of fibrosis. We investigated the significance of monocytes in peripheral blood stem cells (PBSC) for the treatment of liver cirrhosis.
Rat CD14+ monocytes in PBSC were mobilized with granulocyte-colony-stimulating factor (G-CSF) and harvested by magnetic cell sorting (MACS). Female rats with carbon tetrachloride (CCl₄-induced liver cirrhosis were injected CM-DiI-labeled monocytes, CD14⁻ cells (1 x 10⁷ cells/rat) or saline via the portal vein.
Rat CD14+ and CD11b+ monocytes in PBSC were partly positive for CD34, CD45, CD44, Oct3/4 and Sox2, suggesting monocytes with progenitor capacity. Compared with CD14⁻ cell-infused and saline-injected rats, rats undergoing monocyte transplantation showed a gradually increased serum albumin level and decreased portal vein pressure, resulting in a significantly improved survival rate. Meanwhile, monocyte transplantation apparently attenuated liver fibrosis by analysis for fibronectin, α2-(1)-procollagen, α-smooth muscle aorta (SMA) and transforming growth factor (TGF)-β. Transplanted monocytes mainly clustered in periportal areas of liver, in which 1.8% cells expressed hepatocyte marker albumin and CK18. The expression level of hepatocyte growth factor (HGF), TGF-α, extracellular matrix (EGF) and vascular endothelial growth factor (VEGF) increased, while monocyte transplantation enhanced hepatocyte proliferation. On the other hand, the activities and expression of matrix metalloproteinases (MMP) increased while tissue inhibitor of metalloproteinase (TIMP)-1 expression significantly reduced in monocyte-transplanted livers. Some transplanted monocytes expressed MMP-9 and -13.
The data suggest that CD14+ monocytes in PBSC contribute to hepatocyte regeneration and extracellular matrix (ECM) remodeling in rat liver cirrhosis much more than CD14⁻ cells, and might offer a therapeutic alternative for patients with liver cirrhosis.
循环单核细胞已被用于体外肝细胞的重要祖细胞资源，并在纤维化的清除中发挥作用。我们研究了外周血干细胞（PBSC）中的单核细胞在肝硬化治疗中的意义。
用粒细胞集落刺激因子（G-CSF）动员大鼠 PBSC 中的 CD14+单核细胞，并用磁细胞分选（MACS）收获。通过门静脉向四氯化碳（CCl₄）诱导的肝硬化雌性大鼠注射 CM-DiI 标记的单核细胞、CD14⁻细胞（1 x 10⁷ 个/大鼠）或生理盐水。
大鼠 PBSC 中的 CD14+和 CD11b+单核细胞部分呈 CD34、CD45、CD44、Oct3/4 和 Sox2 阳性，提示具有祖细胞能力。与 CD14⁻细胞输注和生理盐水注射大鼠相比，单核细胞移植大鼠的血清白蛋白水平逐渐升高，门静脉压力降低，生存率显著提高。同时，单核细胞移植通过纤维连接蛋白、α2-(1)-前胶原、α-平滑肌肌动蛋白（SMA）和转化生长因子（TGF）-β分析明显减轻肝纤维化。移植的单核细胞主要聚集在肝门脉周围区域，其中 1.8%的细胞表达肝细胞标志物白蛋白和 CK18。肝细胞生长因子（HGF）、TGF-α、细胞外基质（EGF）和血管内皮生长因子（VEGF）的表达水平增加，而单核细胞移植增强了肝细胞增殖。另一方面，单核细胞移植增加了基质金属蛋白酶（MMP）的活性和表达，同时组织金属蛋白酶抑制剂（TIMP）-1的表达显著降低。一些移植的单核细胞表达 MMP-9 和 MMP-13。
数据表明，PBSC 中的 CD14+单核细胞对大鼠肝硬化中肝细胞再生和细胞外基质（ECM）重塑的贡献比 CD14⁻细胞多，可能为肝硬化患者提供一种治疗选择。
