骨髓间充质干细胞构建组织工程化肝脏组织模型

Construction of tissue engineered liver with bone marrow mesenchymal stem cells

目的以骨髓间充质干细胞接种材料体外肝样细胞定向诱导后回植,修复肝脏巨大缺损的效果观察,从而探讨以骨髓间充质干细胞构建组织工程化肝脏组织的可行性。方法将第一代(P1)骨髓间充质干细胞接种于聚羟基乙酸/聚乳酸(polyglycolic acid/polylactid acid,PGA/PLA)支架材料上,经肝细胞生长因子(HGF)、20ng/mL,成纤维生长因子-4(FGF-4)10ng/mL及地塞米松40ng/mL体外联合诱导2周。通过绿色荧光蛋白(GFP)基因标记细胞,示踪回植于肝功能衰竭模型内的细胞转归。以单纯肝切模型为对照。术后8周取材,分别进行免疫组织化学、分子生物学检测,观察骨髓间充质干细胞与PGA/PLA支架材料的细胞材料复合物在大鼠肝脏修复中的作用。结果术后8周,PGA/PLA完全降解,新生肝脏组织生长,缺损肝脏基本恢复正常大小。病理学及免疫组织化学结果提示新生肝脏组织具有肝脏管腔样结构,能表达Alb和CK18,而AFP表达阴性,与对照组比较,差异无统计学意义。结论骨髓间充质干细胞在体外结合组织工程材料的定向诱导后回植有利于修复肝脏巨大缺损。

Objective To explore the feasibility of constructing tissue engineered liver with bone marrow mesenchymal stem cells in vitro. Methods Bone marrow rnesenehymal stem cells isolated from rat were cultured and induced by HGF and FGF-4. Cells at passage 1 were seeded on polyglycolic acid/polylactid acid （PGA/PLA）nowwoven fibers to form a cell-scaffold complex. After cultured in vitro for 2 weeks , the complexes were then implanted into the liver of rats with part-liver dissected. Engineered liver was observed continuously and harvested after 8 weeks for gross and histological evaluation. Less part of the liver dissecting model was observed as control. Results The engineered tissue in the liver gradually repaired the injured liver, and came to a complete one after 8 weeks. PGA/PLA was totally dissolved after 8 weeks. Histologically, the engineered liver was relatively regular and similar to the control. The implanted cells were confirmed by GFP expression under fluorescent microscope. By immunohistochemical examination, no significant difference of Alb, CK18 and AFP in the tissue were found between the engineered liver and control one. Conclusion Tissue engineered liver may be formed with bone marrow mesenchymal stem cells in liver microenvironment.