脐带间充质干细胞体外分化为有功能的低免疫原性肝细胞样细胞

目的 观察人脐带来源的间充质干细胞(UC-MSCs)体外诱导分化为肝细胞样细胞(DHC)后,是否具有肝细胞的生物学特性和功能,以及其免疫原性的变化.方法 采用改良的二步法肝细胞分化培养体系体外诱导UC-MSCs向肝细胞分化,并用RT-PCR和免疫荧光染色法检测诱导后不同时间DHC肝细胞特异性标记的表达;采用ELISA法检测细胞培养液中白蛋白(ALB)和尿素的浓度,以及混合淋巴细胞培养检测DHC对淋巴细胞增殖能力的影响.结果 UC-MSCs低表达甲胎蛋白(AFP)、ALB和细胞角蛋白-19(CK-19)的mRNA和蛋白,成肝诱导分化后14和28 dDHC均高表达肝细胞标志AFP、ALB、CK-19以及色氨酸2,3-加双氧酶基因.诱导后的DHC能够以时间依赖方式产生ALB和分泌尿素,不表达人白细胞DR抗原,而且能够抑制淋巴细胞增殖.结论 UC-MSCs在体外能够分化为有功能的DHC且具有低免疫原性的特征.

Differentiation of Human Umbilical Cord Derived Mesenchymal Stem Cells into Low Immunogenic and Functional Hepatocyte-like Cells in vitro

Objective To investigate the biological function of hepatocyte-like cells derived from mesenchymal stem cells that isolated from human umbilical cord ( UC-MSCs) in vitro, and to detect the chan-ges in the immunogenicity of the differentiated hepatocyte-like cells (DHC). Methods Transdifferentiation of UC-MSCs into hepatic lineage in vitro was induced in modified two-step induction medium. The expressions of hepatic specific markers were detected by RT-PCR analysis and immunofluorescence staining at different time points after induction. The levels of albumin and urea in the supernatants of cultures were measured by enzyme-linked immunosorbent assay. Furthermore, the immunosuppressive property of DHC was detected by one-way mixed lymphocyte culture. Results The mRNA and proteins of alpha fetoprotein ( AFP), albumin (ALB) , and cytokeratin-19 (CK-19) were expressed in naive UC-MSCs at low levels. DHC highly expressed hepatic markers AFP, ALB, CK-19, and tryptophan 2, 3-dioxygenase 14 and 28 days after hepatic differentiation and were accompanied by an increased production of ALB and urea in supernatant in a time-dependent manner. DHC did not express human leukocyte antigen DR antigen and significantly decreased the lymphocyte prolifera-tion. Conclusion UC-MSCs are able to differentiate into functional hepatocyte-like cells in vitro, while the immunogenicity of DHC remains low.