Department of Public Health, Microbiology and Virology, University of Milan, Milan, Italy.
Cell Biol Int. 2010 Aug;34(8):783-90. doi: 10.1042/CBI20090236.
UCB (human umbilical cord blood) contains cells able to differentiate into non-haematopoietic cell lineages. It also contains cells similar to primitive ESCs (embryonic stem cells) that can differentiate into pancreatic-like cells. However, few data have been reported regarding the possibility of expanding these cells or the differential gene expression occurring in vitro. In this study, we expanded formerly frozen UCB cells by treatment with SCF (stem cell factor) and GM-CSF (granulocyte-macrophage colony stimulating factor) in the presence of VPA (valproic acid). Gene expression profiles for beta cell differentiation and pluripotency (embryo stem cell phenotype) were analysed by RT-PCR and immunocytochemistry. The results show a dramatic expansion (>150-fold) of haematopoietic progenitors (CD45+/CD133+) which also expressed embryo markers of pluripotency (nanog, kfl-4, sox-2, oct-3/4 and c-myc), nestin, and pancreatic markers such as pax-4, ngn-3, pdx-1 and syt-1 (that is regulated by pdx-1 and provides the cells with a Ca++ regulation mechanism essential for insulin exocytosis). Our results show that UCB cells can be expanded to produce large numbers of cells of haematopoietic lineage that naturally (without the need of retroviral vectors or transposons) express a gene pattern compatible with endocrine pancreatic precursors and markers of pluripotency. Further investigations are necessary to clarify, first, whether in this context, the embryogenes expressed are functional or not, and secondly, since these cells are safer than cells transfected with retroviral vectors or transposons, whether they would represent a potential tool for clinical application.
UCB（人类脐带血）含有能够分化为非造血细胞谱系的细胞。它还含有类似于原始胚胎干细胞（embryonic stem cells）的细胞，能够分化为胰腺样细胞。然而，关于这些细胞体外扩增的可能性或发生的差异基因表达的相关数据很少。在这项研究中，我们通过使用 SCF（干细胞因子）和 GM-CSF（粒细胞-巨噬细胞集落刺激因子）处理以前冷冻的 UCB 细胞，并在 VPA（丙戊酸）存在的情况下，对这些细胞进行了扩增。通过 RT-PCR 和免疫细胞化学分析了β细胞分化和多能性（胚胎干细胞表型）的基因表达谱。结果显示造血祖细胞（CD45+/CD133+）的显著扩增（>150 倍），这些细胞还表达胚胎多能性标志物（nanog、kfl-4、sox-2、oct-3/4 和 c-myc）、巢蛋白（nestin）以及胰腺标志物，如 pax-4、ngn-3、pdx-1 和 syt-1（受 pdx-1 调节，为胰岛素分泌提供细胞必需的 Ca++调节机制）。我们的结果表明，UCB 细胞可以扩增产生大量的造血谱系细胞，这些细胞天然（无需逆转录病毒载体或转座子）表达与内分泌胰腺前体和多能性标志物相容的基因模式。需要进一步的研究来阐明，首先，在这种情况下，表达的胚胎基因是否具有功能，其次，由于这些细胞比转染逆转录病毒载体或转座子的细胞更安全，它们是否代表一种潜在的临床应用工具。
