Human umbilical cord blood AC133+ cells expressed neural marker in different inductions / 中国组织工程研究

ABSTRACT

BACKGROUND: At present, hemopoietic stem cells have been proved to differentiate into nerves in rodents animals. As for the human, this topic is in debate.OBJECTIVE: To investigate the neural differentiation potential of human umbilical cord blood-derived AC133+ cells. DESIGN, TIME AND SETTING: Control experiments by grouping were performed in the Hematology Institute of Tianjin Hematology Hospital and Central Laboratory of Neurosurgery in Yuquan Hospital of Tsinghua University from August 2005 to December 2007.MATERIALS Human umbilical cord blood was sampled from full-term newborn infant. Fetal brain-derived trophic support cells were harvested from aborted fetus of 22 weeks old.MAIN OUTCOME MEASURES: After the induction, human cord blood cells were collected at weeks 1, 2 and 4. RT-PCR was used to detect the expression of nestin, bone morphogenetic protein-2 and neural cell adhesion molecule. Immunocytochemistry method was applied to detect the cytotype-specific antigen. RESULTS: In the culture medium containing epidermal growth factor and basic fibroblast growth factor, human cord blood AC133+ cells could express nestin and bone morphogenetic protein-2, which were down-regulated even closed up in suboptimal condition. In the DMEM/F12 medium supplemented with epidermal growth factor, basic fibroblast growth factor and brain-derived neurotrophic factor, the gene expression of bone morphogenetic protein-2 and nestin continued in optimal condition at 2 weeks. Moreover neural cell adhesion molecule, another gene of neural cells, also expressed in this condition. AC133+ cells co-cultured with fetal brain-derived trophic support cells exhibited similar expressions. In the optimal non-cell-cell contact co-culture system, glial fibrillary acidic protein-positive cells were found by immuocytochemistry, while neuronal marker β-tubulin Ⅲwas expressed in the cell-cell direct contact system. These outcomes indicated that human cord blood isolated AC133+ cells may have an effect through gene rearrangement on inducing stem cells to express nerve cell development factors.CONCLUSION: The human umbilical cord blood-derived AC133+ cells contain some multipotential stem cells with differentiation potential, neural differentiation-related antigen when exposed to a suitable microenvironment.