Objects: Nestin is an intermediate protein and a well-known specific neural stem cell antigen. Some bone marrow stem cells can generate not only blood cells but also neurons and glial cells under specific culture conditions. Furthermore, in vitro cultured bone marrow stem cells also express nestin antigen. However, it is unclear whether cord blood cells also differentiate into neural cells or not. In this study, we investigated the expression of nestin on human cord blood monocytes (HCMNCs) and we discuss the relevance of this finding upon future therapeutic applications of HCMNCs in neurological diseases.
Methods: HCMNCs were prepared from normal placenta after full-term normal delivery. Immunocytochemical staining and reverse transcriptase polymerase chain reaction (RT-PCR) for nestin and CD133 antigen were performed to confirm nestin and CD133 antigen expression in the HCMNCs.
Results: Some nestin expressing HCMNCs were found. Immunocytochemical staining showed that some of the blood stem cell marker CD133 expressing cells co-expressed nestin. RT-PCR demonstrated nestin and CD133 mRNA in HCMNCs, but not in adult blood monocytes. Approximately, 60 +/- 8% of CD133 expressing cells expressed nestin.
Conclusion: In the present study, we found that more than 60% of CD133 expressing HCMNCs also express nestin antigen in their cytoplasm, which supports the idea that cord blood stem cells can adopt a neuronal fate.