Purpose: Mesenchymal stem cells, which exist in every part of thehuman body, have the ability to differentiate into various kinds of tissue.If cells isolated from these tissues can differentiate into hepatocytes,they can be used to supply a secure source of cells, which is a majorlimitation in liver targeted cell therapy. Prior to evaluating the possibilityof differentiating these cells into hepatocytes, cells from fat, cord bloodand placenta tissues were tested to see if they have stem cellcharacteristics.
Method: After the fat tissue had been chopped into small piece andtreated with collagenase I for 60 minutes, the fat derived mesenchymalstem cells were separated. Umbilical cord blood monocytes wereseparated from the umbilical cord blood following centrifugation for 25minutes in 2000 rpm. Using Percoll density gradient centrifugation,following treatment with trypsin and DNAase, monocytes were isolatedfrom the placental tissues. Cells isolated from each tissue wereimmunophenotyped by Flow cytometry, using CD14, 29, 31, 34, 44, 45,73, 90, 105 and 106 antibodies, to search for mesenchymal stem cellsmarkers after 3 - 5 orders of cultivation in each special culture media.
Result: The cultured cells all had a single nucleus and square shape. The CD29, 44 and 73 antibodies were all positive in the cells detachedinform the umbilical cord blood, placenta and fat tissues. The CD 14, 31,34, 45 and 106 antibodies were negative in all the cells. The CD90 antibody was positive in the cells isolated from the placenta and fattissues, but the CD105 antibody was only positive in the cells from fattissue.
Conclusion: Cells isolated from the umbilical cord blood, placenta and fattissues are assumed to be mesenchymal stem cells, but have nocharacteristics of hematopoietic cells. Especially, cells from fat tissueseem to have more mesenchymal stem cell characteristics. Validations, through differentiation into the various cell types, will be required toconfirm their special quality as stem cells.