Very small embryonic-like stem cells for regenerative medicine: WO2010039241

Background: The application is in the field of stem cells and regenerative medicine. Objective: It aims at identifying and characterising a population of pluripotent stem cells present in adult tissues. Methods: Cells were isolated and purified using Fluorescence-Activated Cell Sorting and Direct ImageStream analysis from various adult and umbilical cord tissues of rodents and humans. Cells were propagated in the presence of trophic factors and feeder cell layers of C2C12 cells. Cells were characterised by electron microscopy and immunocytology. Results: A population of cells that do not express a panleukocytic antigen CD45 and are negative for other markers of haematopoietic lineages were isolated and purified. The isolated cells elicit morphological features of embryonic stem cells (ESCs). They express markers of pluripotent stem cells, such as Nanog, Oct-4 and SSEA-1. On culturing on feeder cell layers, the isolated and purified cells generate embryoid body-like sphere. Conclusion: The identified and characterised cells elicit features of pluripotent stem cells and similarities with ESCs. They are termed very small embryonic-like stem cells (VSELs). The application claims the use of VSELs for cellular therapy and regenerative medicine.