Objective: EMBRYONIC STEM CELLS (ESC) are defined by two main properties of self-renewal and their multipotency to differentiate into virtually all cell types of the body, including endothelial CELLS. ESCs have been widely regarded as an unlimited source of CELLS in regeneration medicine and also an ideal in vitro model to investigate complex developmental processes. Here, we report a simple and efficient in vitro model to derive a nearly pure population of endothelial CELLS from a murine ESC line.Material and Methods: CCE ES CELLS are exposed to alpha-MEM medium containing 10% FBS for 4 days and then cultured in endothelial basal-2 medium containing vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), insulin-like growth factor (IGF), epidermal growth factor (EGF), and 2% FBS for 42 days.Results: The CELLS acquired a relatively uniform endothelial cell morphology and were able to propagate and expand in culture. When murine ES cell–derived endothelial CELLS (MESDECs) were cultured on Matrigel and incubated for 48 h, vessel-like tube structures consisting of CD31 (PECAM-1) or BS-1 immunoreactive CELLS were developed. Immunocytochemistry and RTPCR analyses revealed that MESDECs express endothelial cell-specific marker proteins such as Flk-1, PECAM-1, Tie- 1, and Tie-2, in which the expressions persist for long periods of time after differentiation. The CELLS were also capable of taking up acetylated low-density lipoprotein (LDL) in culture.Conclusion: Our data suggest that MESDECs could provide a suitable in vitro model to study molecular events involved in vascular development and open up a new therapeutic strategy in regeneration medicine of cardiovascular disorders

Introduction: With regard to the importance of BMPs roles in the formation, development and function of various vital sySTEMs during fetal life, the aim of this study was to evaluate the effect of different doses of BMP4 on the viability and proliferation of CCE mouse EMBRYONIC STEM (ES) CELLS.Materials and Methods: CCE ES CELLS were tripsinized and cell suspension was prepared. The CELLS were counted and cultured in 96 well microplate. Each well of this plate containing 3Χ104 CELLS in 20% FCS in DMEM media. The CELLS incubated for 1 day, washed with PBS and cultured in DMEM containing different doses of BMP4 (1, 5, 25, 50 and 100ng/ml) as experimental groups. Control group was cultured in BMP4 free medium. ES CELLS incubated at 37oC overnight, washed with PBS, tripsinized and cell suspension was prepared separately from each well. In order to investigate the viability and proliferation rates of CCE ES CELLS, staining with trypan blue and counting were done. The mean number of whole CELLS and living CELLS were considered as proliferation and survival rates respectively. Data analysis was done with ANOVA test.Results : No significant differences were found between the mean number of whole CELLS in the different doses (p=0.18), but the mean percent of living CELLS showed that BMP4 in 5 and 100 ng/ml concentration had the best and the worst effects on the viability of ES CELLS respectively (65.56 vs. 27.24%).Conclusion: Evaluation of proliferation and viability rates using cell count and data analysis showed that addition of 5ng/ml BMP4 increased the proliferation and viability rates of CCE ES CELLS whereas high doses decreased these criteria. This suggests that different doses of BMP4 signaling may have different effects on ES CELLS behavior.

Mammalian development has been thought to be an one way process, which starts with a few EMBRYONIC founder CELLS, that become more and more restricted and ultimately give rise to all specialized cell types of the body. The cloning of the sheep Dolly from an adult mammary gland cell has refuted this dogma and demonstrated that the developmental clock of a mature cell can be reset, or "reprogrammed" by the egg into that of an EMBRYONIC cell, which can support development of a copy of the donor animal. To exclude the possibility that adult STEM CELLS served as donors in suCCEssful cloning experiments, we have generated cloned mice from mature lymphocytes that carried immunoglobulin rearrangements in all tissues. This experiment demonstrated that even the nuclei of terminally differentiated adult CELLS remain competent to give rise to an entire cloned animal. In addition, reprogramming research has enormous therapeutic potential in humans as it may allow for the derivation of EMBRYONIC CELLS from patients’ CELLS suffering from degenerative disorders such as Alzheimer’s disease, Parkinson’s disease or diabetes; because EMBRYONIC CELLS have the ability to give rise to all cell types of the body when exposed to the right combination of growth factors, these CELLS may provide a unique source of replacement tissue for regenerative medicine. We have generated a mouse model to prove this concept by combining nuclear transfer with gene and cell therapy to treat a severe combined immunodeficiency disorder in mice.