Mesenchymal stem cells (MSCs) as a kind of adult stem cells possess two properties of long term selfrenewal ability and multilineage differentiation potential into skeletal cell lineages. MSCs were first isolated and described from bone marrow samples. Further investigations have identified several other tissues as alternative sources for these cells. In spite of the clinical importance of MSCs, some biological aspects of them including their SELF-RENEWAL proliferation and differentiation potential have not yet been fully understood. Furthermore, the specific surface markers for these cells remained to be investigated. In present paper, the existing data regarding to the different aspects of mesenchymal stem cells including the history, isolation method, surface markers, in vitro culture and expansion of the cells, SELF-RENEWAL proliferation and finally their differentiation potential have been reviewed.

Background and Objectives: Umbilical cord blood hematopoietic stem cells (UCB-HSCs) have high potential capabilities in the treatment of hematological and non-hematological disorders. Awareness of biology, selfrenewal, homing, expansion, storage, and transplantation can lead to optimal use of these cells. Materials and Methods: In this Review article in order to investigate the advances and challenges in cord blood banks, the expansion, storage, homing and transplantation of umbilical cord blood stem cells, we used key words like umbilical cord blood, hematopoietic stem cells and stem cell banks for searching published articles in the PubMed database during 2000 to 2020. Results: Over time, many advances in biology, expansion, storage, and transplantation of cord blood cells have been made by researchers around the world with a growth in the number of private and public cord blood banks in parallel. Despite these advances, there are still challenges to the optimal use of these cells. Conclusions: Increasing our awareness about the achievements and shortcomings in the area of UCB-HSCs, can lead to the formation of new strategies and further studies for the optimal use of these cells.

Human embryonic stem cells (hESCs) are undifferentiated cells characterized by their functional capacity to both SELF-RENEWAL and to differentiate into cell types representing the three embryonic germ lineages (e.g., ectoderm, mesoderm, and endoderm). Applying proteomics to explore the programs that control selfrenewal, differentiation, and plasticity will provide valuable insight into ESCs biology. We used a microarray- and DIGE-based transcriptome and proteome approaches, respectively, to analyze hESCs differentiation to neural cells at three different stages: early neural differentiation, neural ectoderm, and differentiated neural cells. Owing to comparative analyses, several proteins and mechanisms emerged as key participants in stem cells proliferation and differentiation. Furthermore, using siRNA approach, we analyzed the function of two genes, MAGOHB and BCAS2, which were down-regulated at both transcript and protein levels during neural differentiation. The knockdown of these genesresulted in an increase in the expression of neural progenitor markers such as PAX6 and NESTIN. The knockdown of BCAS2 led to a decrease in NANOG expression level and an increase in the abundance of P53. The suppression of MAGOHB resulted in down-regulation of early endoderm and mesodermal gene markers, suggesting that it may play a role in enhancing neurogenesis through inhibition of endomesodermal formation.

Introduction: Monthly regeneration of endometrium after cyclical mensturation confirmed the ability of specific population of the cells that presence in the basalis layer and undergone consecutive hormonal changes that could prepared the endometrial layer for probable implantation. These cells, known as, stem cell. The aim of this study was the isolation and culture of human endometrial derived mesenchymal stem/stromal cells (EnMSCs). Methods: . In this study, human endometrial tissues were collected after fully-informed patient consent, which attended the Research and Clinical Center for Infertility. After washing and enzymatic treatment, EnMSCs were isolated and cultured in vitro. Results: Cells from endometrium were successfully isolated using enzymatically treatment and mechanically dissociation, then cultured and expanded for several passages for further characterization and evaluations. Endometrium derived cells were morphologically similar to mesenchymal stem/stromal cells (MSCs). Conclusion: The results of the present study confirm previous reports in vitro studies for the isolation and culture of human EnMSCs. Endometrial tissue is a part of uterus with available source of MSCs with selfrenewal and differentiation capacity that undergoes a cyclical regeneration every month in normal women’ s life span. In this regard, human EnMSCs could be used for future novel therapeutic methods in regenerative medicine for treatment of uterine-factor infertile patients, which can lead to recurrent pregnancy loss (RPL) and finally resolve of surrogacy problems.

Aim: In this study, the effect of newborn rat brain extract to induce neuronal differentiation in P19 embryonal carcinoma (EC) stem cells was investigated.Material and Methods: Newborn rat brain extract was collected in sterile condition and the concentration of its total protein was determined. Then, the amount of cell viability was determined after treatment with brain extract. In order to differentiation, the embryoid bodies resulted from cells suspension culture were exposed to culture medium containing 3% serum that supplemented by the extract, for 7-14 days. Specific staining and real-time PCR methods were applied to evaluate neural differentiation.Results: Cresyl violet staining confirmed neuronal morphology of the differentiated cells. The gene expression of neural specific was confirmed by real–time PCR. Developing brain extract, which contains numerous neorotrophic factors, could induce expression of synaptophysin (presynaptic membrane protein) and nestin (intermediate filament of stem cells in the neural tube) genes. In addition, the expression of transcription factor Nanog, an important factor for pluripotency and selfrenewal of stem cells, decreased under the influence of newborn rat brain extract.Conclusion: The results of the present study indicated that newborn rat brain extract can induce neuronal phenotype as well as neuronal specific gene expression in P19 stem cells. This study suggests the potential use of combined newborn rat brain extract and stem cell therapy to improvement of deficits in neurodegenerative diseases.

Introduction: Ex vivo proliferation of hematopoietic stem cells (HSCs) of umbilical cord is widely used by combination of cytokine and stromal mesenchymal stem cells (MSCs) as feeder layer due to increase the cell doses, adequately. However, numerous studies have shown that ex vivo proliferation of these cells impairs their functions, including reduced selfrenewal ability, apoptosis induction, and disordered cell cycle. MSCs have different sources such as amniotic membrane with a stable karyotype and high quality because of isolation from embryonic tissues, so that they are considered as a useful source for MSCs. Materials and Methods: In this study, isolated mesenchymal cells from the amniotic membrane were used as feeders for the HSCs proliferation. Four different cultures with various conditions were used; first one containing cytokines (stem cell factor, thrombopoietin, and FMS-related tyrosine kinase 3 ligand), second one with MSCs co-cultured with the aforementioned cytokines, third medium co-cultured with MSCs without cytokines, and finally the control medium was without co-culture condition and cytokines. Expression of mRNAs of HOXB4, GATA2, BCL2, and Survivin genes was also investigated. Results: The findings showed that the expression of mRNAs of these genes decreased in culture with cytokine, solely; however the expression of these genes was significantly higher in co-cultured system with cytokine rather than just with cytokine. Conclusion: : In general, the findings of this study indicate that the derived MSCs from amniotic membrane is a good source for the proliferation of umbilical cord blood CD34+ cells” . Because these cells increase the UCBCD34+ quantity and their preservation properties.

Introduction: Stem cell biology has been the subject of much recent discussion. Embryonic stem (ES) cells, derived from the inner cell mass of the blastocyst stage of early mammalian embryos are expected to become a powerful tool in future regenerative medicine and developmental biology due to their capacity of selfrenewal and pluripotency. In the present study, the ultrastructural development of mouse ES cell derived cardiomyocytes was compared with invivo cardiomyocytes..Methods: Cardiomyocytes were derived from mouse ES line (Royan B1) which developed spontaneously. The cultured cardiomyocytes were processed 3, 7, 14 and 21days after plating (day 7) for immuno histochemistry and transmission electron microscopy (TEM). The in vivo cardiomyocytes were derived from16 days old fetuses and 2 and 8 days old pups.Results: The beating cells expressed a-actinin. The maturation of the ultrastructure of cardiomyocytes depended on enhancement of development and expressed as myofibrillar bundle organization and exhibited intercalated discs, Z-disc, A, I, and H-bands, and M-line. While 7+21 days old cardiomyocytes showed all sarcomeric components such as A, I, and H-bands, Z-disc, and also M-line, T-tubule, sarcoplasmic reticulum and intercalated discs, early stage (7+3d, 7+7d and 7+14d) cardiomyocytes had few primary characteristics of subcellular structure. In fetal and 2-days old pups, the M-line was not visible. M-line was present in 8-days old pups frequently.Conclusion: Based on our data, mature cardiomyocytes can be produced from ES cells, and ES cell provide a good model for cardiomyocyte development. The cells can be used for cell therapy in future.