Background: The unique properties of Mesenchymal Stem Cells (MSCs) have made them powerful tools in cell therapy and genetic engineering and Murine Mesenchymal Stem Cells are a suitable model for study in this field.Compared with human Mesenchymal Stem Cells, murine Mesenchymal Stem Cells have different features such as heterogeneity and slow growth rate. Several reports have shown that microRNAs are involved in many cell regulatory processes such as hypoxia. In this study, the effect of hypoxia was investigated on the expression of hypoxia related microRNA in murine Mesenchymal Stem Cells isolated from adipose tissue (AD-MSC).Methods: AD-MSCs were cultured in two hypoxic and normoxic conditions. The expressions of mir-21 and mir-130a in the primary and immortality phase of AD-MSC were evaluated by using Real-time PCR technique.Also, the expression of MSCs surface markers were investigated by flow cytometry in the two mentioned phases.Findings: Our study showed the expression of mir-21 and mir-130a was increased in hypoxic conditions compared to normoxia. Also expressions of surface markers were different in primary and immortality phase.Conclusion: Considering that Stem Cells are sensitive to environmental oxygen levels, over-expression of mir-21 and mir-130a could promote the survival of MSCs exposed to hypoxia.

Introduction: An induction of osteogenic differentiation in rat bone marrow stromal cell cultures by dexamethasone was reported. Materials and Methods: The marrow stromal Cells obtained from 4 to 6 weeks - old Spruge-Dawely male rats were grown in primary culture for 7 days and then subcultured for 20 days. The Cells were cultured in either DMEM medium containing 15% fetal calf serum, antibiotics and ascorbic acid; or the above medium supplemented with either 10 mM Na-b glycerophosphate (Na-β GP), 10-8 M dexamethasone (Dex) or a combination of both. The cultures were stainded with cresyl violet, toluidine blue and alizarin red S and examined under phase-contrast microscopy. Results: Primary culture: The stromal Cells in the primary culture formed cell colonies at day 5 and reached confluency by day 7. Subculture: The bone marrow stromal Cells in the subculture formed cell colonies by day 2. All subcultures reached confluency after 3 to 5 days; except those Cells grown in primary cultury and subculture in the presence of Dex or Dex and Na-bGP which failed to reach confluency at any time. The later cultures formed isolated islands of Cells. At the 8th day, dense cultures of polygonal Cells became evident in the centers of these islands. The cultures increased in size with time. Conclusion: Three-dimentional nodular structures developed in relation to the clusters at 10th to 11th days in the cultures containing both Dex and Na-bGP Introduction: An induction of osteogenic differentiation in rat bone marrow stromal cell cultures by dexamethasone was reported. Materials and Methods: The marrow stromal Cells obtained from 4 to 6 weeks - old Spruge-Dawely male rats were grown in primary culture for 7 days and then subcultured for 20 days. The Cells were cultured in either DMEM medium containing 15% fetal calf serum, antibiotics and ascorbic acid; or the above medium supplemented with either 10 mM Na-b glycerophosphate (Na-β GP), 10-8 M dexamethasone (Dex) or a combination of both. The cultures were stainded with cresyl violet, toluidine blue and alizarin red S and examined under phase-contrast microscopy. Results: Primary culture: The stromal Cells in the primary culture formed cell colonies at day 5 and reached confluency by day 7. Subculture: The bone marrow stromal Cells in the subculture formed cell colonies by day 2. All subcultures reached confluency after 3 to 5 days; except those Cells grown in primary cultury and subculture in the presence of Dex or Dex and Na-βGP which failed to reach confluency at any time. The later cultures formed isolated islands of Cells. At the 8th day, dense cultures of polygonal Cells became evident in the centers of these islands. The cultures increased in size with time. Conclusion: Three-dimentional nodular structures developed in relation to the clusters at 10th to 11th days in the cultures containing both Dex and Na-βGP.

Background: Extracellular vesicles are particles ranged from 30 nm to 5μ m and subcategorized into three groups; exosomes, microvesicles and apoptotic bodies, each of which have different biological impact. Lack of a standard method for the detection and isolation of MVs has led to a challenging issue that is a worth considering. In this study, we isolated MVs from the conditioned medium of UC-MSCs by four different schemes of ultracentrifugation. Methods: We examined the efficacy of differential centrifugation ranging from 10, 000×g to 60, 000×g on UCMSCs-derived microvesicles yield and purity. The fractions were evaluated by Dynamic Light Scattering (DLS) method, total protein quantification and flow cytometry. Results: UC-MSCs were spindle Cells that adhered to plastic culture flasks. These Cells expressed MSC markers such as CD44 and CD73, whereas were negative for hematopoietic markers CD45 and CD34. UC-MSCparticles were successfully isolated. Particles were heterogeneous vesicles of approximately 50 to 1250 nm in diameter that bear the surface-expressed molecules UC-MSCs such as; CD90, CD106, CD166 and CD44, and negative for CD34, CD63, and CD9. According to the results of DLS method, centrifugation at 10, 000, 20, 000, 40, 000 and 60, 000 ×g, all gave MVs of less than 1000 nm. It is of notion that only at the centrifugation rates of 40, 000 and 60, 000×g, particles of less than 100 nm in diameter were also obtained. Conclusion: The choice of exact speed greatly influences the purity of MVs and their yield. Our findings indicate that centrifugation at 20, 000×g is appropriate for the purification of UC-MSC-MVs.