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Background and Objective: Epidermis is the outer layer of skin, regenerating continuously. Epidermal stem cells play important roles in tissue regeneration, scar regeneration and neoplasm formation.This study was displayed for the isolation and culture of interfollicular epidermal stem cells from newborn mouse skin without feeder layer. Materials and Methods: This experimental study was displayed on 0-3 old-day newborn NMRI mouse skin 60-70 gr weight. The epidermal keratinocytes were separated mechanically and enzymatically from 0-3 old day newborn mice skin (NMRI strain) and seeded on fibronectin-collagen culture substrates. Putative epidermal stem cells were selected by rapid adherence for 10 minutes on this composite matrix of type 1 collagen and fibronectin and the unattached cells were discarded and attached cells were cultured in essential minimal eagle medium (EMEM) (ca+2-free culture medium containing 0.05 mM Ca+2, 9% FBS, 50% conditioned medium, EGF (epidermal growth factor) and Cholera Toxin. The immunocytochemistry of β1-integrin analysis used to indicate their stemness nature. Results: The results indicated that rapid adherence yields 50% purity. By using this method, the stem cells have been subcultured continuously without any change in the cell properties. The isolated interfollicular epidermal stem cells, expressed epidermal stem cells special marker (β1-integrin) in high levels, which indicates stem cell nature. Conclusion: This new method yields pure viable epidermal stem cells that can be used in regenerative medicine and cell therapy.

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Background and Objective: Degeneration of neurons in the central nervous system occurs during aging. Transplantation of neural stem cells (NSCs) can be preventing the degeneration of neurons. In addition to neuronal replacement, with the production of neurotrophic factors, increased survival and proliferation of endogenous cells. This study was done to compare the cell proliferation, neurotrophic factors expression and features of NSCs harvested from different areas of the central nervous system in vitro. Materials and Methods: In this laboratory study NSCs have been harvested from subgranular zone (SGZ), subventricular zone (SVZ) and central canal of spinal cord from adult Wistar rats with mechanical, enzymatical digestion and subsequently was cultured in α-MEM medium supplemented with serum as monolayer or adherent conditions and passaged for 13 times. Immunocytochemistry was used to determine expression of the nestin and GFAP markers. Semi-quantitative RT–PCR was used to confirm genes expression (NGF, CNTF, NT3, NT4/5, GDNF and BDNF). Results: Morphological features of stem cells extracted from different regions of the central nervous system were similar in the culture. Doubling time NSCs in the SVZ (37.45 hr) is shorter than in the SGZ (44.04 hr) and central canal of spinal cord (57.22 hr). The culture conditions as well as monolayer neural stem cells are capable of producing neurospheres. Also, nestin and GFAP markers, expressed by NSCs. Neurotrophic gene expression pattern profiles were similar to each other in stem cells extracted from the SGZ, SVZ and central canal of spinal cord. Conclusion: Neurotrophic gene expression in stem cells extracted from different regions of the central nervous system were similar, but proliferation capacity was higher in NSCs, which have been harvested from the SVZ.

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Background and Objective: Stem cells are a suitable treatment method for improvement of central nervous system diseases. Neuron regeneration is occure in damaged region using stem cell transplantation. This study was done to determine the effect of bone marrow mesenchymal stem cells on memory and neuronal cells graft number in the trimethyltin chloride damaged hippocampus. Methods: In this experimental study, 28 wistar male rats were allocated into four groups including control, model, Vehicle and treatment groups. Animals were received 8 mg/kg/bw of neurotoxin trimethyltin chloride by the intraperitoneal injection for causing damaged in hippocampus. One week after intraperitoneal injection of trimethyltin chloride, stem cells was injected by stereotaxy method. Six weeks after stem cells injection, the spatial memory was assessed by Morris water maze and histological studies were done by Nissl staining and normal cells count by Olysia bio report software. Results: After bone marrow mesenchymal stem cells graft, the number of normal cells were more in the treatment group (74±15.190) in compared to the Vehicle (44.67±12.971) and Model (48.56±18.105) groups (P<0.05). Also in Morris water maze test, the treatment group (387.35±189.18), (31.30±13.67) spent shorter distance and escape latency to reach the hidden platform, but this reduced non significantly in compared to Vehicle (438.18±192.56), (40.14±14.89) and model (407.98±225.44), (37.68±17.15) groups. The model and Vehicle groups spent longer distance to reach the hidden platform in comparision with the control (275.45±165.10) group (P<0.05). Also the traveled distance in target quarter had significant increased in the treatment groups (799.80±125.91) in compared to model (588.51±136.94) and Vehicle (546.48±86.47) groups (P<0.05). Conclusion: Using the bone marrow mesenchymal stem cells leads to reduce hippocampal lesions and increase the number of pyramidal neurons and improving memory in damaged hippocampus in animal model.

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Background and Objective: Some problems such as low viability and apoptosis after injection to the body because of exposure to toxic factors such as hypoxia, thermal stress, oxidative stress and food deprivation are encountered with stem cell application. It is suggested that preconditioning of the cells with cytotoxic factors before injection could enhance their efficiency. This study was done to determine the mesenchymal stem cell proliferation exposed to hypoxia by cobalt chloride. Methods: In this experimental study, Mesenchymal stem cells were isolated from rat bone marrow and cultured at least for four times. The cells were cultured in 96 well plates and treated with different concentration (0, 5, 10, 20, 50, 70, 90, 100, 120, 150 and 200 µM) of cobalt chloride for 6, 12, 24 and 46 hours. Cell proliferation was detected by MTT assay [3-(4,5-Dimethylthiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide]. Results: The cells isolated from bone marrow were propagated easily in culture condition. The cells morphology was not altered after exposure to cobalt chloride. Preconditioning of mesenchymal stem cells with 120 µM for 6 hours, 20µM for 12 and 24 hours and 5µM for 48 hours significantly improved cell proliferation after hypoxia in cell culture (P<0.05). Conclusion: Hypoxia preconditioning increases proliferation of mesenchymal stem cell.

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Background and Objective: Alkaline phosphatase, BMP, and GATA proteins are important factors in the process of spermatogenesis. This study aims to investigate the effect of alkaline phosphatase, GATA, and BMP expression on spermatogenic stem cells, embryonic cells, and embryonic stem-like cells (ES-like) in C57BL mice.
Methods: In this experimental study, spermatogonial stem cells were isolated from three heads of 4-week-old C57BL mice, and embryonic stem cells and ES-like cells were prepared. Alkaline phosphatase staining test was performed on spermatogenic stem cells, embryonic cells, and ES-like cells. The expression of BMP and GATA genes was analyzed using Fluidigm PCR. Protein-protein interaction networks were isolated and drawn using databases.
Results: Positive alkaline phosphatase expression in stem cells and negative expression in testicular Sertoli cells indicated the presence of this enzyme in pluripotent cells. The gene expression of BMP and GATA in spermatogonial stem cells (6.3 and 2.7, respectively), embryonic cells (3.2 and 4.4, respectively), and ES-like cells (8.5 and 2.5, respectively) was positive, but not statistically significant. Bioinformatics studies showed the regulatory role of these genes and their direct effect on alkaline phosphatase.
Conclusion: BMP and GATA genes, along with alkaline phosphatase enzymes, play a crucial role in controlling embryonic and spermatogonial stem cells, maintaining their pluripotency, and guiding them towards differentiated cells.
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