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BACKGROUND:Currently, bone marrow mesenchymal stem cel s can differentiate into nerve cel s via many approaches. Different methods for inducing bone marrow mesenchymal stem cel s differentiating into nerve cel s have different ratios. OBJECTIVE:To investigate the difference between chemical method and co-culture method to induce the differentiation of rat bone marrow mesenchymal stem cel s into nerve cel s. METHODS:Rat bone marrow mesenchymal stem cel s were isolated and purified using whole bone marrow culture method, and then randomly divided into two groups:chemical group,β-mercaptoethanol was added;co-culture group, co-cultured in a Transwel chamber. RESULTS AND CONCLUSION:Visible protrusions from induced cel s showed radiation growth at 1 week of induced culture, and neuron-specific enolase staining was positive at 2 weeks of culture. Star-like structure of nerve cel s was visible in the co-culture group within 4-5 days of culture, and then more protrusions formed. Meanwhile, the positive rate of neuron-specific enolase was (70.82±2.46)%. After 6-7 days of culture, neuron-like cel s formed and were interconnected in the chemical group;while, the positive rate of neuron-specific enolase was (52.37±1.83)%. These findings suggest that cel microenvironment plays a leading role in the differentiation of bone marrow mesenchymal stem cel s into nerve cel s, and chemical induction method is inferior to the co-culture method.
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BACKGROUND:Adipose-derived stem cel s and bone marrow mesenchymal stem cel s are used widely in cartilage tissue engineering, and there are many similarities in biological characteristics between two kinds of cel s. OBJECTIVE:To compare the chondrogenic potential of bone marrow mesenchymal stem cel s and adipose-derived stem cel s in vitro. METHODS:Adipose-derived stem cel s were isolated from the 3-month-old New Zealand white rabbits’ abdomen. Bilateral femurs of rabbits were obtained, and then the bone marrow mesenchymal stem cel s were separated with the adherence screening method. The growth curve of the passage 3 adipose-derived stem cel s and bone marrow mesenchymal stem cel s were drawn, and the doubling time of two kinds of cel s was compared. Then the passage 3 adipose-derived stem cel s and bone marrow mesenchymal stem cel s were treated with chondrogenic induction. After induced for 14 days, the adipose-derived stem cel s and bone marrow mesenchymal stem cel s were treated with toluidine blue staining and type Ⅱ immunohistochemistry staining respectively. RESULTS AND CONCLUSION:Primary bone marrow mesenchymal stem cel s showed aggregative growth, while the primary adipose-derived stem cel s were in single and scattered growth. The proliferation speed of adipose-derived stem cel s was faster than that of bone marrow mesenchymal stem cel s, while the doubling time of adipose-derived stem cel s was shorter than that of the bone marrow mesenchymal stem cel s. After chondrogenic induction for 14 days, both adipose-derived stem cel s and bone marrow mesenchymal stem cel s could express glycosaminoglycans and type Ⅱcol agen, and the expression level of type Ⅱ col agen in bone marrow mesenchymal stem cel s after chondrogenic induction was higher than that in the adipose-derived stem cel s. The in vitro proliferation of adipose-derived stem cel s and bone marrow mesenchymal stem cel s was rapid and stable, but the proliferative ability of adipose-derived stem cel s was faster than that of bone marrow mesenchymal stem cel s. When cultured in single layer, both adipose-derived stem cel s and bone marrow mesenchymal stem cel s could transform into chondrocytes under certain conditions, but bone marrow mesenchymal stem cel s seemed to be more potential than adipose-derived stem cel s.
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BACKGROUND:The repair and management of ful-thickness skin defects resulting from burns and chronic wounds remain a significant unmet clinical chal enge. Using epidermal stem cel s and keratinocyte growth factor for ful-thickness wound repair is a promising approach. Low-frequency electromagnetic fields which are a non-invasive physical stimulation therapy have been recognized as a good method to enhance wound healing. OBJECTIVE:To develop a new strategy to accelerate wound healing by transplanting transfected epidermal stem cel s and keratinocyte growth factor and treating with low-frequency electromagnetic fields in a mouse model. METHODS:Epidermal stem cel s from Sprague-Dawley neonatal rats were isolated and cultured in vitro, then the cel s were labeled with 5-bromo-2-deoxyuridine and transfected by Ad-KGF, a recombinant adenovirus carrying the keratinocyte growth factor. Mice were given to create ful thickness skin wound on the dorsum and randomly assigned to four groups:control group, transplantation of epidermal stem cel s group, transplantation of keratinocyte growth factor gene modified epidermal stem cel s group, and transplantation of keratinocyte growth factor gene modified epidermal stem cel s plus low-frequency electromagnetic field exposure group. RESULTS AND CONCLUSION:The best healing pattern was observed in the keratinocyte growth factor gene modified epidermal stem cel s plus low-frequency electromagnetic field exposure group (P<0.05) at days 9 and 16. 5-Bromo-2-deoxyuridine labeled cel s existed in the wound in the treated groups at day 9. A significantly increased expression of endogenous keratinocyte growth factor was detected in the transplantation of Keratinocyte Growth Factor gene modified epidermal stem cel s group, and transplantation of keratinocyte growth factor gene modified epidermal stem cel s plus low-frequency electromagnetic field exposure group at day 16. A wel-advanced epithelialization was observed in transplantation of keratinocyte growth factor gene modified epidermal stem cel s plus low-frequency electromagnetic field exposure group at days 16 and 30. These results suggest that low-frequency electromagnetic fields enhanced wound healing fol owing the transplantation of keratinocyte growth factor gene modified epidermal stem cel s.
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BACKGROUND:Cel transplantation offers a new promise of rebuilding the damaged myocardium. But the results of them are not consistent. It is not clear if the transplanted cel s can permanently improve heart function and the mechanism underlying this therapeutic effect. OBJECTIVE:To study the effect of intracoronary autologous bone marrow mononuclear cel transplantation on cardiac function, and angiogenesis and cytokine production in canines with acute myocardial infarction. METHODS:Left anterior descending coronary artery ligation was used to produce acute myocardial infarction models in hybrid canines. Bone marrow mononuclear cel s were harvested by using puncture of anterior crest and posterior superior iliac spine to prepare cel suspension. Sixteen hybrid canines were randomly divided into transplantation group (n=10) and control group (n=6). Bone marrow mononuclear cel s (transplantation group, n=10) or normal saline (control group, n=6) were intracoronarily infused into infarction-related arteries 2 hours after acute myocardial infarction. To evaluate the heart function, we used echocardiography at 2 hours and 6 weeks after acute myocardial infarction. Capil ary density was assessed 6 weeks after transplantation by using von Wil ebrand factor test. The mRNA levels of vascular endothelial growth factor 188, vascular endothelial growth factor 164, basic fibroblast growth factor and matrix metal oproteinase-9 in the infarct area were determined by reverse transcription-PCR at 6 weeks after transplantation. RESULTS AND CONCLUSION:In contrast to the control group, ejection fraction and stroke volume at 6 weeks after transplantation increased significantly in the transplantation group. The transplantation group had a greater amount of new vessels in the peri-infarct area than the control group. Compared with the control group, the mRNA levels of vascular endothelial growth factor 188, vascular endothelial growth factor 164, and basic fibroblast growth factor significantly increased in the transplantation group, but the mRNA level of matrix metal oproteinase-9 significantly decreased in the transplantation group. These findings suggest that intracoronary transplantation of autologous bone marrow mononuclear cel s may improve the cardiac function, and increase capil ary density, especial y in the border zone of infarcted myocardium. Otherwise, bone marrow mononuclear cel transplantation can increase the mRNA levels of vascular endothelial growth factor 188, vascular endothelial growth factor 164, and basic fibroblast growth factor, but decrease the mRNA level of matrix metal oproteinase-9.
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BACKGROUND: Some studies have shown that bone marrow mesenchymal stem cells and al ograft bone have a certain role for repairing bone defects, but the effectiveness on cancel ous bone defects is seldom reported so far. OBJECTIVE: To observe the effectiveness of bone marrow mesenchymal stem cells combined with al ogeneic bone on cancel ous bone defects. METHODS: The models of cancel ous bone defects (0.6 cm×1.2 cm) were made artificial y in both condylus lateralis femoris of New Zealand white rabbits: one side served as model group implanted with combination of bone marrow mesenchymal stem cells and al ogeneic bone, and the other side was considered as control group implanted with al ogeneic bone. RESULTS AND CONCLUSION: The model group was better than the control group in new bone growth and defect repair at 4, 8, 12 weeks after implantation, which was confirmed by general observation, X-ray examination and hematoxylin-eosin staining. There was a large amount of trabecular bone formation and mature lamel ar bone tissue in bone defects of model group by histological observation at 12 weeks after implantation, and bone defects of the model group were repaired basical y; while there were only abundant woven bones in the control group, and bone defects in the control group were not repaired effectively. Scores on Lane-Sandhu’s X-ray combined with histological observation were higher in the model group than the control group (P < 0.05). Biomechanical test showed that the maximum pressure load of the femoral condyle and load/strain ratio in the model group were significantly higher than those in the control group at 12 weeks after implantation (P < 0.05),while the maximum strain and displacement of the model group was lower than that of the control group (P < 0.05). These findings suggest that the combination of bone marrow mesenchymal stem cells and al ogeneic bone is superior to simple al ogeneic bone implantation in the repair of cancel ous bone defects of the femoral condyle.
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BACKGROUND:Currently, transplantation of bone marrow mesenchymal stem cel s into the spinal cord is very limited to the recovery of animals fol owing spinal cord injury. Methylcobalamin is a common drug for the treatment of neurological diseases and injuries, but its effects on bone marrow mesenchymal stem cel s are unclear. OBJECTIVE:To study the feasibility of bone marrow mesenchymal stem cel s differentiating into neuron-like cel s induced by methylcobalamin in vitro and to observe the cel viability and proliferation of differentiated cel s. Methods:Rat bone marrow mesenchymal stem cel s were isolated, cultured and purified by density gradient centrifugation and adherent culture. The fourth to fifth generation of bone marrow mesenchymal stem cel s were treated for 24, 48 and 72 hours with different concentrations (25, 50 and 100 mg/L) of methylcobalamin. The morphological changes and cel growth were continuously observed under an inverted phase constract microscope. The viability of induced cel s was detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The expressions of Nestin and neuron-specific enolase were identified by reverse transcription PCR and western blot. RESULTS AND CONCLUSION:Most of bone marrow mesenchymal stem cel s could differentiate into neuron-like cel s after induction with methylcobalamin. The expressions of Nestin and neuron-specific enolase were up-regulated after 48 hours of methylcobalamin treatment at different concentrations, especial y after treatment with 100 mg/L methylcobalamin. Similarly, the expressions of Nestin and neuron-specific enolase could be increased significantly after 100 mg/L methylcobalamin treatment for 24, 48 and 72 hours, especial y for 72 hours. It is indicated that methylcobalamin can induce bone marrow mesenchymal stem cel s differentiating into neuron-like cel s, and the optimal concentration of methylcobalamin is 100 mg/L.
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BACKGROUND:Bone marrow mesenchymal stem cel transplantation is considered as a promising therapy for spinal cord injury. How to more effectively promote the survival of bone marrow mesenchymal stem cel s in the area of spinal cord injury and to accelerate the recovery of motor function after spinal cord injury is a current study focus. Previous studies have found that low-frequency electromagnetic fields can promote bone marrow mesenchymal stem cel proliferation and differentiation, but whether the low-frequency electromagnetic fields can be applied to bone marrow mesenchymal stem cel transplantation for treatment of spinal cord injury requires further studies. OBJECTIVE:To discuss the effects of low-frequency electromagnetic fields on motor function of spinal cord injury rats after transplantation of bone mesenchymal stem cel s. METHODS:Sixty-four rat models of incomplete spinal cord injury at T 10 were established by compression method and then randomized into control group, transplantation group (bone mesenchymal stem cel transplantation), electromagnetic field group and combination group (electromagnetic field+bone mesenchymal stem cel transplantation). After successful modeling, bone mesenchymal stem cel s labeled with 5-bromo-2'-deoxyuridine were injected into the original injured site in the transplantation group and combination group, which were isolated and purified with the fast adherence method;while alpha-minimum essential medium was injected into the electromagnetic field group and control group for instead. At 24 hours post-operation, the electromagnetic field group and combination group were explored to low-frequency electromagnetic fields (frequency 50 Hz, magnetic indaction intensity 5 mT) for 60 minutes per day. RESULTS AND CONCLUSION:After cel transplantation for 21 days, the Basso, Beattie, and Bresnahan scores in the combination group was higher than the other groups (P<0.05). 5-Bromo-2'-deoxyuridine positive cel s grew wel , and integrated into the normal spine;syringomyelia was reduced, and the number of spinal neural cel s was increased in the combination group. In addition, glial fibril ary acidic protein expression was decreased in the combination group, while matrix metal oproteinase 2 expression was increased. It indicates that low-frequency electromagnetic fields could promote recovery of motor function in the spinal cord injury rats transplanted with bone mesenchymal stem cel s, which could be associated that low-frequency electromagnetic fields facilitate the survival of transplanted bone mesenchymal stem cel s, up-regulate the expression of matrix metal oproteinase 2, and reduce glial scar formation in the spinal cord injured site.
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BACKGROUND: Intramyocardial transplantation of autologous umbilical cord-derived mesenchymal stem cells for repair of myocardial tissue damage is paid increasing attention in the cardiovascular field. OBJECTIVE: Human umbilical cord mesenchymal stem cells were isolated and cultured. Passage 2 human umbilical cord mesenchymal stem cells were treated with various concentratins of 5-azacytidine (2.5, 5, 10, 20, 40, 80 μmol/L) for 24 hours . After removal of 5-azacytidine, cells were cultured for another 4 weeks. RESULTS AND CONCLUSION: Before 5-azacytidine treatment, filament-like structures or particles were not observed in the cells, but the amount of cytoplasm was less and uniform, nuclear/cytoplasm ratio was high, cells exhibited typical fusiform appearance and grew in a swirl-like manner, and nucleolus was obvious. After treatment with 5-azacytidine for 24 hours, some cells died in each group, and typical fusiform appearance turned into stick-like or column-like appearance, especial y in the 40 and 80 μmol/L 5-azacytidine groups. Reverse transcription-PCR results showed that atrial natriuretic peptide and α-skeletal actin gene expression levels were detected on human umbilical cord mesenchymal stem cells after treatment with 2.5 or 40 μmol/L 5-azacytidine for 4 weeks or with 5, 10, 20 μmol/L 5-azacytidine for 1, 2, 3 and 4 weeks. These findings suggest that 5-azacytidine-induced human umbilical cord mesenchymal stem cells express the specific gene of myocardiocytes.
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10.3969/j.issn.2095-4344.2013.23.005
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10.3969/j.issn.2095-4344.2013.23.011
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10.3969/j.issn.2095-4344.2013.23.015
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10.3969/j.issn.2095-4344.2013.23.001