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BACKGROUND:Bone marrow mesenchymal stem cel s have attracted widespread attention for the capabilities of self-renewal and muti-differentiation, which have been used in treatment of various diseases. OBJECTIVE:To study the effect of three-dimensional spheroid culture system on the stemness and senescence of bone marrow mesenchymal stem cel s. METHODS:Mesechyaml stem cel s were isolated from the bone marrow of C57/B6 mice, 3 weeks old, and cultured onto the culture plates coated with or without chitosan. After 5 days of culture, the cel phenotype and expression of stemness related markers CD44 and Sca-1 were analyzed by flow cytometry. PI and Annexin-V staining were used to detect cel apoptosis. Also,β-Gal staining was applied for identification of aging. RESULTS AND CONCLUSION:The mouse mesenchymal stem cel s began to form spheroids on day 3. The stemness-related markers, including CD44 and Sca-1, expressed higher in spheroid mesenchymal stem cel s than the cel s under normal culturing. Compared with the normal culture group, the apoptosis and senescence of cel s from spheroid culture were lower. The results indicate that the formation of spheroids on chitosan films can increase the stemness, decrease the apoptosis and slow the senescence of mesenchymal stem cel s.
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BACKGROUND:Previous studies have found that embryonic bone marrow mesenchymal stem cel s can promote human Th17 cel proliferation, but the inherent regulatory mechanisms stil need to be elucidated. OBJECTIVE:To investigate the role of Tol-like receptor 3 in the immunoregulation of Th17 cel s by mesenchymal stem cel s. METHODS:Human CD4+T cel s from healthy donors were isolated by immunomagnetic bead method, and then cultured alone or co-cultured with embryonic bone marrow mesenchymal stem cel s for 4 days. The mRNA expression level of interleukin-17, Tol-like receptor 3 and MyD88 was detected by real-time PCR. RESULTS AND CONCLUSION:Compared with CD4+T cel cultured alone group, the mRNA level of interleukin-17 was significantly higher in the co-culture group (3.59±0.11 vs. 1.14± 0.08, P<0.01). Consistent with the expression of interleukin-17 mRNA, increased level of Tol-like receptor 3 mRNA was detected in the co-culture group compared with the CD4+T cel cultured alone group (3.10±1.60 vs. 0.94± 0.01, P<0.05). Furthermore, MyD88 in the co-culture group was significantly higher than that in CD4+T cel cultured alone group (2.29±0.05 vs. 1.85±0.31, P<0.01). Tol-like receptor 3 may be involved in the immunoregulation of Th17 cel s by embryonic bone marrow mesenchymal stem cel s, which provides experimental evidence for potential cel therapeutic strategy.
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BACKGROUND:Studies have found that bone marrow mesenchymal stem cel s, under certain conditions, can be induced to differentiate into neurons and glial cel s, which to some extent solves the problem of the source of seed cel s. Induction methods currently used are different, and their efficiencies are not the same. OBJECTIVE:To observe the effects of different antioxidants on differentiation of rat bone marrow mesenchymal stem cel s into neuron-like cel s in vitro. METHODS:Bone marrow mesenchymal stem cel s from Wistar rats were divided into four groups:non-intervention group,β-mercaptoethanol group, retinoic acid group,β-mercaptoethanol+retinoic acid group. Changes in cel morphology and positive rate of neuron-specific enolase and microtubule-associated protein 2 were observed and detected at 5 hours, 12 hours, 1 day, 3 days, 5 days, 7 days, and 10 days after induction. RESULTS AND CONCLUSION:Except non-intervention group, bone marrow mesenchymal stem cel s in the other three groups were gradual y becoming spindle-shaped, and gave birth to many smal protrusions that were interconnected into a network, showing neuron-like cel morphology. Immunocytochemical staining showed that the efficiency of theβ-mercaptoethanol+retinoic acid group was the highest at 10 days after induction, and the positive rates of neuron-specific enolase and microtubule-associated protein 2 were 71.63%and 79.72%, respectively. The results show thatβ-mercaptoethanol can be combined with retinoic acid to accelerate the differentiation of bone marrow mesenchymal stem cel s into neuron-like cel s.
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BACKGROUND:Mesenchymal stem cel s can differentiate into nerve cel s by chemical induction or co-culture method, but whether mesenchymal stem cel s co-cultured with Schwann cel s differentiate into neuronal-like cel s or Schwann-like cel s is stil controversial. OBJECTIVE:To explore the inductive role of Schwann cel s derived from rats in the differentiation of human umbilical cord mesenchymal stem cel s. METHODS:Cocultures of human umbilical cord mesenchymal stem cel s (1×109/L) and Schwann cel s (1×109/L) from neonatal rats were performed using transwel culture dishes. After 2 weeks of cocultures, morphology of the cultured human umbilical cord mesenchymal stem cel s was observed, and the phenotypic changes of cel s were also detected with immumocytochemistry techniques. RESULTS AND CONCLUSION:After 2 weeks of cocultures, some differentiated cel s showed neuron-like morphology, and expressed nestin, NF-200 andβ-III-tubulin, but did not express Schwann cel special marker S100 and oligodendrocytes special marker MAB1580. These findings indicate that human umbilical cord mesenchymal stem cel s can transdifferentiate into neuronal-like cel s by cocultures with rat’s Schwann cel s.
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BACKGROUND:The development of tissue engineering techniques provides new methods and ideas for the repair and functional reconstruction of articular cartilage defects. OBJECTIVE:To summarize the research progress in the application of mesenchymal stem cel s, as seed cel s, in articular cartilage tissue engineering. METHODS:A computer-based retrieval was performed to search articles describing articular cartilage tissue engineering and mesenchymal stem cel s published between January 1st, 2000 and September 30th, 2014 in PubMed database with the key words of“articular cartilage defects;cartilage tissue engineering;mesenchymal stem cel s”in English. Seventy articles were retrieved initial y, and only 49 were included in further analysis. RESULTS AND CONCLUSION:The ability of the articular cartilage for defect self-repair is limited, and current clinical treatments cannot be satisfactory. Development of tissue engineering provides a new idea for problem-solving. In the selection of seed cel s, chondrocyte is limited to dedifferentiate, and embryonic stem cel is restricted by ethical, legal and other aspects. Autologous mesenchymal stem cel s, which are easy to be amplified and exhibit excel ent cartilage differentiation potential, have gained widespread attention. But there is stil some controversy on the current application of tissue engineering techniques for repair of articular cartilage defects, including a certain gap between the long-term effects and the clinical applications. So the effect of mesenchymal stem cel s on biological structure and mechanical function stil needs further studies.
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BACKGROUND:Studies have shown that bone loss can lead to a series of diseases, such as osteoporotic fractures, thus seeking to increase bone mass has become a goal of the majority of researchers. OBJECTIVE:To summarize the current studies of improving bone mass by using stem cel transplantation, hoping to the extensive application of stem cel transplantation in the clinical treatment of osteoporosis as early as possible. METHODS:A computer-based search of PubMed and CNKI was performed by the first author to retrieve articles relevant to stem cel therapy for osteoporosis published from January 1997 to October 2014. The keywords were“to improve bone mass, regenerative medicine, bone marrow mesenchymal stem cel transplantation, stem cel therapy”in Chinese and English, respectively, which appeared in the title, abstract or keywords. Articles published recently or in authoritative journals were preferred, and final y 28 articles were included in result analysis. RESULTS AND CONCLUSION:Bone marrow mesenchymal stem cel s which are isolated and cultured easily can proliferate rapidly and have multi-lineage differentiation potential. Studies have shown that the osteogenic differentiation of bone marrow mesenchymal stem cel s can real y improve bone mass, and obtain more achievements in the treatment of orthopedic disorders. This new cel therapy can help to accelerate bone healing and reduce treatment time, offering a new therapeutic choice for orthopedic surgery, plastic surgery, oral and maxil ofacial surgery, and therefore, it has broad application prospects.
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BACKGROUND:With the development of biochemistry and cel biology, fracture has being study deeper, blood supply has been known to be an important factor influencing the fracture healing. Endothelial progenitor cel s with good ability of angiogenesis wil have a good clinical prospect in fracture healing. OBJECTIVE:To review the recent research of endothelial progenitor cel s in fracture healing. METHODS:A computer-based online search of CNKI, Wanfang, PubMed databases was performed to col ect articles published between 1980 and 2014 with the key words“endothelial progenitor cel , fracture, neovascularization, angiogenesis”in Chinese and English. A total of 48 articles addressing endothelial progenitor cel for angiogenesis in fracture healing were included in result analysis. RESULTS AND CONCLUSION:Increasing evidence has shown that endothelial progenitor cel s have great ability of neovascularzition and angiogenesis. Endothelial progenitor cel s used in tissue engineering scaffolds can promote the survival rate of scaffolds in vivo, which is appropriate to a great part of delayed union and nonunion patients. However, the large-scale treatment with endothelial progenitor cel s stil has many problems, such as isolation, culture and amplification of endothelial progenitor cel s in vitro, the number of transplanted cel s and selection of scaffolds for transplanted cel s, which need further research.
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BACKGROUND:Coculture of bone marrow mesenchymal stem cel s and human umbilical vein endothelial cel s can improve both osteogenic and angiogenic outcomes and provide a promising strategy for bone tissue engineering and osteanagenesis. OBJECTIVE:To summarize recent researches and related progresses in coculture of human umbilical vein endothelial cel s and bone marrow mesenchymal stem cel s. METHODS:A computer-based online search of CNKI database from January 2000 to March 2012, PubMed database and Web of Knowledge database from January 1980 to March 2012, was performed with the keywords of“human umbilical vein endothelial cel s, bone mesenchymal stem cel s, coculture, tissue engineering”both in Chinese and English. A total of 135 articles were screened out, 103 of them were excluded due to unrelated study objective and repeated contents, and final y 32 articles were involved in further analysis. RESULTS AND CONCLUSION:At present, studies on coculture of bone marrow mesenchymal stem cel s and human umbilical vein endothelial cel s mainly focus on mimicking in vivo environments, the interactions between cel s, and the influence of different cel ratios and culture media. Most of these researches play important roles in bone tissue engineering and bone regeneration therapy, but the mechanism of action and concrete regulation in vivo between bone marrow mesenchymal stem cel s and human umbilical vein endothelial cel s stil need further research and analysis.
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BACKGROUND:Mesenchymal stem cel s as potential seeded cel s have been widely used in tissue engineering and clinic therapy;thus, the precise, safe, effective isolation of mesenchymal stem cel s is the particular important premise to build culture system. OBJECTIVE:To review the methods of isolating mesenchymal stem cel s and to compare the merit and demerit of different methods, thereby providing theoretical basis for safe and high-effective isolation of mesenchymal stem cel s. METHODS:A computer-based online research of CNKI and PubMed databases was performed to col ect articles, which included reviews, clinical trials and experiments, published between 1965 and 2014 with the key words of“mesenchymal stem cel s (MSCs), isolation methods”in Chinese and English. A total of 52 articles were included according inclusion and exclusion criteria RESULTS AND CONCLUSION:(1) The whole bone marrow culture method can derive a mass of mesenchymal stem cel s, which need to be purified. (2) The density gradient centrifugation method which uses the media with the density of 1.073 g/mL can be used to harvest more purified cel s. (3) The tissue digestion method is suitable for digestion and isolation of adipose tissue and umbilical cord tissue. Type II col agenase digestion is better, but they are both limited by a high demand for operative techniques. (4) Immunomagnetic bead separation is appropriate to study the biological characteristics of a kind of subpopulation of mesenchymal stem cel s which express special surface markers. (5) The combination method is also an optimal way. (6) Some new methods limited by few dates require further studies.
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BACKGROUND:Bone marrow mesenchymal stem cel s from chickens are important cel models for embryonic developmental biology, immunology and oncology research. However, it is difficult to keep bone marrow mesenchymal stem cel s with good undifferentiated potential in a large-scale expansion system. OBJECTIVE:To establish a culture system in vitro with laminin coating to expand bone marrow mesenchymal stem cel s from chickens. METHODS:Isolated bone marrow mesenchymal stem cel s from chickens were seeded in laminin-coated plates and traditional two-dimensional plates, respectively. After expansion in vitro, the morphological characteristics, expression of surface markers, expansion characteristics and adipogenic differentiation of bone marrow mesenchymal stem cel s in both conditions were analyzed and compared. RESULTS AND CONCLUSION:There were no statistical differences in the morphological characteristics and expression of surface markers of bone marrow mesenchymal stem cel s expanded by laminin-coated plates and traditional two-dimensional plates. But, the expansion characteristics and adipogenic differentiation of bone marrow mesenchymal stem cel s cultured in laminin-coated plates were better than those in traditional two-dimensional plates. Laminin culture system could quickly amplify out of a large number of chicken bone marrow mesenchymal stem cel s with better proliferation ability and undifferentiated performance. Al above results indicated that a more efficient expansion system with laminin coating is established.
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BACKGROUND:Bone marrow mesenchymal stem cel s are the ideal cel s for tissue repair. Whether the ability of in vitro proliferation can be enhanced is a key factor to promote tissue repair. OBJECTIVE:To observe the effect of transforming growth factorβ1 on the proliferation of bone marrow mesenchymal stem cel s in vitro. METHODS:Blood samples were taken from the central artery of rabbits to prepare platelet-rich fibrin by centrifugation method which was then placed into fresh DMEM at 37℃for 7, 14, 21, 28 days to col ect exudates. The mass concentrations of transforming growth factor-β1 in the exudates of platelet-rich fibrin were detected. Rabbit bone marrow mesenchymal stem cel s were col ected and cultured in the conditioned medium made by the exudates of platelet-rich fibrin, and the proliferation of cel s was observed. RESULTS AND CONCLUSION:Concentration of transforming growth factorβ1 was increased with time increasing, increased fastest at 21-28 days, and peaked at 28 days. Under the same stimulus concentration, the proliferation of bone marrow mesenchymal stem cel s was reduced at 0-1 day, increased obviously at 1-2 days, and entered into a steady phase at 2-3 days. Under 150 ng/L transforming growth factorβ1, bone marrow mesenchymal stem cel s proliferated fastest. Experimental findings indicate that with the increase of time, the concentration of transforming growth factorβ1 in the exudates of platelet-rich fibrin increase gradual y, and the conditioned media containing different concentrations of transforming growth factorβ1 play different roles in promoting the proliferation of bone marrow mesenchymal stem cel s. Bone marrow mesenchymal stem cel s cultured in the conditioned medium containing 150 ng/L transforming growth factorβ1 for 2-3 days can proliferate fastest.
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BACKGROUND:Animal studies have indicated ultrasound-mediated microbubbles can significantly enhance the effect of stem cel transplantation to treat ischemic diseases. But its mechanism is stil unknown. OBJECTIVE:To explore the mechanism of ultrasound-mediated microbubbles to significantly enhance the effect of stem cel transplantation in the treatment of ischemic diseases. METHODS:Bone marrow mesenchymal stem cel s and vascular endothelial cel s of rats were cultured in vitro, and then randomized to three groups:control group with no intervention, ultrasound group exposed to ultrasound at 1 MHz, 1 W/cm2 for 90 seconds, and ultrasound-mediated microbubble group treated with 5μL liposomes ultrasound microbubbles containing fluorocarbon gases (about 2×1011/L) and ultrasound exposure at 1 MHz, 1 W/cm2 for 90 seconds. RESULTS AND CONCLUSION:Compared to the control group, ultrasound-mediated microbubbles significantly increased expressions of vascular endothelial growth factor and stromal cel-derived factor 1 in the supernatant of vascular endothelial cel s (P0.05). These findings suggest that 1 W/cm2 ultrasound-mediated microbubbles can promote vascular endothelial growth factor and stromal cel-derived factor 1 secretion by vascular endothelia cel s, and meanwhile promote CXCR4 gene expression in bone marrow mesenchymal stem cel s. This may be the mechanism of the ultrasound-mediated microbubbles enhancing homing effect of transplanted stem cel s.
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BACKGROUND:With the development of stem cel culture technology, stem cel transplantation has been a research hotspot in the biological cytology. OBJECTIVE:To review the current situation and progress of basic research on stem cel transplantation for human refractory diseases. METHODS:A computer-based search of CNKI, VIP, Wanfang and PubMed databases was performed for articles related to animal experiments of stem cel transplantation published from January 2008 to October 2014. The key words were“induced pluripotent stem cel s, neural stem cel s, top-up between stem cel s, transplantation”in Chinese and English in the title and abstract. Papers published in authoritative journals or recently were preferred. Total y 113 articles were searched initial y, and only 50 articles were included in result analysis. RESULTS AND CONCLUSION:With the progress of stem cel culture technology, basic research on the stem cel transplantation for human diseases have been promoted and carried out, and these researches have achieved phased outcomes that provide conditions for more extensive and in-depth fundamental research. It is believed that with the development of basic research on stem cel transplantation to solve a series of difficult problems, stem cel transplantation wil bring hope for treatment of human disease, especial y for treatment of refractory disease.
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BACKGROUND:There are various methods for the treatment of osteonecrosis of femoral head, but there is no satisfactory method to promote the repair of osteonecrosis of femoral head. In recent years, bone marrow mesenchymal stem cel transplantation for the treatment of osteonecrosis of femoral head has achieved certain effect. OBJECTIVE:To review the application progress and problems of bone marrow mesenchymal stem cel transplantation for the treatment of osteonecrosis of femoral head. METHODS:A computer-based online search was performed in PubMed database, Wanfang database and CNKI database for the related articles from 1999 to 2012. The articles on the isolation, culture, differentiation, labeling and in vivo tracing of bone marrow mesenchymal stem cel s were selected, as wel as the basic and clinical researches on bone marrow mesenchymal stem cel transplantation for the treatment of osteonecrosis of femoral head. A total of 39 articles were included for review. RESUTLS AND CONCLUSION:At present, the method for the isolation of bone marrow mesenchymal stem cel s includes adherence screening method, density gradient centrifugation, flow cytometry separation and magnetic activated cel sorting method;the commonly used method for cel labeling and tracing includes isotope tracing method, antigen labeling method, antigen labeling, fluorescent labeling and MRI contrast enhancer labeling method. The method for the treatment of osteonecrosis of femoral head with bone marrow mesenchymal stem cel s includes pith dril ing decompression combined with bone marrow mesenchymal stem cel injection and transplantation, intervention plus bone marrow mesenchymal stem cel transplantation, gene transfection combined with bone marrow mesenchymal stem cel transplantation and tissue engineering technology of bone marrow mesenchymal stem cel s. Although, the research on the bone marrow mesenchymal stem cel transplantation for the treatment of osteonecrosis of femoral head has achieved great progress, there are stil problems needed to be further solved.
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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:The viability of human umbilical cord-derived mesenchymal stem cel s is often declined with the commonly used transplantation storage solution in clinics, which may influence the therapeutic effects of cel ular transplantation. However, reasons for this are stil unknown. OBJECTIVE:To investigate the role of oxidative stress in the reduction of human umbilical cord-derived mesenchymal stem cel s viability in the storage process during clinical transplantation and to observe the effects of radical scavenger on the results. METHODS:Human umbilical cord-derived mesenchymal stem cel s were harvested and cultured in normal saline for 0, 2, 4 and 6 hours at room temperature. Intracel ular reactive oxygen levels were detected at those time points. Antioxidant enzyme activities and levels of malondialdehyde were measured to determine the intracel ular oxidative stress levels after storage. Cel adhesion rate changes were retested after adding N-acetyl cysteine to the storage solution. RESULTS AND CONCLUSION:The reactive oxygen levels in human umbilical cord-derived mesenchymal stem cel s were increased significantly after normal saline storage and levels of malondialdehyde were increased in a time-dependent manner. Activities of superoxide dismutase, catalase and glutathione peroxidase were al reduced. Addition of N-acetyl cysteine into the storage medium decreased the reactive oxygen levels and improved the human umbilical cord-derived mesenchymal stem cel s viabilities. Experimental findings indicate that, increased reactive oxygen species in human umbilical cord-derived mesenchymal stem cel s is one of the reasons for reduced cel viability. Adding the radical scavenger N-acetyl cysteine can improve the storage effects of human umbilical cord-derived mesenchymal stem cel s.
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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: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:Umbilical cord-derived mesenchymal stem cel s are gaining more attention in clinical treatments. Cel viability prior to transplantation has a direct impact on clinical prognosis. Despite trypan blue staining is a widely performed procedure to assess the viability of umbilical cord-derived mesenchymal stem cel s, it cannot reflect the functional capacity of those cel s accurately because of some subjective factors. OBJECTIVE:To explore sensitive and accurate assay for the functions of umbilical cord-derived mesenchymal stem cel s. METHODS:Human umbilical cord-derived mesenchymal stem cel s were isolated and cultured in vitro. Cultured umbilical cord-derived mesenchymal stem cel s were preserved in 0.9%saline for 0, 2, 4 and 6 hours at 4 ℃. Various methods (trypan blue staining, AnnexinV-PI, terminal deoxynucleotidyl transferase dutp nick end labeling, cel counting kit-8, live-dead assay, cel adherent assay) were used to determine the viability of post-storage umbilical cord-derived mesenchymal stem cel s, and the results were compared with colony-forming efficiency, a measure of cel function. RESULTS AND CONCLUSION:Human umbilical cord-derived mesenchymal stem cel s cultured in vitro showed a spindle shape and attached growth, the third-generation umbilical cord-derived mesenchymal stem cel s were positive for CD29, CD44, CD105, and negative for CD 34 and CD 45. Umbilical cord-derived mesenchymal stem cel s incubated in the adipogenic and osteogenic medium were both positive. Cel viability measured with trypan blue correlated moderately with colony-forming efficiency, while the percentage of viable cel s measured with other methods correlated better with colony-forming efficiency, among which adherent assay was the most obvious. It is proved that cel adherent assay-measured viability is the most accurate indicator.