TrkA regulates the regenerative capacity of bone marrow stromal stem cells in nerve grafts

We previously demonstrated that overexpression of tropomyosin receptor kinase A(TrkA)promotes the survival and Schwann celllike differentiation of bone marrow stromal stem cells in nerve grafts,thereby enhancing the regeneration and functional recovery of the peripheral nerve.In the present study,we investigated the molecular mechanisms underlying the neuroprotective effects of TrkA in bone marrow stromal stem cells seeded into nerve grafts.Bone marrow stromal stem cells from Sprague-Dawley rats were infected with recombinant lentivirus vector expressing rat TrkA,TrkA-shRNA or the respective control.The cells were then seeded into allogeneic rat acellular nerve allografts for bridging a 1-cm right sciatic nerve defect.Then,8 weeks after surgery,hematoxylin and eosin staining showed that compared with the control groups,the cells and fibers in the TrkA overexpressing group were more densely and uniformly arranged,whereas they were relatively sparse and arranged in a disordered manner in the TrkA-shRNA group.Western blot assay showed that compared with the control groups,the TrkA overexpressing group had higher expression of the myelin marker,myelin basic protein and the axonal marker neurofilament 200.The TrkA overexpressing group also had higher levels of various signaling molecules,including TrkA,pTrkA(Tyr490),extracellular signal-regulated kinases 1/2(Erkl/2),pErk1/2(Thr202/Tyr204),and the anti-apoptotic proteins Bcl-2 and Bcl-xL.In contrast,these proteins were downregulated,while the pro-apoptotic factors Bax and Bad were upregulated,in the TrkA-shRNA group.The levels of the TrkA effectors Akt and pAkt(Ser473)were not different among the groups.These results suggest that TrkA enhances the survival and regenerative capacity of bone marrow stromal stem cells through upregulation of the Erk/Bcl-2 pathway.All procedures were approved by the Animal Ethical and Welfare Committee of Shenzhen University,China in December 2014(approval No.AEWC-2014-001219).

In vitro differentiation of adipose-derived stem cells and bone marrow-derived stromal stem cells into neuronal-like cells

Adipose-derived stem cells and bone marrow-derived stromal stem cells were co-cultured with untreated or Aβ1-40-treated PC12 cells, or grown in supernatant derived from untreated or Aβ1-40-treated PC12 cells. Analysis by western blot and quantitative real-time PCR showed that protein levels of Nanog, Oct4, and Sox2, and mRNA levels of miR/125a/3p were decreased, while expression of insulin-like growth factor-2 and neuron specific enolase was increased. In comparison the generation of neuron specific enolase-positive cells was most successful when adipose-derived stem cells were co-cultured with Aβ1-40-treated PC12 cells. Our results demonstrate that adipose-derived stem cells and bone marrow-derived stromal stem cells exhibit trends of neuronal-like cell differentiation after co-culture with Aβ1-40-treated PC12 cells. This process may relate to a downregulation of miR-125a-3p mRNA expression and increased levels of insulin-like growth factor-2 expression.

miR-124 and miR-128 differential expression in bone marrow stromal cells and spinal cord-derived neural stem cells

BACKGROUND： MicroRNA （miRNA） expression in stem cells provides important clues for the molecular mechanisms of stem cell proliferation and differentiation. Bone marrow stromal cells and spinal cord-derived neural stem cells exhibit potential for neural regeneration. However, miRNA expression in these cells has been rarely reported. OBJECTIVE： To explore differential expression of two nervous system-specific miRNAs, miR-124 and miR-128, in bone marrow stromal cells and spinal cord-derived neural stem cells. DESIGN, TIME AND SETTING： An In vitro, cell biology experiment was performed at the Department of Biotechnology, Shanxi Medical University from June 2008 to June 2009. MATERIALS： TaqMan miRNA assays were purchased from Applied Biosystems. METHODS： Rat bone marrow stromal cells were isolated and cultured using the whole-bone marrow method, and rat spinal cord-derived neural stem cells were obtained through neurosphere formation. TaqMan miRNA assays were used to measure miR-124 and miR-128 expression in bone marrow stromal cells and spinal cord-derived neural stem cells. MAIN OUTCOME MEASURES： Morphology of bone marrow stromal cells and spinal cord-derived neural stem cells were observed by inverted microscopy. Expression of the neural stem cell-specific marker, nestin, the bone marrow stromal cell surface marker, CD71, and expression of miR-124 and miR-128, were detected by real-time polymerase chain reaction. RESULTS： Cultured bone marrow stromal cells displayed a short fusiform shape. Flow cytometry revealed a large number of CD71-positive cells （〉 95%）. Cultured spinal cord-derived neural stem cells formed nestin-positive neurospheres, and quantitative detection of miRNA demonstrated that less miR-124 and miR-128 was expressed in bone marrow stromal cells compared to spinal cord-derived neural stem cells （P 〈 0.05）. CONCLUSION： Bone marrow stromal cells and spinal cord-derived neural stem cells exhibited differential expression of miR-124 and miR-128, which suggested different characteristics in miRNA expression.

Bone marrow stromal cell versus neural stem cell transplantation in a C6 glioma rat model

BACKGROUND： Embryonic neural stem cells （NSCs） have provided positive effects for the treatment of glioma. However, the source for embryonic NSCs remains limited and high amplification conditions are required. Bone marrow stromal cells （BMSCs） have been proposed for the treatment of glioma. OBJECTIVE： To investigate biological changes in NSCs and BMSCs following transplantation into rat models of glioma. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Embryonic Stem Cell Research Laboratory of Yunyang Medical College from February 2006 to August 2008. MATERIALS： The rat C6 glioma cell line was purchased from Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences; mouse anti-bromodeoxyuridine （BrdU） monoclonal antibody and Cy3-1abeled goat anti-mouse IgG antibody was purchased from Upstate, USA. METHODS： A total of 95 Sprag6ue Dawley rats were randomly assigned to three groups： NSC （n = 35）, transplanted with 〉 6 × 10^6 NSCs via left medial hind limb; BMSC （n = 35）, transplanted with 〉 1 × 10^6 BMSCs via left medial hind limb; model group （n = 25）, injected with the same volume of 0.1 mmol/L phosphate buffered saline. MAIN OUTCOME MEASURES： Gliomal growth and size were assessed by nuclear magnetic resonance, and glioma morphological features were observed following hematoxylin-eosin staining and BrdU immunohistochemistry 3 and 4 weeks following transplantation. RESULTS： The average survival of rats in the BMSC, NSC, and model groups was 4.03, 4.28, and 3.88 weeks. At 3 weeks, there was no significant difference in the average glioma diameter between the BMSC and model groups （P 〉 0.05）. However, gliomal diameter was significantly decreased in the NSC group compared with the model group （P 〈 0.05）. At 4 weeks, there was no statistical difference between the groups （P 〉 0.05）. BrdU immunohistochemistry revealed that BMSCs and NSCs appeared to migrate to the gliomas. CONCLUSION： NSCs inhibited glioma cell growth and prolonged rat survival. BMSCs did not significantly suppress glioma cell growth.

Construction of Sox9 Gene Eukaryotic Expression Vector and Its Inductive Effects on Directed Differentiation of Bone Marrow Stromal Cells into Precartilaginous Stem Cells in Rats

Sox9 gene was cloned from immortalized precartilaginous stem cells and its eukaryotic expression vector constructed in order to explore the possibility of bone marrow-derived stromal cells differentiation into precartilaginous stem cells induced by Sox9. A full-length fragment of Sox9 was obtained by RT-PCR, inserted into pGEM-T Easy clone vector, and ligated with pEGFP-IRES2 expression vector by double digestion after sequencing. The compound plasmid was transfected into born marrow-derived stromal cells by Lipofectamine 2000, and the transfection efficacy and the expression of Sox9 and FGFR-3 were observed. Flow cytometry was used to identify the cell phenotype, and MTT was employed to assay proliferative viability of cells. Sequencing, restrictive endonuclease identification and RT-PCR confirmed that the expansion of Sox9 and construction of Sox9 expression vector were successful. After transfection of the recombinant vector into bone marrow-derived stromal cells, the expression of Sox9 and FGFR-3 was detected, and proliferative viability was not different from that of precartilaginous stem cells. It was concluded that Sox9 gene eukaryotic expression vector was successfully constructed, and the transfected bone marrow-derived stromal cells differentiated into the precartilaginous stem cells.

Bone Marrow Stromal Cells Express Neural Phenotypes in vitro and Migrate in Brain After Transplantation in vivo

Objective To investigate the differentiation of bone marrow stromal cells （BMSC） into neuron-like cells and to explore their potential use for neural transplantation. Methods BMSC from rats and adult humans were cultured in serum-containing media. Salvia miltiorrhiza was used to induce human BMSC （hBMSC） to differentiate. BMSC were identified with immunocytochemistry. Semi-quantitative RT-PCR was used to examine mRNA expression of neurofilamentl （NF1）, nestin and neuron-specific enolase （NSE） in rat BMSC （rBMSC）. Rat BMSC labelled by Hoschst33258 were transplanted into striatum of rats to trace migration and distribution. Results rBMSC expressed NSE, NFI and nestin mRNA, and NF1 mRNA and expression was increased with induction of Salvia miltiorrhiza. A small number of hBMSC were stained by anti-nestin, anti-GFAP and anti-S 100. Salvia miltiorrhiza could induce hBMSC to differentiate into neuron-like cells. Some differentiated neuron-like cells, that expressed NSE, beta-tubulin and NF-200, showed typical neuron morphology, but some neuron-like cells also expressed alpha smooth muscle protein, making their neuron identification complicated, rBMSC could migrate and adapted in the host brains after being transplanted. Conclusion Bone marrow stromal cells could express phenotypes of neurons, and Salvia milliorrhiza could induce hBMSC to differentiate into neuron-like cells, If BMSC could be converted into neurons instead of mesenchymal derivatives, they would be an abundant and accessible cellular source to treat a variety of neurological diseases.

Mechanism of in Vitro Differentiation of Bone Marrow Stromal Cells into Neuron-like Cells

Summary: In order to study whether marrow stromal cells (MSCs) can be induced into nerve-like cells in vitro, and the mechanism, the MSCs in Wistar rats were isolated and cultured, and then induced with DMSO and BHA in vitro. The expression of specific marking proteins in neurons, glia and neural stem cells were detected before preinduction, at 24 h of preinduction, at 6 h, 24 h, and 48 h of neuronal induction by using immunohistochemistry and Western blotting. The ultrastructural changes after the inducement were observed. The results showed that after the inducement, many MSCs turned into bipolar, multipolar and taper, and then intersected as network structure. At the same time, some MSCs had the typical neuron-like ultrastructure. Immunohistochemistry revealed that NeuN and Nestin expression was detectable after inducement, but there was no GFAP and CNP expression. Western blotting showed the expression of Nestin was strong at 6 h of neuronal induction, and decreased at 24 h, 48 h of the induction. NeuN was detectable at 6 h of neuronal induction, and increased at 24 h, 48 h of the induction. It was concluded MSCs were induced into neural stem cells, and then differentiated into neuron-like cells in vitro.

Feridex-labeled bone marrow stromal cells for analysis of sciatic nerve defects in rabbits

BACKGROUND： Traumatic approaches, such as sacrifice and perfusion sampling, have been used to evaluate efficiency of stem cell transplantation. However, these methods are not applicable to human studies. Cell tracing, in combination with non-invasive imaging technology, can be utilized to trace cell survival following transplantation to evaluate the efficacy of cell transplantation therapy. OBJECTIVE： To explore feasibility of magnetic resonance imaging （MRI） to observe in vivo repair of injured sciatic nerves following feridex and polylysine （FE-PLL） complex-labeled bone marrow stromal cell （BMSC） transplantation. DESIGN, TIME AND SE＇I-rlNG： A randomized, controlled, animal experiment was performed at the Laboratory of the Department of Neurosurgery, Zhujiang Hospital from March to December 2008. MATERIALS： Feridex was purchased from Advanced Magnetic, USA, and polylysine was purchased from Sigma, USA. METHODS： BMSCs were harvested from adult rabbit femurs and were cultured in vitro with neural stem cell culture medium, leukemia inhibitory factor, and basic fibroblast growth factor. Bone marrow stromal cell-derived neural stem cells （BMSC-D-NSCs） were obtained and labeled with FE-PLL complex. The right sciatic nerve （0.8 mm） was excised from healthy, New Zealand rabbits, aged 1.5 months, and the epineuria of distal stumps underwent turnover and were anastomosed at the proximal ends. FE-PLL labeled BMSC-D-NSC suspension or culture medium was transplanted into the epineunal lumen using a microsyringe. The left sciatic nerve was left intact and sewed as the normal control. MAIN OUTCOME MEASURES： Cellular morphology, proliferation, and differentiation, as well as expression of nestin and neuron-specific enolase （NSE）, of BMSCs-D-NSCs were observed. Efficacy of FE-PLL labeling and effects on cells were measured. In addition, neural regeneration at 2, 8, and 16 weeks following transplantation was observed by MRI. Histopathology and mean number of regenerated nerve fibers in the proximodistal-injured sciatic nerve were evaluated by hematoxylin and eosin and Bielschowsky staining. RESULTS： Results demonstrated that BMSCs expanded, proliferated, and differentiated into neural-like cells with slim, long processes. The cells expressed nestin and NSE, as detected by immunocytochemistry. BMSC-D-NSCs were effectively labeled by FE-PLL, with a labeling efficiency of 98%. In addition, cell viability was not influenced by the FE-PLL complex. MRI results revealed low signals in the FE-labeled BMSC-D-NSC-implanted region of the sciatic nerve. A low-signal region was observed at 2 weeks, which was widely spread at 8-16 weeks after cell transplantation. The regenerated nerve fibers were orderly arranged in the cell transplantation group and exhibited no significant differences compared with the normal control side （P 〉 0.05）. CONCLUSION： BMSCs were successfully cultured in vitro, and the cells proliferated and trans-differentiated into neuronal-like cells, which expressed nestin and NSE. The FE-PLL complex effectively labeled rabbit BMSC-D-NSCs in vitro and did not affect peripheral neural regeneration following cell transplantation. Results demonstrated that MRI could be used to track FE-labeled BMSC-D-NSCs transplanted in the sciatic nerve.

Mesenchymal stem cells: Molecular characteristics and clinical applications

Mesenchymal stem cells (MSCs) are non-hematopoietic stem cells with the capacity to differentiate into tissues of both mesenchymal and non-mesenchymal origin. MSCs can differentiate into osteoblastic, chondrogenic, and adipogenic lineages, although recent studies have demonstrated that MSCs are also able to differentiate into other lineages, including neuronal and cardiomyogenic lineages. Since their original isolation from the bone marrow, MSCs have been successfully harvested from many other tissues. Their ease of isolation and ex vivo expansion combined with their immunoprivileged nature has made these cells popular candidates for stem cell therapies. These cells have the potential to alter disease pathophysiology through many modalities including cytokine secretion, capacity to differentiate along various lineages, immune modulation and direct cell-cell interaction with diseased tissue. Here we first review basic features of MSC biology including MSC characteristics in culture, homing mechanisms, differentiation capabilities and immune modulation. We then highlight some in vivo and clinical evidence supporting the therapeutic roles of MSCs and their uses in orthopedic, autoimmune, and ischemic disorders.

WJSC 6^(th) Anniversary Special Issues(2):Mesenchymal stem cells Mesenchymal stem cells in the treatment of spinal cord injuries:A review

With technological advances in basic research,the intricate mechanism of secondary delayed spinal cord injury(SCI)continues to unravel at a rapid pace.However,despite our deeper understanding of the molecular changes occurring after initial insult to the spinal cord,the cure for paralysis remains elusive.Current treatment of SCI is limited to early administration of high dose steroids to mitigate the harmful effect of cord edema that occurs after SCI and to reduce the cascade of secondary delayed SCI.R ecent evident-based clinical studies have cast doubt on the clinical benefit of steroids in SCI and intense focus on stem cell-based therapy has yielded some encouraging results.An array of mesenchymal stem cells(MSCs)from various sources with novel and promising strategies are being developed to improve function after SCI.In this review,we briefly discuss the pathophysiology of spinal cord injuries and characteristics and the potential sources of MSCs that can be used in the treatment of SCI.We will discuss the progress of MSCs application in research,focusing on the neuroprotective properties of MSCs.Finally,we will discuss the results from preclinical and clinical trials involving stem cell-based therapy in SCI.

Characterization of mouse clonal mesenchymal stem cell lines established by subfractionation culturing method

AIM:To characterize single-cell-derived mouse clonal mesenchymal stem cells (mcMSCs) established with bone marrow samples from three different mouse strains. METHODS:We established mcMSC lines using subfractionation culturing method from bone marrow samples obtained from long bones.These lines were characterized by measuring cell growth, cell surface epitopes, differentiation potential, lineage-specific gene expression and T-cell suppression capability. Nonclonal MSCs isolated by the conventional gradient centrifugation method were used as controls. RESULTS:All mcMSC lines showed typical nonclonal MSC-like spindle shape morphology. Lines differed inoptimal growth density requirement.Cell surface epitope prof iles of these mcMSC lines were similar to those of nonclonal MSCs. However, some lines exhibited different expression levels in a few epitopes, such as CD44 and CD105. Differentiation assays showed that 90% of the mcMSC lines were capable of differentiating into adipogenic and/or chondrogenic lineages, but only 20% showed osteogenic lineage differentiation. T-cell suppression analysis showed that 75% of the lines exhibited T-cell suppression capability. CONCLUSION:mcMSC lines have similar cell morphology and cell growth rate but exhibit variations in their cell surface epitopes, differentiation potential, lineage-specifi c gene expression and T-cell suppression capability.

兔肩袖腱骨愈合过程中基质细胞衍生因子1的表达及作用机制

背景:近年在腱骨损伤领域部分学者将基质细胞衍生因子1搭载在组织工程支架上用以促进腱骨愈合,取得了较好的成效,但在基质细胞衍生因子1促进腱骨愈合机制及自然愈合过程中其是否参与修复,目前尚未明确。目的:研究兔肩袖全层冈上肌断裂后腱骨愈合过程中基质细胞衍生因子1表达,及其在腱骨损伤时对干细胞的迁移作用和最佳体外促迁移浓度。方法:随机取成年新西兰大白兔18只建立肩袖损伤模型,另取3只为空白对照。于造模后3,5,7,14,21,28 d各处死3只并处死空白组兔,取腱骨连接处组织保存在-80℃冰箱。应用ELISA反应检测损伤后各时间点愈合处基质细胞衍生因子1表达。取幼兔股骨骨髓间充质干细胞分离培养鉴定,通过transwell实验验证基质细胞衍生因子1对干细胞的促迁移作用效果及体外促迁移最佳浓度,将培养到P3代的干细胞与Brdu共培养后注入兔耳缘静脉,通过免疫组化染色验证干细胞是否迁移至损伤处。结果与结论:①基质细胞衍生因子1在肩袖腱骨愈合过程呈双峰表达,于伤后3 d明显增高(P<0.01)随后下降,于伤后5 d达最低,后再次升高于伤后14 d达峰值(P<0.01),然后下降;②细胞免疫组化染色可见标记有Brdu的干细胞确有迁移至损伤处;③transwell实验结果表明60-80 ng/mL的基质细胞衍生因子1对干细胞促迁移效果最好,而200 ng/mL浓度反而会起到抑制迁移作用;④基质细胞衍生因子1参与了肩袖腱骨愈合的炎症反应期和增殖期的愈合过程,其作用机制可能为通过促进干细胞迁移至损伤处并分化为各类细胞促进修复,并且基质细胞衍生因子1的促迁移作用存在于一定浓度范围,超出范围则可能起到抑制作用。

初级纤毛/鞭毛转运系统介导力学反应性信号通路促骨髓基质干细胞成骨分化

背景:目前已证实力学刺激可以促进骨髓基质干细胞成骨分化,但其机制未完全明了。初级纤毛是重要的力学感受器并调控TGF-β1/BMP-2/SMAD等多种信号通路,很可能是骨髓基质干细胞力学调控的重要靶点。目的:探讨流体剪切力对骨髓基质干细胞成骨分化的影响及机制。方法:将大鼠骨髓基质干细胞分为对照组、力学刺激组(通过摇床施加流体剪切力学干预)、力学刺激+IFT88沉默组(力学刺激+使用siRNA沉默IFT88表达),干预24 h后,采用qRT-PCR检测转化生长因子β1、骨形成蛋白2的表达、Western blot检测磷酸化SMAD2/3蛋白的表达,初级纤毛免疫荧光染色及形态学分析。结果与结论:剪切力刺激可促进骨髓基质干细胞的初级纤毛表达,转化生长因子β1及骨形成蛋白2基因转录激活,提高磷酸化SMAD2/3蛋白表达。siRNA干扰初级纤毛生成后,这一力学反应效应明显减低。骨髓基质干细胞的初级纤毛面积改变比值与转化生长因子β1及骨形成蛋白2基因转录增高比例具有Spearman相关性。结果表明:初级纤毛/鞭毛转运系统介导了流体剪切力反应性的TGF-β1/BMP-2/SMAD信号通路激活,促进骨髓基质干细胞成骨分化。

SDF-1对骨髓间充质干细胞迁移和细胞外基质形成的影响

目的探讨基质细胞衍生因子(stromal cell-derived factor-1,SDF-1)对大鼠骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMSCs)迁移、胶原RNA表达及细胞膜片细胞外基质表达的影响。方法CCK-8和Transwell细胞迁移实验观察SDF-1对BMSCs增殖和迁移的影响;实时荧光定量PCR检测BMSCs胶原RNA的表达水平;蛋白质印迹法检测BMSCs细胞膜片胶原蛋白的表达水平;酶联免疫吸附试验检测BMSCs细胞膜片培养基上清透明质酸(HA)的表达水平。结果SDF-1趋化BMSCs迁移作用的强度与浓度相关,对细胞的增殖无明显影响;SDF-1降低BMSCsⅠ型胶原与Ⅲ型胶原RNA和蛋白相对表达量的比值,并显著升高BMSCs细胞膜片透明质酸表达水平(P<0.05)。结论SDF-1在适宜的浓度范围内,可显著促进BMSCs的迁移,降低Ⅰ型胶原与Ⅲ型胶原RNA和蛋白相对表达量的比值,并可提高透明质酸的表达水平。

蛇床子素对体外培养骨髓基质干细胞增殖与成骨性分化的影响

目的研究蛇床子素对体外培养大鼠骨髓基质干细胞(bone marrow stromal stem cells,BMSCs)增殖与成骨性分化的影响。方法取大鼠股骨及胫骨全骨髓,利用全骨髓培养法培养单核层细胞,培养于含10%FBS的DMEM-F12培养液中,3d后首次换液,9d后传代培养。培养基中蛇床子素终浓度分别为1×10-4、1×10-5、1×10-6、1×10-7mol·L-1。增殖分析采用MTT法,于成骨性诱导培养d4、8、12、16测碱性磷酸酶(alkaline phosphatase,ALP)活性、钙盐沉积量、骨钙素分泌量,d15进行钙化结节组织化学染色及计数。成骨性诱导后不同时间点提取Total RNA,RTReal-Time PCR法检测bFGF、IGF-1、Osterix与Runx-2的基因表达情况。结果蛇床子素剂量依赖性抑制BMSCs增殖,但能明显促进其向成骨性分化,表现为提高BMSCs的ALP活性、促进骨钙素分泌、钙盐沉积量、增加钙化结节数量、提高bFGF、IGF-1、Osterix和Runx-2的mRNA表达水平。结论终浓度为1×10-5mol·L-1蛇床子素能明显促进BMSCs的成骨性分化,证明蛇床子素是中药蛇床子抗骨质疏松的有效成分。

骨髓间充质干细胞向神经细胞定向分化的体外研究

目的 探讨骨髓间充质干细胞( marrow stromal stem cells,MSCs)向神经细胞定向分化中神经蛋白分子的表达情况。 方法 取第5～7代体外培养Wistar大鼠MSCs,以0 .5μmol/ L全反式视黄酸( all- trans retinoidacid,ATRA)预诱导2 4 h后,换用改良神经细胞培养基( modified neuronal medium,MNM)继续培养。在ATRA作用2 4 h及MNM作用2、6、9、18及36 h,免疫组织化学检测巢蛋白( Nestin)、神经元特异性核心抗原( neuron- specificnuclear protein,Neu N)、微管相关蛋白2 ( microtubule- associated protein 2 ,MAP- 2 )和胶质纤维酸性蛋白的表达情况。 结果 ATRA和MNM作用后,MSCs呈典型神经元样,伸出较多的突起和分支,形成网络。Nestin最先表达,ATRA作用2 4 h出现,Neu N其次,MNM作用2 h检测到,MAP- 2最晚,MNM作用9h检测到。Nestin在MNM作用18h后表达最强,其阳性率为92 .3%±3.4 % ;36 h后表达明显减弱,阳性率仅为12 .3%±3.4 % ,而其它标志蛋白则持续表达。 结论 ATRA和MNM能促进MSCs向神经前体细胞和神经元转化,神经蛋白分子的表达顺序与神经细胞发育过程一致。

脂肪干细胞向软骨细胞方向诱导的初步研究

目的 :研究脂肪干细胞的分离及向软骨方向定向诱导的方法。方法 :从成年兔颈后部或腹股沟处脂肪组织取材 ,酶消化法分离、培养脂肪干细胞 ;免疫荧光测定CD3 4 抗原的表达 ;流式细胞仪测定CD3 4 抗原百分比 ;分别用15 %牛血清、少血清 (5 % )及无血清诱导培养基定向软骨细胞方向诱导 ;组化及免疫组化鉴定软骨细胞特性。结果 :从兔脂肪组织中能分离出生长旺盛的干细胞 ,CD3 4 抗原表达阳性 ,表达百分比与骨髓干细胞无明显差异 ;定向诱导后表现出软骨细胞的特性 ,诱导效果无血清诱导培养基效果最好。结论 :从兔脂肪组织中能分离出干细胞 ;生物学特性与骨髓干细胞相似 ;能向软骨细胞方向诱导 ;无血清诱导培养基效果最好。

骨髓基质干细胞与生物衍生骨复合修复山羊胫骨缺损的研究

目的 探讨骨髓基质干细胞 (marrow stromal stem cells,MSCs)与生物衍生骨复合修复山羊胫骨的长段骨 -骨膜缺损的可行性。 方法 将 12月龄山羊 35只双侧胫骨制备成中段 2 0 mm的骨 -骨膜缺损 ,其中 33只 ,将MSCs与生物衍生骨于体外复合培养后 ,将其植入右侧缺损处 ,常规钢板螺钉内固定作为实验组 ,以单纯生物衍生骨植入左侧作为对照组 ,另 2只为空白组不植入任何材料 ,在 2、4、6、8、12、16及 2 4周各时间点分别行大体标本、组织学观察 ,以及生物力学测试 ,比较 3组骨缺损修复的能力。 结果 4周时实验组支架材料部分吸收 ,植入物表面有纤维骨痂形成 ,对照组支架材料少量吸收 ,植入物表面有少量骨样组织形成 ;8周时 ,大体标本、组织学观察 ,实验组中的支架材料已完全降解 ,骨缺损部分修复 ,对照组中植入物两端少量新骨形成 ,材料中为纤维骨样组织 ,但 8周时 ,实验组与对照组的生物力学强度差异无统计学意义 (P>0 .0 5 ) ;12周时 ,实验组骨缺损完全修复 ,对照组植入物两端有新骨包绕 ,与骨端连接紧密。 12～ 2 4周实验组弯曲应力大于对照组有统计学意义 (P<0 .0 5 ) ;2 4周时空白组骨缺损未修复。 结论 所构建的组织工程骨修复能力较强 ,成骨迅速 ,且量大 。

淫羊藿苷对体外培养成人骨髓基质干细胞增殖与成骨性分化的影响

目的研究淫羊藿苷对体外培养成人骨髓基质干细胞(human bone marrow stromal stem cells,hBMSCs)增殖与成骨性分化的影响。方法取住院患者术后骨髓标本(男,40岁),利用骨髓细胞处理试剂盒分离单核层细胞,培养于含10%FBS的DMEM培养液中,3d后首次换液,12d后传代培养。培养基中淫羊藿苷终浓度分别为5×10-5、1×10-5、5×10-6、1×10-6、5×10-7、1×10-7mol/L。增殖分析采用MTT法,于成骨性诱导培养第8d测碱性磷酸酶(alkaline phosphatase,ALP)活性,第14d进行茜素红染色及钙化结节计数。结果原代培养细胞呈典型成纤维细胞样形态;淫羊藿苷剂量依赖性抑制hBMSCs增殖,但能显著促进其向成骨性分化,表现为提高hBMSCs的ALP活性,增加钙化结节数量。结论终浓度为5×10-5mol/L淫羊藿苷显著促进hBMSCs的成骨性分化,证明淫羊藿苷是中药淫羊藿抗骨质疏松的有效成分。

恒河猴骨髓基质细胞体外诱导分化成神经干细胞的实验研究

为研究恒河猴骨髓基质细胞 (BMSC)体外培养及诱导分化为神经干细胞的可行性 ,分离恒河猴BMSC ,在体外应用神经干细胞培养液和细胞因子进行诱导分化 ,利用免疫细胞化学方法进行鉴定。结果发现 ,恒河猴BMSC能在体外培养中增殖、分化和表达干细胞特异性抗原神经巢蛋白 (Nestin) ,并最终能分化为胶质细胞样细胞和神经元样细胞 ;免疫细胞化学检测可见有神经元特异性烯醇化酶(NSE)和胶质原性纤维酸性蛋白 (GFAP)抗原表达 ;未发现维甲酸 (RA)、表皮生长因子 (EGF)和碱性成纤维细胞生长因子 (bFGF)对骨髓基质干细胞的诱导分化具有明显影响作用。提示恒河猴BMSC是具有较强的自我更新能力和多分化潜能的细胞 ,在一定条件下 ,可分化为表达神经系细胞 (神经元和神经胶质细胞)抗原的细胞 ,可作为神经细胞的种子细胞。