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.     

人脐带间充质干细胞的生物学特性及向软骨细胞、骨细胞分化实验研究

目的 研究人脐带华尔通胶来源间充质干细胞的特性及向软骨细胞、骨细胞的分化能力,为椎间盘再生研究寻找新的细胞来源.方法 取人的正常分娩或剖腹产胎儿的脐带,酶消化法从Wharton胶中分离干细胞,应用复合胶原酶NB4、dispaseⅡ和透明质酸的组合混合酶消化,检测人脐带来源的MSCs的细胞表面标记;分别应用成软骨诱导液、成骨诱导液诱导人脐带来源的MSCs向软骨细胞、骨细胞分化.用免疫细胞化学方法对分化和未分化的细胞进行鉴定.结果 人脐带分离培养的贴壁细胞,体外生长形态类似于成纤维细胞,可以维持在未分化状态稳定增殖,这类细胞MSCs的表面标记CD44、CD105、CD90和D73呈现高表达,而不表达CD45、CD34、CD14、CD19及HLA-DR.向软骨细胞、骨细胞诱导结果提示P3代细胞有向终末软骨细胞、骨细胞分化能力,具有干细胞的特性.结论 人脐带华尔通胶含有丰富的MSCs,易于培养扩增.人脐带来源的MSCs能分化为软骨细胞、骨细胞,这类细胞可能成为椎间盘移植的一个干细胞来源.

Abstract：

Objective To investigate the isolation and expansion of mesenchymal stem cells (MSCS) from human umibilical cord Wharton's jelly and their biological identities , and explore the possibility of inducing human umbilical cord-derived MSCS to differentiate into chondrogenic and osteogenic cells. Methods The hUCMSCs were isolated form human umbilical cord by tissue adherence and digested with collagenaseNB4, dispase Ⅱ and hyaluronidase. The morphology, proliferation and immunophenotype of the 3rd passage cells were analyzed, and then the chondrogenic and osteogenic differentiation was tested and evaluated by specific staining methods. cells were induced to chondrogenic and osteogenic differentiation in vitro. Results The isolation of hUCMSCs by digestion with collagenaseNB4, dispase Ⅱ and hyaluronidase was efficient. After seeded for 24 hours, the adherent cells showed spindle shape and fibroblast cell-like shape and the size of hUCMSCs was homogeneous. Flow cytometry analysis revealed that the hUCMSCs were positive for CD44,CD105, CD90, CD73, but were negative for CD45, CD34, CD14, CD19 and HLA-DR.These cells could be induced to differentiate into chondrogenic and osteogenic cells under proper inducing conditions. The hUCMSCs retained the appearance and phenotype even after being expanded more than 40 passages in vitro. Conclusions The human MSCs could be isolated from human umbilical cord Wharton's jelly ,and it was easy to propagate these MSCs. An in vitro method for isolation and purification of hUCMSCs from human umbilical cord has been established. The cultured cells were composed of only undifferentiated cells and their biological properties were stable. The hUCMSCs are expected to be a new type of stem cells of tissue engineering.     

Targeted induction of differentiation of human bone mesenchymal stem cells into neuron-like cells

A systematic method of isolating and culturing human bone mesenchymal stem cells （hMSCs）, and inducing them to differentiate into neuron-like cells in vitro was established. The hMSCs were isolated from bone marrow with the lymphocyte-separating medium, cultured and expanded in vitro, and induced after addition of compound neuro-revulsants. The morphological changes of hMSCs were observed, and the expression of surface markers in induced hMSCs was immunocytochemically identified during induction period. The hMSCs could be separated, cultured and expanded in vitro. After induction by compound neuro-revulsants for 48 h, the changes of neuron-like cells, such as cellular shrinkage and neurite growth, were observed in some cells. The immunochemical staining revealed nestin （＋） or NF （＋）, and GFAP （-）. It was concluded that hMSCs were successfully cultured and induced to differentiate into neuron-like cells.     

Effects of Co-grafts Mesenchymal Suspension in the Repair of Spinal Stem Cells and Nerve Growth Factor Cord Injury

To investigate effect of the transplantation of mesenchymal stem cells （MSCs） in combination with nerve growth factor （NGF） on the repair of spinal cord injury （SCI） in adult rats, spinal cord of adult rats （n= 32） was injured by using the modified Allen＇ s method. One week after the injury, the injured cords were injected with Dubeeeo-modified Eagles medium （DMEM , Group Ⅰ ）, MSCs （Group Ⅱ ）, NGF （Group Ⅲ）, and MSCs plus NGF （Group Ⅳ）. One month and two months after the injury, rats were sacrificed and their injured cord tissues were sectioned for the identification of the transplanted cells. The axonal regeneration and the differentiation of MSCs were examined by immunoeytoehemieal staining. At the same time, rats were subjected to behavioral tests by using the open-field BBB scoring system. Immunoeytoehemieal staining showed that axonal regeneration and the transplanted cells partially expressed neuron-specific nuclear protein （NeuN） and glial fibrillary acidic protein （GFAP）. At the same time, significant improvement in BBB locomotor rating scale （P〈0. 05） were observed in the treatment group. More importantly, further functional improvement were noted in the combined treatment group. MSCs could differentiate into neurons and astroeytes. MSCs and NGF can promote axonal regeneration and improve functional recovery. There might exist a synergistic effect between MSCs and NGF.     

Conversion of mononuclear cells from human umbilical cord blood into hepatocyte-like cells

Objective: To evaluate the differentiation of human umbilical cord blood cells into hepatocyte-like cells. Methods: Mononuclear cells (MNCs) derived from human umbilical cord blood were isolated using Ficoll. The experiment was derived into 3 categories:(1) MNCs co-cultured with 50 mg minced liver tissue separated by a trans-well membrane and then collected at 0 h,24 h,48 h and 72 h; (2) MNCs cultured along supplemented with 100 ml/L FBS. 100μ/ml penicillin, 100μg/ml streptomycin. 4. 7μg/ml linoleic acid, 1×ITS, 10-4 mol/L L-Ascorbic acid 2-P and a combination of FGF4 (100 ng/ml) and HGF (20 ng/mL). Cells were then collected at 0 d and 16 d to examine the expression profile of hepatocyte correlating markers;(3) 0. 2-0. 3 ml of MNCs with a cell density of 2×107/ml were transplanted into prepared recipient mice [n = 12, injected with 0. 4 ml/kg (20%) CCl4 and 150 ng/kg 5-fluorouracil (5-Fu) prior the transplant 24 h and 48 h, respectively] via injection through tail vein. Mice were sacrificed 4 weeks after transplantation. The hepatocyte correlating mRNAs and proteins were determined by RT-PCR, immunohistochemical analysis and immunoflurence technique. Results: (1) After 72 h. a number of glycogen positive stained cells were observed with MNCs co-cultured with damaged mouse liver tissues. The expression of hepatocyte markers, human albumin (ALB),α-fetal protein (AFP) and human GATA4 mRNA and proteins were detected by RT-PCR and immunohistochemistry as well. For the confirmation, the DNA sequencing of PCR products was performed. In control groups, MNCs co-cultured with normal mouse hepatocytes or MNCs cultured alone, all markers remained negative. (2) In growth factor supplemented culture system, MNCs developed into larger volume with richer cytoplasm and binucleation after 16 d. Positive expression of ALB, AFP, CK18 and CK19 mRNA were detected with RT-PCR, and ALB positive staining was observed by immunocytochemistry as well. In contrast. MNCs cultured without exogenous growth factors scarcely attached to the culture dish and ALB mRNA was not detected. (3) In transplantation experiment, both of ALB and AFP mRNA were detected by RT-PCR and HSA, PCNA and ALB positive staining were observed in the livers of recipient mice by immunocytochemistry. Conclusion: MNCs from human umbilical cord blood could convert into hepatocyte-like cells in 3 different ways, indicating their potential use in the clinic applications for the treatment of human liver diseases.     

Human umbilical cord-derived endothelial progenitor cells promote growth cytokines-mediated neorevascularization in rat myocardial infarction

Background Cell-based vascular therapies of endothelial progenitor cells （EPCs） mediated neovascularization is still a novel but promising approach for the treatment of ischemic disease. The present study was designed to investigate the therapeutic potentials of human umbilical cord blood-derived EPCs （hUCB-EPCs） in rat with acute myocardial infarction. Methods Human umbilical cord blood （hUCB） mononuclear cells were isolated using density gradient centrifugation from the fresh human umbilical cord in healthy delivery woman, and cultured in M199 medium for 7 days. The EPCs were identified by double-positive staining with 1,1＇-dioctadecyl-3,3,3＇,3＇-tetramethylindocarbocyanine percholorate-labeled acetylated low-density lipoprotein （DiI-Ac-LDL） and fluorescein isothiocyanate-conjugated Ulex europaeus lectin （FITC-UEA-I）. The rat acute myocardial infarction model was established by the ligation of the left anterior descending artery. The hUCB-EPCs were intramyocardially injected into the peri-infarct area. Four weeks later, left ventricular function was assessed by a pressure-volume catheter. The average capillary density （CAD） was evaluated by anti-VIII immunohistochemistry staining to reflect the development of neovascularization at the peri-infarct area. The graft cells were identified by double immunofluorescence staining with human nuclear antigen （HNA） and CD31 antibody, representing human origin of EPCs and vascular endothelium, respectively. Expressions of cytokines, proliferating cell nuclear angigen （PCNA）, platelet endothelial cell adhesion molecule （PECAM） and vascular endothelial growth factor （VEGF） were detected to investigate the underlying mechanisms of cell differentiation and revascularization. Results The donor EPCs were detectable and integrated into the host myocardium as confirmed by double-positive immunofluorescence staining with HNA and CD31. And the anti-VIII staining demonstrated a higher degree of microvessel formation in EPCs transplanted rats, associated with a significant improvement of global heart function in terms of the increase of left ventricular end-systolic pressure （LVESP）, ＋dp/dtmax and -dp/dtmax as well as the decrease of LVEDP in rats with EPCs therapy comparing to the control rats （P〈0.05）. Moreover, the expression of the rat PCNA mRNA and PECAM were both enhanced in the EPCs group compared with that of the control group. Conclusions The human umbilical cord blood-derived EPCs could incorporate into new-born capillaries in rat myocardium, induce revascularization and improve the proliferation activity in the peri-infarct area, resulting in the improvement of global heart function. This may indicate a promising stem cell resource in cell-based therapy for ischaemic diseases.     

Experimental study on MyoD gene induced differentiation of bone marrow mesenchymal stem cells into myoblasts in vitor

Objective:To explore the possibility of the transfection of MyoD gene induced bone marrow mesenchymal stem cells(MSCs) to differentiate into myoblasts in vitro.Methods:The eukaryotic expression plasmid vector pIRES2-EGRP-MyoD was transfected into MSCs with lipotransfection method,and the positive cells were selected by G418;The expression of MyoD was detected in the transfected MSCs with RT-PCR and the amplified,purified product was identified by sequencing;The reporter gene enhanced green fluorescence protein(EGFP)was observed in the transfected cells under a fluorescent and a laser confocal microscopes;Immunohistochemical methods was used to examine the expressions of MyoD,myogenin,myosin,myoglobin and desmin in the differentiated,cells.The ultrastructure changes of the cells before and after transfection were observed with electron microscopy.Results:The expression of MyoD was detected in the transfected MSCs with RT-PCR and the amplified,purified product was as same in sequence as thwat from Genbank;Green fluorescence was observed in the transfected cells under a fluorescent and a laser confocal microscopes;Immunohistochemical methods indicated that MyoD,myogenin,myosin,myoglobin and desmin were expressed in the transfected cells;The transfected cells showed the morphologcal characteristics of matrue cells with filaments in their cytoplasm.Conclusion:MyoD gene can induce cultured MSCs to successfully differentiate into myoblasts,probably providing an experimental foundation for trauma repair.     

人脐带间充质干细胞向心肌细胞诱导分化并体内移植的研究

目的探讨人脐带间充质干细胞(MSCs)经5-氮杂胞苷(5aza)诱导后能否向心肌样细胞分化及诱导后细胞移植到心肌梗死大鼠心脏后能否存活,为心肌细胞的移植探索新的细胞来源。方法从人脐带华尔通氏胶培养出MSCs,检测人脐带来源的MSCs的细胞表面标记。经5aza诱导,采用免疫组化方法及RT-PCR方法检测诱导后细胞能否表达心肌细胞标记物,诱导后细胞经5-溴-2-脱氧尿苷(BrdU)标记后移植到梗死心肌,观察移植后细胞能否存活。结果人脐带间充质干细胞经5aza诱导后能表达心肌细胞标记物,诱导后细胞移植到心肌梗死模型大鼠心肌后细胞能存活。结论人脐带间充质干细胞经5aza诱导能向心肌样细胞分化,诱导后细胞移植至体内能存活,人脐带间充质干细胞可以作为心肌细胞移植的来源。     

人脐带来源的基质细胞分化为神经细胞

目的探索人脐带组织来源的基质细胞向神经细胞分化的可能性,为神经移植探寻新的细胞来源。方法采用组织块培养法培养人脐带基质细胞,酶消化法对细胞进行传代,应用免疫细胞化学的方法对细胞进行鉴定。结果从脐带组织成功培养出基质细胞,这种细胞可以随机分化为平滑肌细胞,表达平滑肌肌动蛋白;丹参注射液诱导基质细胞向神经细胞分化,分化的神经元样细胞具有典型的神经细胞的形态,早期表达巢蛋白、β-管蛋白和神经元特异性烯醇化酶,后期表达神经微丝200;在合适的诱导条件下,分化的神经元样细胞的比例在90％左右,分化的细胞中星型胶质细胞的比例在1％左右,无髓鞘基础蛋白的表达,说明无少突胶质细胞产生。结论脐带组织来源的基质细胞可以表达神经细胞的标志物,在体外能够分化为形态复杂的神经元样细胞,这种细胞有可能成为神经移植的种子细胞。     

当归对人脐血间充质干细胞增殖的影响

目的:探讨当归对人脐血间充质干细胞(mesenchymal stem cells,MSCs)增殖的影响及当归诱导后脐血间充质干细胞nestin变化情况。方法:无菌条件下收集新生儿脐血,以Ficoll-Hypaque淋巴细胞分离液密度梯度法分离单个核细胞(mononuclear cells,MNCs)。分离获得的MNCs采用DMEM/F12培养基/10%胎牛血清进行MNCs培养传代。向培养基内加入1μl/ml当归注射液,分为两组,阳性对照组为加当归注射液,阴性对照组不加当归注射液,进行台盼兰染色活细胞计数,以平均数为结果分别绘制两组的细胞生长曲线。对人脐血间充质干细胞进行神经标志物nestin的免疫组化检查。结果:阳性对照组脐血MSCs细胞生长曲线比阴性对照组高,在体外应用当归诱导后表达nestin。结论:当归注射液有促进脐血MSCs分化增值的作用,脐血MSC具有较强的可朔性,当归在体外使脐血间充质干细胞nestin表达增高。     

OECs无血清上清液体外诱导UB-MSCs向神经细胞分化

目的:观察大鼠嗅鞘细胞无血清上清液诱导脐血间充质干细胞向神经细胞分化的作用。方法:采用差速贴壁联合阿糖胞苷抑制法获得较高纯度的嗅鞘细胞,在最佳状态细胞无血清培养后取上清液。收集正常足月剖腹产胎儿的脐带血,经肝素抗凝,用淋巴细胞分离液分离脐血的单个核细胞,采用差速贴壁法纯化间充质干细胞,传第三代后用上述收集的嗅鞘细胞无血清上清液诱导,观察诱导分化过程,免疫组化鉴定分化结果。结果:用差速贴壁和阿糖胞苷抑制法可获得纯度高达95%的嗅鞘细胞,使用无血清嗅鞘细胞上清液培养脐血间充质干细胞后,发现能诱导脐血间充质干细胞向神经细胞形态分化,胞体呈椭圆形,伸出长突起。诱导7天后相差显微镜下可观察到神经干细胞、神经元和胶质细胞形态的细胞,与NSE、GFAP细胞免疫组化结果一致。结论:大鼠嗅鞘细胞无血清上清液有明显诱导脐血间充质干细胞分化为神经细胞的作用。     

Differentiation of mesenchymal stem cells into dopaminergic neuron-like cells in vitro

INTRODUCTION The therapy of Parkinson’s disease is difficult, sopeople have been exploring more effective methods.Drugs can only treat symptoms of the diseases, andbrain tissue transplantation has been the most prosp-ective way, but the sources of transplantation cells needto be explored. The people have a new viewpoint ofthe central nervous system (CNS) regeneration andthe therapy of CNS diseases[1,2] because of the recentdiscovery of stem cell populations in CNS. But adultneura…     

筛选后的巢蛋白阳性细胞流式鉴定及诱导分化

目的观察胎儿胰腺来源的巢蛋白阳性细胞(符合医学伦理学)是否具有与间充质干细胞类似的表面标志以及多向分化的潜能.方法从胎儿胰腺中分离的巢蛋白阳性细胞筛选后进行扩增,用流式细胞仪分析表面标志,并探讨这类细胞的成脂和成骨的分化潜能.结果筛选纯化后的巢蛋白阳性细胞的表面标志与骨髓间充质干细胞表面标志相似:此类细胞可在体外诱导为脂肪细胞或骨细胞.结论筛选纯化的胎儿胰腺来源的巢蛋白阳性细胞具有一定间充质干细胞的特性.     

脐血单个核细胞体外分离和定向分化为神经干细胞的实验研究

目的 探讨人脐血单个核细胞的分离培养和诱导后神经干细胞(NSCs)标志物mRNA的表达.方法 使用密度梯度离心法得到脐血单个核细胞,用体外贴壁生长的方法获得脐血间质干细胞(MSCs),观察培养过程中脐血MSCs形态的变化,通过流式细胞仪检测干细胞表面抗原的表达,使用NGF和RA联合诱导后,用RT-PCR方法鉴定诱导前后NSCs标志物巢蛋白(nestin)及Musashi-1蛋白mRNA的表达.结果 脐血单个核细胞贴壁生长后大部分细胞呈梭形,诱导后可分化为神经元样细胞.流式细胞仪检测该细胞不表达CD34、CD11a、CD11b和强表达CD29,符合MSCs特征.诱导后,NSCs表面标志Nestin及Musashi-1表达明显增强,48h达高峰,然后逐渐减弱.结论 脐血中存在间质干细胞,分离后可以体外扩增,诱导后分化为神经元样细胞,并表达NSCs表面标志.脐血能够成为NSCs的新来源.     

体外诱导人脐血单个核细胞向肝细胞样细胞的分化

目的:探讨人脐血单个核细胞（MNC）能否在体外诱导分化为肝细胞样细胞。方法:采集正常产妇脐血,淋巴细胞分离液分离MNC,流式细胞仪检测其表面标志。分别用肝细胞生长因子(HGF)、成纤维细胞生长因子-4(FGF4)、HGF+FGF4、无生长因子4种处理因素 进行诱导培养,于诱导前及诱导后的第7、14、21、28天采用RT-PCR检测AFP、白蛋白及C-met、FGFR₂ mRNA的表达,免疫细胞化学法检测肝细胞抗原和CK18的表达,PAS 法进行糖原染色。结果:诱导前检测到C-met、FGFR₂ mRNA的表达,诱导后第7和21天分别检测出AFP和白蛋白mRNA的表达,第28天检测出CK18、肝细胞抗原的表达及糖原染色阳性细胞,无生长因子诱导组未检测到肝系细胞标志。HGF+FGF4诱导组肝系细胞标志阳性率均高 于单独生长因子诱导组(P<0.05)。结论：HGF、FGF4均能在体外诱导人脐血MNC分化为肝细胞样细胞,且二者在一定程度上有联合作用。