Biological Characteristics of Human Bone Marrow Mesenchymal Stem Cell Cultured in Vitro

Some biological characteristics of human bone marrow mesenchymal stem cells (MSCs) cultured in vitro were observed, hMSCs were isolated from bone marrow and purified by density gradient eentrifugation method, and then cultured in vitro. The proliferation and growth characteristics of hMSCs were observed in primary and passage culture. MSCs of passage 3 were examined for the purify by positive rate of CD29 and CD44 through flow eytometry. Human bone marrow MSCs showed active proliferation capacity in vitro. The purify of MSCs separated by our method was higher than 90%. It was concluded that hMSCs have been successfully cultured and expanded effectively. It provided a foundation for further investigation and application of MSCs。     

In vitro Culture of Bone Marrow Mesenchymal Stem Cells in Rats and Differentiation into Retinal Neural-like Cells

In order to study the in vitro culture and expansion of bone marrow mesenchymal stem cells in rats(rMSCs) and the possibility of rMSCs differentiation into retinal neural cells,the bone marrow-derived cells in SD rats were isolated and cultured in vitro.The retinal neural cells in SD rats were cultured and the supernatants were collected to prepare conditioned medium.The cultured rMSCs were induced to differentiate by two steps.Immunofluorescence method and anti-nestin,anti-NeuN,anti-GFAP and anti-Thy1.1 antibodies were used to identify the cells derived from the rMSCs.The results showed that the in vitro cultured rMSCs grew well and expanded quickly.After induction with two conditioned media,rMSCs was induced to differentiate into neural progenitor cells,then into retinal neural-like cells which were positive for nestin,NeuN,GFAP and Thy1.1 detected by fluorescence method.The findings suggested that rMSCs could be culture and expanded in vitro,and induced to differentiate into retinal neural-like cells.     

Effect of Electromagnetic Fields on Proliferation and Differentiation of Cultured Mouse Bone Marrow Mesenchymal Stem Cells

Previous clinical observations and animal ex periments showed that EMFs could stimulate newbone formation of the fractures and increase thebone mineral density[1], but the manner in whichEMFs influence the behavior of bone remains poor ly understood. Recent studies[2] found that signaltransduction system plays an important role in thebiological effect of EMFs. Intracellular cAMP wasan important second messenger in signal transduc tion pathway. The cellular proliferation …     

Biocompatibility Studies on Fibrin Glue Cultured with Bone Marrow Mesenchymal Stem Cells in Vitro

By culturing bone marrow mesenchymal stem cells of rabbits with fibrin glue in vitro,the biocompatibility of fibrin glue was investigated to study whether this material can be used as scaffolds in bone tissue engineering. After 2-months old New Zealand rabbits had been anesthetized, about 4--6 ml of bone marrow were aspirated from rabbit femoral trochanter. The monocytes suspension was aspirated after bone marrow was centrifuged with lymphocyte separating medium and cultured primarily. Then the cells were divided into two groups: one was cultured with complete medium and the other with induced medium. The cells of the two groups were collected and inoculated to the culture plate containing fibrin glue. In the control group, cells were inoculated without fibrin glue. The implanted cells and materials were observed at different stages under a phase-contrast microscope and scanning electron microscope. MTT and alkaline phosphatase (ALP) were measured. Bone marrow mesenchymal stem cells grew on the surface of fibrin glue and adhered to it gradually. Cells light absorption value (A value) and the ALP content showed no significant difference. Fibrin glue had no inhibitory effect on cell morphology, growth, proliferation and differentiation. It has good biocompatibility and can be used as scaffold materials for bone marrow mesenchvmal stem cells in bone tissue engineering.     

Wild-type Smad3 Gene Enhances the Osteoblastic Differentiation of Rat Bone Marrow-derived Mesenchymal Stem Cells in Vitro

This study examined the effect of wild-type Smad3 gene on the osteoblastic differentiation of rat bone marrow-derived mesenchymal stem cells in vitro. Bone marrow-derived mesenchymal stem cells （MSCs） were stably transfected with the complexes of PeDNA3.0-Myc-Smad3 or PeDNA3.0- Mye-Smad3△C and Lipofectamine reagent. Immunofluorescence staining was performed to evaluate the c- Myc signal in MSCs. The cell proliferation was detected by MTT method. To clarify the osteoblastic characteristics in stably transfected MSCs, alkaline phosphatase （ALP） mRNA and core binding factor α1 （Cbfal） mRNA were investigated by RT-PCR, and ALP activity and mineralization were examined by p-nitrophenolphosphate method and alizarin red staining respectively. PD98059, a specific inhibitor of the ERK signaling pathway, was used to determine the role of ERK in Smad3MSCs osteoblastic differentiation, c-Myc signal was detected in Smad3-MSCs and Smad3△C- MSCs. The proliferation of Smad3-MSCs was slower than that of Smad3/△C-MSCs or V-MSCs. The relative levels of ALP mRNA and Chfal mRNA in Smad3-MSCs, as well as ALP activity and mineralization, were markedly higher than those in Smad3/△C-MSCs or V-MSCs. Although ALP activity and mineralization were slightly lower in Smad3-MSCs.treated with PD98059 than in those without PD98059 treatment, no significant difference was found between them （P〉0.05）. It is concluded that the wild-type Smad3 gene, which is a crucial component promoting bone formation, can inhibit the proliferation of MSCs and enhance the osteoblastic differentiation of uncommitted MSCs and the maturation of committed MSCs independent of the ERK signaling pathway.     

Differentiation of Bone Marrow Mesenchymal Cells to Neural Cells

Summary： To explore the possibility and condition of differentiation of bone marrow mesenchymal ceils （BMSCs） to neural ceils in vitro, BMSCs from whole bone marrow of rats were cultured. The BMSCs of passage 3 were identified with immunocytochemical staining of CD44 （ ＋ ）, CD71 （ ＋ ） and CD45（-）, There were type I and type H ceils in BMSCs. Type I BMSCs were spindlehaped and strong positive in immunocytochemical staining of CD44 and CD71, whereas flat and big type H BMSCs were lightly stained. The BMSCs of same passage were induced to differentiate into neural ceils by β-mercaptoethanol （BME）. After induction by BME, the type I BMSCs withdrew to form neuron-like round soma and axon-like and dendrite-like processes, and were stained positively for neurofilament （NF）. The type H BMSCs did not change in the BME medium and were negatively or slightly stained of NF.     

Astrocytes Facilitate the Growth and Differentiation of Co-cultured Mesenchymal Stem Cells

The effect of astrocytes on the growth and differentiation of co-cultured mesenchymal stem cells （MSCs） was studied. MSCs of Wistar rats were isolated, cultured and labeled with Hoechst33342. The labeled MSCs were co-cultured with astrocytes in DMEM/F12/10%FBS. The growth status and morphologic change of MSCs were observed. The expression of specific protein NeuN, GFAP and CNP was detected by using immunofluorescence staining. The results showed that the two kinds of co-cultured cells grew well. Some labeled MSCs stretched out long processes with spin, triangle and star shapes. Immunofluorescence stain showed that these cells expressed NeuN, GFAP or CNP. It was suggested that astrocytes could promote the prolifevation of co-cultured MSCs and induce them to differentiate into neural 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.     

In Vitro Chondrogenic Phenotype Differentiation of Bone Marrow-derived Mesenchymal Stem Cells

In order to study the chondrogenic phenotype differentiation of adult sheep bone marrowderived mesenchymal stem cells (MSCs) in a defined medium as potential seed cells for cartilage tissue engineering, MSCs were isolated by density centrifugation with Percoll solution from bone marrow aspirated from sheep iliac crest. The third passage of MSCS were induced with H-DMEM containing TGF-β3 .IGF-I, Dexamethasone and VitC. The shape and ultrastructure of cells were observed, toluidine blue stain for GAG and immunohistochemistry for type II collagen were applied for chondrogenic phenotype identification. After 14 days of induction, MSCs changed from a spindlelike appearance to a polynal shape, a large amount of endoplasmic reticulum, Golgi complex and mitochondria were observed, and the differentiation of MSCs chondrogenic phenotype was verified by positive staining of toluidine blue and immunohistochemistry. MSCs derived from bone marrow can differentiate to chondrogenic phenotype when induced in vitro and can be used as optimal seed cells for cartilage tissue engineering.     

体外培养大鼠骨髓间充质干细胞成骨基因表达谱的检测

目的:探讨体外培养大鼠骨髓间充质干细胞(MSC)成骨相关基因的表达谱,明确体外培养大鼠骨髓MSC的成骨潜能。方法:体外培养SD大鼠骨髓MSC,取第3代细胞提取总核糖核酸(RNA),制备杂交探针,并运用SuperArray公司提供的大鼠Oligo GEArray骨再生基因芯片(每张芯片可测113种基因)进行杂交,化学发光检测,通过X线胶片或台式扫描获得化学发光的芯片图像,使用网上提供的综合型GEArry表达分析配套软件(GEArryExpression Analysis Suite)进行完整的芯片数据分析。结果:检测体外培养大鼠骨髓MSC的113种成骨相关的基因,其中有31种基因表达强度较低,45种基因呈中等强度表达,37种基因表达强度较高。结论:体外培养大鼠骨髓MSC具有部分成骨细胞基因表型特征,但成熟成骨细胞的特征基因表达量较低,提示大鼠MSC是具有较强成骨细胞分化潜能的成纤维样细胞。     

Ectopic osteogenesis and scaffold biodegradation of tissue engineering bone composed of chitosan and osteo-induced bone marrow mesenchymal stem cells in vivo

Background Chitosan （CS） scaffolds combined with osteogenically induced bone marrow mesenchymal stem cells （BMSCs） have been proved to be promising substitutes for repairing bone defects.Nevertheless,the bone-forming and scaffold-biodegrading processes are seldom studied.This study aimed to determine the osteogenic ability of CS/osteoinduced BMSC composites by observing the bone-forming process and explore the relationship between bone formation and scaffold biodegradation.Methods The CS/osteo-induced BMSC composites （CS＋cells group） and the CS scaffolds （CS group） were,respectively,implanted into SD rat thigh muscles.At 2,4,6,8,and 12 weeks postoperatively,the rat femurs were scanned by CT,and the CT values of the implants were measured and comparatively analyzed.Subsequently,the implants were harvested and stained with hematoxylin and eosin and Masson trichrome,and the percentages of bone area,scaffold area,and collagen area were calculated and compared between the two groups.Results The imaging results showed that the densities of implants of the two groups gradually increased along with time,but the CT values of implants in the CS＋cells group were much higher than in the CS group at the same time point （P ＜0.05）.The histological results showed that the de novo bone and collagen formed in the pores of the scaffolds and gradually increased since 2 weeks postoperation in both groups,and the scaffold gradually degraded along with the boneforming process.However,the comparative analysis results showed that the CS＋cells group gained more de novo bone and collagen formation and had less scaffold than the CS group at the same time point （P ＜0.05）.Conclusion The CS/osteo-induced BMSC composites are excellent bone tissue engineering substitutes,and the scaffold biodegradation is accordant with the bone formation.     

壳聚糖复合成骨诱导后的骨髓间充质干细胞组织工程骨的异位成骨及支架降解的实验研究

摘要 背景及目的：壳聚糖支架复合成骨诱导后的骨髓间充质干细胞已经被证实是修复骨缺损的良好替代材料。然而,其成骨的具体过程以及支架的降解却研究较少。本研究的目的是通过观察壳聚糖支架复合成骨诱导后的骨髓间充质干细胞后的异位成骨过程来证实该复合材料的成骨能力,并探索支架降解与骨形成之间的关系。 方法：壳聚糖支架复合成骨诱导后的骨髓间充质干细胞（壳聚糖复合细胞组）和单纯壳聚糖支架（壳聚糖组）被分别植入SD大鼠的股骨肌袋内。 于术后2、4、6、8、12周,分别对大鼠股骨行CT扫描,并测定、统计分析两组的植入物CT值。随后取出标本,行HE染色和Masson染色,并测定、统计分析骨面积分数、支架面积分数以及胶原面积分数。 结果：影响学结果显示两组植入物的密度随时间延长而逐渐增高,但是在同一时间点,壳聚糖复合细胞组植入物的CT值明显高于壳聚糖组（P<0.05）。组织学检测结果显示从术后2周开始,两组均可观察到支架孔隙内的新骨和胶原蛋的形成并且随着时间延长而逐渐增加,以及支架随着骨形成的过程而逐渐降解。然而,统计分析结果显示,在同一时间点,壳聚糖复合细胞组的新生骨量以及胶原蛋白表达量明显高于壳聚糖组,而剩余支架要明显少于壳聚糖组。 结论：壳聚糖支架复合成骨诱导后的骨髓间充质干细胞是一种优秀的组织工程骨替代物,支架的降解与异位成骨过程一致。     

骨髓间充质干细胞的免疫调节活性

骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMSCs)是一种多潜能的非造血干细胞,可以向多系分化,如骨、脂肪和软骨,并优先归巢于损伤组织,有利于组织修复。体外研究显示它们不诱导免疫应答,对识别、清除同种异体抗原的免疫细胞具有抑制作用。在动物实验中,骨髓间充质干细胞可以诱导外周免疫耐受并向损伤处迁移,抑制致炎细胞因子的释放,促进损伤组织修复。这种独特作用说明它们在细胞治疗和自身免疫性疾病治疗中发挥了积极作用。     

Biological features of mesenchymal stem cells from human bone marrow

Objective To study the biological characteristics of mesenchymal stem cells (MSCs) from human bone marrow. Methods A culture of mesenchymal stem cells was initiated from bone marrow low-density mononuclear cells separated by Percoll Centrifugation and maintained in low-glucose Dulbecco’s modified Eagle’s medium (DMEM) with 10% selected fetal calf serum. Cell growth pattern and its responses to cytokines were evaluated by trypan blue exclusion and MTT test, respectively. Cell cycle and surface antigenic features were analyzed by flow cytometry technique. Cytochemistry characteristics of MSCs were determined.Results Easy-handling methods to isolate and culture expand MSCs were developed in this study. MSCs were unique in their phenotypes. They were positive for CD29, CD44, CD166, and negative for CD34, CD45, HLA-DR and Ulex europaeus. Cytochemistry evaluation showed that MSCs were homogeneously positive for acid α-naphthl acetate esterase (ANAE), glycogen (periodic acid Schiff reaction, PAS), and negative for acid phosphatase (ACP) and the Sudan black reaction (SB). Around 5% of them were positive for alkaline phosphatase (ALP). The cells had a population doubling time of 30 hours and cell cycle analysis showed that approximately 10% of them were in S phase. MSCs grew at significantly different rates when incubated in the presence of various recombinant human cytokines, of which interferon γ, tumor necrosis factor α, stem cell factor and insulin-like growth factor promoted the proliferation of MSCs dramatically, while others tested had no effects on cell growth. Conclusions MSCs are a homogenous population of cells that have unique growth, phenotypical and cytochemical characteristics. Furthermore, the diverse responses of MSCs to different cytokines provide a clue for the selection of optimal expansion and maintenance of MSCs.     

大鼠骨髓间质干细胞的分离培养及生物学特性研究

目的建立大鼠骨髓间质干细胞(MSCs)最佳的体外分离培养方法,并研究其基本的生物学特性。方法采用密度梯度离心和贴壁培养两种方法分离大鼠的MSCs,进行形态学观察及增殖生长方面的测定;免疫细胞化学染色鉴定表面标志。结果大鼠MSCs体外培养呈梭形;细胞生长曲线为“S”型;密度梯度离心法原代培养15d达到80%～90%的融合,而改良的直接贴壁法只需要5d;细胞周期显示G0/G1期88.29%;免疫细胞化学染色显示CD44表达阳性,CD34、CD45为阴性。结论两种方法均可获得骨髓间质干细胞,但贴壁培养法操作更简便、快速,具有对细胞活性影响较小,更利于其贴壁和增殖的优点。MSCs体外培养条件下生长性状稳定,适于做组织工程的种子细胞。     

合成成骨生长肽对大鼠骨髓基质干细胞的促成骨作用

目的研究合成成骨生长肽（sOGP）对体外培养的大鼠骨髓基质干细胞（BMSCs）的作用,并与经典的成骨诱导剂地塞米松相对比。方法取大鼠股骨骨髓,贴壁法分离骨髓基质干细胞进行体外培养,加入不同浓度的sOGP,观察细胞形态变化,细胞增殖率,细胞内碱性磷酸酶（ALP）的表达,RT—PCR法检测3种主要成骨标志物（ALP、Ⅰ型胶原、骨钙素）的表达,组织化学染色检测碱性磷酸酶、Ⅰ型胶原的表达及钙质的沉积并进行图像分析。结果sOGP对BMSCs增殖的影响随浓度不同呈现双向作用。sOGP和地塞米松在mRNA和蛋白水平均能促进各成骨标志物的表达,定量分析结果显示,sOGP在10^-9mol／L浓度组促成骨的作用最强,明显高于对照组和地塞米松组。结论sOGP能明显促进大鼠BMSCs向成骨方向转化。这种促成骨能力与其浓度密切相关,以10^-9mol／L浓度下促成骨能力最强。     

骨髓间充质干细胞在心脏组织工程中的应用

骨髓间充质干细胞(BMSCs)具有多向分化潜能，体外可诱导分化为心肌细胞，采用组织工程学技术可在体外构建组织工程化心肌组织。文章从心脏组织工程的角度对BMSCs作一概述。     

人胎盘来源间充质干细胞和大鼠骨髓间充质干细胞的生物学特征比较

目的:从人足月的胎盘羊膜中和Wistar 大鼠股骨及胫骨骨髓中分离、培养间充质干细胞（MSCs）,研究人胎盘来源MSCs（HPMSCs）和大鼠骨髓来源MSCs（BMSCs）的分离培养方法和生物学特征、表面标志及其多分化潜能。方法:将人足月胎盘组织通过胶原酶Ⅱ消化培养获取HPMSCs,采用全骨髓贴壁法从4周龄Wistar大鼠双侧股骨及胫骨中分离、纯化大鼠BMSCs,运用活细胞计数法检测其增殖能力,采用流式细胞术检测2种细胞表面标志物的表阳性率;
用地塞米松、维生素C和β磷酸甘油诱导其向成骨细胞分化,用茜素红染色鉴定;用胰岛素、地塞米松、IBMX和吲哚美辛诱导其向脂肪细胞分化,以油红O染色鉴定。结果:HPMSCs为梭形贴壁细胞,增殖能力较强,CD44和CD34表达阳性率分别为94.45%和1.67%;BMSCs为圆形、梭形和多角形,增殖能力强,CD44和CD34表达阳性率分别为93.11%和2.68%。2种细胞经过成脂诱导液和成骨诱导液诱导后,茜素红和油红O染色结果均为阳性,表明2种细胞均可向脂肪细胞和成骨细胞分化。结论:HPMSCs与大鼠BMSCs的生物学特征相似,同样具有多分化潜能,HPMSCs具有更强的增殖能力。     

pEGFP-C1-PEX真核表达载体的构建及其在大鼠骨髓间质干细胞中的表达

目的构建pEGFP-C1-PEX真核表达载体并转染大鼠骨髓间质干细胞(MSCs),观察其在MSCs内的表达。方法用RT-PCR法从大鼠C6胶质瘤细胞中扩增出带有XhoI、BamHI酶切位点的PEX基因片段,将PEX基因片段克隆到增强型绿色荧光蛋白(EGFP)基因真核表达载体pEG-FP-C1上,通过脂质体将pEGFP-C1-PEX转染入大鼠MSCs。结果pEGFP-C1-PEX真核表达载体构建成功,荧光显微镜下观察,pEGFP-C1-PEX表达载体转染到MSCs24h后可见PEX融合蛋白表达。结论pEGFP-C1-PEX真核表达载体能够在大鼠MSCs中表达PEX融合蛋白。