人骨髓间充质干细胞定向诱导分化为成骨细胞及其鉴定

目的探讨将成人骨髓间充质干细胞(MSCs)定向诱导分化为成骨细胞的方法,并对所诱导细胞的成骨特性进行鉴定. 方法分离人骨髓,梯度离心并结合全骨髓法进行培养,培养基中添加成骨诱导剂地塞米松、β-甘油磷酸钠及抗坏血酸.贴壁细胞传代,取第3代细胞鉴定其成骨特性;在倒置相差显微镜下观察细胞形态,钙-钴法染色检测碱性磷酸酶(ALP)表达,免疫组织化学检测Ⅰ型胶原表达,原位杂交检测骨连接素(ON)、骨桥素(OP)表达,Von Kossa 染色检测钙结节形成. 结果第3代人MSCs呈典型的成骨细胞形态,可连续传代10次;ALP染色阳性率达85%;Ⅰ型胶原、ON和OP表达阳性;Von Kossa 染色可见钙结节形成. 结论成功地将人MSCs诱导分化为成骨细胞,所诱导的细胞具有典型的成骨细胞特性.     

长期体外培养对人脂肪源性间充质干细胞生物学特性的影响

目的通过观察长期体外培养对人脂肪源性间充质干细胞(ADSCs)生物学特性的影响,鉴定ADSCs作为组织工程种子细胞的优越性。方法通过流式细胞技术观察长期体外培养对人ADSCs表面抗原表达和凋亡的影响。通过碱性磷酸酶染色、Von Kossa染色及RT-PCR检测长期体外培养对人ADSCs成骨分化潜能的影响。结果原代ADSCs表面高表达间充质干细胞表面标记物,而不表达血源性细胞表面标记物,标记物不随传代次数变化。早期ADSCs凋亡率为1%～2%,随传代次数增多凋亡率逐渐增加．但幅度不大。碱性磷酸酶染色、Von Kossa染色和RT-PCR检测显示ADSCs传至第8代时仍能保持成骨分化潜能。结论ADSCs生物学特性稳定,是较为理想的组织工程及再生医学研究的种子细胞。     

兔脂肪干细胞体外成骨诱导培养及成骨活性鉴定的实验研究

目的体外分离培养兔脂肪干细胞（adipose-derived stem cells,ADSCs）,在成骨诱导条件下鉴定其成骨活性。方法取4月龄新西兰大白兔腹股沟区脂肪,Ⅰ型胶原酶消化,分离、培养及传代原细胞,将第3代ADSCs消化后,加入成骨培养液中诱导分化,分别行碱性磷酸酶染色、茜素红染色、VonKoss（a钙结节）染色,以鉴定分化结果。结果体外分离培养的细胞增殖活跃,成骨诱导后碱性磷酸酶染色、茜素红染色及Von Kossa染色均呈阳性表达。结论脂肪干细胞具有成骨分化能力,是一种理想的骨组织工程种子细胞。     

人骨髓间充质干细胞表面抗原测定

目的 :研究体外培养的各代间充质干细胞 (MSCs)及其成骨分化后的部分细胞表面抗原变化。方法 :将体外普通培养的骨髓间充质干细胞 ,每隔 1代在流式细胞仪上检测CD48、CD5 6、CD71和CD90阳性表达率。另外 ,为促进成人MSCs体外成骨性分化 ,第 1传代培养时加入成骨性添加剂 ,培养第 6、 12、 18、 2 4、 3 0d时 ,也分别用流式细胞仪分析上述MSCs表面抗原的表达 ,并用碱性磷酸酶组化染色和VonKossa染色。结果 :( 1)在普通培养条件下 ( 10 %DMEM ) ,从第 1代起 ,MSC的表面抗原CD48、CD5 6、CD71、CD90都呈阳性表达。 ( 2 )诱导培养的MSCs表面抗原CD48、CD90阳性表达率在诱导第 12、 18、 2 4及 3 0d时 ,分别与第 6d相比都有显著差异。 ( 3 )在成骨诱导条件下 ,MSCs表现出AKP染色增强和VonKossa染色可见钙化的基质沉积。当MSC开始向成骨细胞分化后 ,CD71阳性率下降最明显。结论 :( 1)目前采用的体外普通培养条件下 ,培养、传代方法对MSCs表面抗原CD48,CD5 6,CD71及CD90表达并无明显影响。 ( 2 )诱导成骨培养的MSCs的CD71从高阳性率转变为极低阳性率可能与MSCs向成骨细胞系的分化成熟相对应。 ( 3 )CD90及CD48也可能与MSCs的细胞分化状态特别是向成骨细胞系的改变有关     

大鼠骨髓基质细胞体外培养诱导成骨能力的研究

目的：观察大鼠骨髓基质细胞在体外培养生长时的生物学特性，及诱导分化为成骨细胞的能力。方法：取成年大鼠2只，处死后分离、培养骨髓基质细胞，第8天时添加矿化液诱导培养，细胞经传代后绘制生长曲线。应用倒置相差显微镜、透射电镜观察其生长特性，并进行甲苯胺蓝染色，Won Kossa染色，碱性磷酸酶染色。结果：培养的大鼠骨髓基质细胞呈成纤维细胞样生长，增殖活跃。经诱导后，细胞碱性磷酸酶活性高，连续培养30天，Von-KaSSR染色显示有局灶状钙盐沉积。结论：MSCs易于分离培养，体外扩增速度快，在矿化条件下，骨髓基质细胞在体外即具有很强的成骨能力，为研究其作为骨组织工程种子细胞植入体内成骨奠定基础。     

骨形成蛋白-2基因转染人骨髓间质干细胞诱导异位成骨的实验研究

目的 评价腺病毒介导的人骨形成蛋白—2基因(Adv—hBMP—2)转染人骨髓间质干细胞(MSCs)的诱导成骨能力。方法 从人骨髓中分离培养获取MSCs，分为三组：①Adv—hBMP—2转染细胞组；②Adv—βgal转染细胞组；③未转染细胞组。分别于体外行western immunoblot试验、碱性磷酸酶(ALP)和Von Kossa染色、ALP定量测定，以及裸鼠肌内诱导成骨试验。共9只裸鼠，双例股后肌群内注射，每组6例。结果 Adv—hBMP—2组MSCs可分泌BMP—2蛋白；转染后第9天ALP染色多数细胞为阳性，其它两组ALP染色阳性细胞少见；ALP活性第3天开始升高，12天达高峰为14．76单位，与其它两组比较有统计学意义(P＜0．05)；于第21天后出现钙结节，而其它两组未见。裸鼠肌内注射后4周Adv—hBMP—2组X线片均有异位成骨，Adv—βgal转染细胞组未见明显成骨，未转染细胞组仅有少量骨形成。组织学检查发现：Adv—hBMP—2组也可见典型的板层骨和骨髓腔形成，Adv—βgal组主要为纤维组织，未转染组也可见散在骨小粱形成。结论 Adv—hBMP—2基因转染可诱导人骨髓问质干细胞成骨。     

人骨髓间充质干细胞的生物学特性及成骨诱导分化的研究

[目的]探讨成人骨髓间充质干细胞分离、纯化、培养及鉴定的方法,观察其成骨分化过程中Runx2基因的动态表达以及生物学特性。[方法]取自人股骨近端骨髓标本,利用联合密度梯度离心和差异贴壁法分离骨髓间充质干细胞,体外扩增和传代培养,流式细胞仪检测细胞表面标记,诱导向成骨细胞分化,并采用RT-PCR和Western blot方法检测Runx2的动态表达。[结果]原代和传代细胞呈纺锤状外观,生长增殖能力良好,骨髓间充质干细胞的生长曲呈成"S"形,细胞表面标记物CD90阳性表达,CD34和CD45阴性表达。经定向诱导分化后,细胞分别呈现成骨细胞的表型特征,随着诱导时间的增加,Runx2的表达也明显增加,与对照组相比有统计学差异(P<0.05)。[结论]该方法能从人骨髓中高效分离和扩增MSCs,生物学性状稳定,具有成骨分化潜能,为骨组织工程提供理想的种子细胞,同时证实Runx2在成骨分化中起到重要的调控作用。     

人骨髓间充质干细胞分离培养及体外诱导分化为成骨细胞

[目的]建立人骨髓来源的间充质干细胞( hBMSCs)分离、培养及传代的方法,观察成hBMSCs体外成骨潜能.[方法]采用全骨髓贴壁筛选法分离培养hBMSCs,流式细胞仪检测细胞表型;所得细胞第3代用含100 nmol/L地塞米松、5mmol/Lβ -甘油磷酸钠,50 μg/ml抗坏血酸的条件培养基进行骨诱导,茜素红染色鉴定.[结果]分离培养的细胞流式细胞术检测显示CD44、CD105阳性,而CD34、CD45阴性,符合MSCs特征;hBMSCs经骨诱导后可形成钙结节,茜素红染色显示阳性.[结论]全骨髓贴壁筛选法可分离获得高纯度的hBMSCs,其在体外具有成骨潜能.     

胎儿毛乳头细胞的培养和鉴定及其体外诱导分化

目的探讨胎儿毛乳头细胞（dermal papilla cells，DPCs）生物学特性和体外诱导分化潜能，论证作为组织工程种子细胞的可行性。方法Ⅰ型胶原酶消化法分离毛乳头，Eagle动物细胞培养基（DMEM）／F12（3：1）中培养细胞，通过免疫荧光检测α平滑肌动蛋白（smooth muscle actin-α，SMA—α）、Ⅰ型胶原、Ⅱ型胶原、层粘连蛋白，对细胞的生物学特性进行鉴定。取第3、7代细胞以成脂诱导液、成骨诱导液体外定向诱导7～10d，油红染色和Von Kossa染色、骨桥蛋白免疫荧光检测鉴定细胞的成脂和成骨特性。结果体外培养的DPCs表达SMA—α、Ⅰ型胶原、Ⅳ型胶原和层粘连蛋白，成脂诱导10d后油红染色可见细胞胞浆内红色脂滴形成，成骨诱导7d后Von Kossa染色细胞间有黑色钙结节形成，细胞表达骨桥蛋白。结论体外培养DPCs具有干细胞特性，可作为皮肤组织工程和骨组织工程一种新的种子细胞。     

成人间充质干细胞体外诱导分化为成骨细胞的研究

目的 研究成人骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMSCs)体外培养定向诱导分化为成骨细胞,探讨其作为骨组织工程种子细胞的可行性和应用价值.方法 抽取健康成年骨髓,Ficoll密度梯度离心结合贴壁培养法经连续传代后改用含10 nmol/L地塞米松、10 mmol/Lβ-甘油磷酸钠、50 μmol/L维生素C的条件培养基培养,在相差显微镜下观察细胞形态变化,流式细胞仪细胞表面分子标志鉴定,免疫组化和RT-PCR检测Ⅰ型胶原蛋门的表达,同时测定细胞内碱件磷酸酶的含量.结果 BMSCs原代和传代培养的细胞具有活跃的增殖能力,诱导培养后细胞形态向成骨细胞转化,经RT-PCR、流式细胞仪、细胞碱性磷酸酶活性、糖原染色鉴定为成骨细胞.结论 BMSCs经合理的体外诱导培养后符合成骨细胞的形态特征和生物学特性,有望成为理想的骨组织工程种子细胞来源.     

Culture expanded canine mesenchymal stem cells possess osteochondrogenic potential in vivo and in vitro

Mesenchymal Stem Cells (MSCs) possessing the capacity to differentiate into various cell types such as osteoblasts, chondrocytes, myoblasts, and adipocytes have been previously isolated from the marrow and periosteum of human, murine, lapine, and avian species. This study documents the existence of similar multipotential stem cells in canine marrow. The cells were isolated from marrow aspirates using a modification of techniques previously established for human MSCs (hMSCs), and found to possess similar growth and morphological characteristics, as well as osteochondrogenic potential in vivo and in vitro. On the basis of these results, the multipotential cells that were isolated and culture expanded are considered to be canine MSCs (cMSCs). The occurrence of cMSCs in the marrow was determined to be one per 2.5 × 10⁴ nucleated cells. After enrichment of the cMSCs by centrifugation on a Percoll cushion, the cells were cultivated in selected lots of serum. Like the hMSCs, cMSCs grew as colonies in primary culture and on replating, grew as a monolayer culture with very uniform spindle morphology. The population doubling time for these cMSCs was approximately 2 days. The morphology and the growth kinetics of the cMSCs were retained following repeated passaging. The osteogenic phenotype could be induced in the cMSC cultures by the addition of a synthetic glucocorticoid, dexamethasone. In these osteogenic cultures, alkaline phosphatase activity was elevated up to 10-fold, and mineralized matrix production was evident. When cMSCs were loaded onto porous ceramics and implanted in autologous canine or athymic murine hosts, copious amounts of bone and cartilage were formed in the pores of the implants. The MSC-mediated osteogenesis obtained by the implantation of the various MSC-loaded matrix combinations is the first evidence of osteogenesis in a canine model by implantation of culture expanded autologous stem cells. The identification and isolation of cMSCs now makes it feasible to pursue preclinical models of bone and cartilage regeneration in canine hosts.     

Raloxifene: its ossification-promoting effect on female mesenchymal stem cells

Background  

Raloxifene acts like estrogen in preventing bone loss in postmenopausal women, but it selectively activates biological responses in bone tissue. It has a direct effect on osteoblasts’ differentiation and bone formation in bone marrow culture. However, the point at which raloxifene has an effect on bone marrow-derived mesenchymal stem cells (MSCs), regardless of sex difference, is not known. The purpose of this study was to examine the osteogenic effect of raloxifene on MSCs derived from female and male rats and to assess the sex difference of raloxifene with or without osteogenic supplements (OSs) in the regulation of bone formation.     

同种异体血清在体外培养骨髓间充质干细胞的作用研究

[目的]适当的血清浓度可维持骨髓间充质干细胞(MSCs)的体外培养,血清浓度过低不利于细胞的生长,而高浓度血清则易引起细胞分化。而血清的不同来源对MSCs的培养同样产生影响。传统的培养方法用胎牛血清作为营养支持,临床应用时存在潜在的风险。本研究探讨同种异体血清在体外培养人骨髓间充质干细胞(hBM-SCs)的可行性。[方法]无菌条件下收集人骨髓悬液,分离hBMSCs,分别用含胎牛血清和人血清的培养基培养。分别测定2种方法培养的hBMSCs细胞生长曲线;采用流式细胞仪检测分析培养的hBMSCs表面抗原类型;并将培养的hBMSCs诱导分化为软骨细胞及神经细胞,诱导后的软骨细胞及神经细胞采用免疫组化染色分析。[结果]2种方法培养的间充质干细胞表面抗原CD29、CD44、CD105阳性,CD34、CD45、CD106以及HLA-DR阴性,表达强度无显著性差异;人血清培养的hBMSCs细胞生长速度快于胎牛血清培养组,但分化效率低于后者。[结论]通过生长特性、表面抗原表达以及分化潜能等方面的对比研究,人血清培养hBMSCs与胎牛血清培养差别不大,可以作为一种适合临床的安全培养方法。     

The osteogenic potential of culture-expanded rat marrow mesenchymal cells assayed in vivo in calcium phosphate ceramic blocks

When whole marrow is introduced into porous calcium phosphate ceramic, bone forms on the walls of the pores. As an extension of earlier studies, bone marrow cells derived from the femora of inbred rats were introduced into tissue culture, and the adherent cells were cultivated, mitotically expanded, subcultured, harvested, placed in small cubes of porous calcium phosphate ceramic, and grafted into subcutaneous sites of syngeneic rats. Primary marrow-derived, cultured mesenchymal cells introduced into ceramic showed strong osteogenic potential, with bone forming in the pore regions of ceramic as early as two weeks after in vivo implantation; cartilage was observed infrequently in pores that appeared to be avascular. Osteogenesis could be observed after the 18th subculture (over 36 population doublings) when the cells were tested in ceramic at subcutaneous sites, whereas chondrogenesis was observed with only the first and second subcultured cells in the ceramic delivery vehicle. With increasing numbers of subcultures, the initiation of osteogenesis and the apparent rate of bone formation declined, and the course of osteogenesis was delayed. Cultured, marrow-derived mesenchymal cells, even after the 21st subculture (over 40 population doublings), exhibited a positive histochemical reaction for alkaline phosphatase. However, the in vivo osteogenic potential of these cells was not correlated with their alkaline phosphatase activity. The implantation of cell pellets or the injection of cell suspensions of fresh or cultured, adherent marrow cells never produced bone or cartilage in heterotopic sites. These data indicate that porous ceramic provides an excellent delivery vehicle for cells that are capable of osteogenic expression and suggest that the composite graft of marrow-derived mesenchymal cells and porous ceramic may be useful for repair of massive bone defects. It may be possible to culture marrow mesenchymal cells as a source for reparative cells for implantation back into autogeneic sites.     

Early osteoblastic differentiation induced by dexamethasone enhances adenoviral gene delivery to marrow stromal cells.

We investigated the implications of induced osteogenic differentiation on gene delivery in multipotent rat marrow stromal cells (MSCs). Prior to genetic manipulation cells were cultured with or without osteogenic supplements (5x10(-8) M dexamethasone, 160 microM l-ascorbic acid 2-phosphate, and 10 mM beta-glycerophosphate). Comparison of liposome, retroviral, and adenoviral vectors demonstrated that all three vectors could mediate gene delivery to primary rat MSCs. When these vectors were applied in the absence or presence of osteogenic supplements, we found that MSCs differentiated prior to transduction with adenovirus type 5 vectors produced a 300% increase in transgene expression compared to MSCs that were not exposed to osteogenic supplements. This differentiation effect appeared specific to adenoviral mediated gene delivery, since there was minimal increase in retroviral gene delivery and no increase in liposome gene delivery when MSCs were treated with osteogenic supplements. In addition, we also determined this increase in transgene production to occur at a higher concentration of dexamethasone (5x10(-8) M) in the culture medium of MSCs prior to adenoviral transduction. We found that this increased transgene production could be extended to the osteogenic protein, human bone morphogenetic protein 2 (hBMP-2). When delivered by an adenoviral vector, hBMP-2 transgene production could be increased from 1.4 ng/10(5) cells/3 days to 4.3 ng/10(5) cells/3 days by culture of MSCs with osteogenic supplements prior to transduction. These results indicate that the utility of MSCs as a therapeutic protein delivery mechanism through genetic manipulation can be enhanced by pre-culture of these cells with dexamethasone.     

人脐血源和骨髓源间充质干细胞神经前体细胞分化的研究

目的 对比研究人脐血和骨髓来源的间充质干细胞(mesenchymal stem cells,MSCs)体外的分离、培养和生物学特性,并观察其分化潜能和形态学变化,为组织工程选取种子细胞提供实验依据.方法 Ficoll密度梯度离心结合贴壁培养法分别分离纯化成人骨髓和脐血源MSCs,体外培养和连续传代,并在含有2%B27的Neurobasal培养基中添加碱性成纤维细胞生长因子、表皮生长因子,将获得的MSCs向神经干细胞定向诱导,利用倒置显微镜连续观察细胞培养、传代和向神经细胞表型转化过程的形态学变化;采用免疫组化和荧光免疫组化法对诱导后细胞进行鉴定.结果 原代分离的骨髓间充质干细胞(BMSCs)在接种后48 h贴壁,7 d细胞呈长梭形,有一定的方向性,并达到90%融合;而脐血间充质干细胞(UMSCs)48 h后贴壁,似乎贴的不牢,持续14d才能形成小丛、小簇、小集落,21 d排列才有一定的方向性.培养基添加神经营养因子诱导后的细胞呈现典型的神经前体细胞样表型,免疫组化和免疫荧光结果显示,诱导后的细胞能特异性表达神经元特异性标志β微管蛋白(β-tubulin)和星形胶质细胞特异性标志神经胶质相关蛋白(GFAP).结论 人脐血和骨髓中含MSCs,且具备其基本恃征,体外培养UMSCs生长速度比BMSCs缓慢10 d～15 d左右,传代以后的各组细胞生长速度与形态无明显差异.骨髓和脐血来源的MSCs在体外可定向诱导分化为神经细胞.