白藜芦醇体外诱导大鼠骨髓基质细胞向神经元样细胞的分化

目的研究白藜芦醇体外诱导大鼠骨髓基质细胞(Marrow stroma cells,MSCs)向神经元样细胞的分化。方法采用全骨髓贴壁法分离培养MSCs,取第3代MSCs分为白藜芦醇诱导组、对照组和正常组,白藜芦醇诱导组先加入预诱导液(含10μg/L bFGF的DMEM/F12培养基)培养24 h,再更换诱导液(含15μmol/L白藜芦醇的DMEM/F12培养基)诱导6 h,然后更换维持液(含15μmol/L白藜芦醇,10μg/L bFGF,2%B27的DMEM/F12培养基),继续培养至72 h;对照组预诱导与白藜芦醇诱导组相同,诱导时仅加入DMEM/F12培养基诱导6 h,再更换维持液(含10μg/L bFGF,2%B27的DMEM/F12培养基),继续培养至72 h,倒置显微镜下观察诱导分化后MSCs形态;各组分别于诱导前及诱导后2、6、24、72 h采用间接免疫荧光法、Western blot法和RT-PCR法检测nestin、NSE蛋白及mRNA表达。结果白藜芦醇诱导后细胞胞体收缩,伸出长突起,类似神经元,间接免疫荧光染色显示诱导后细胞nestin和NSE阳性,对照组未见阳性细胞。白藜芦醇诱导组nestin、NSE蛋白及mRNA表达较对照组明显升高,诱导后2 h,nestin蛋白及mRNA表达达最高(P<0.01),之后逐渐下降;而NSE蛋白及mRNA表达逐渐升高,诱导后72 h达最高(P<0.01),对照组则无明显变化。结论白藜芦醇在体外可诱导大鼠骨髓基质细胞分化为神经元样细胞,为白藜芦醇在干细胞移植领域的应用提供了实验依据。     

体外诱导微环境对骨髓间充质干细胞成神经分化的影响及分化后的自发逆转现象

目的体外定向诱导大鼠骨髓间充质干细胞(Mesenchymal stem cells,MSCs)成神经分化,并探讨诱导微环境对其分化的影响及分化后的自发逆转现象。方法体外分离培养大鼠MSCs,流式细胞仪检测细胞表面标志。采用改良神经元诱导液[Modified neuronal induction media(MNM)]定向诱导MSCs,免疫荧光检测神经细胞表面标志。观察胎牛血清(FBS)浓度、细胞密度、MNM剂量、新鲜与使用过的MNM等不同诱导微环境对MSCs成神经分化的影响。结果 MSCs经MNM诱导后,6h即可见尼氏体,表达神经元特异性表面标志神经元特异性烯醇化酶(NSE)、巢蛋白(Nestin)和微管相关蛋白-2(MAP-2)。随着诱导微环境的改变,MSCs成神经分化率及神经元表面标志表达亦发生改变,且分化后的神经元样细胞可自发逆转。结论 MSCs能够在MNM微环境中定向成神经分化,但诱导微环境的改变可以从量和质两个层面影响MSCs定向分化。     

大鼠骨髓间充质干细胞向肝样细胞的定向诱导分化

目的 探讨肝细胞生长因子(Hepatocyte growth factor,HGF)和碱性成纤维细胞生长因子(Basic fibroblast growthfactor,bFGF)诱导大鼠骨髓间充质干细胞(Bone marrow mesenchymal stem cells,BM-MSCs)分化为肝样细胞的可行性。方法取SD大鼠股骨骨髓,直接贴壁法分离纯化BM-MSCs,并体外传代,流式细胞术和成骨诱导对其进行鉴定。取第3代BM-MSCs,分为2组:实验组用HGF(20 ng/ml)和bFGF(10 ng/ml)进行诱导,阴性对照组不加诱导剂,倒置显微镜下观察细胞形态变化;RT-PCR法检测诱导后细胞甲胎蛋白(Alpha fetoprotein,AFP)和白蛋白(Albumin,ALB)基因mRNA的转录水平;免疫细胞化学染色法检测诱导后细胞的AFP和ALB蛋白的表达。结果第3代BM-MSCs表型标志和功能特性均符合MSCs的特点。BM-MSCs经HGF和bFGF诱导后呈肝样细胞形态。实验组细胞可检测出AFP和ALB基因mRNA的表达。实验组细胞诱导后第7天,AFP蛋白开始表达,第14天时表达降低,第21天时不表达;ALB于诱导后第14天出现表达,并随诱导时间的延长表达逐渐增加。结论 HGF和bFGF具有体外诱导BM-MSCs向肝样细胞分化的作用。     

骨髓间充质干细胞在脊髓损伤模型大鼠体内的转化

目的观察静脉移植骨髓间充质干细胞(MSCs)在脊髓损伤模型大鼠体内向神经样细胞转化的情况。方法体外扩增培养MSCs,流式细胞仪检测表面标志CD34和CD44的表达;采用击打法制备大鼠脊髓损伤模型;Brdu标记的MSCs经尾静脉移植入脊髓损伤模型大鼠体内,输注后21d,取脊髓组织进行免疫组化染色,检测神经元特异性烯醇化酶(NSE)的表达。结果体外扩增的MSCs经流式细胞仪检测不表达CD34,表达CD44;激光共聚焦显微镜下观察可见,移植Brdu标记的MSCs组在大鼠损伤的脊髓组织中可同时表达Brdu和NSE。结论移植的MSCs可迁移到损伤的脊髓组织,并可转化为神经样细胞。     

骨髓基质干细胞诱导分化滑膜样细胞移植预防屈肌腱粘连的实验研究

目的探讨移植的骨髓基质干细胞诱导分化的滑膜样细胞是否具有明显的防止屈肌腱粘连的功效。方法提取兔骨髓基质干细胞诱导下分化为滑膜样细胞。经鉴定后,将滑膜样细胞移植于大白兔损伤的跟腱处,术后l、2、4、8周取材,进行大体标本粘连等级评定、生物力学测试及组织学观察。结果对分化的滑膜样细胞鉴定,光镜下、电镜下均符合滑膜细胞结构特征,免疫组化Vimentin阳性,CD68阴性,符合成纤维细胞样滑膜细胞(B型滑膜细胞)的特征。滑膜样细胞移植术后,光镜及扫描电镜发现肌腱表面光滑,被覆大量滑膜样细胞。同一时相点实验组同对照组相比粘连明显减轻(P<0.05)。结论骨髓基质干细胞在一定条件下可以诱导分化为滑膜样细胞。滑膜样细胞移植可以有效的防止肌腱粘连。     

上海生科院等发现纳米材料可调节多巴胺神经元分化

正近日,国际学术期刊Nanomedicine在线发表了中国科学院上海生命科学研究院健康科学研究所乐卫东研究组题为Graphene oxide promotes the differentiation of mouse embryonic stem cells to dopamine neurons的研究论文,报道了纳米材料氧化石墨烯(graphene oxide,GO)在胚胎干细胞向多巴胺神经元分化过程中的重要作用。中脑多巴胺能神经元的退行性死亡是帕金森病的最显著特征,通过干细胞诱导多巴胺神经元分化并进行细胞移植治疗已经成为潜在的帕金森病治疗方法。然而,对于胚胎干细胞向多巴胺能神经元的发育过程     

骨髓间充质干细胞向视网膜神经节样细胞的分化

目的探讨乳鼠视网膜细胞条件分化液诱导骨髓间充质干细胞(BMSCs)的神经分化情况,以期为视网膜退行性疾病提供治疗方案。方法体外分离培养Wistar大鼠乳鼠BMSCs,观察BMSCs的增殖情况并进行鉴定;制备乳鼠视网膜细胞条件分化液,以其诱导BMSCs,观察BMSCs的神经分化情况,并行免疫组化鉴定。结果体外培养获得了较纯的BMSCs;在乳鼠视网膜细胞条件分化液的环境中,诱导后72h,BMSCs胞体收缩成锥形或球形,细胞突起变细、变长,呈神经细胞的典型形态;免疫组化结果显示,部分细胞呈神经元特异性烯醇化酶(NSE)、巢蛋白(nestin)和Thy1.1阳性反应。结论乳鼠视网膜细胞条件分化液可诱导BMSCs分化成视网膜神经节样细胞。     

大鼠骨髓间充质干细胞的体外分离培养与鉴定

目的建立大鼠骨髓间充质干细胞(Mesenchymal stem cells,MSCs)体外分离培养及鉴定的方法 ,为MSCs的系列研究奠定基础。方法采用全骨髓直接贴壁筛选法分离培养MSCs并传代,倒置相差显微镜下观察细胞形态,以MTT法检测细胞增殖水平并绘制生长曲线。取第3代MSCs,流式细胞术检测细胞周期和细胞表型,应用成骨细胞诱导液和脂肪样细胞诱导液诱导MSCs定向分化,鉴定其分化能力。结果全骨髓细胞培养5d,镜下可见贴壁细胞增殖明显,细胞形态较均一,大部分呈梭形,7d左右可传代,经2～3次传代后细胞呈单一梭形的成纤维样细胞,即MSCs;细胞生长曲线呈S形;经流式细胞仪检测,MSCs细胞76.01%处于G0/G1期,7.13%处于G2/M期,16.86%处于S期;MSCs表面不表达CD34;在特定诱导液作用下,MSCs可分别向成骨样细胞及脂肪样细胞分化。结论已成功建立了分离培养及鉴定MSCs的方法 ,可用来评价体外培养的MSCs。     

细胞传代对骨髓间充质干细胞成软骨细胞分化的影响

目的 观察在成软骨诱导培养条件下,细胞传代对骨髓间充质干细胞(MSCs)体外成软骨能力的影响.方法 不同代MSCs成软骨诱导后,观察细胞生物学特性以及通过免疫荧光,RT-PCR测定特异性软骨细胞外基质aggrecan的表达情况.结果 经成软骨诱导后,第2、4代MSCs表达aggrecan明显较第6、8代细胞高.结论 MSCs很可能由多种形态功能接近,分化潜能有略有差异的细胞组成;在成软骨诱导培养条件下,对此传代后成软骨能力减弱.     

血清神经元特异性烯醇化酶在癫患者中的应用价值

目的探讨癫患者发作后不同时间神经元特异性烯醇化酶(NSE)的动态变化。方法采用放射免疫法测定20例癫患者发作后48h内、2~4d、5~7d血清中NSE水平,并与22例正常健康体检者进行对照。结果癫患者发作48h内及2~4d血清NSE水平与对照组比较有显著性差异(t=4.31,2.57;P<0.01,0.05)。结论癫发作后血清NSE水平升高可能与脑神经元损害有关。     

Effects of Normal Synovial Fluid and Interferon Gamma on Chondrogenic Capability and Immunomodulatory Potential Respectively on Equine Mesenchymal Stem Cells

Synovial fluid contains cytokines, growth factors and resident mesenchymal stem cells (MSCs). The present study aimed to (1) determine the effects of autologous and allogeneic synovial fluid on viability, proliferation and chondrogenesis of equine bone marrow MSCs (BMMSCs) and (2) compare the immunomodulatory properties of equine synovial fluid MSCs (SFMSCs) and BMMSCs after stimulation with interferon gamma (INF-γ). To meet the first aim of the study, the proliferation and viability of MSCs were evaluated by MTS and calcein AM staining assays. To induce chondrogenesis, MSCs were cultured in a medium containing TGF-β1 or different concentrations of synovial fluid. To meet the second aim, SFMSCs and BMMSCs were stimulated with IFN-γ. The concentration of indoleamine-2,3-dioxygenase (IDO) and nitric oxide (NO) were examined. Our results show that MSCs cultured in autologous or allogeneic synovial fluid could maintain proliferation and viability activities. Synovial fluid affected chondrocyte differentiation significantly, as indicated by increased glycosaminoglycan contents, compared to the chondrogenic medium containing 5 ng/mL TGF-β1. After culturing with IFN-γ, the conditioned media of both BMMSCs and SFMSCs showed increased concentrations of IDO, but not NO. Stimulating MSCs with synovial fluid or IFN-γ could enhance chondrogenesis and anti-inflammatory activity, respectively, suggesting that the joint environment is suitable for chondrogenesis.     

小鼠骨髓间充质干细胞对异基因肝移植大鼠淋巴细胞增殖的抑制作用

目的观察小鼠骨髓间充质干细胞(Mesenchymal stem cells,MSCs)移植后,在异基因肝移植模型大鼠胸腺、脾脏及骨髓中的迁徙、定居情况及对淋巴细胞增殖的抑制作用,以探讨MSCs诱导异基因移植免疫耐受的可能性。方法体外分离、纯化并培养小鼠MSCs;将小鼠肝组织块埋入大鼠肝脏切口,建立异基因肝移植大鼠模型;经尾静脉移植DAPI标记的小鼠MSCs,通过激光共聚焦显微镜观察24 h及5 d时,MSCs在模型大鼠胸腺、脾脏及骨髓内的迁徙及定居;采用体外淋巴细胞增殖实验检测小鼠MSCs对异基因肝移植大鼠淋巴细胞增殖的抑制作用。结果MSCs移植后,24 h即散在分布于胸腺、脾脏及骨髓内,5 d时集中在血管周围;经MSCs治疗后,大鼠胸腺和脾脏淋巴细胞增殖均受到抑制,与未经治疗的模型大鼠相比,差异有显著意义。结论小鼠MSCs可迁徙至异基因肝移植大鼠免疫器官内,并具有抑制淋巴细胞增殖的作用。     

Promoting Effect of Basic Fibroblast Growth Factor in Synovial Mesenchymal Stem Cell-Based Cartilage Regeneration

Synovial mesenchymal stem cell (SMSC) is the promising cell source of cartilage regeneration but has several issues to overcome such as limited cell proliferation and heterogeneity of cartilage regeneration ability. Previous reports demonstrated that basic fibroblast growth factor (bFGF) can promote proliferation and cartilage differentiation potential of MSCs in vitro, although no reports show its beneficial effect in vivo. The purpose of this study is to investigate the promoting effect of bFGF on cartilage regeneration using human SMSC in vivo. SMSCs were cultured with or without bFGF in a growth medium, and 2 × 10⁵ cells were aggregated to form a synovial pellet. Synovial pellets were implanted into osteochondral defects induced in the femoral trochlea of severe combined immunodeficient mice, and histological evaluation was performed after eight weeks. The presence of implanted SMSCs was confirmed by the observation of human vimentin immunostaining-positive cells. Interestingly, broad lacunae structures and cartilage substrate stained by Safranin-O were observed only in the bFGF (+) group. The bFGF (+) group had significantly higher O’Driscoll scores in the cartilage repair than the bFGF (−) group. The addition of bFGF to SMSC growth culture may be a useful treatment option to promote cartilage regeneration in vivo.     

Hematopoietic–Mesenchymal Signals Regulate the Properties of Mesenchymal Stem Cells

It is well known that the properties of hematopoietic stem/progenitor cells (HSCs), such as their self-renewal ability and multipotency, are maintained through interactions with mesenchymal stem/stromal cells (MSCs). MSCs are rare cells that are present in the bone marrow and are useful for clinical applications due to their functional ability. To obtain the necessary number of cells, MSCs must be cultured to expand, but this causes a remarkable decrease in stem cell properties, such as multipotency and proliferation ability. In this study, we show that the c-Mpl signal, which is related to the maintenance of hematopoietic stem cells, has an important effect on the proliferation and differentiation ability of MSCs. Utilizing a co-culture system comprising MSCs and HSCs, it is suggested that signaling from hematopoietic cells to MSCs supports cell proliferation. Interestingly, the enhanced proliferation ability of the HSCs was decreased in c-Mpl knock-out HSCs (c-Mpl-KO). In addition, the MSCs co-cultured with c-Mpl-KO HSCs had reduced MSC marker expression (PDGFRa and Sca-1) compared to the MSCs co-cultured with c-Mpl-wild-type HSCs. These results suggest that a hematopoietic–mesenchymal signal exists, and that the state of the HSCs is important for the stability of MSC properties.     

Osteogenic Efficacy of Human Trophoblasts-Derived Conditioned Medium on Mesenchymal Stem Cells

Trophoblasts play an important role in the regulation of the development and function of the placenta. Our recent study demonstrated the skin regeneration capacity of trophoblast-derived extracellular vesicles (EV). Here, we aimed to determine the potential of trophoblast-derived conditioned medium (TB-CM) in enhancing the osteogenic differentiation of bone marrow mesenchymal stem cells (MSCs). We found that TB-CM promoted the osteogenic differentiation of MSCs in a dose-dependent manner. Furthermore, it inhibited adipogenesis of MSCs. We also found that the primary trophoblast-derived conditioned medium (PTB-CM) significantly enhanced the proliferation and osteogenic differentiation of human MSCs. Our study demonstrated the regulatory mechanisms underlying the TB-CM-induced osteogenesis in MSCs. An upregulation of genes associated with cytokines/chemokines was observed. The treatment of MSCs with TB-CM stimulated osteogenesis by activating several biological processes, such as mitogen-activated protein kinase (MAPK) and bone morphogenetic protein 2 (BMP2) signaling. This study demonstrated the proliferative and osteogenic efficacies of the trophoblast-derived secretomes, suggesting their potential for use in clinical interventions for bone regeneration and treatment.