胎肝Sca-1+细胞在体外向神经元分化研究

目的:观察胚胎肝Sca-1⁺细胞能否在体外向神经组织细胞分化。方法: 免疫磁珠法分离孕14.5 d C57BL/6J小鼠的胚胎肝的Sca-1⁺细胞, 以DMEM/F12+10%胎牛血清培养液培养, 当细胞融合达80%, 按1∶3比例传代。第5代细胞用BME和RA先后诱导24 h, 再用无血清培养基培养5 h至5 d。免疫细胞化学检测细胞特点。结果: 胚胎肝Sca-1⁺细胞经诱导后表现神经元形态, 并表达神经元特异蛋白如神经元特异性核蛋白(NeuN)、神经丝蛋白M、神经元特异性微管蛋白1(TuJ-1), 但是无微管相关蛋白Tau、MAP-2和星形胶质细胞特异酸性蛋白(GFAP)表达。结论: 胚胎肝Sca-1⁺细胞(主要为造血干细胞)具有可塑性, 在体外能分化为早期未成熟的神经元样细胞。这提示胚胎肝细胞可能用于神经系统疾病的细胞治疗和基因治疗。     

The in vitro migration of murine fetal liver cells to thymic rudiments.

The migration of murine fetal liver cells to thymus rudiments was studied in vitro using a migration under agar technique. There appeared to be a minor population that migrated specifically to the thymus from the age of 10 to 14 days of gestation. The specificity of migration was demonstrated in 12-day fetal liver cells by a series of competition studies. The ability of these cells to colonize a thymus rudiment was shown by further incubation after invasion of the epithelial thymus rudiments: small colonies of lymphoid cells were present in invaded tissue but absent from uninvaded control tissue. At 13 to 14 days of gestation, there appeared an additional population that migrated specifically to the spleen, as demonstrated, again, with a competition protocol. Studies with avian and human tissue as attractants in the same system showed that migration was specific to the thymus and did cross species barriers. This observation was used to demonstrate a similar attractant activity in cell-free conditioned medium from human thymus epithelial cultures, and to demonstrate the absence of such a cell-attractant factor in the conditioned medium from the thymus of a child with previously documented severe combined immunodeficiency disease.     

大鼠羊膜上皮细胞体外诱导可分化为类神经干细胞

背景：以往研究发现修复神经损伤的细胞来源主要有许旺细胞、嗅鞘细胞、神经干细胞、激活的巨噬细胞等,但这些细胞存在着来源困难、有成瘤性、异体排斥等缺点。而羊膜上皮细胞不存在以上缺陷,且具有多向分化潜能,经诱导后可向心肌样细胞、神经干细胞、肝细胞、成骨和软骨细胞等分化。 目的：体外培养大鼠羊膜上皮细胞,并诱导其向类神经干细胞方向分化。 方法：取妊娠晚期大鼠,采用胰酶消化法获得羊膜上皮细胞,用无血清的神经干细胞条件培养基对细胞进行诱导分化,并用免疫细胞化学法和RT-PCR对诱导前后的细胞相关标志物进行鉴定。 结果与结论：形态学观察结果显示,条件培养基诱导后的羊膜上皮细胞胞体回缩,胞核部分折光性增强,出现类似于树突及轴突样结构,这些突起可交织成网状,细胞贴壁牢靠。免疫细胞化学检测结果显示,与诱导前相比,条件培养基诱导后的羊膜上皮细胞中巢蛋白、胶质纤维酸性蛋白荧光强度较强,而特异性胚胎抗原4、波形蛋白荧光强度较弱。RT-PCR检测显示,与诱导前相比,条件培养基诱导后的羊膜上皮细胞的巢蛋白、胶质纤维酸性蛋白、微管相关蛋白mRNA的表达增强,而平滑肌22α、Sox-2及Nanog mRNA的表达减弱。说明体外诱导的大鼠羊膜上皮细胞可成功分化为类神经干细胞。     

红景天苷体外诱导大鼠骨髓间充质干细胞分化为神经元样细胞*◇

背景：前期实验证明红景天苷能诱导骨髓间充质干细胞向神经元样细胞定向分化,但是具体的影响方式尚不清楚。 目的：以骨髓间充质干细胞为研究对象,进一步探讨红景天苷诱导其向神经元样细胞定向分化的作用方式和分子机制。 方法：选取第2代Wistar大鼠骨髓间充质干细胞,按照不同的诱导剂分为维甲酸诱导组、红景天苷诱导组和对照组,通过不同的时间点对细胞进行观察。 结果与结论：两诱导组细胞不同时间点神经干细胞标志物巢蛋白、神经细胞分化相关的兔抗微管蛋白和神经微管相关蛋白2表达阳性率均高于对照组(P < 0.01);神经胶质纤维酸性蛋白阳性率维甲酸组显著高于红景天苷组(P < 0.01)。Real Time-PCR结果显示,维甲酸和红景天苷诱导不同时间,两组细胞均有神经细胞相关基因神经元特异性烯醇化酶、神经微管相关蛋白2 mRNA表达,与诱导时间有关且不完全相同,两组间神经胶质纤维酸性蛋白mRNA的高丰度出现于诱导早期;诱导后两组神经元特异性烯醇化酶蛋白的表达随时间延长显著增加,兔抗微管蛋白表达出现于诱导早期。说明红景天苷能促进骨髓间充质干细胞向神经细胞分化,其诱导效应与维甲酸相似,且向神经元样细胞定向分化方面优于维甲酸。      

Characterization of human mast cells developed in vitro from fetal liver cells cocultured with murine 3T3 fibroblasts.

Cocultures of dispersed human fetal liver cells with murine Swiss 3T3 fibroblasts resulted in the development of human mast cells after 1 to 4 weeks of culture. Mast cells were detected by immunohistochemistry using a murine monoclonal anti-tryptase antibody, before metachromasia appeared with toluidine blue. When subjected to double immunohistochemistry using murine monoclonal anti-chymase and anti-tryptase antibodies, 94% +/- 10% (SD) of the mast cells seen at day 30 of culture were of the MCT type. These results contrast with those obtained with human mast cells derived from cord blood mononuclear cells cocultured with murine 3T3 fibroblasts which are comprised of substantially greater numbers of MCTC cells, averaging 48% +/- 31% (SD) at day 30 of culture. Mast cells developed in vitro from fetal liver cells or cord blood mononuclear cells contained similar amounts (+/- SD) of histamine (0.9 +/- 0.5 pg/cell and 1.1 +/- 1 pg/cell, respectively) and tryptase (1.7 +/- 0.4 pg/cell and 1.9 +/- 1.2 pg/cell, respectively) on day 30 of culture. Fetal-liver-derived mast cells from a 30-day-old culture were identified by immunoelectron microscopy using gold-labelled antitryptase antibody. Typically, these mast cells appeared immature as they had large nuclear to cytoplasmic ratio and a small number of ill-formed cytoplasmic granules. For both fetal-liver- and cord-blood-derived mast cells, there was no evidence of conversion of the MCT type into the MCTC type provided by this study. These results suggest that commitment to develop as an MCT or MCTC type of mast cell may have occurred in mast cell precursors present in fetal liver and cord blood mononuclear cells, prior to granulation.     

Development of T cell precursor activity in the murine fetal liver

The generation of T cell precursors in the liver of murine embryos was studied. The total number of T cell precursors in the liver was measured in thymic organ cultures by a limiting dilution assay. Sixty T cell precursors were detected in the liver at day 11 of gestation. By day 12 the number of precursors showed a 20-fold increase, half of which could be explained by in situ proliferation as ascertained by a fetal liver organ culture assay. By day 13 a further 2 – 3-fold increase was observed. Whereas the number of total liver cells continued to increase, that of T cell precursors declined in the following days, suggesting a massive exit of these cells after day 13. The capacity to generate a TCRB repertoire in the cells was evaluated by a PCR assay. T cell precursors in day 11 fetal liver developed a TCRB repertoire at day 8 of culture. The cells from days 12 – 15 developed an identically diverse repertoire by day 6, suggesting that day 11 precursors are more immature than those of later days. A mechanism for yielding a single wave of T cell precursors in the fetal liver is discussed with a proposed model.     

Age-related capacity of neuroendocrine factors to differentiate T cells in vitro.

The present report shows the capacity of hypothalamic extract (HE) to differentiate bone marrow cells to Thy-1+ cells in vitro. A two-step short-term culture was used. In the first step thymus and pituitary were co-cultured in the presence of HE. Supernatant was then transferred to a bone marrow cell suspension and following a period of culture, the percentage of Thy-1+ cells was determined by a microcytotoxicity assay. Results indicated that: (a) HE from young mice show a very efficient differentiating capacity; (b) HE from young mice is equally efficient when old pituitary, thymus and marrow are used; (c) HE from old donors has no capacity to differentiate T cells; (d) there is a progressive age-related decline of this capacity; and (e) there is a feed-back mechanism involved in this process. It is concluded that hypothalamic factors can regulate the differentiation of T cells and that this effect operates through a mechanism involving pituitary and thymus.     

黄连素诱导大鼠骨髓间质干细胞分化为神经元样细胞

目的:黄连素体外定向诱导SD大鼠骨髓间质干细胞分化为神经元样细胞。方法:用全骨髓细胞悬液体外扩增和纯化骨髓间质干细胞。选用第5代以后骨髓间质干细胞进行诱导分化,用含10 μg/L碱性细胞生长因子(bFGF)的完全培养液预诱导24 h,后更换含黄连素的无血清DMEM诱导骨髓间质干细胞分化为神经元样细胞。免疫组化鉴定神经元烯醇酶(NSE)、神经丝蛋白(NF)、胶质纤维酸性蛋白(GFAP)的表达。结果:大鼠骨髓间质干细胞体外扩增第5代后细胞形态达到均一,成梭形。加黄连素诱导1h-8 h,间质干细胞胞体逐渐增大并伸出细长突起,形似神经细胞。免疫组化显示诱导的神经元样细胞NSE、NF表达阳性,GFAP阴性。结论:黄连素可诱导骨髓间质干细胞分化为神经元样细胞。     

人脐带间充质干细胞体外诱导分化为成纤维细胞

背景：脐带间充质干细胞具有多向分化能力,但其向成纤维细胞分化研究较少。 目的：验证人脐带间充质干细胞向成纤维细胞的分化能力。 方法：采用贴壁法分离脐带间充质干细胞,流式细胞仪分析其表面抗原。取第3代脐带间充质干细胞进行成脂成骨诱导分化,以碱性成纤维细胞生长因子诱导脐带间充质干细胞向成纤维细胞分化。 结果与结论：贴壁法能稳定从脐带中分离出干细胞,脐带间充质干细胞极低表达 CD31、CD45 、CD40、HLA-DR,强表达 CD29、CD90、CD44、CD105。脐带间充质干细胞成脂诱导后油红O染色显示胞浆中充满红色的油滴;成骨诱导后茜素红染色可在细胞密集区见红色的钙结节。碱性成纤维细胞生因子诱导后细胞表达Ⅰ型胶原明显高于对照组。提示贴壁法分离脐带间充质干细胞可靠、纯度高,碱性成纤维细胞生长因子可诱导脐带间充质干细胞向成纤维细胞分化。中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程全文链接：     

黄芩甙体外诱导大鼠骨髓基质细胞成为神经细胞

目的:探讨黄芩甙体外诱导成年大鼠骨髓基质细胞(MSCs)分化为神经细胞的条件。方法:采用黄芩甙诱导6h后,继续维持诱导6d。免疫细胞化学染色评价神经细胞特异性烯醇化酶(NSE)、神经微丝(NF)、胶质纤维酸性蛋白(GFAP)和波形蛋白(vimentin)的表达率;Hoechst33258染色评价细胞存活率。结果:诱导6d后MSCs形态改变,胞体成锥形,突起交织成网。免疫细胞化学染色NSE、NF、GFAP和vimentin表达率分别为70.5%±11.6%,68.3%±13.4%,＜1%,＜1%,细胞存活率为88.4%±5.0%。结论:黄芩甙可以诱导成年大鼠MSCs在体外分化成为神经细胞,该方法将为神经系统细胞移植和基因治疗提供新的思路。     

T cell progenitors emerge earlier than B cell progenitors in the murine fetal liver

The developmental potential of individual cells in the Lin-c-kit+CD45+IL-7R+ (IL-7R+) population from murine fetal liver was investigated using a clonal assay capable of determining the potential of a progenitor to give rise to myeloid, T, and B cells. Unipotent progenitors generating T cells (p-T) or B cells (p-B) but not other types of progenitors were found in the IL-7R+ population. A large proportion of progenitors at day 12 of gestation are p-T, whereas the frequency of p-T dramatically decreases with gestational age. In marked contrast, p-B are very rare by day 12, but they rapidly increase thereafter. These findings strongly suggest that the commitment of multipotent progenitors to T and B cell lineages occurs independently.     

5-氮胞苷诱导体外培养的胚胎干细胞向心肌样细胞分化

目的研究5-氮胞苷(5-aza)体外诱导胚胎干细胞分化为心肌细胞的可行性。方法将P19细胞接种于培养板中或铺有琼脂的培养板中,5μmol/L5-aza培养7d后用不含5-aza的培养基继续培养。倒置显微镜观察细胞跳动情况,用免疫细胞化学、RT-PCR检测及电镜观察等方法鉴定细胞分化。结果5-aza暴露结合悬浮培养可诱导P19细胞分化为有节律跳动的心肌细胞。分化的细胞表达心肌特异的GATA-4、α-MHC mRNA及α-sarcomeric actin、cTnT蛋白,同时透射电镜观察到细胞质内有明显的肌丝。结论5-aza在体外可诱导胚胎干细胞向心肌样细胞分化,悬浮培养有助于细胞的心肌化过程。     

隐丹参酮诱导猴骨髓间质干细胞分化为神经元样细胞

目的： 体外培养猴骨髓间质干细胞（MSCs）并定向诱导分化为神经元样细胞。 方法： 体外分离培养猴MSCs，流式细胞仪检测其表面标志，用含隐丹参酮的无血清L-DMEM诱导MSCs分化为神经元样细胞，免疫细胞化学检测单克隆抗体特异性神经元烯醇化酶（NSE）、神经丝蛋白（NF）、胶质纤维酸性蛋白（GFAP）的表达。 结果： 体外培养的猴MSCs表达CD29、CD44、CD105、CD166，并且具有正常的二倍体核型，不随传代而发生改变。bFGF预诱导24 h 后，隐丹参酮可以将MSCs诱导为神经元样细胞，免疫细胞化学显示NSE、NF表达阳性，阳性率分别为68.3％±3.5％、70.3％±1.5％，而GFAP表达阴性。 结论： 隐丹参酮可以在体外将猴MSCs诱导分化为神经元样细胞。     

肝细胞生长因子诱导骨髓间质干细胞分化为心肌细胞

目的:探讨肝细胞生长因子(HGF)体外诱导骨髓间质干细胞(MSC)定向分化心肌细胞的一种新方法。方法: 分离SD大鼠骨髓MSC,培养至4-6代后,添加HGF(终浓度10 μg/L)持续培养30 d,倒置显微镜下动态观察分化细胞的自律性搏动和对0.1%异丙肾上腺素和无Ca²⁺孵育液的反应,并行心肌肌凝蛋白表达鉴定。结果: 分化第14-20 d骨髓间质干细胞增殖形成集落,10%-50%克隆中开始出现持续节律收缩的细胞群体,节律频率为70-90次/min,异丙肾上腺素加快其搏动速率,无Ca²⁺孵育液则抑制之。细胞心肌肌凝蛋白表达鉴定为心肌细胞。结论: HGF可诱导骨髓间质干细胞分化为心肌细胞,且有较高的诱导效率。     

淫羊藿苷体外诱导小鼠胚胎干细胞分化为心肌细胞

目的研究淫羊藿苷(icariin,ICA)体外诱导小鼠胚胎干细胞(embryonic stem cells,ESCs)ES-E14细胞分化为心肌细胞的作用。方法复苏的ESCs经直接悬浮法形成拟胚体(EBs),应用ICA定向诱导,相差显微镜下观察分化细胞的形态学变化,免疫细胞荧光技术及Western blot(WB)分别检测心肌细胞特异性肌钙蛋白I(TnI)、心室肌球蛋白轻链(Mlc-1v)的蛋白表达及表达量的变化;透射电镜观察分化细胞的超微结构。结果经ICA诱导后第5天的EBs出现了细胞跳动点,ICA诱导后第3天的细胞心肌细胞特异性肌钙蛋白I(TnI)、心室肌球蛋白轻链(Mlc-1v)的蛋白表达均阳性,于诱导后的第3天(早期)、第12天(中期)及第20天(晚期)心肌细胞特异性肌钙蛋白I(TnI)、心室肌球蛋白轻链(Mlc-1v)的表达逐渐增多,晚期明显高于早期及中期;透射电镜下可见大量平行排列的肌丝。结论用直接悬浮法,ICA体外能诱导鼠ESCs分化为心肌细胞,分化的心肌细胞两种心肌特异性结构蛋白量的表达随分化进程的进展逐渐增多。     

小鼠胎肝Sca-1+细胞分化为骨骼肌细胞

探讨小鼠胚胎肝组织中干细胞抗原-1阳性的细胞(Sca-1+细胞)向骨骼肌细胞分化的潜能.取14.5d的小鼠胎肝,制作细胞悬液;用单克隆免疫磁珠细胞分离技术分离Sca-1+细胞;用PCR鉴别Y染色体性别决定区域(SRY)基因序列;将2×103个雄性小鼠Sca-1+细胞输注给经致死剂量(10Gy)60钴全身照射的雌性小鼠体内;于移植后2个月,处死受体小鼠,取骨骼肌组织固定、制片;用免疫组织化学染色和荧光原位杂交检测雌性受体小鼠骨骼肌组织内供体小鼠胎肝Sca-1+细胞向骨骼肌细胞分化情况.结果在骨骼肌组织内发现存在Y染色体阳性的供体来源的细胞,同时呈现骨骼肌组织的部分特征,表型为Dystrophin+/Flt-1-/CD45-F4/80-.提示小鼠胎肝Sca-1+细胞(其中绝大部分是造血干细胞)具有向骨骼肌组织细胞分化的潜能.     

碱性成纤维细胞生长因子体外诱导大鼠骨髓间充质干细胞分化为心肌样细胞

Objective To study the feasibility of basic fibroblast growth factor （bFGF）in inducing bone marrow mesenchymal stem cells(BMSCs) to differentiate into cardiomyocyte-like cells in vitro. Methods SD rat BMSCs were isolated and cultured from rat bone marrow, and then induced by bFGF. The cultured cells were observed by a phase-contrast microscope. The immunohistochemical technique and laser scanning confocal microscope (LSCM) were used for examination of the expression of desmin, α-actin and C-TnT. The ultrastructure of induced cells was observed by a transmission electron microscope. GATA4 andα-MHC expressions were detected by relative quantitative RT-PCR after 7, 21, 28 days of induction respectively. Results After primary cells were cultured for 48 hours,most of them became fusiform fibroblast-like shape with two or three processes and a few of them were flat in shape. The morphology of BMSCs induced by bFGF changed obviously. After being induced by bFGF for one week, the cells became larger and most of them became myocyte-like short column in shape or long shuttle-shape while paralleled. After four weeks, most cells became short column-shape and touched with adjacent cells tightly to form myotube-like structure,with apparent directionality of cell arraying. BMSCs induced by bFGF were identified by the positive staining for desmin, α-sarcomeric actin and C-TnT. Of BMSCs, there were more desmin positive and α-actin-positive cells made up higher of all BMSCs than C-TnT-positive cells. Desmin and α-actin-positive cells were about 33.82% and 58.64%, and C-TnT-positive cells were about 28.94%. Desmin(α-actin ) appeared red, and C-TnT was green under a laser scaning confocal microscopy. Their co-expression appeared yellow. Transmission electron microscope showed that the induced cells were rod in shape and the ovoid nuclei were positioned in the center of the cell. lots of mitochondria, rough endoplasmic reticulum, ribosome and paralleled myofilaments were founded in plasm.RT-PCR assessment showed that the differentiated cells began to express GATA-4 from day 7 to day 28 of differentiation and began to express α-myosin heavy china(α-MHC) fro     

Placenta-derived multipotent cells differentiate into neuronal and glial cells in vitro

Stem cells have great potential for clinical application because of their self-renewal property and ability to differentiate into many types of cells, but because there are ethical and biological limitations with current sources of stem cells, the search continues for more suitable sources of multipotent cells. We have reported previously on a population of multipotent cells isolated from the human term placenta, an ethically unproblematic and easily available source of tissue. These placenta-derived multipotent cells (PDMCs) can differentiate into lineages of mesenchymal tissues, including osteoblasts and adipocytes, as well as non-mesenchymal tissue of neuron-like cells. We further examined the ability of PDMCs to differentiate into all 3 types of neural cells--neurons, astrocytes, and oligodendrocytes--under various induction conditions, including retinoic acid (RA), 1-methyl-3-isobutylxanthine (IBMX), and co-culture with neonatal rat brain cells. PDMCs exhibited outgrowth of processes and the expression of neuron-specific molecules such as neuron-specific enolase upon induction. Co-culture with neonatal rat brain cells also induced neural differentiation. Our results indicate that PDMCs can be differentiated into neural cell types of the human nervous system upon exposure to RA, IBMX, or primary rat brain cells.     

Single transient potassium channels in human neuroblastoma cells induced to differentiate in vitro

Single channel recordings were obtained from inside-out patches of cultured human neuroblastoma cells (cell line SH-SY5Y) treated with a phorbol ester, 12-o-tetradecanoylphorbol-13-acetate (TPA) to induce differentiation. An outward current reversing near the calculated reversal potential for potassium was detected. This channel is transiently active at membrane potentials between -40 and -70 mV but with preceding hyperpolarizing pulses also at more positive potentials, up to +75 mV. The current seems to consist of two components; a slowly activating component at potentials negative to -40 mV and a fast component, more sensitive to 4-aminopyridine, seen at more positive potentials.