bFGF在人胚胎干细胞中自我更新的研究进展

人胚胎干细胞具有自我更新和多向分化的独特生物学特性。维持人和小鼠胚胎干细胞增殖的生长因子不同,白血病抑制因子（LIF）不能维持人胚胎干细胞的生长。目前已经确定了数种维持人胚胎干细胞（hESCs）自我更新的生长因子,其中碱性成纤维细胞生长因子（bFGF）信号系统是人胚胎干细胞自我更新中最重要的调节因素之一。将从bFGF及其受体在人胚胎干细胞中的表达和作用的最新进展进行综述。     

胚胎小鼠纹状体神经干细胞的体外培养和分化

目的：探索胚胎小鼠纹状体神经干细胞(striatum-neural stem cells，^strNSC)的体外培养和分化鉴定方法。方法：无菌条件下分离E15天胚胎小鼠纹状体，制成单细胞悬液，在bFGF和B27存在的培养基中培养扩增，通过免疫细胞化学显色鉴定神经干细胞及其子代细胞的分化方向。结果：培养的部分细胞在B27和bFGF存在的无血清培养基中可以在体外分裂增殖，同时表达神经干细胞特异性抗原nestin，并在撤出B27和bFGF的有血清培养基中向神经细胞和神经胶质细胞分化。结论：胚胎小鼠纹状体存在具有多分化潜能的神经干细胞，它们能在体外培养、传代和自然分化．     

小鼠胚胎干细胞体外培养的新方法

正维持胚胎干细胞(embryonic stem cells,ES)增殖同时抑制其分化倾向,才能保持ES分化全能性~([1-4])。小鼠胚胎干细胞(mouse embryonic stem cells,mESCs)是研究细胞增殖分化等领域的有效手段~([5-6])。mESCs体外培养有无饲养层法和有饲养层法。无饲养层法是加入抑制mESCs分化的白血病抑制因子(1eukemia inhibitory factor,LIF),但LIF价格昂贵,培养代价     

切应力诱导间充质干细胞分化成内皮细胞的研究

目的研究绿色荧光蛋白（GFP）小鼠骨髓间充质干细胞（MSCs）体外分离培养及扩增及其在流体剪切力条件下向内皮细胞（EC）定向分化能力。方法选用GFP小鼠作为研究对象,分离培养骨髓间充质干细胞,并在体外进行细胞的扩增和传代。应用流体剪切力刺激方法对骨髓间充质干细胞进行诱导,并观测其对GFP小鼠骨髓间充质干细胞分化为内皮细胞的积极作用,对其结果进行免疫荧光检测,计算阳性细胞比例,统计分析。结果GFP小鼠骨髓间充质干细胞每扩增一代,细胞数量增加5-8倍。检测诱导后MSCs,结果显示在诱导3 d时出现vWF表达阳性细胞。结论GFP小鼠MSCs在体外的培养扩增能力强,MSCs在流体剪切应力的作用下可以转化成内皮细胞。     

人胚胎成纤维细胞对人胚胎生殖细胞生长的作用

目的：研究人胚胎成纤维细胞对人胚胎生殖细胞（EG细胞）生长的作用。方法：采用组织块体外培养法体外培养人EG细胞,不添加任何细胞因子,利用源于胚胎组织自身的成纤维细胞作为饲养层,收集培养3d和9d的上清液,用抗体夹心ABC-ELISA法定量检测其白血病抑制因子（LIF）、干细胞生长因子（SCF）和碱性成纤维细胞生长因子（bFGF）的含量。培养的细胞用免疫细胞化学法进行SSEA-3、OCT-4的检测。结果：培养9d的上清液中3种因子均含量为LIF55．25pg／ml、SCF90．39pg／ml、bFGF26．06pg／ml．均高于培养3d相应的平均含量。培养的细胞SSEA-3、OC-4呈强阳性表达。结论：上清液中LIF、SCF和bFGF的含量与胚胎成纤维细胞的生长呈正比,胚胎成纤维细胞能分泌这些细胞因子,以维持EG细胞体外增殖并抑制其分化。     

小鼠胚胎干细胞的体外培养及诱导分化成酪氨酸羟化酶阳性神经元

探索小鼠胚胎干细胞 (ES)在体外培养及向酪氨酸羟化酶阳性神经元诱导分化的可能性。将小鼠胚胎干细胞在含有白血病抑制因子 (LIF)的ES培养基中扩增 ,并通过以下几个步骤 :胚胎体的形成、巢蛋白 (Nestin)阳性细胞的筛选、Nestin阳性细胞的体外扩增及撤除碱性成纤维细胞生长因子等后观察向酪氨酸羟化酶阳性神经元的分化。结果表明小鼠胚胎干细胞在含有LIF的特定培养基中能够稳定传代并保持不分化状态 ,经过无血清培养基的筛选和培养 ,在SonicHedgehog(SHH)及成纤维细胞生长因子 (fibroblastgrowthfactor 8,FGF8)等细胞因子的作用下能定向分化成酪氨酸羟化酶阳性神经元。这种方法有望为帕金森病等神经变性病的细胞移植治疗提供充足的细胞来源。     

骨髓间充质干细胞及其向肝样细胞分化的潜能

背景：研究表明,在一定条件下骨髓间充质干细胞可诱导分化为肝样细胞,为治疗急性肝衰竭等终末期肝病提供了新的思路。 目的：对骨髓间充质干细胞的发现、分离培养、诱导分化及应用前景等方面做一综述。 方法：计算机检索中国期刊网全文数据库以及PubMed数据库1999至2014年期间有关骨髓间充质干细胞及其向肝样细胞分化的文章。检索词分别为“肝样细胞,骨髓间充质干细胞,细胞分化”和“hepatocyte-like cells,bone marrow mesenchymal stem cells,differentiation”。最后选择52篇文章纳入结果分析。 结果与结论：目前,肝组织工程的首要问题是寻找性状稳定具有肝特异性功能的种子细胞,成熟肝细胞获取难度较大,并具有产生免疫排斥反应、体外培养困难等缺陷,严重限制了肝移植的开展。骨髓间充质干细胞具有多向分化、自我更新快、易于扩增及培养等优点,被认为是最有前途的细胞来源。已有研究表明骨髓间充质干细胞在体内外均可分化为肝细胞,并具有肝细胞的合成和分泌功能。但如何大量扩增此类细胞的同时又能保持其良好的分化潜能、体外培养的最佳条件、诱导分化机制和临床应用的安全性等尚需进一步研究和探讨。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：     

利用细胞外基质大规模扩增临床级人脂肪间充质干细胞

背景:如何运用无血清培养体系大规模扩增处于未分化状态的脂肪间充质干细胞,并使其保持"干性"是脂肪间充质干细胞临床应用转化中急待解决的难题。目的:建立含细胞外基质的脂肪间充质干细胞体外培养系统,验证其扩增细胞的高效性、有效性及安全性。方法:在无血清培养条件下,将体外分离得到的脂肪间充质干细胞分别接种在包被细胞外基质的培养板和传统二维塑料培养板上。经过体外扩增后,比较2种条件下细胞数量、细胞表面标记物表达、细胞衰老状况以及体外多向分化能力(诱导成脂、成骨和成软骨)的差异,考察脂肪间充质干细胞在含细胞外基质的培养条件下扩增后的临床安全性。结果与结论:脂肪间充质干细胞扩增到第5代时,包被细胞外基质培养板的细胞产量已经是传统二维塑料培养板的10倍以上,流式细胞检测表明,在含细胞外基质条件下扩增的脂肪间充质干细胞仍保持了干细胞表面特定标记物的表达。细胞衰老检测结果显示,使用包被细胞外基质的培养板扩增脂肪间充质干细胞至第15代时,细胞仍几乎无老化现象,而使用二维塑料培养板扩增的细胞在第5代时已出现明显老化,传代后细胞增殖能力明显下降。体外多向诱导分化实验显示,脂肪间充质干细胞在含细胞外基质条件下扩增至第15代时仍具有成脂、成骨和成软骨的分化功能,并且与第5代时没有明显差异,同时显著优于传统培养条件下的第5代脂肪间充质干细胞。染色体核型分析及小鼠成瘤性试验结果表明,脂肪间充质干细胞在含细胞外基质条件下扩增后仍具备临床应用的安全性。以上结果证实,含细胞外基质的无血清培养系统可以更高效且安全地扩增出具有临床应用潜能的脂肪间充质干细胞。     

胎盘源间充质干细胞对T淋巴细胞体外增殖的影响

目的从人胎盘组织中分离培养获得间充质干细胞（mesenchymal stem cells,MSCs）,并进一步研究其对T淋巴细胞体外增殖的影响。方法首先从胎盘组织中分离培养胎盘间充质干细胞（PMSCs）,在体外观测其形态,并通过细胞表面抗原表达、分化潜能等特征进行鉴定;然后将体外分离培养扩增的PMSCs,按照不同比例加入双向混合淋巴细胞培养体系（mixed lymphocyte reaction,MLR）中,共同培养6d后,测定T淋巴细胞的增殖。结果从人胎盘组织中分离培养获得问充质干细胞,具有与骨髓间充质于细胞（BMSCs）极为相似的细胞形态及细胞表面标志,表达CD29、CD44和CD105,不表达CD34、CD45、CD106和HLA—DR,并且还具有与BMSCs相似的跨胚层分化能力,能在一定条件下被诱导分化出神经元样细胞。PMSCs与同种异体混合淋巴细胞共同培养能抑制T淋巴细胞的体外增殖。结论胎盘组织是MSCs的有效来源,PMSCs具有与BMSCs相似的生物学特性及免疫调节机制。它为问充质干细胞的研究提供了又一重要的细胞来源。     

维甲酸诱导小鼠胚胎干细胞向神经样干细胞分化

目的探讨维甲酸（RA）诱导体外培养的小鼠胚胎干细胞（ESC）向神经样干细胞定向分化。方法在无白血病抑制因子（LIF）存在的条件下,将体外培养的ESC悬浮培养4天,形成拟胚体（EB）,再经RA诱导4天后进行细胞冰冻切片,行免疫细胞化学染色计数生殖特异性基因Oct-4和神经干细胞特异性标志物Nestin的表达百分率。结果经诱导的ESC呈现Oct-4阳性细胞百分率为67．34％,而Nestin阳性细胞百分率为36．52％。结论体外培养的小鼠ESC经RA诱导后有部分细胞定向诱导分化为神经样干细胞。     

Leukemia Inhibitory Factor in Human Reproduction

PROBLEM: Leukemia inhibitory factor (LIF) is a pleiotropic cytokine of the interleukin-6 family and has different biological actions in various tissue systems. Although named for its ability to inhibit proliferation of a myeloid leukemic cell line by inducing differentiation, it also regulates the growth and differentiation of embryonic stem cells, primordial germ cells, peripheral neurons, osteoblasts, adipocytes, and endothelial cells. LIF is crucial for successful implantation of the embryo in mice. Currently, there is an accumulation of data about the role of LIF in human reproduction. METHOD OF STUDY: This review of the literature and of our studies focuses on the expression, regulation, and effects of LIF in the human endometrium, fallopian tube, and ovarian follicle. RESULTS: Human endometrium expresses LIF in a menstrual cycle-dependent manner. Maximal expression is observed between days 19 and 25 of the menstrual cycle, coinciding with the time of implantation. Various cytokines and growth factors induce endometrial LIF expression in vitro. LIF receptor is expressed in endometrial tissue throughout the menstrual cycle and on human blastocysts in a stage-dependent manner. Affecting the trophoblast differentiation pathway toward the adhesive phenotype, LIF plays a role in implantation. LIF is also expressed and secreted by the epithelial cells of the fallopian tube. Its increased expression in the tubal stromal cell cultures by the inflammatory cytokines suggests a link between salpingitis and ectopic implantation in the tube. The rising follicular fluid LIF level around the time of ovulation indicates that LIF may play a role in ovulatory events, early embryonic development, and implantation. CONCLUSIONS: There is growing evidence that LIF may be one of the entities that plays a role in human reproduction.     

Localization of the Murine Leukemia Inhibitory Factor Gene Near the Centromere on Chromosome 11

Abstract

Leukemia inhibitory factor (LIF) is a glycoprotein with divergent activities: It induces the differentiation of certain myeloid leukemic cells, inhibits the differentiation of embryonic stem cells, and promotes bone remodelling in vivo and in vitro. The murine LIF gene has been assigned to the proximal region of chromosome 11 at sub-bands A1-A2, by analysis of a panel of mouse x Chinese hamster somatic cell hybrids and by in situ hybridization. Interestingly, the proximal portion of chromosome 11 has been shown, by virtue of its parental origin effects, to contain gene(s) involved in fetal growth. It is also interesting that there is a preponderance of chromosome 11 abnormalities in embryonal carcinoma cells. The localization of the murine LIF gene confirms the homology of a portion of murine chromosome 11 with human chromosome 22q, the site of the human LIF gene.     

The development of a quantitative RIA for basic fibroblast growth factor using polyclonal antibodies against the 157 amino acid form of human bFGF: The identification of bFGF in adherent elicited murine peritoneal macrophages

Polyclonal antibodies which have the capacity to neutralize the biological activity of basic fibriblast growth factor (bFGF) in vitro, have been raised in rabbits against the 157 amino acid form of bFGF purified from human placenta. In a dot blot assay the anti-bFGF antibodies do not recognize the acidic form of FGF (aFGF) with which the basic form shares significant amino acid sequence homology. As determined by immunoblotting, bFGF antibodies recognized only bFGF in a mixture of placentally derived heparin-binding proteins, demonstrating the specificity of these antibodies. Using the anti-human bFGF antibodies, we have developed a solid-phase competitive radioimmunoassay sensitive to 7.8 ng/ml (0.4 pmol/ml) for bFGF. aFGF does not compete with bFGF for binding to the antibodies in the radioimmunoassay even at 2.04 μg/ml. The specificity of the assay was further demonstrated by a lack of competition of cytochrome C, myoglobin, epidermal growth factor or bovine serum albumin with bFGF for binding to the antibodies. We have identified bFGF in extracts of adherent thioglycollate-stimulated mouse peritoneal macrophages by immunological criteria including the ability of the extract to compete with ¹²⁵I-bFGF for binding to affinity-purified anti-human bFGF antibodies in the RIA and the ability of these antibodies in inhibit the bFGF-like biological activity of the macrophage extract.     

碱性成纤维细胞生长因子对体外培养的乳兔软骨细胞中p53 mRNA表达的影响

目的 探讨在乳兔关节软骨细胞体外培养过程中,成纤维细胞生长因子（bFGF）对p53mRNA表达水平的影响及意义。方法 原代体外培养乳兔关节软骨细胞并传代,实验组加入10ng／ml的bFGF,光镜下观测各代细胞形态学变化,RT—PCR检测各代细胞中p53基因在mRNA水平上的表达。结果光镜观察体外培养的软骨细胞,对照组第4代培养细胞始出现凋亡细胞,bFGF组第7代出现少量凋亡细胞;RT—PCR检测bFGF组p53的目的基因指数（p53吸光光度值,β—actin吸光光度值）明显低于对照组（P〈0．05）。结论 在体外培养的兔关节软骨细胞中bFGF下调p53基因mRNA水平表达。     

Propranolol inhibits angiogenesis via down-regulating the expression of vascular endothelial growth factor in hemangioma derived stem cell

Background: Oral propranolol (PRN) has recently been shown to be highly effective for infantile hemangiomas (IHs), and is currently recommended as the first-line treatment of complicated IHs. However, the therapeutic mechanism(s) still remain unclear. Methods: In this study, we tested hemangioma-derived stem cells for expression of vascular endothelial growth factor (VEGF) in vitro and studied the inhibition of VEGF expression. We used PCR, Elisa, Western blotting and immunohistochemistry in vivo and in vitro trial. Results: The study demonstrated that application of PRN at a “normal” concentration equivalent to plasma concentration did not inhibit proliferation or promote apoptosis of hemangioma derived stem cells (HemSCs) isolated from IH patients. PRN suppressed expression of vascular endothelial growth factor (VEGF) and basic Fibroblast Growth Factor (bFGF) in HemSCs in vitro. Morphological, histological and immunohistological improvement were observed in vivo using murine IH model in which HemSCs pre-treated with PRN were implanted into BALB/c-nu mice. In the pre-treated HemSC grafts, mean micro-vessel density (MVD) significantly decreased and protein levels of VEGF markedly decreased, while bFGF was still detectable. Conclusions: The results suggested PRN inhibited angiogenesis via down-regulating the expression of vascular endothelial growth factor in hemangioma derived stem cell. These findings provide critical insight into the potential mechanisms of PRN action on IH.     

碱性成纤维细胞生长因子及胰岛素样生长因子1对精原干细胞增殖凋亡影响的机制

文题释义：碱性成纤维细胞生长因子：是细胞生长和分化的重要调节因子,具有促血管生成、细胞增殖、细胞趋化、细胞迁移等活性,在细胞分化和机体发育过程中发挥重要作用。碱性成纤维细胞生长因子通过与细胞膜表面的特异性配体结合,进而引发细胞内的一系列级联反应,从而产生各种生物学效应。 胰岛素样生长因子1：是多功能细胞增殖调控因子,主要分布在肝脏中,其与胰岛素样生长因子2、胰岛素及其受体一起构成了胰岛素样生长因子家族,其对细胞生长和代谢具有多效作用。 背景：生长因子作为体外细胞培养和体内细胞生长及增殖必需的调节因子,一直被广泛的关注。 目的：探讨碱性成纤维细胞生长因子(basic fibroblast growth factor,bFGF)与胰岛素样生长因子1(insulin-like growth facter,IGF-1)联合作用对小鼠精原干细胞增殖、凋亡的影响。 方法：从6-8 d龄昆明雄性小鼠睾丸内分离培养精原干细胞并进行鉴定。将精原干细胞接种于经丝裂霉素C处理过的胚胎成纤维细胞饲养层上,分组干预：对照组加入正常DMEM培养基进行培养;bFGF、IGF-1组分别加入含20 μg/L bFGF、20 μg/L IGF-1的DMEM培养基进行培养;bFGF+IGF-1组同时加入含20 μg/L bFGF及20 μg/L IGF-1的DMEM培养基进行培养。采用CCK-8、EDU染色法分别检测精原干细胞增殖活性,流式细胞仪检测精原干细胞生长周期和细胞凋亡情况,Western blot检测增殖和凋亡相关蛋白PCNA、Bax、Bcl-2的表达。 结果与结论：①与对照组比较,bFGF组、IGF-1组、bFGF+IGF-1组吸光度值显著升高,与bFGF组、IGF-1组比较,bFGF+IGF-1组吸光度值进一步升高(P < 0.05),EDU染色得到与CCK-8实验一致的结论;②bFGF+IGF-1组S+G₂/M期细胞比例明显高于其他3组(P < 0.05),IGF-1组、bFGF组S+G₂/M期细胞比例高于对照组(P < 0.05);③与对照组比较,bFGF组、IGF-1组、bFGF+IGF-1组凋亡细胞降低;与bFGF组、IGF-1组比较,bFGF+IGF-1组凋亡细胞进一步降低;④与对照组比较,bFGF组、IGF-1组、bFGF+IGF-1组细胞中Bax蛋白相对表达水平显著下降(P < 0.01),Bcl-2和PCNA蛋白相对表达水平均显著升高(P < 0.05)。与bFGF组、IGF-1组比较,bFGF+IGF-1组细胞中Bax蛋白相对表达水平进一步下降(P < 0.01),Bcl-2和PCNA蛋白相对表达水平进一步升高(P < 0.05);⑤结果表明,bFGF、IGF-1通过上调PCNA和Bcl-2蛋白的表达,下调Bax蛋白的表达,促进细胞增殖,抑制细胞凋亡,二者联合作用效果最佳。 ORCID: 0000-0001-5693-3713(李宏) 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     

Radioimmunoassay of Serum Thymic Factor (FTS)

We established a radioimmunoassay (RIA) method which enables a quantitative estimation of serum thymic factor (FTS). This assay is based on the displacement of ¹²⁵I-(Lys[Tyr] ³)-FTS bound to the anti-FTS antibodies by FTS. Formaldehyde-fixed Staphylococcus aureus Cowan I cells were used to precipitate the antigen-antibody complex. The anti-FTS antiserum was raised in rabbit by repeated injections of FTS-conjugated bovine serum albumin. The antiserum seemed to recognize the carboxy-terminal seven amino acid residues, Lys-Ser-Gln-Gly-Gly-Ser-Asn-OH, of the FTS molecule. As little as 0.5 to 1 pg FTS can be detected by this method.

To measure the FTS content in the serum, a serum sample was pretreated with 10% trichloroacetic acid and then with ethanol for removal of serum proteins. The FTS content in pig serum was around 22 pg/ml, and that in BALB/c mouse serum was 1.3 pg/ml. The FTS contents in the sera of DBA/2, C57BL/6 and (C57BL/6 × DBA/2)F₁ mice were also less than 5 pg/ml. Since more than 70% of FTS exogenously added to pig or mouse serum was recovered, the mouse serum probably contains only a small amount of FTS.