富血小板纤维蛋白对兔骨髓间充质干细胞成软骨分化的影响

目的：观察自体富血小板纤维蛋白（platelet-rich fibrin,PRF）对体外培养的兔骨髓间充质干细胞（Bonemarrowmesenchymalstemcells,BMSCs）成软骨分化的影响。方法：兔心脏采血制备PRF,电镜观察其超微结构;分离培养兔BMSCs,取第3代细胞用于实验．分为PIuF组、阳性对照组、空白对照组。诱导培养21d后,对三组细胞分别进行形态学观察,成软骨鉴定染色（甲苯胺蓝、Ⅱ型胶原免疫组化染色）,软骨相关基因表达检测（Ⅱ型胶原、Aggrecan、SOX9）。结果：PRF组和阳性对照组中BMSCs经诱导后,细胞由长梭形变为三角形、多角形、圆形;甲苯胺蓝、Ⅱ型胶原免疫组化染色均为阳性;Ⅱ型胶原、Aggrecan、SOX9基因表达水平均较高,两组比较无统计学差异,空白对照组未见相关分化现象。结论：PRF在体外可促进兔BMSCs成软骨分化,可作为自体生物材料,在构建组织工程软骨中发挥更好的作用。     

富血小板纤维蛋白对兔骨髓间充质干细胞成软骨分化的影响*

摘要目的：观察自体富血小板纤维蛋白（platelet-rich fibrin, PRF）对体外培养的兔骨髓间充质干细胞（Bone marrow mesenchymal stemcells, BMSCs）成软骨分化的影响。方法：兔心脏采血制备PRF,电镜观察其超微结构;分离培养兔BMSCs,取第3代细胞用于 实验,分为PRF组、阳性对照组、空白对照组。诱导培养21d 后,对三组细胞分别进行形态学观察,成软骨鉴定染色（甲苯胺蓝、II 型胶原免疫组化染色）,软骨相关基因表达检测（Ⅱ型胶原、Aggrecan、SOX9）。结果：PRF 组和阳性对照组中BMSCs经诱导后,细 胞由长梭形变为三角形、多角形、圆形;甲苯胺蓝、II 型胶原免疫组化染色均为阳性;Ⅱ型胶原、Aggrecan、SOX9基因表达水平均 较高,两组比较无统计学差异,空白对照组未见相关分化现象。结论：PRF在体外可促进兔BMSCs 成软骨分化,可作为自体生物 材料,在构建组织工程软骨中发挥更好的作用。     

兔BMSCs复合纤维蛋白胶在体外分化为角膜基质细胞的研究

目的：探讨体外诱导兔骨髓间充质干细胞（BMSCs）分化为角膜基质细胞的可行性,并观察纤维蛋白胶（FG）作为细胞支架材料的效果。方法：密度梯度法获得BMSCs,体外诱导实验将细胞分为三组：对照组用普通培养皿、BMSCs培养条件并不加角膜基质细胞共培养的条件下培养;非FG共培养组使用普通培养皿并与角膜基质细胞共培养诱导BMSCs分化;FG共培养组使用铺有FG的培养皿并与角膜基质细胞共培养诱导BMSCs分化。培养1w及2w后用WestenBlot法检测三组细胞Keratocan的表达,在相差显微镜下进行形态学观察。结果：原代培养的BMSCs表现出成体干细胞潜能,CD29染色阳性,符合骨髓基质干细胞的特征。诱导培养2周后对照组BMSCs融合成单层、呈条索状生长;非FG共培养组部分细胞体积变小、多突起,局部呈梭形生长;FG共培养组细胞生长状态良好,部分细胞呈梭形或纺锤形,与FG生物相容性好。Westen检测结果：BMSCs细胞在纤维蛋白胶或普通培养皿上特定培养条件下均能诱导表达角膜基质细胞的特异性蛋白Keratocan。结论：骨髓间充质干细胞在条件培养基下可分化为角膜基质细胞,有望作为治疗角膜疾病及角膜组织工程的备选材料,纤维蛋白胶组织相容性好,可为组织工程提供移植细胞片。     

阿司匹林对体外培养骨髓基质细胞成骨性分化的影响

目的:探讨阿司匹林对骨髓基质细胞成骨性分化的影响。方法:培养SD大鼠骨髓基质细胞(BMSCs),传代3次后进行成骨诱导分化,诱导培养基中加入不同浓度阿司匹林(0.5、1、2、5、10mmol/L),同时设立对照组。采用cck-8法分析细胞增殖情况。比较阿司匹林组与对照组在细胞碱性磷酸酶(ALP)活性、骨钙素(OC)分泌量、钙结节染色等方面的成骨性差异。结果:阿司匹林无促进细胞增殖活性,而高浓度阿司匹林能够强烈抑制细胞增殖。0.5、1、2mmol/L浓度阿司匹林可促进BMSCs的成骨性分化,中低浓度组碱性磷酸酶含量、骨钙素分泌量在不同阶段显著高于对照组。14天茜素红染色可见中低浓度组钙结节数量高于对照组。结论:中低浓度阿司匹林作用于骨髓基质细胞可促进其成骨细胞特性表达,这表明阿司匹林有促进骨代谢合成的作用。     

基因沉默组织型转谷氨酰胺酶抑制SaOS-2细胞成骨分化

目的研究组织型转谷氨酰胺酶(tissue transglutaminase,TG2)是否参与人SaOS-2细胞系成骨分化过程。方法使用携带短发夹RNA(short hairpin RNA,shRNA)的慢病毒转染SaOS-2细胞以敲减TG2表达,以SaOS-2细胞及转染了含阴性对照shRNA病毒的SaOS-2作为对照组,分别进行体外成骨诱导培养,并进行以下检测:诱导14 d后各组矿化情况(茜素红染色);诱导4、7 d后碱性磷酸酶活性及I型胶原、骨钙素、骨形态发生蛋白-2(BMP-2)的mRNA表达,并与诱导前的表达水平相比较。结果 SaOS-2细胞组及转染阴性对照shRNA组在体外成骨诱导过程中I型胶原、骨钙素、BMP-2的mRNA表达和ALP活性逐渐增加,14 d时形成明显矿化结节,而TG2敲减后的SaOS-2细胞在诱导14 d时矿化水平显著低于对照组,诱导7 d时ALP活性及I型胶原、骨钙素、BMP-2的mRNA表达水平显著低于对照组。结论组织型转谷氨酰胺酶参与SaOS-2细胞体外成骨分化及矿化。     

阿司匹林对体外培养骨髓基质细胞成骨性分化的影响

目的：探讨阿司匹林对骨髓基质细胞成骨性分化的影响。方法：培养SD大鼠骨髓基质细胞（BMSCs）,传代3次后进行成骨诱导分化,诱导培养基中加入不同浓度阿司匹林（0.5、1、2、5、10mmol/L）,同时设立对照组。采用cck-8法分析细胞增殖情况。比较阿司匹林组与对照组在细胞碱性磷酸酶（ALP）活性、骨钙素（OC）分泌量、钙结节染色等方面的成骨性差异。结果：阿司匹林无促进细胞增殖活性,而高浓度阿司匹林能够强烈抑制细胞增殖。0.5、1、2mmol/L浓度阿司匹林可促进BMSCs的成骨性分化,中低浓度组碱性磷酸酶含量、骨钙素分泌量在不同阶段显著高于对照组。14天茜素红染色可见中低浓度组钙结节数量高于对照组。结论：中低浓度阿司匹林作用于骨髓基质细胞可促进其成骨细胞特性表达,这表明阿司匹林有促进骨代谢合成的作用。     

心肌微环境对诱导大鼠骨髓间充质干细胞分化为心肌样细胞的影响

目的:探讨体外心肌微环境对骨髓间充质干细胞(BMSCs)分化为心肌样细胞的诱导作用。方法:分离大鼠骨髓间充质干细胞(BMSCs)和心肌细胞并在体外培养纯化。以2×10~4/mL的细胞密度种植心肌细胞,培养72h后收集上清,在BMSCs的培养基内加入心肌细胞培养上清诱导BMSCs分化为心肌样细胞,实验共分6组:10%、20%、30%、40%及50%心肌细胞培养上清组及含10%胎牛血清的对照组,均诱导BMSCs7d,每天在倒置显微镜下观察细胞的形态变化;应用免疫细胞化学技术检测不同浓度心肌细胞培养上清组诱导7d后BMSCs中a-平滑肌肌动蛋白(a-sMA)、β-肌动蛋白(β-actin)、心肌特异性肌钙蛋白T(Troponin-T)、CD31以及FactorⅧ的表达。结果:心肌细胞培养上清组诱导BMSCs7d后,细胞的形态没有改变。10%、20%、30%、40%及50%心肌细胞培养上清组a-sMA、。-actin以及Troponin-T的表达均呈阳性,以30%心肌细胞培养上清组的蛋白表达量最高(P<0.01),而CD31和FactorⅧ的表达呈阴性。结论:心肌细胞的培养上清能够诱导BMSCs分化为心肌样细胞,且30%心肌细胞培养上清是诱导BMSCs向心肌样细胞分化的最适浓度。     

大鼠骨髓基质干细胞的分离培养与向神经元样细胞诱导分化的实验研究

目的 探讨大鼠骨髓基质干细胞的提取、分离培养和体外扩增的最佳条件,研究其在体外培养中定向诱导分化为神经元样细胞的可能。方法 通过密度梯度离心和贴壁培养法从成年大鼠骨髓中分离骨髓基质干细胞,进行培养扩增,观察其生长特性;用2-巯基乙醇(β-mercaptoethanol,β-ME)对传代细胞诱导分化,并通过免疫细胞化学染色鉴定分化细胞的类型。结果 原代培养时形成由基质干细胞组成的细胞集落,细胞集落14d时接近融合,传代后,细胞体积变大,约5～7d传代一次。β-ME诱导后,70％以上的细胞在形态上呈神经元样,免疫细胞化学染色呈NSE阳性,GFAP阴性,说明诱导分化的细胞为神经元,而不是星形胶质细胞。结论 骨髓基质干细胞在体外培养条件下生长良好,并可连续传代;在β-ME作用下可被诱导分化为神经元样细胞。     

淫羊藿素促进BMSCs成软骨分化的研究北大核心CSCD

研究淫羊藿素在GDF-5诱导BMSCs成软骨分化过程中的作用。全骨髓贴壁法分离培养SD大鼠骨髓间充质干细胞(BMSCs),取P3代细胞随机分成4组:对照组,淫羊藿素(Icaritin)组,Growth differentiation factor 5(GDF-5)组,Icaritin+GDF-5联合组。连续诱导培养14 d,倒置相差显微镜观察细胞形态,Alcian Blue染色检测细胞的蛋白聚糖改变,RT-PCR检测软骨分化标记基因Aggrecan、COL2、Sox9及COL1的表达情况,Western Blot检测COL2和COL1蛋白表达水平。结果提示,与对照组及GDF-5组相比,Icaritin+GDF-5联合组蛋白聚糖染色更深;软骨分化标记基因Aggrecan、COL2、Sox9明显增加;Ⅱ型胶原蛋白表达量均明显增加。淫羊藿素能够促进GDF-5诱导BMSCs成软骨分化。     

淫羊藿素促进BMSCs成软骨分化的研究

研究淫羊藿素在GDF-5诱导BMSCs成软骨分化过程中的作用。全骨髓贴壁法分离培养SD大鼠骨髓间充质干细胞(BMSCs),取P3代细胞随机分成4组:对照组,淫羊藿素(Icaritin)组,Growth differentiation factor 5(GDF-5)组,Icaritin+GDF-5联合组。连续诱导培养14 d,倒置相差显微镜观察细胞形态,Alcian Blue染色检测细胞的蛋白聚糖改变,RT-PCR检测软骨分化标记基因Aggrecan、COL2、Sox9及COL1的表达情况,Western Blot检测COL2和COL1蛋白表达水平。结果提示,与对照组及GDF-5组相比,Icaritin+GDF-5联合组蛋白聚糖染色更深;软骨分化标记基因Aggrecan、COL2、Sox9明显增加;Ⅱ型胶原蛋白表达量均明显增加。淫羊藿素能够促进GDF-5诱导BMSCs成软骨分化。     

Nucleoside diphosphate kinase Nm23-M1 involves in oligodendroglial versus neuronal cell fate decision in vitro

The adult glial progenitor cells were recently shown to be able to produce neurons in central nervous system (CNS) and to become multipotent in vitro. Although the fate decision of glial progenitors was studied extensively, the signals and factors which regulate the timing of neuronal differentiation still remain unknown. To elucidate the mechanisms underlying the neuronal differentiation from glial progenitors, we modified the gene expression profile in NG2⁺ glial progenitor cells using enhanced retroviral mutagen (ERM) technique followed by phenotype screening to identify possible gene(s) responsible for glial-neuronal cell fate determination. Among the identified molecules, we found the gene named non-metastatic cell 1 which encodes a nucleoside diphosphate kinase protein A (Nm23-M1 or NME1). So far, the Nm23 members have been shown to be involved in various molecular processes including tumor metastasis, cell proliferation, differentiation and cell fate determination. In the present study, we provide evidence suggesting the role of NME1 in glial-neuronal cell fate determination in vitro. We showed that NME1 is widely expressed in neuronal structures throughout adult mouse CNS. Our immunohistochemical results revealed that NME1 is strongly colocalized with NF200 through white matter of spinal cord and brain. Interestingly, NME1 overexpression in oligodendrocyte progenitor OLN-93 cells potently induced the acquisition of neuronal fate, while its silencing was shown to promote oligodendrocyte differentiation. Furthermore, we demonstrated that dual-functional role of NME1 is achieved through cAMP-dependent protein kinase (PKA). Our data therefore suggested that NME1 acts as a switcher or reprogramming factor which involves in oligodentrocyte versus neuron cell fate specification in vitro.     

体细胞重编程逆转为干细胞的研究进展

目前细胞和发育生物学上的研究成果为生物医学研究提供了广泛的前景.将完全分化的细胞重编程,不经过胚胎逆转为多能干细胞状态,这点燃了再生医学应用的新希望,这一成果从法律、道德、伦理等不同方面被人们所接受.通过体细胞克隆胚胎获得干细胞所面临的破坏胚胎的伦理限制,促使研究者去寻求将分化细胞重编程逆转为干细胞的新方法.主要论述了体细胞重编程的原理、过程及不经过胚胎逆转为多能干细胞的方法.     

胚胎干细胞起源的探讨

目前胚胎干细胞(ESCs)建系的取材来源包括桑椹胚的卵裂球、囊胚的内细胞团(ICM)、上胚层细胞和原始生殖细胞(PGCs),甚至从新生鼠睾丸细胞也分离得到类ES样细胞系。这就提出了一个问题,什么是ESCs最接近的体内细胞来源。传统观念常常把ESCs等同于ICM细胞,也有学者认为ESCs更象上胚层细胞,而在已知的分子标记基因方面,ESCs所具有的特征更接近体内早期生殖细胞。不清楚ESCs最接近的体内细胞来源,可能是制约许多品系小鼠和大多哺乳类动物建系成功率提高的原因之一。ESCs系与EG细胞系的分离条件不同表明,加强对ESCs多能性维持基因调控研究具有重要意义。本文从ESCs的经典概念及其发展,早期胚胎细胞和生殖细胞发育规律,早期胚胎细胞、早期生殖细胞和ESCs的关系等方面进行综合分析,认为ESCs可能有多种接近的体内细胞来源。进一步应通过对ESCs建系不同的取材细胞和不同品系的ESCs间进行比较研究,以便弄清ESCs的来源和转化机制,为提高不同物种ESCs建系效率提供理论支持。     

Induction of γδT cells from HSC-enriched BMCs co-cultured with iPSC-derived thymic epithelial cells

T cells bearing γδ antigen receptors have been investigated as potential treatments for several diseases, including malignant tumours. However, the clinical application of γδT cells has been hampered by their relatively low abundance in vivo and the technical difficulty of inducing their differentiation from hematopoietic stem cells (HSCs) in vitro. Here, we describe a novel method for generating mouse γδT cells by co-culturing HSC-enriched bone marrow cells (HSC-eBMCs) with induced thymic epithelial cells (iTECs) derived from induced pluripotent stem cells (iPSCs). We used BMCs from CD45.1 congenic C57BL/6 mice to distinguish them from iPSCs, which expressed CD45.2. We showed that HSC-eBMCs and iTECs cultured with IL-2 + IL-7 for up to 21 days induced CD45.1⁺ γδT cells that expressed a broad repertoire of Vγ and Vδ T-cell receptors. Notably, the induced lymphocytes contained few or no αβT cells, NK1.1⁺ natural killer cells, or B220⁺ B cells. Adoptive transfer of the induced γδT cells to leukemia-bearing mice significantly reduced tumour growth and prolonged mouse survival with no obvious side effects, such as tumorigenesis and autoimmune diseases. This new method suggests that it could also be used to produce human γδT cells for clinical applications.     

Whole cell biocatalysts stabilization for l-carnitine production

We present how whole cells can be used in different ways to stabilize enzyme catalysts in the cell environment to perform biotransformations. Some of the factors which affect their use in biotransformations, such as the nature of the substrate/product, the reusability of cells, the extension of cell viability by cell activation periods or the addition of energetic substrates and the stabilization in solids supports, are considered. The use of sufficiently active enzymes in the cell environment to perform biotransformations within growing, resting, permeabilized, dried, osmotically stressed, freely suspended and immobilized cells, is discussed in the text. The different cell states of enterobacteria, such as Escherichia coli and Proteus sp., can be used to produce l-carnitine from crotonobetaine or d-carnitine substrate, are analyzed.     

树突状细胞与CIK细胞共培养诱生的DCCIK细胞群对肿瘤的杀伤作用

由树突状细胞(DC)与细胞因子诱导的同源杀伤细胞(CIK)的共培养诱生的细胞群(DCCIK)对肿瘤细胞的细胞毒活性的研究。DCCIK细胞体外杀伤肿瘤靶细胞A549(MTT法),效靶比为10∶1、5∶1时杀伤率分别为61%、52%。DCCIK细胞诱导培养3周后,效靶比为10∶1、5∶1时杀伤率分别为64%和56%。数据亦表明DCCIK细胞对靶细胞的杀伤优于CIK细胞。动物体内实验分荷瘤A549、BEL7404和A375三组,每组分(A)DCCIK 化疗、(B)单用化疗。治疗20天、35天后测量各组肿瘤消失率。结果显示:DCCIK 化疗的抑瘤效果明显好于单纯化疗。提示DCCIK细胞有临床应用前景。     

Phthalimide Polymer Donor Guests Enable over 17% Efficient Organic Solar Cells via Parallel‐Like Ternary and Quaternary Strategies

Ternary strategies show over 16% efficiencies with increased current/voltage owing to complementary absorption/aligned energy level contributions. However, poor understanding of how the guest components tune the active layer structures still makes rational selection of material systems challenging. In this study, two phthalimide based ultrawide bandgap polymer donor guests are synthesized. Parallel energies between the highest occupied molecular orbitals of host and guest polymers are achieved via incorporating selnophene on the guest polymer. Solid‐state ¹⁹F magic angle spinning nuclear magnetic spectroscopy, graze‐incidence wide‐angle X‐ray diffraction, elemental transmission electron microscopy mapping, and transient absorption spectroscopy are combined to characterize the active layer structures. Formation of the individual guest phases selectively improves the structural order of donor and acceptor phase. The increased electron mobility in combination with the presence of the additional paths made by the guest not only minimizes the influence on charge generation and transport of the host system but also contributes to increasing the overall current generation. Therefore, phthalimide based polymers can be potential candidates that enable the simultaneous increase of open‐circuit voltage and short‐circuit current‐density via fine‐tuning energy levels and the formation of additional paths for enhancing current generation in parallel‐like multicomponent organic solar cells.     

Conventional, regulatory, and unconventional T cells in the immunologic response to Helicobacter pylori

Infection by the gastroduodenal pathogen Helicobacter pylori elicits a complex immunologic response in the mucosa involving neutrophils, plasma cells, eosinophils, and lymphocytes, of which T cells are the principal orchestrators of immunity. While so-called classical T cells (e.g. T-helper cells) that are activated by peptide fragments presented on antigen-presenting cells have received much attention in H. pylori infection, there exists a diverse array of other T cell populations that are potentially important for the outcome of the ensuing immune response, some of which have not been extensively studied in H. pylori infection. Pathogen-specific regulatory T cells that control and prevent the development of immunopathology associated with H. pylori infection have been investigated, but these cells can also benefit the bacterium in helping to prolong the chronicity of the infection by suppressing protective immune responses. An overlooked T cell population, the more recently described Th17 cells, may play a role in H. pylori-induced inflammation, due to triggering responses that ultimately lead to the recruitment of polymorphs, including neutrophils. The so-called innate or unconventional T cells, that include two conserved T cell subsets expressing invariant antigen-specific receptors, the CD1d-restricted natural killer T cells which are activated by glycolipids, and the mucosal-associated invariant T cells which play a role in defense against orally acquired pathogens in the intestinal mucosa, have only begun to receive attention. A greater knowledge of the range of T cell responses induced by H. pylori is required for a deeper understanding of the pathogenesis of this bacterium and its ability to perpetuate chronic infection, and could reveal new strategies for therapeutic exploitation.