ISOLATION AND CUTURE EMBRYONIC STEM-LIKE CELLS DERIVED HUMAN AMNIOTIC FLUID CELLS

Stem cells are classified into embryonic stem (ES) cells and adult stem cells, which are the progenitors of any cell types of the body or tissues, and have the ability to self-renew and produce one or more differentiated cell types. Stem cells can be widely used to replace dysfunctional cells within a tissue. It is speculated that stem cells may prove to have the potential to treat or cure a myriad of diseases, including Parkinson and Alzheimer diseases, heart disease,diabetes, stroke,spinal cord injuries, and burns. ES cells and em-bryonic germ (EG) cells derived early embryo or primordial germcells (PGCs) of zonads, zonadal ridzes and mesenteries, analozies     

Application of Stem Cells in Tissue Engineering

Stem cells have become an important source of seed cells for tissue engineering because they are relatively easy to expand in vitro and can be induced to differentiate into various cell types in vitro or in vivo. In the current stage, most stem cell researches focus on in vitro studies, including in vitro induction and phenotype characterization. Our center has made a great deal of effort in the in vivo study by using stem cells as seed cells for tissue construction. We have used bone marrow s…     

神经干细胞和脊髓损伤

Preface 1. Concept of neural stem cells Stem cells are multipotential cells that have the capacity to proliferate in an undifferentiated state, to self-renew, and to give rise to all the cell types of a particular tissue.     

NEURAL STEM CELLS AND SPINAL CORD INJURY

Preface1. Concept of neural stem cells Stem cells are multipotential cells that have the capacity to proliferate in an undifferentiated state, to self-renew, and to give rise to all the cell types of a particular tissue. In the developing embryo, neuroepithelial cells of the neural tube generate a variety of lineage-restricted precursor cells that migrate and differentiate into neurons, astrocytes, and oligodendrocytes. These stem cells could potentially be used to promote neurogenesis follo…     

Immunology of stem cells and cancer stem cells

The capacity of pluri-potent stem cells to repair the tissues in which stem cells reside holds great promise in development of novel cell replacement therapeutics for treating chronic and degenerative diseases. However, numerous reports show that stem cell therapy, even in an autologous setting, triggers lymphocyte infiltration and inflammation. Therefore, an important question to be answered is how the host immune system responds to engrafted autologous stem cells or allogeneous stem cells. In this brief review, we summarize the progress in several related areas in this field, including some of our data, in four sections： （1） immunogenicity of stem cells; （2） strategies to inhibit immune rejection to allograft stem cells; （3） immune responses to cancer stem cells; and （4） mesenchymal stem cells in immune regulation. Improvement of our understanding on these and other aspects of immune system-stem cell interplay would greatly facilitate the development of stem cell-based therapeutics for regenerative purposes. Cellular ＆ Molecular Immunology.     

Stem cell niche, the microenvironment and immunological crosstalk

The concept of stem cells, their physiological existence, the intricate anatomical localization, the known and the unknown functions, and their exclusive utility for the purpose of regenerative medicine, are all now encompassed within an emergent question, ＇how compatible these cells are immunologically？＇ Indeed, the medical aspects of stem cells are dependent on a large number of queries based on the basic properties of the cells. It has greatly been emphasized to probe into the basic research on stem cells before any successful therapeutic attempts are made. One of the intricate aspects of the adult stem cells is its immunological behavior in relation to the microenvironmental associates, the stromal cells in the presence of a suitable target. Cellular ＆ Molecular Immunology.     

Effect of Microgravity on the Mesenchymal Stem Cell (MSC) Characteristics of Limbal Fibroblasts

正The research group was interested in the therapeutic potential of limbal fibroblasts,which are present in the corneal limbus.Recently,in much stem cell research,researchers and advocates are stressing the importance of utilizing cells from the niche which they will target.This means,that adipose tissue and bone marrow derived stem cells,are likely not appropriate and even dangerous to apply u-     

Biological characteristics and immunoregulation of exosomes derived from mesenchymal stem cells北大核心

BACKGROUND: Clarifying the synthesis and regulation of exosomes derived from mesenchymal stem cells is of great significance to the research and application of exosomes in the future. OBJECTIVE: To summarize the biological characteristics in exosomes derived from different mesenchymal stem cells and the role of these exosomes in the immune regulation, which hopes to find new breakthroughs in the study of exosomes in the future and provide ideas for cell-free therapy. METHODS: The articles were searched on PubMed, CNKI and Wanfang using the keywords of “stem cells, mesenchymal stem cells, exosomes, immunomodulation, inflammatory mediator, biological characteristics of exosomes, biological characteristics of mesenchymal stem cells, regeneration” in Chinese and English. Finally, 105 articles were included for review. RESULTS AND CONCLUSION: Mesenchymal stem cells are a type of pluripotent stem cells that exist widely in various tissues of the body. Mesenchymal stem cells not only have stem cell characteristics, but also play an important role in the immunosuppressive properties. Mesenchymal stem cells had been clinically applied for the treatment of many diseases. Therefore, mesenchymal stem cells were used to manage novel coronavirus pneumonia, and had ideal treatment effect. Exosomes are endosome-derived nanometer-scale vesicles (40–200 nm in diameter). Exosomes derived from mesenchymal stem cells have the same immune regulation function as its maternal cells, including that carrying immunosuppressive factors, promoting macrophages polarization into M2 type, preventing differentiation of pro-inflammatory T cell subsets and inhibiting antigen presentation. © 2022, Publishing House of Chinese Journal of Tissue Engineering Research. All rights reserved.     

nduced pluripotent stem cell （iPSCs） and their application n immunotherapy

The ever-improving technology to generate induced pluripotent stem cells （iPSCs） has increased their potential use as novel candidates for disease modeling, drug screening, regenerative medicine and cell therapy. Indeed, iPSCs offer extensive capacity for self-renewal without the ethical concerns faced by embryonic stem cells （ESCs）. With respect to potential applications in the immune system, many studies provide evidence to support that there are exclusive advantages to using iPSCs over other systems. Both hematopoietic stem cells and several types of mature immune cells have successfully been reprogrammed to iPSCs and vice versa, paving a path toward our ability to effectively model patient-specific diseases and provide potentially alternative cell sources for transfusion medicine. Despite these potential advances, some limitations regarding the use of iPSCs in the clinic still remain, including the immunogenicity of iPSCs and their derivatives, which is currently under debate in the field. In this review, we mainly focus on discussing the recent progress being made in the latest differentiation methods and clinical implications of iPSCs with respect to the immune system. Additionally, current issues regarding the clinical application of iPSCs are addressed, especially the controversy surrounding immunogenicity, along with various other perspectives.     

Biology and function of pericytes in the vascular microcirculation

Pericytes are the main cellular components of tiny arteries and capillaries. Studies have found that pericytes can undergo morphological contraction or relaxation under stimulation by cytokines, thus affecting the contraction and relaxation of microvessels and playing an essential role in regulating vascular microcirculation. Moreover,due to the characteristics of stem cells, pericytes can differentiate into a variety of inflammatory cell phenotypes, which then affect the immune function. Additi...     

库普弗细胞对原代培养贮脂细胞激活的调节作用

目的：观察库普弗细胞在贮脂细胞激活中的促进转化、促增殖及促进细胞外基质合成的效应；方法：采用库弗细胞和贮脂细胞分离培养，流式细胞仪测定ＤＮＡ含量，免疫组化和图像分析对贮脂细胞中Ⅰ、Ⅲ、Ⅳ型胶原和纤维粘连蛋白进行定量分析，液闪法检测贮脂细胞中＾３Ｈ－脯氨酸参入量；结果：（１）分离培养的贮脂细胞完全符合该细胞的各种特征；（２）贮脂细胞是肝纤维化中细胞外基质过度沉积的重要细胞来源之一；（３）库普弗细胞可     

大鼠骨髓间质干细胞体外诱导分化为胰岛素分泌细胞的实验研究

目的研究体外定向诱导大鼠骨髓间质干细胞（BMSCs）横向分化为胰岛素分泌细胞的可能性,并了解该细胞是否具备分泌胰岛素和胰高血糖素的功能.方法从健康成年大鼠骨髓中分离BMSCs,通过传代对细胞进行纯化和扩增.采用两期诱导方案,用诱导液1使BMSCs向巢蛋白（nestin）阳性的祖细胞分化;用诱导液2使nestin阳性的祖细胞向胰岛素分泌细胞分化.用双硫腙染色鉴定胰岛素分泌细胞团;免疫细胞化学法检测诱导前后nestin、胰岛素及胰高血糖素蛋白的表达;采用放射免疫分析法检测葡萄糖刺激后上清中胰岛素的量.结果BMSCs经第一期诱导5d可分化成nestin阳性的祖细胞,双硫腙染色阳性.免疫细胞化学显示,经两期,诱导后的细胞表达胰岛素、胰高血糖素等激素.放射免疫分析结果显示,诱导后的细胞团可以分泌胰岛素,糖反应性较弱.结论健康成年大鼠骨髓间质干细胞在体外可以被诱导分化为胰岛样细胞团,且具有可重复性.     

NT-3基因修饰施万细胞促进移植的神经干细胞在损伤脊髓内分化为神经元样细胞

目的探讨神经营养素-3（NT-3）基因修饰施万细胞（SCs）对植入全横断性脊髓损伤处的神经干细胞（NSCs）分化为神经元样细胞的影响。方法将NSCs单独移植或与NT-3基因修饰SCs、LacZ基因修饰SCs和SCs联合移植到全横断性脊髓损伤处,67d后用免疫组织化学方法观测NSCs的分化,并计算其中神经元样细胞的分化率。结果NSCs在损伤脊髓内可分化为神经元样细胞和神经胶质样细胞,与未基因修饰的SCs的作用相比,NT-3基因修饰的SCs能更有效地提高NSCs向神经元样细胞的分化率,而LacZ基因修饰的SCs与未修饰SCs没有明显区别。结论NT-3基因修饰SCs能促进NSCs在损伤脊髓内向神经元样细胞分化。     

体外诱导人脐静脉间充质干细胞分化为神经元样细胞的实验研究

探讨来源于人脐静脉内皮及内皮下分离的间充质干细胞(MSCs)向神经元样细胞分化的可能性,以期为脐静脉MSCs的神经移植提供理论依据。通过在无菌条件下收集正常足月剖宫产新生儿脐带并对脐静脉进行胶原酶消化,将获取的内皮及内皮下贴壁细胞进行培养。经传代培养及免疫细胞化学鉴定后,取第2代细胞用β-巯基乙醇和二甲基亚砜诱导其向神经元方向分化,并以免疫细胞化学方法对分化细胞进行鉴定。结果表明脐静脉经胶原酶消化后的贴壁细胞主要表现为间充质样细胞和内皮细胞;传2代后,间充质样细胞可得到纯化和扩增。免疫细胞化学染色显示诱导前细胞不表达血管性血友病因子(vWF),诱导后MSCs表达巢蛋白(nestin)和神经元特异性烯醇化酶(NSE),而不表达胶质纤维酸性蛋白(GFAP)。以上结果提示,来源于脐静脉内皮及内皮下的MSCs在体外可以培养、扩增,并具备在诱导剂的作用下向神经元样细胞分化的潜能,可作为神经系统疾病细胞移植治疗的备选来源。     

嗅鞘细胞对神经干细胞增殖与分化的影响

观察嗅鞘细胞(OECs)对神经干细胞(NSCs)增殖与分化的影响。取孕14d的SD胚鼠嗅球和腹侧中脑组织,分为OECs+NSCs共培养组和NSCs单独培养组进行培养。用p75免疫组化法,p75、BrdU/nestin、GFAP、NF(神经原纤维)和p75/nestin免疫荧光法分别鉴定OECs和NSCs并观察其增殖与分化。在培养7d时,绝大多数OECs呈梭形且发出2~3个突起,少量呈扁平椭圆形,两者均呈p75阳性。在7d时,单独培养的NSCs表现为典型的神经球悬浮生长,呈BrdU/nestin阳性;14d后偶见神经球贴壁分化,球中的少数细胞呈绿色荧光标记的NF阳性,大部分呈GFAP阳性。在5d时,OECs+NSCs共培养组形成神经球;10d时球体积不断增大,球心透亮度良好;12d后神经球的体积不再增大,开始贴附在OECs上生长,可见神经球向四周伸出突起并开始分化;14d时NSCs紧贴OECs生长并同OECs广泛交织在一起,可见NSCs和OECs分别呈nestin和p75阳性,NSCs中的大部分呈NF阳性,小部分为GFAP阳性。NSCs单独培养组和OECs+NSCs共培养组中NF阳性细胞率分别为47.2%和69.5%,前者明显少于后者(P<0.05)。以上研究结果提示OECs有促进NSCs增殖和诱导其分化的作用。     

鸡胚原始生殖细胞定向诱导分化为脂肪和神经元样细胞

目的探索培养传代后鸡胚原始生殖细胞(EPGCs)的多向分化潜能,比较不同诱导程序、不同特异性化学诱导剂及其协同作用。方法分别获取发育至19期和28期的鸡胚PGCs,体外培养传代到第4代。采用不同诱导程序、不同组合的诱导剂地塞米松、胰岛素、3-异丁基-1-甲基黄嘌呤(IBMX)诱导EPGCs向脂肪细胞分化。采用不同诱导程序、不同组合的诱导剂维甲酸(RA)、丁化羟基苯甲醚(BHA)I、BMX、二甲基亚砜(DMSO)诱导EPGCs向神经元样细胞分化。结果1.EPGCs被诱导7~21d后,分化成脂肪细胞,其中诱导程序(2)(见正文中叙述)的诱导分化效果较好,第192、8期分化率分别为89%和91%。诱导剂联合协同作用的诱导效果极显著地(P<0.01)高于单独作用的诱导效果。诱导的脂肪细胞经特异性的油红O和苏丹红染色为阳性,并检测到特异性过氧化物酶体增生物激活受体γ(PPAR-γ)的表达。2.EPGCs被诱导3~7d后,分化成神经元样细胞,RAI、BMX单独使用对神经元样细胞的形成率分别为82%和83%,极显著地(P<0.01)高于RA、BHA、DMSO和IBMX的协同作用的效果。诱导的神经元样细胞特异性免疫组织化学检测显示,均有神经元特异性烯醇化酶(NSE)和神经丝蛋白M(NFM)的表达,而无胶质纤维酸性蛋白(GFAP)的表达。结论鸡EPGCs体外培养传代后仍具有多向分化潜能,在特异化学物质的诱导下,可被定向诱导分化为脂肪细胞、神经元样细胞。     

胎儿骨髓间质干细胞体外诱导为神经细胞的初步实验研究

目的：体外定向诱导胎儿骨髓问质干细胞(MSC)分化为神经细胞。方法：采用Ficoll淋巴细胞分离液分离MSC，体外扩增、传代，采用β-巯基乙醇等诱导剂诱导MSC分化为神经细胞，免疫组化鉴定神经丝蛋白(NF200)、神经元烯醇化酶(NSE)、胶质纤维酸性蛋白(GFAP)，并且用RT-PCR鉴定NF200、NSE和GFAP的mRNA表达情况。结果：胎儿骨髓MSC在体外扩增第5代以后，经诱导后，形态学上可呈现神经细胞形态特征；免疫组化显示诱导出的神经细胞NF200、NSE和GFAP均有阳性表达；RT-PCR也显示诱导后表达量明显增加。结论：胎儿骨髓MSC在体外可以分化为神经细胞。     

凋亡生精细胞的观察

用瑞－姬法观察凋亡生精细胞的各种形态，即凋亡的初级精母细胞、次级精母细胞、精子细胞，并观察了凋亡的前列腺上皮细胞的形态，就生精细胞凋亡原因进行了分析。     

施万细胞对培养的神经干细胞存活及其分化的影响

目的：探讨施万细胞能否在体外促进神经干细胞的存活和分化。方法：分离和克隆新生大鼠海马组织的神经干细胞；同时获取从神经和臂丛神经，从中分离和纯化施万细胞。将施万细胞和神经干细胞进行共培养，借助免疫细胞化学技术检测培养的神经干细胞巢蛋白（nestin)的表达及其分化后神经丝蛋白（NF）和胶质原纤维酸性蛋白（GFAP）的表达。应用扫描电镜观察神经干细胞的形态变化。结果：与施万细胞一起培养的神经干细胞存活数量增加，分为为神经元样细胞的数量也明显增加。这些神经元样细胞的初级突起比对照组的明显增长。施万细胞能使神经干细胞胞体表面不规则的凹凸变得平整。共培养的施万细胞和神经干细胞可以3种方式接触生长：1．胞体与胞体接触；2．胞体与突起接触；3．突起与突起接触。结论：施万细胞促进体外培养的神经干细胞的存活及其分化为神经元样细胞。     

大鼠Sertoli细胞与精原细胞的分离及共培养

目的 分离纯化14 d大鼠Sertoli细胞与精原细胞,用Sertoli细胞作为饲养层对大鼠精原细胞进行体外培养研究.方法 酶消化法制备大鼠睾丸组织单细胞悬液,采用牛血清白蛋白(BSA)不连续密度梯度沉降法分离Sertoli细胞和精原细胞.结果 经分离的Sertoli细胞与精原细胞的纯度分别达到92.73%和78.36%.Sertoli细胞与精原细胞共培养,可见精原细胞发生分裂增殖等行为.结论 在添加EGF、bFGF和GDNF等细胞因子的10%胎牛血清DMEM/F12培养基中,精原细胞能够存活一定时间;而Sertoli细胞表现为旺盛的生长状态,并可促进精原细胞的分裂与增殖.