2种气管黏膜上皮细胞体外培养技术的研究

目的为以猪气管黏膜上皮为细胞模型的研究奠定物质基础,进一步探讨猪气管黏膜上皮细胞的体外传统培养和气液界面培养技术,从而使2种培养技术优势互补。方法对猪气管上皮分离、纯化、培养和传代,并探索上皮细胞最佳冻存复苏条件;复苏后的气管上皮细胞进行气液界面培养,绘制细胞生长曲线和观察细胞纤毛生发情况。利用免疫组化法鉴定上皮细胞。结果4步纯化法可以得到高纯度的气管上皮细胞。使用胎牛血清、DMEM/F12培养液和DMSO的体积分数为50%、40%和10%的冻存体系保存的气管上皮,复苏后细胞存活率平均可达89%。优化后的传统方式培养的上皮细胞可连续传代到第8代,但从第2代开始便观察不到纤毛,转换成气液界面连续培养2代后重新生发纤毛,细胞存活期延长。免疫组化结果显示分离培养细胞为上皮细胞。结论成功建立了2种猪气管上皮细胞培养技术,并找到适宜的气管上皮细胞冻存条件,节省了不断原代取材的成本和时间,并成功实现传统培养细胞冻存复苏后很快适应气液界面的培养并恢复细胞的天然结构,为猪气管黏膜上皮相关研究提供丰富的细胞来源。     

兔胚胎神经干细胞的分离、培养和鉴别

目的：研究兔胎脑神经干细胞体外生长特性,为探讨神经干细胞的临床应用及神经系统的发育奠定基础。方法：采用含碱性成纤维细胞生长因子（bFGF）和表皮细胞生长因子（EGF）的N2无血清培养技术,取18天龄兔胚胎脑组织,分离神经干细胞,并观察分离的细胞体外培养、增殖、分化潜能,免疫组化鉴定。结果：从18天龄兔胎脑皮质和纹状体中成功分离出具有自我更新和多分化潜能的神经干细胞,在无血清培养时细胞呈半贴壁状态生长,形成神经球,可传代。细胞呈Nestin免疫反应阳性;在含血清培养基中培养时则分化,分化后的细胞表达神经元细胞、星形胶质细胞和少突胶质细胞的特异性抗原。结论：来自兔胎脑神经干细胞能在体外培养、增殖并保持传代能力。无血清N2EGF、bFGF培养基有利于兔胎脑神经干细胞的存活和增殖,含血清培养基能诱导兔胎脑神经干细胞分化。     

成人宫颈上皮细胞的原代培养及鉴定

目的:探索采用无血清培养基原代培养成人宫颈上皮细胞的方法。方法:以成人的宫颈上皮组织为研究对象,采用胰蛋白酶-EDTA消化法获得宫颈上皮细胞悬液,于上皮细胞专用无血清培养基中培养,采用免疫细胞化学法测定细胞中角蛋白及波形蛋白的表达,对细胞纯度进行鉴定。结果:原代培养10-15天细胞融合达60%,传代至4-6代,细胞出现生长衰退。早期细胞生长状态良好,细胞纯度在90%以上。结论:采用酶消化法及K-SFM无血清培养基培养可获得纯度高的成人宫颈上皮细胞。     

猪呼吸道上皮细胞体外分化模型的建立及其应用研究

猪是许多呼吸道病毒感染的天然宿主,其与人类在肺生理学、呼吸道形态学和呼吸道细胞类型以及受体分布都有相似之处。为了解呼吸道病毒感染机制和筛选呼吸系统疾病药物,选择以猪肺组织为原料采用无血清气液界面培养法构建一种猪呼吸道上皮细胞(Porcine airway epithelial cell,PAEC)体外分化模型,然后通过扫描电子显微镜、电生理和免疫组织化学等方法鉴定该模型。采用三质粒共转染法构建重组腺相关病毒rAAV6-GFP(rAAV6-green fluorescent protein,rAAV6-GFP),通过顶端表面感染PAEC模型,探讨AAV6在PAEC模型中基因治疗领域的应用。结果显示分化成熟的PAEC模型为多层上皮结构,顶端表面含有纤毛细胞、黏液分泌细胞和基底细胞。rAAV6-GFP能通过顶端表面感染PAEC,有效地介导外源基因的长期表达。本文建立的猪呼吸道上皮细胞体外分化模型为呼吸道病原体感染和呼吸系统疾病药物筛选和基因疗法等研究奠定了良好的基础。     

兔关节软骨细胞体外三维培养条件的优化

实验使用海藻酸钠水凝胶作为细胞支架.模拟软骨细胞体内生长的三维环境,研究了体外三维培养条件下,不同浓度的胎牛血清(FBS)和硒酸复合液(ITS)体系对兔透明软骨细胞(hyaline cartilage)的牛长、增殖和细胞外基质分泌活动的影响.结果 表明,三维模式培养21天,透明软骨细胞仍然具有较好的增殖活性.在硒酸复合液及低浓度血清时,细胞未去分化,保持分泌Ⅱ型胶原(Collagen Ⅱ)和软骨聚集蛋白聚糖(Aggrecan)的能力,与之比较,高浓度胎牛血清(10%)培养条件下,在21天开始细胞去分化,即硒酸复合液在一定的血清浓度下有助于维持软骨细胞生长、增殖,避免了软骨细胞受高浓度血清影响而去分化.     

B7-2小鼠胚胎癌细胞的无血清培养

本文报道以RPMI-1640,DMEM和HAM/F 12人工培养基做基础培液,加入牛血清白蛋白、胰岛素和转铁蛋白等物质,发展了一种无血清(B7-85)培液。在B7-85液中,B7—2EC细胞生长速率虽略低于含10％小牛血清常规培液,但细胞形态、生长行为和在同系宿主体内的长瘤率及分化潜能,均未发现存在区别。因此,B7-85液是适于B7-2EC细胞生长的无血清人工培液。这种人工培液中除胰岛素外,没有人为地增添外源性多肽生长因子,这将有利于分析B7-2EC细胞和其分化细胞产生的内源性生长因子。     

维胺酸对体外转化人支气管上皮细胞及体内构建人支气管上皮组织的抑制作用

癌前改变是肿瘤演变过程中的关键阶段。许多研究显示维甲类化合物对动物肿瘤及体外恶性细胞系具有抑制作用,但尚未见其对肺癌前病变作用的实验室研究报道。人类肺癌的绝大部分起源于支气管上皮,为研究维胺酸对体外转化人支气管上皮M细胞系以及在大鼠气管构建后移植到裸鼠体内生长的具有癌前病变特点的人支气管上皮组织的抑制作用,采用上皮细胞无血清培养技术,人支气管上皮组织大鼠气管内构建／裸鼠皮下移植生长技术,流式细胞学分析,免疫组化、凋亡细胞原位末端标记以及病理学检查等研究方法发现,维胺酸可抑制体外培养的转化人支气管上皮细胞的增殖,使S期细胞比例下降,以及细胞增殖标志Ki-67、mpm-2阳性反应细胞比例下降;明显诱导细胞凋亡。裸鼠腹腔注射给予维胺酸也可使大鼠气管内构建后移植到裸鼠体内生长的癌前期人支气管上皮组织的生长率明显降低,病变程度明显减轻;同样可以诱导细胞凋亡。研究结果提示,维胺酸对体外培养的转化人支气管上皮细胞系及大鼠气管构建／裸鼠体内移植生长的人支气管上皮组织均有明显的抑制作用,是有希望的肺癌化学预防药物。     

诱导胚胎干细胞向角膜上皮细胞分化的实验研究

探索胚胎干细胞在表层角膜缘基质诱导下向角膜上皮细胞分化的可能性.体外培养带GFP标记的ES-D3细胞,并利用视黄酸进行预诱导,然后将预诱导后的细胞接种在表层角膜缘基质上,细胞融合形成单层后,随机分为3组进行研究:第1组传代后直接进行检测;第2组在气-液界面上培养10天,然后植入裸鼠皮下以进行体内诱导;第3组作为对照组,不给予GFP-ES-D3细胞特殊诱导条件,细胞自由分化.诱导分化的细胞植入裸鼠皮下体2周后没有畸胎瘤形成.诱导分化的细胞呈现上皮样外观,体内诱导组和体外诱导组免疫组织化学染色均检测到CK3,P63和PCNA表达阳性,电子显微镜检查可见两组细胞表面都有微绒毛和细胞间紧密连接形成.实验对照组部分细胞脱落和死亡,大部分表现神经样细胞的树突样外观,小部分未死亡的贴壁细胞呈多态性,这些结果表明胚胎干细胞在特定条件下经表层角膜基质诱导能够分化为角膜上皮细胞.胚胎干细胞诱导分化有可能为眼表重建和组织工程化角膜的构建提供上皮种子细胞.     

诱导胚胎干细胞向角膜上皮细胞分化的实验研究

探索胚胎干细胞在表层角膜缘基质诱导下向角膜上皮细胞分化的可能性. 体外培养带GFP标记的 ES-D3细胞, 并利用视黄酸进行预诱导, 然后将预诱导后的细胞接种在表层角膜缘基质上, 细胞融合形成单层后, 随机分为3组进行研究: 第1组传代后直接进行检测; 第2组在 气-液界面上培养10天, 然后植入裸鼠皮下以进行体内诱导; 第3组作为对照组, 不给予GFP-ES-D3细胞特殊诱导条件, 细胞自由分化. 诱导分化的细胞植入裸鼠皮下体2周后没有畸胎瘤形成. 诱导分化的细胞呈现上皮样外观, 体内诱导组和体外诱导组免疫组织化学染色均检测到CK3, P63和PCNA表达阳性, 电子显微镜检查可见两组细胞表面都有微绒毛和细胞间紧密连接形成. 实验对照组部分细胞脱落和死亡, 大部分表现神经样细胞的树突样外观, 小部分未死亡的贴壁细胞呈多态性, 这些结果表明胚胎干细胞在特定条件下经表层角膜基质诱导能够分化为角膜上皮细胞. 胚胎干细胞诱导分化有可能为眼表重建和组织工程化角膜的构建提供上皮种子细胞.     

无血清无饲养层条件下培养小鼠胚胎干细胞

目的研究在无血清无饲养层条件下小鼠胚胎干细胞的培养方法,为最终建立无血清无饲养层培养系统打下基础。方法比较小鼠胚胎干细胞ES-S8株在无血清培养体系和有血清培养体系中的生长情况,分析ES-S8细胞克隆形成效率,测定其生长速度;然后在撤去血清和饲养层的条件下培养ES-S8细胞,进行AKP染色和表面标记物SSEA-1免疫荧光检测。结果ES-S8细胞在无血清培养条件下细胞生长速度减缓,克隆形成率降低,但AKP染色、SSEA-1免疫荧光均显阳性;在无血清无饲养层条件下ES-S8细胞培养仍能形成克隆,且AKP染色、SSEA-1免疫荧光均显阳性。结论研究表明ES-S8细胞能够在无血清无饲养层的培养条件下生长,保持其良好的未分化特性。     

Rat tracheal epithelial cell differentiation in vitro

Summary In vitro culture conditions enabling rat tracheal epithelial (RTE) cells to differentiate to mucociliary, mucous, or squamous phenotypes are described. Medium composition for rapid cell growth to confluence in membrane insert cultures was determined, and the effects of major modifiers of differentiation were tested. Retinoic acid (RA), collagen gel substratum, and an air-liquid interface at the level of the cell layer were required for expression of a mucociliary phenotype which most closely approximated the morphology of the tracheal epithelium in vivo. Large quantities of high molecular weight, hyaluronidase-resistant glycoconjugates, most likely mucin glycoproteins, were produced in the presence of RA when the cells were grown with or without a collagen gel and in submerged as well as in interface cultures. However, extensive ciliagenesis was dependent on the simultaneous presence of RA, collagen gel, and an air-liquid interface. When RA was omitted from the media, the cells became stratified squamous and developed a cornified apical layer in air-liquid interface cultures. This phenotype was accompanied by loss of transglutaminase (TGase) type II and keratin 18 and expression of the squamous markers TGase type I and keratin 13. The ability to modulate RTE cell phenotypes in culture will facilitate future studies investigating molecular regulation of tracheal cell proliferation, differentiation, and function.     

An air-liquid interface promotes the differentiation of gastric surface mucous cells (GSM06) in culture

The gastric surface epithelium is situated at an air-liquid interface because the luminal surface of the alimentary tract is in continuity with the air phase. However, the effects of this microenvironment on the gastric epithelium remain unclear. The aim of this study was to clarify the effects of an air-liquid interface on gastric epithelial cell biology. Gastric surface mucous cells (GSM06) were cultured at an air-liquid interface. Cultured cells were examined by histology, histochemistry, and transmission electron microscopy. When the cells were cultured at an air-liquid interface, the surface cells on the collagen gel became tall columnar and secreted periodic acid-Shiff-positive substances at the apical surface. These cells indicated many mucous granules in the apical cytoplasm and organized the basal lamina at the contact side with the gel. In contrast, under immersed condition, the surface cells showed immature features. This is the first report of an air-liquid interface promoting the differentiation of gastric surface mucous cells in a reconstruction culture of the gastric surface epithelial layer, suggesting that an air-liquid interface may function as a crucial luminal factor to maintain the homeostasis of gastric mucosa.     

Murine nasal septa for respiratory epithelial air-liquid interface cultures

Air-liquid interface models using murine tracheal respiratory epithelium have revolutionized the in vitro study of pulmonary diseases. This model is often impractical because of the small number of respiratory epithelial cells that can be isolated from the mouse trachea. We describe a simple technique to harvest the murine nasal septum and grow the epithelial cells in an air-liquid interface. The degree of ciliation of mouse trachea, nasal septum, and their respective cultured epithelium at an air-liquid interface were compared by scanning electron microscopy (SEM). Immunocytochemistry for type IV beta-tubulin and zona occludens-1 (Zo-1) are performed to determine differentiation and confluence, respectively. To rule out contamination with olfactory epithelium (OE), immunocytochemistry for olfactory marker protein (OMP) was performed. Transepithelial resistance and potential measurements were determined using a modified vertical Ussing chamber SEM reveals approximately 90% ciliated respiratory epithelium in the nasal septum as compared with 35% in the mouse trachea. The septal air-liquid interface culture demonstrates comparable ciliated respiratory epithelium to the nasal septum. Immunocytochemistry demonstrates an intact monolayer and diffuse differentiated ciliated epithelium. These cultures exhibit a transepithelial resistance and potential confirming a confluent monolayer with electrically active airway epitheliumn containing both a sodium-absorptive pathway and a chloride-secretory pathway. To increase the yield of respiratory epithelial cells harvested from mice, we have found the nasal septum is a superior source when compared with the trachea. The nasal septum increases the yield of respiratory epithelial cells up to 8-fold.     

Reconstruction of a rabbit corneal epithelium on a lyophilized amniotic membrane using tilting air-liquid interface culture followed by tilting submerged culture

Herein, we reconstructed a rabbit corneal epithelium on a lyophilized amniotic membrane (LAM) using a modified version of two Teflon rings (the Ahn’s supporter). We compared the corneal epithelial cells we had differentiated in vitro using air-liquid interface (6 days, 12 days) and submerged (6 days, 12 days) cultures and followed a six-day tilting dynamic air-liquid interface culture with a six-day tilting submerged culture. We characterized the reconstructed corneal epithelium using digital photography, histological imaging, and transmission electron microscopy. The reconstructed corneal epithelium created under air-liquid interface culture exhibited a healthier basal corneal epithelial layer than that created under submerged culture. The reconstructed corneal epithelium on the LAM that was produced using the tilting dymanic culture exhibited a healthy basal layer. We therefore proposed that tilting submerged culture not only supplied nutrients from the medium to the corneal epithelial cells on the LAM, but it also removed the horny layer in the upper part of the reconstructed corneal epithelium, presumably by mimicking the effects of blinking. This study demonstrated that corneal epithelium reconstruction on a LAM using a tilting submerged culture after a tilting air-liquid interface culture may be useful not only for allogeneic or autologous transplantation, but also for in vitro toxicological test kits.     

Isolation and culture of primary equine tracheal epithelial cells

Culture of airway epithelial cells is a useful model to investigate physiology of airway epithelia and airway disease mechanisms. In vitro models of airway epithelial cells are established for various species. However, earlier published method for isolation and culture of equine tracheal epithelial cells requires significant improvements. In this report, the development of a procedure for efficient isolation, characterization, culture, and passage of primary equine tracheal epithelial cells are described. Epithelial cells were isolated from adult equine trachea by exposing and stripping the mucosal epithelium from the adjacent connective tissue and smooth muscle. The tissue was minced and dissociated enzymatically using 0.25% trypsin-ethylenediaminetetraacetic acid (EDTA) solution for 2 h at 37 degrees C. Cells were collected by sieving and centrifugation, and contaminating fibroblasts were removed by differential adhesion. This procedure resulted in a typical yield of 1 x 10(7) cytokeratin-positive epithelial cells per gram tracheal lining tissue. Viability was 95% by trypan blue exclusion and isolates contained approximately 94% cytokeratin-positive cells of epithelial origin. Cells seeded at a density of 6.9 x 10(4) cells/cm(2) in serum-free airway epithelial cell growth medium formed monolayers near confluency within a week. Confluent cells were dissociated using dispase II and first passages (P1) and second passages (P2) were successfully established in serum-free medium. Collagen coating of tissue culture flask was not required for cell adhesion, and cultures could be maintained at the level of P2 over 30 d. In the present study, we could establish a high-yield protocol for isolation and culture of equine tracheal epithelial cells that can serve for in vitro/ex vivo studies on the (patho-)physiology of equine airway disease as well as pharmacological and toxicological targets relevant to airway diseases.     

Differentiated cultures of primary hamster tracheal airway epithelial cells

Summary Primary airway epithelial cell cultures can provide a faithful representation of the in vivo airway while allowing for a controlled nutrient source and isolation from other tissues or immune cells. The methods used have significant differences based on tissue source, cell isolation, culture conditions, and assessment of culture purity. We modified and optimized a method for generating tracheal epithelial cultures from Syrian golden hamsters and characterized the cultures for cell composition and function. Soon after initial plating, the epithelial cells reached a high transepithelial resistance and formed tight junctions. The cells differentiated into a heterogeneous, multicellular culture containing ciliated, secretory, and basal cells after culture at an air-liquid interface (ALI). The, secretory cell populations initially consisted of MUC5AC-positive goblet cells and MUC5AC/CCSP double-positive cells, but the makeup changed to predominantly Clara cell secretory protein (CCSP)-positive Clara cells after 14 d. The ciliated cell populations differentiated rapidly after ALI as judged by the appearance of β tubulin IV-positive cells. The cultures produced mucus, CCSP, and trypsin-like proteases and were capable of wound repair as judged by increased expression of matrilysin. Our method provides an efficient, high-yield protocol for producing differentiated hamster tracheal epithelial cells that can be used for a variety of in vitro studies including tracheal cell differentiation, airway disease mechanisms, and pathogen-host interactions.     

Growth and differentiation of mouse tracheal epithelial cells: selection of a proliferative population

Highly regulated programs for airway epithelial cell proliferation and differentiation during development and repair are often disrupted in disease. These processes have been studied in mouse models; however, it is difficult to isolate and identify epithelial cell-specific responses in vivo. To investigate these processes in vitro, we characterized a model for primary culture of mouse tracheal epithelial cells. Small numbers of cells seeded at low density (7.5 x 10(4) cells/cm2) rapidly proliferated and became polarized. Subsequently, supplemented media and air-liquid interface conditions resulted in development of highly differentiated epithelia composed of ciliated and nonciliated cells with gene expression characteristic of native airways. Genetically altered or injured mouse tracheal epithelial cells also reflected in vivo patterns of airway epithelial cell gene expression. Passage of cells resulted in continued proliferation but limited differentiation after the first passage, suggesting that transit-amplifying cell populations were present but with independent programs for proliferation and differentiation. This approach provides a high-fidelity in vitro model for evaluation of gene regulation and expression in mouse airway epithelial cells.