牛乳腺上皮细胞的分离培养及其生物学特性

采用胶原酶消化法和胰蛋白酶选择性消化法分离、培养和纯化牛乳腺上皮细胞。形态学观察表明,培养的细胞具有典型的上皮细胞形态特征;染色体分析结果表明,培养的细胞具有正常的染色体数目。通过荧光免疫细胞染色方法鉴定了培养的细胞表达上皮细胞特异的角蛋白5和8。该细胞在添加胰岛素、氢化可的松以及羊催乳素的无血清培养液中诱导培养时,用RT-PCR方法检测到了β-酪蛋白基因的转录。这些结果表明,分离培养的细胞是乳腺上皮细胞,这些细胞在诱导培养的条件下能够转录表达β-酪蛋白。     

牛乳腺上皮细胞的分离培养及其生物学特性

采用胶原酶消化法和胰蛋白酶选择性消化法分离、培养和纯化牛乳腺上皮细胞。形态学观察表明，培养的细胞具有典型的上皮细胞形态特征；染色体分析结果表明，培养的细胞具有正常的染色体数目。通过荧光免疫细胞染色方法鉴定了培养的细胞表达上皮细胞特异的角蛋白5和8。该细胞在添加胰岛素、氢化可的松以及羊催乳素的无血清培养液中诱导培养时，用RT-PCR方法检测到了β-酪蛋白基因的转录。这些结果表明，分离培养的细胞是乳腺上皮细胞，这些细胞在诱导培养的条件下能够转录表达β-酪蛋白。     

牛αS1-酪蛋白5′调控序列驱动人α-LA基因与LacZ基因在牛乳腺上皮细胞中的表达

将牛αS1-酪蛋白5′调控序列约1.2 kb的片段,连接到含SV40启动子调控下β-半乳糖苷酶基因(LacZ)的PSV载体上,做为启动子,在其后连接0.76 kb的人α-乳白蛋白基因(α-LA),构建真核表达载体 αS1-LA-psv．采用组织块接种法,培养奶牛乳腺上皮细胞,经传代纯化后,对细胞接种存活率、群体倍增时间、生长曲线、形态学等生物学性状进行检测,用免疫荧光细胞染色法对培养的奶牛乳腺上皮细胞进行角蛋白18鉴定,结果表明,成功建立奶牛乳腺上皮细胞系,细胞传至20代以上时仍保持旺盛的增殖活力．将构建的真核表达载体 αS1-LA-psv 转染奶牛乳腺上皮细胞,培养24～120 h均检测到了β-半乳糖苷酶的表达;培养72 h检测到细胞中人α-乳白蛋白的表达,表达量约为0.64 g/L．实验结果表明,建立的奶牛乳腺上皮细胞系具有外源基因表达活性,得到的牛αS1-酪蛋白5′调控序列能作为启动子指导外源基因的表达,构建的真核表达载体能在体外培养的牛乳腺上皮细胞中同时表达人α-乳白蛋白和β-半乳糖苷酶．     

牛αS1-酪蛋白5''调控序列驱动人α-LA基因与LacZ基因在牛乳腺上皮细胞中的表达

将牛αS1-酪蛋白5′调控序列约1.2 kb的片段,连接到含SV40启动子调控下β-半乳糖苷酶基因(LaeZ)的PSV载体上,做为肩动子,在其后连接0.76kb的人仅α-乳白蛋白基凼(α-LA),构建真核表达载体αS1-LA-psv.采用组织块接种法,培养奶牛乳腺上皮细胞,经传代纯化后,对细胞接种存活率、群体倍增时间、生长曲线、形态学等生物学性状进行检测,用免疫荧光细胞染色法对培养的奶牛乳腺上皮细胞进行角蛋白18鉴定,结果表明,成功建立奶牛乳腺上皮细胞系,细胞传至20代以上时仍保持旺盛的增殖活力.将构建的真核表达载体αS1-LA-psv转染奶牛乳腺上皮细胞,培养24～120h均检测到了β-半乳糖苷酶的表达;培养72 h检测到细胞中人α-乳白蛋白的表达,表达量约为0.64 g/L.实验结果表明,建它的奶牛乳腺上皮细胞系具有外源基因表达活性,得到的牛αS1-酪蛋白5′调控序列能作为启动子指导外源基因的表达,构建的真核表达载体能在体外培养的牛乳腺上皮细胞中同时表达人α-乳白蛋白和β-半乳糖苷酶.     

牛αS1-酪蛋白5＇调控序列驱动人α-LA基因与LacZ基因在牛乳腺上皮细胞中的表达

将牛αS1-酪蛋白5＇调控序列约1．2kb的片段,连接到含SV40启动子调控下β-半乳糖苷酶基因（LacZ）的PSV载体上,做为启动子,在其后连接0．76kb的人α-乳白蛋白基因（α-LA）,构建真核表达载体αS1-LA-psv．采用组织块接种法,培养奶牛乳腺上皮细胞,经传代纯化后,对细胞接种存活率、群体倍增时间、生长曲线、形态学等生物学性状进行检测,用免疫荧光细胞染色法对培养的奶牛乳腺上皮细胞进行角蛋白18鉴定,结果表明,成功建立奶牛乳腺上皮细胞系,细胞传至20代以上时仍保持旺盛的增殖活力．将构建的真核表达载体αS1-LA-psv转染奶牛乳腺上皮细胞,培养24～120h均检测到了β-半乳糖苷酶的表达;培养72h检测到细胞中人α-乳白蛋白的表达,表达量约为0．64g／L．实验结果表明,建立的奶牛乳腺上皮细胞系具有外源基因表达活性,得到的牛αS1-酪蛋白5＇调控序列能作为启动子指导外源基因的表达,构建的真核表达载体能在体外培养的牛乳腺上皮细胞中同时表达人α-乳白蛋白和β-半乳糖苷酶．     

转溶菌酶基因山羊乳腺上皮细胞的原代培养及特性分析

采用组织块法、胰酶差速消化法分离了人溶菌酶(hLYZ)转基因山羊的乳腺上皮细胞,建立了转基因羊乳腺上皮细胞(TGMEC)的体外培养体系,并对其生长与体外分泌特性进行了分析.研究显示其体外生长曲线符合典型的S型,传代期间二倍体染色体数正常;通过免疫荧光染色、RT-PCR发现该细胞能表达上皮细胞所特有的角蛋白18,并能表达内源性乳蛋白(酪蛋白与乳球蛋白);进一步通过酶联免疫试验发现该乳腺上皮细胞在体外培养中可持续稳定地分泌重组人溶菌酶.由此获得的人溶菌酶转基因羊乳腺上皮细胞系为乳腺生物反应器研究提供了一个重要细胞膜型.     

胶原酶Ⅰ消化法体外分离培养奶牛乳腺上皮细胞

为获得纯净的奶牛乳腺上皮细胞,该研究采用胶原酶I消化法,在不添加外源激素及生长因子的条件下培养奶牛乳腺上皮细胞。采用差时消化与差速贴壁方法,对奶牛乳腺上皮细胞进行纯化。采用Western blot方法检测细胞中β-酪蛋白(β-casein,CNS2)的水平。通过免疫荧光技术对细胞进行鉴定。结果显示,纯化后的细胞呈现典型的"铺路石"或"鹅卵石"样。细胞角蛋白-18(cytokeratin-18,CK-18)反应呈阳性,波形蛋白反应呈阴性。细胞传至15代冻存并复苏后生长状态依然良好。这提示,胶原酶I消化法在不添加外源激素及生长因子的条件下可以获得奶牛乳腺上皮细胞,以用于后续实验。     

牦牛乳腺上皮细胞系的建立与生物学特性

本研究旨在建立牦牛乳腺上皮细胞体外培养体系。采用胶原酶消化法成功地建立了牦牛乳腺上皮细胞系(YMEC),通过免疫细胞化学、超微结构观察和RT-PCR 法对YMEC 细胞进行了鉴定,并研究了其形态、活力、生长曲线以及核型等生物学特性。结果表明,YMEC 细胞染色体2n = 60,群体倍增时间为45 ～ 48 h,持续培养25 代后出现细胞分化;细胞呈典型的“铺路石样”形态,其表面有丰富的微绒毛,细胞质内含丰富的线粒体和粗面内质网。污染检测结果为阴性。在激素诱导培养时,检测到了β - 酪蛋白mRNA 的表达。表明本研究成功建立了保留泌乳功能的牦牛乳腺上皮细胞系,为研究牦牛乳腺上皮细胞的功能提供了理想的工具。     

波形蛋白在实验性肾间质纤维化上皮-间充质转分化中的表达及意义

目的明确肾脏纤维化中波形蛋白表达在上皮-间充质转分化观察中的意义。方法雄性SD大鼠12只,随机分成假手术组和模型组,模型组行单侧输尿管梗阻术。造模后14天处死大鼠,分别采用免疫组织化学染色和Western印迹法对梗阻侧肾组织波形蛋白和α平滑肌肌动蛋白作定性和定量检测。并通过体外实验用TGF-β1刺激诱导人近端小管上皮细胞株(HK-2)发生上皮-间充质转分化。采用间接免疫荧光法对E-钙粘蛋白和波形蛋白进行染色,采用激光共聚焦显微镜观察细胞形态改变,并用蛋白印迹法定量检测HK-2细胞波形蛋白和α平滑肌肌动蛋白表达水平。结果萎缩和扩张的肾小管上皮细胞出现波形蛋白和α平滑肌肌动蛋白表达,肾组织中波形蛋白和α平滑肌肌动蛋白表达量显著增加;正常的HK-2细胞,细胞形态为不规则圆形,TGF-β1刺激后细胞伸展成长梭形;细胞α平滑肌肌动蛋白表达水平显著增加,波形蛋白表达水平无显著变化。结论体内实验研究上皮-间充质转分化,将波形蛋白作为间充质细胞标志物具有较好的参考价值,而体外研究中,其标志作用尚存在争议。     

大鼠胚胎后肾间充质细胞的分离、培养及鉴定

分离、培养大鼠胚胎后肾间充质细胞(MMCS),取孕13d大鼠胚胎,分离胚胎肾脏,去除输尿管芽,消化后置37℃、5%CO2、饱和湿度的培养箱中培养.倒置相差显微镜下观察培养细胞,并行HE染色、电镜观察、生长曲线测定;ABC免疫酶染色法检测波形蛋白、角蛋白、nestin、CD133、CD34;直接免疫荧光法检测双花扁豆凝集素(Dolichos Biflorus,DB),并流式细胞术定量检测.MMCS形态为成纤维细胞样,贴壁生长,48～72h达生长高峰;波形蛋白、nestin、CD133表达阳性;角蛋白、CD34、DB表达阴性;MMCS以DB标记后流式细胞检测为单峰.结果表明:培养细胞为后肾间充质细胞,纯度较高并符合干细胞特征.     

Immunocytochemical identification of proliferating cell types in mouse mammary gland

To study cell proliferation in different cell types and segments of the mammary gland, we devised a dual staining procedure, combining nuclear labeling by 5-bromo-2'-deoxy-uridine (BrdU) uptake (revealed by a dark-brown precipitate) and an alternative (red or blue) cytoplasmic labeling by antibodies specific for the differentiation proteins of epithelial, myoepithelial, and secretory cell types. The following markers, revealed by APAAP or beta-galactosidase procedure, were selected: alpha-smooth muscle actin for the myoepithelial cells, keratin (detected by AE1 monoclonal) for the luminal epithelial cells, alpha-lactalbumin and beta-casein for the secretory cells. To follow the full process of organogenesis, the study was conducted in mouse mammary glands from virgin, primed, and lactating animals and from glands cultured in vitro under specific hormone stimulation. Cell proliferation was localized mainly in focal areas (end buds), and mostly corresponded to "null" undifferentiated cells. Estrogen and progestin stimulation induced a relative increase of proliferating differentiated cells of either epithelial or myoepithelial type, localized in ducts and alveolar structures. Prolactin stimulation induced proliferation in secretory cells.     

An in vitro model of epithelial cell growth stimulation in the rodent mammary gland

Abstract. Mouse mammary epithelial cell cultures previously described bring about extensive proliferation and a cell population with the appropriate markers for luminal ductal epithelial cells, and also the ability to form normal tissue after implantation into mice. This success may result from a culture environment that resembles certain aspects of the environment in the mammary gland. Mouse mammary epithelial cells, whose proliferation is limited when plated alone, can be stimulated to multiply by contact with lethally irradiated cells of the LA7 rat mammary tumour line. Most of the proliferative stimulus is imparted by direct cell contact between LA7 and mouse mammary cells. Junctions, including adherens junctions, form among all cells in the culture, much as junctions form in the mammary gland. LA7 cells secrete TGFα and bFGF, factors found in the mammary gland, and factors to which mouse mammary cells respond in culture. Mouse mammary cells express keratins 8 and 18, markers for luminal cells of the mammary duct. LA7 cells express keratin 14 and vimentin, markers for myoepithelial cells. These facts, taken together, fit a model of cell replacement in an epithelial tissue and also imitate the relationship between luminal ductal cells and myoepithelial cells in the mammary gland. This method of culturing cells is useful, not only for in vitro – in vivo carcinogenesis studies, but also for the study of mechanisms by which growth signals are imparted from one cell to another.     

Regulation of glycosylation-dependent cell adhesion molecule 1 (GlyCAM-1) gene in the mouse mammary gland differs from that of casein genes

Mouse glycosylation-dependent cell adhesion molecule 1 (GlyCAM-1), also known as mC26 and homologous to bovine PP3, is a milk protein synthesized in the mammary gland. Several studies have investigated the regulation of casein, the major milk protein, gene in the mammary gland, but little is known about GlyCAM-1. Here we examined GlyCAM-1 gene expression in mouse mammary epithelial cells. First, we detected GlyCAM-1 expression in mammary epithelial cells in situ by immunohistochemistry; almost all mammary epithelial cells of the lactating mouse expressed GlyCAM-1. Second, mammary epithelial cells were digested with collagenase and cultured with insulin, prolactin and/or glucocorticoid. alpha-Casein and beta-casein genes were expressed following treatment with insulin, prolactin and glucocorticoid. In contrast, GlyCAM-1 expression could not be detected with any combination of these three hormones. We also analyzed changes in the levels of GlyCAM-1 and caseins mRNAs in cultured cells. The addition of hormones to the culture medium increased casein mRNAs, but surprisingly reduced GlyCAM-1 mRNA. Our results suggest that the mechanisms that regulate GlyCAM-1 gene in mammary cells of lactating mice are different from those involved in the regulation of casein genes.     

Localization of vimentin in myoepithelial cells of the rat mammary gland

Summary Myoepithelial cells in the virgin rat mammary gland have been shown to contain vimentin, using a polyclonal antiserum to vimentin purified from hamster fibroblasts. This antiserum has been shown to be specific for vimentin by immunoblotting and ELISA techniques. Similar results were obtained with a monoclonal antibody to vimentin. In the mammary glands of pregnant rats, the staining with vimentin antibodies is much weaker in the myoepithelial cells of the developing alveolar buds than in the main ducts. Similarly, in lactating glands, the staining of myoepithelial cells is much weaker in the secretory alveoli than in lactiferous sinuses. In each case, staining with antivimentin co-localizes with staining with polyclonal antisera to callous keratin (which specifically stain myoepithelial cells in the rat mammary gland).     

Dermal cylindroma. Expression of intermediate filaments, epithelial and neuroectodermal antigens.

We report on immunohistochemical staining patterns in so-called apocrine tumors of skin with special emphasis on the dermal cylindroma. The results were compared with apocrine tubular adenoma, syringocystadenoma papilliferum and the normal eccrine sweat gland. A relationship of dermal cylindroma to the apocrine gland is suggested by expression of lysozyme and alpha 1-antichymotrypsin. The tumor shares keratin, epithelial membrane antigen (EMA) and EGF-receptor expression with eccrine and apocrine glands. The presence of intermingled cells with a coexpression of keratin and vimentin argues for a partial myoepithelia-like differentiation. Neuroectodermal antigens are missing. Therefore, dermal cylindroma is classified as an adnexal tumor of skin with a variable rate of cells of apocrine secretory, myoepithelial and undifferentiated phenotypes.     

Early expression of vimenti in human mammary cultures

Summary The intermediate filaments of most epithelial cells in vivo consist solely of cytokeratins. Using monoclonal antibodies to vimentin or keratin, we have examined the expression of vimentin in homologous specimens of frozen tissue sections and primary cultures of normal human mammary epithelium. In frozen sections, only epithelial cells reacted with the antikeratin antibody, whereas antivimentin reactivity was associated with stromal cells. All epithelial cultures were positive for cytokeratin and in addition coexpressed vimentin as strongly as cultured fibroblasts and as early as the 4th d after initiation of the culture. Two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblot analysis of cytoskeletal preparations of secondary cultures of normal mammary epithelium have also demonstrated the appearance of a moiety identical to the vimentin found in cultured fibroblasts. Our observations are consistent with the hypothesis that vimentin expression is induced, possibly as a result of changes in cell shape or growth rate, when cells are freed from three-dimensional restirctions imposed by the tissue of origin