Primary Culture of Bovine Mammary Epithelial Cells

[ Objective] To investigate the feasibility of the primary culture of bovine mammary epithelial cells in biochemical incubator. [ Method] In vitro, bovine mammary epithelial cells were isolated and cultured by the tissue explant method in order to investigate the optimal culture conditions. The morphology observation and identification of the cultured cells were performed by inverted microscope observation, Giemsa staining and cytokeratin immunohistochemistry. [ Result] Observed with inverted microscope, most of the bovine mammary epithelial cells were polygonal and displayed typical slabstone-like appearance. As it can be seen from cell staining results, the cell body was big and the nucleus was stained dark blue and was round or oval in shape, with clearly visible nucleoli, generally 2 -4 nucleoli. The tissue-specific expression of cytokeratin 14 and cytokeratin 18 genes in mammary epithelial cells was identified by cytokeratin immunohistochemistry. [ Conclusion] Primary bovine mammary epithelial cells were successfully cultured in biochemical incubator.

Current status and challenges for cell-cultured milk technology: a systematic review

Cellular agriculture is an innovative technology for manufacturing sustainable agricultural products as an alternative to traditional agriculture.While most cellular agriculture is predominantly centered on the production of cultured meat,there is a growing demand for an understanding of the production techniques involved in dairy products within cellular agriculture.This review focuses on the current status of cellular agriculture in the dairy sector and technical challenges for cell-cultured milk production.Cellular agriculture technology in the dairy sector has been classified into fermentation-based and animal cell culture-based cellular agriculture.Currently,various companies synthesize milk components through precision fermentation technology.Nevertheless,several startup companies are pursuing animal cell-based technology,driven by public concerns regarding genetically modified organisms in precision fermentation technology.Hence,this review offers an up-to-date exploration of animal cell-based cellular agriculture to produce milk components,specifically emphasizing the structural,functional,and productive aspects of mammary epithelial cells,providing new information for industry and academia.

Comparison of human nasal epithelial cells grown as explant outgrowth cultures or dissociated tissue cultures in vitro

The purpose of this study was to compare cell growth characteristics,ciliated cell differentiation,and function of human nasal epithelial cells established as explant outgrowth cultures or dissociated tissue cultures.Human nasal mucosa of the uncinate process was obtained by endoscopy and epithelial cell cultures were established by explant outgrowth or dissociated tissue culture methods.Epithelial cell growth characteristics were observed by inverted phase contrast microscopy.Ciliated cell differentiation was detected byβ-tubulin IV and ZO-1 immunocytochemistry.Basal and ATP-stimulated ciliary beat frequency(CBF)was measured using a high-speed digital microscopic imaging system.Both the explant and dissociated tissue cultures established as monolayers with tight junctions and differentiated cell composition,with both types of cultures comprising ciliated and non-ciliated epithelial cells.Fibroblasts were also frequently found in explant cultures but rarely seen in dissociated tissue cultures.In both culture systems,the highest ciliated cell density appeared at 7th–10th culture day and declined with time,with the lifespan of ciliated cells ranging from 14 to 21 days.Overall,10%of the cells in explant cultures and 20%of the cells in the dissociated tissue cultures were ciliated.These two cultures demonstrated similar ciliary beat frequency values at baseline(7.78±1.99 Hz and 7.91±2.52 Hz,respectively)and reacted equivalently following stimulation with 100μM ATP.The results of this study indicate that both the explant outgrowth and dissociated tissue culture techniques are suitable for growing well-differentiated nasal ciliated and non-ciliated cells,which have growth characteristics and ciliary activity similar to those of nasal epithelial cells in vivo.

THE LOCALIZATION OF ADRENOMEDULLIN IN RAT KIDNEY TISSUE AND ITS INHIBITORY EFFECT ON THE GROWTH OF CULTURED RAT MESANGIAL CELLS

OBJECTIVE: To observe the localization of adrenomedullin (AM) in rat kidney tissue and its inhibitory effect on the growth of cultured rat mesangial cells (MsC). METHODS: A monoclonal antibody against AM developed by our laboratory was used to detect the localization of AM protein in rat kidney tissue by avidin-biotin complex immunohistochemistry. The expressions of AM and its receptor CRLR mRNA on cultured glomerular epithelial cells (GEC) and MsC were investigated by Northern blot assay, and the possible effect of AM secreted by GEC on MsC proliferation was observed using [3H]thymidine incorporation as an index. RESULTS: A specific monoclonal antibody against AM was succesfully developed. AM was immunohistochemically localized mainly in glomeruli (GEC and endothelial cells), some cortical proximal tubules, medullary collecting duct cells, interstitial cells, vascular smooth muscle cells and endothelial cells. Northern blot assay showed that AM mRNA was expressed only on cultured GEC, but not on MsC, however, AM receptor CRLR mRNA was only expressed on MsC. GEC conditioned medium containing AM can inhibit MsC growth and AM receptor blocker CGRP8-37 may partially decreased this inhibitory effect. CONCLUSION: AM produced by GEC inhibits the proliferation of MsC, which suggests that AM as an important regulator is involved in glomerular normal physiological functions and pathologic processes.

花鲈肠上皮细胞原代培养及鉴定方法的探讨研究

为探究建立稳定可靠的花鲈肠上皮细胞原代培养方法,通过组织块法和酶消化法培养花鲈肠上皮细胞,确定酶消化法的最佳消化液及消化时间,所得细胞悬液于L-15培养液中进行培养。利用形态学观察、透射电镜观察和碱性磷酸酶染色方法对细胞进行鉴定。结果显示:组织块法细胞迁出情况不稳定,且迁出时间较长;酶消化法的最佳消化液为胶原酶Ⅰ、Ⅳ联合消化液,最佳消化时间为45 min;胶原酶Ⅰ、Ⅳ联合消化法获得的细胞连接紧密、排列整齐、呈上皮细胞典型的“铺路石”状,细胞相对独立、界限清晰。透射电镜观察和碱性磷酸酶染色进一步证实所培养的细胞为肠上皮细胞。总之,经胶原酶Ⅰ、Ⅳ联合消化液消化45 min、培养48 h可得到初始条件一致、生长旺盛的花鲈原代肠上皮细胞。

相思子碱通过P53/mTOR通路缓解脂多糖对水牛乳腺上皮细胞β-酪蛋白合成的影响

【目的】探究相思子碱(Abrine)通过调节P53/mTOR通路缓解脂多糖(Lipopolysaccharide,LPS)对水牛乳腺上皮细胞酪蛋白合成的影响,为缓解乳房炎引起的水牛乳品质下降提供理论依据。【方法】使用脂多糖构建水牛乳腺上皮细胞炎症模型,同时使用相思子碱、P53抑制剂(Pifithrin-μ)、P53激活剂(Kevetrin hydrochloride)与水牛乳腺上皮细胞共同孵育12 h;通过HE染色观察水牛乳腺组织形态,采用CCK-8法检测细胞活性,使用ELISA试剂盒检测水牛乳腺上皮细胞β-酪蛋白分泌水平,利用实时荧光定量PCR测定NF-κB、IL-1β、TNFα、β-casein、mTOR、P53、JAK2、STAT5和AKT1基因相对表达量,并以Western blotting检测NF-κB、IL-1β、TNFα、β-casein、mTOR和P53蛋白相对表达量。【结果】临床型乳房炎乳腺组织间隙及腺泡腔被大量中性粒细胞浸润,部分腺泡结构呈现一定程度的萎缩。经1.0μg/mL脂多糖处理,水牛乳腺上皮细胞活力显著降低(P<0.05,下同),2.0、4.0和8.0μg/mL脂多糖处理,水牛乳腺上皮细胞活力极显著降低(P<0.001),25、50、100和200μmol/L相思子碱处理能缓解脂多糖的影响,水牛乳腺上皮细胞活力明显升高。与空白对照组相比,脂多糖处理组水牛乳腺上皮细胞NF-κB、IL-1β、TNFα和P53基因和蛋白相对表达量显著升高,β-酪蛋白表达水平显著降低;与脂多糖组相比,相思子碱+脂多糖处理组水牛乳腺上皮细胞β-酪蛋白水平显著升高,NF-κB、IL-1β、TNFα、P53基因和蛋白相对表达量显著降低;与脂多糖组相比,脂多糖+Pifithrin-μ组水牛乳腺上皮细胞β-酪蛋白表达水平显著升高,与相思子碱组相比,相思子碱+Kevetrin hydrochloride组水牛乳腺上皮细胞β-酪蛋白表达水平显著降低。【结论】脂多糖降低了水牛乳腺上皮细胞β-酪蛋白合成水平与β-酪蛋白合成相关基因及其编码蛋白的表达水平;相思子碱能通过抑制NF-κB通路缓解脂多糖诱导的水牛乳腺上皮细胞炎症,并通过调节P53/mTOR通路缓解脂多糖诱导的水牛乳腺上皮细胞β-酪蛋白合成减少。

氯化两面针碱通过Wnt/mTOR信号通路缓解热应激水牛乳腺上皮细胞β-酪蛋白含量降低

【目的】探究氯化两面针碱(Nitidine chloride,NitC)对热应激水牛乳腺上皮细胞β-酪蛋白含量降低的影响,为实际生产中缓解热应激对水牛乳品质的负面影响提供理论依据。【方法】记录非热应激季节和热应激季节牛舍温湿度指数(Temperature-humidity index,THI),检测水牛呼吸频率和直肠温度以判断水牛是否处于热应激状态;采集奶样进行乳成分分析以探究热应激对水牛奶β-酪蛋白含量的影响;以水牛乳腺上皮细胞为研究对象,经40.5℃处理24 h建立细胞热应激模型,使用LiCl和LGK974分别激活和抑制Wnt通路,检测水牛乳腺上皮细胞β-酪蛋白含量及β-酪蛋白合成相关基因和蛋白的表达水平,探究氯化两面针碱缓解热应激水牛乳腺上皮细胞β-酪蛋白含量降低的作用机制。【结果】与非热应激季节相比,热应激季节牛舍THI升高并超过水牛热应激阈值,水牛呼吸频率和直肠温度显著升高(P<0.05,下同),水牛奶β-酪蛋白含量显著降低;细胞试验结果表明,40.5℃处理24 h能显著降低水牛乳腺上皮细胞β-酪蛋白含量、细胞活力及Wnt2、mTOR、β-casein基因和蛋白的相对表达量;而氯化两面针碱处理能有效缓解热应激对水牛乳腺上皮细胞的影响,显著提高水牛乳腺上皮细胞β-酪蛋白含量、细胞活力及Wnt2、mTOR、β-casein基因和蛋白的相对表达量。【结论】热应激降低了水牛乳腺上皮细胞β-酪蛋白含量及β-酪蛋白合成相关基因和蛋白的相对表达量,氯化两面针碱则通过Wnt/mTOR信号通路提高水牛乳腺上皮细胞β-酪蛋白含量、细胞活力及Wnt2、mTOR、β-casein基因和蛋白的相对表达量,以缓解热应激造成的水牛乳腺上皮细胞β-酪蛋白含量降低。

山羊乳中乳腺上皮细胞的体外分离培养及鉴定

为了探索获得乳腺上皮细胞(MECs)的新途径,试验采用乳汁分离法分离培养山羊乳腺上皮细胞(GMECs),并以山羊耳缘成纤维细胞(GEFs)为对照,通过形态学观察、免疫荧光染色观察细胞形态,油红O染色检测脂滴形成情况;实时荧光定量PCR检测特异性基因;Western-blot检测乳腺分泌的特异性蛋白;此外,对GMECs和GEFs进行转录组测序(RNA-seq)分析及GO功能注释和KEGG信号通路富集分析。结果表明:从山羊奶中分离出来的细胞表现出MECs的结构特征;与GEFs对照相比,GMECs中乳腺上皮特异性基因CDH1、LTF、CSN2、CSN3、EpCAM、KRT18、ELF3和ELF5的相对表达量在第8代(GMEC8)极显著增加(P<0.01),GMEC8可以表达CDH1、EpCAM、CSN2和LTF等蛋白;共获得4481个明显差异表达的基因,其中上调基因1975个,下调基因2506个;上皮的形态发生和上皮发育为显著富集的GO条目;乳腺发育相关的信号通路如WNT、PI3K-Akt和MAPK信号通路明显富集。说明从山羊奶中可以分离出GMECs。

马乳腺上皮细胞的分离培养与鉴定

本试验旨在建立马乳腺上皮细胞的原代培养方法,为马属动物泌乳相关机制的研究提供试验材料和细胞模型。以泌乳期哈萨克母马乳腺组织为研究对象,利用Ⅰ型胶原酶和透明质酸酶分离马乳腺上皮细胞,并进行纯化和鉴定。结果显示:1)利用酶消化法培养的马乳腺上皮细胞形态呈长条状或岛屿状;冻存后复苏培养的马乳腺上皮细胞生长状况良好。2)纯化后的马乳腺上皮细胞具备正常的“S”形生长周期。3)琼脂糖凝胶电泳结果显示,培养的马乳腺上皮细胞能够表达其特异性基因细胞角蛋白18(cytokeratin 18)基因(CK 18)。4)通过免疫荧光技术,运用鼠抗cytokeratin 18作为一抗,对马乳腺上皮细胞进行鉴定,结果呈阳性。综上所述,本研究使用的方法能够成功分离、纯化培养并鉴定出马乳腺上皮细胞。

Traditional and emerging Fusarium mycotoxins disrupt homeostasis of bovine mammary cells by altering cell permeability and innate immune function

High incidence of traditional and emerging Fusarium mycotoxins in cereal grains and silages can be a potential threat to feed safety and ruminants.Inadequate biodegradation of Fusarium mycotoxins by rumen microflora following ingestion of mycotoxin-contaminated feeds can lead to their circulatory transport to target tissues such as mammary gland.The bovine udder plays a pivotal role in maintaining milk yield and composition,thus,human health.However,toxic effects of Fusarium mycotoxins on bovine mammary gland are rarely studied.In this study,the bovine mammary epithelial cell line was used as an in-vitro model of bovine mammary epithelium to investigate effects of deoxynivalenol(DON),enniatin B(ENB)and beauvericin(BEA)on bovine mammary gland homeostasis.Results indicated that exposure to DON,ENB and BEA for 48 h significantly decreased cell viability in a concentration-dependent manner(P<0.001).Exposure to DON at 0.39μmol/L and BEA at 2.5μmol/L for 48 h also decreased paracellular flux of FITC-40 kDa dextran(P<0.05),whereas none of the mycotoxins affected transepithelial electrical resistance after 48 h exposure.The qPCR was performed for assessment of expression of gene coding tight junction(TJ)proteins,toll-like receptor 4(TLR4)and cytokines after 4,24 and 48 h of exposure.DON,ENB and BEA significantly upregulated the TJ protein zonula occludens-1,whereas markedly downregulated claudin 3(P<0.05).Exposure to DON at 1.35μmol/L for 4 h significantly increased expression of occludin(P<0.01).DON,ENB and BEA significant downregulated TLR4(P<0.05).In contrast,ENB markedly increased expression of cytokines interleukin-6(IL-6)(P<0.001),tumor necrosis factorα(TNF-a)(P<0.05)and transforming growth factor-β(TGF-β)(P<0.01).BEA significantly upregulated IL-6(P<0.001)and TGF-β(P=0.01),but downregulated TNF-α(P<0.001).These results suggest that DON,ENB and BEA can disrupt mammary gland homeostasis by inducing cell death as well as altering its paracellular permeability and expression of genes involved in innate immune function.

体外培养的山羊乳腺上皮细胞形态研究

通过有效的细胞培养方法获得山羊乳腺上皮细胞系,对这些细胞形态进行光镜观察,结果发现,细胞可形成闭合型和开放型细胞群,闭合型细胞群边界清晰,细胞之间结合紧密;开放型细胞群边界不清,细胞相互分散存在于一局限的范围内。乳腺上皮细胞与成纤维细胞混生时分区生长,界线明显;细胞之间形成许多腔状结构。纯化的乳腺上皮细胞通过单细胞悬浮后传代,部分细胞形成岛屿状聚集,部分细胞以贴壁的自由单个细胞散在形式存在。上皮细胞增殖可形成圆顶型结构,呈乳头状(称之为乳球体);乳腺上皮细胞可产生并分泌乳汁,分泌到细胞外的乳汁流动形成网状结构。山羊乳腺上皮细胞含不同的细胞类型,大多数上皮细胞呈短梭形或多角形,细胞之间紧密相靠,互相衔接,连接成片,呈蜂窝状;细胞核呈圆形或椭圆形,核仁2～4枚;部分细胞呈圆饼状,体积较大;出现部分长形细胞;部分细胞表面出现绒毛状突起;接触抑制的上皮细胞形态不均一。

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

比较了几种乳腺细胞分离培养方法的特点。实验证明 :胶原酶消化法和组织块种植法均可用于培养牛原代乳腺细胞。其中 ,胶原酶消化法容易得到均匀的乳腺细胞 ,且上皮细胞所占比例也比较高 ;组织块培养法不容易丢失、损伤上皮细胞 ,但上皮细胞长出较晚 ,且占比例较低 ,然而 ,用于培养小动物乳腺组织具有优势 ,并且可结合组织块转移、胰蛋白酶消化纯化上皮细胞 ,用此方法本实验获得了牛乳腺上皮细胞富集的细胞系 ;同时讨论了乳腺上皮细胞增殖与分化的关系 。

组织块种植法体外培养奶牛乳腺上皮细胞

为建立成熟的奶牛乳腺上皮细胞体外培养体系,以组织块种植法培养荷斯坦泌乳期成年母牛乳腺组织,观测长出的上皮细胞在各生长时期的形态变化,绘制生长曲线并计算群体倍增时间,用免疫组化技术鉴定乳腺上皮细胞角蛋白18的表达,用SDS-PAGE电泳和免疫印迹分析技术检测乳腺细胞的酪蛋白分泌情况。试验结果表明,此培养体系可获得良好的奶牛乳腺上皮细胞,原代以及传代培养,细胞增殖旺盛,长势良好;细胞骨架蛋白——角蛋白18表达为阳性,且培养的细胞具有分泌牛乳酪蛋白的功能。

中草药提取物对小鼠乳腺上皮细胞增殖的影响

【目的】研究中草药单味及复方提取物对原代培养的小鼠乳腺上皮细胞增殖的影响,旨在为探明中草药治疗奶牛乳腺疾病机制提供试验依据。【方法】采用组织块种植法培养3月龄、分娩后3-5 d的昆明种远交系小白鼠的乳腺组织,采用胰蛋白酶消化法获得相对纯化的小鼠乳腺上皮细胞,并运用SDS-PAGE法进行鉴定。制备5味中草药（重楼、紫花地丁、木芙蓉、半枝莲、泽兰叶）及治疗奶牛乳房炎用中草药复方提取物,分别作用于对数生长期的乳腺上皮细胞5 d,用四甲基偶氮唑盐法（MTT法）分析细胞活力。【结果】将通过组织块种植法与胰蛋白酶消化法相结合,可得到纯化的有酪蛋白分泌功能的乳腺上皮细胞;中草药重楼、紫花地丁、木芙蓉、半枝莲、泽兰叶提取物在其质量浓度分别为8,40,40,1.6,8 mg/mL时,对小鼠乳腺上皮细胞增殖作用最强;除了紫花地丁,其他4种中草药提取物在其质量浓度为200 mg/mL时,对小鼠乳腺上皮细胞增殖的抑制作用最强。中草药复方提取物质量浓度为8~200mg/mL时,对小鼠乳腺细胞有显著促进作用,随着质量浓度的增加,促增殖作用减弱。【结论】中草药单味及复方提取物在一定质量浓度下对乳腺上皮细胞增殖产生了促进或抑制作用,且中草药复方提取物的适用质量浓度范围较广。

奶牛乳腺上皮细胞的不同培养方法比较及激素和细胞因子对β-酪蛋白mRNA表达的诱导

本试验旨在建立一种高效的奶牛乳腺上皮细胞培养方法,并研究不同激素和细胞因子对其表达β-酪蛋白mRNA的诱导作用。分别采用组织块培养法和机械破碎法培养奶牛乳腺上皮细胞,利用成纤维细胞和乳腺上皮细胞对胰酶的敏感性不同,对获得的细胞进行纯化。通过细胞计数法测定纯化细胞的生长曲线,通过免疫荧光组织化学染色法检测角蛋白18的表达,通过实时定量PCR法检测8种不同激素和细胞因子组合培养液诱导细胞表达β-酪蛋白mRNA的效果。结果表明:通过机械破碎法可以分离得到增殖旺盛的奶牛乳腺上皮细胞,与组织块培养法相比,具有细胞迁出速度快等优点。细胞生长曲线呈典型的"S"型。在纯化的乳腺上皮细胞及第20代乳腺上皮细胞中都检测到角蛋白18的表达。100 ng/mL类胰岛素生长因子Ⅰ(IGF-Ⅰ)显著提高了乳腺上皮细胞中β-酪蛋白mRNA的表达(P<0.05)。由结果可知,本试验采用的机械破碎法是一种高效的奶牛乳腺上皮细胞培养方法,100 ng/mL IGF-Ⅰ对细胞中β-酪蛋白mRNA表达的诱导效果最好。

荷斯坦奶牛乳腺组织冻存及乳腺上皮细胞原代培养技术改进

为了改进奶牛乳腺上皮细胞原代培养技术和探究乳腺组织冻存方法,选用24月龄无泌乳史荷斯坦奶牛,采用组织块种植法,通过侧置和倒置两种方式,分别从新鲜和冻存（8个月）的乳腺组织中分离培养奶牛乳腺上皮细胞。结果表明,侧置处理能使乳腺细胞爬出时间缩短1-2d,并改善组织块贴壁速度和效果;回收于前次培养后的乳腺组织块再分离培养,贴壁第2天即有乳腺上皮细胞爬出;一步冷冻（-80℃）液氮保存较大奶牛乳腺组织块,冻存液A（FBS∶DMSO∶DMEM/F12=7∶2∶1）冻存的组织块存活率为50%,冻存液B（FBS∶DMEM/F12∶DMSO∶HEPES/丙酮酸钠贮存液=10∶7∶2∶1）冻存的组织块存活率为56%。可见,作者建立的侧置处理法和组织块回收法可以用于奶牛乳腺上皮细胞的分离培养,可以缩短组织块种植法实验周期,冻存液中加入缓冲液HEPES/丙酮酸钠后有利于组织块生物活性保持。

奶牛乳腺上皮细胞和成纤维细胞的体外培养与鉴定

为体外培养纯化出稳定的奶牛乳腺上皮细胞和成纤维细胞,试验通过外科手术的方法取妊娠后期或泌乳期的荷斯坦奶牛乳腺组织,分离乳腺腺泡,用组织块法体外培养奶牛乳腺细胞,应用差时胰酶消化法和差速贴壁法将奶牛乳腺上皮细胞和成纤维细胞分别纯化出来,并用免疫组化的方法对细胞的纯度进行鉴定。结果表明:纯化的奶牛乳腺上皮细胞多为多角形,细胞核呈圆形或椭圆形,核仁清晰可见,多呈鹅卵石样或铺路石样生长,并可分泌乳滴,角蛋白-18反应阳性,波形蛋白反应阴性;纯化的奶牛乳腺成纤维细胞多为长梭形,呈旋涡状或放射状生长,角蛋白-18反应阴性,波形蛋白反应阳性;经纯化后2种细胞的纯度均可达95%以上,可满足后续试验的要求。

奶牛乳腺上皮细胞原代培养、纯化及鉴定技术研究进展

奶牛乳腺上皮细胞不仅具有合成和分泌乳汁的功能,而且在乳腺的先天免疫中扮演着重要角色,对泌乳机制、乳房炎发病机制的研究,以及药物筛选具有重要意义。原代培养的奶牛乳腺上皮细胞适宜建立细胞模型,可作为生理、病理、药理等方面研究的良好介质,解决体内试验周期长、成本高、个体差异大的难题。作者主要从奶牛乳腺上皮细胞原代培养的发展历程、培养技术、纯化技术及鉴定方法等方面的最新研究情况进行综述,以期为奶牛乳腺上皮细胞培养相关研究提供参考。

体外培养的牛乳腺上皮细胞形态研究

通过有效的细胞培养方法获得了牛乳腺上皮细胞系,并系统观察了乳腺上皮细胞的长出、贴壁、聚集、迁移、分裂、分化、凋亡等一系列形态变化。结果发现,原代培养的乳腺上皮细胞大多数呈卵圆形,细胞之间连接成片,单层生长,如鹅卵石铺过路面,乳腺上皮细胞和成纤维细胞混生时分区生长,界线明显。传代的乳腺上皮细胞呈岛屿状聚集生长,细胞核呈圆形或椭圆形,核仁2～4枚;在含雌激素的培养液中,细胞出现双核或多核现象,但仍表现一定的接触抑制现象。多次传代后的乳腺上皮细胞含不同的细胞类型,通过光镜观察,部分细胞仍保持较快的分裂增殖能力;部分细胞渐渐分化,出现长形细胞、三角形细胞。上皮细胞增殖分化可形成圆顶型结构,乳腺上皮细胞可产生并分泌乳汁,分泌到细胞外的乳汁流动形成网状结构。