姜黄素对角膜基质细胞纤维化的抑制作用

背景角膜的创伤或手术可导致角膜基质细胞纤维化,进而形成瘢痕。研究表明姜黄素可明显减轻组织的纤维化程度,但姜黄素是否会影响角膜基质细胞纤维化的研究尚少。目的观察不同质量浓度的姜黄素对小鼠角膜基质细胞向成纤维细胞转化过程的影响,探讨姜黄素抗角膜基质纤维化的作用。方法150只6～8周龄BALB／c小鼠,分离角膜基质细胞并在含质量分数10％胎牛血清（FBS）的DMEM中进行培养,以原代角膜基质细胞重悬于DMEM中并分为5组：（1）空白对照组（DMEM＋10％FBS,含质量分数1％。DMSO,CG组）。（2）低剂量组（CG＋7．5mg／L姜黄素组）。（3）中剂量组（CG＋10mg／L姜黄素组）。（4）高剂量组（CG＋12．5mg／L姜黄素组）。（5）无诱导剂组（DMEM,含1％oDMSO）。上述因素干预7d后,用逆转录聚合酶链反应（RT—PCR）法检测各组中细胞表型keratocan、醛脱氢酶（ALDH）、CD90、decorin、fibronectin一1的表达。用MTS法检测姜黄素对角膜基质细胞增生的影响。制备小鼠角膜冰冻切片,采用免疫荧光技术检测角膜基质细胞内fibronectin-1的表达。结果原代培养的角膜基质细胞呈梭形,为细胞质丰富且核大的角膜基质成纤维细胞。随着姜黄素质量浓度的增加,角膜基质细胞中keratocanmRNA、ALDHmRNA的表达量增加,CD90mRNA和decorinmRNA的表达量减少,差异均有统计学意义（P〈O．05）,fibronectin-1mRNA的表达变化差异无统计学意义（P〉0．05）。MTS法检测发现,随着姜黄素质量浓度的增加,对角膜基质细胞增生的抑制率逐渐增加（F=956．00,P〈0．05）。免疫荧光技术检测发现角膜基质细胞中fibronectin-1的表达呈红色荧光。结论姜黄素对离体小鼠角膜基质细胞纤维化有明显的抑制作用,可减轻角膜基质创伤修复过程中的过度纤维化。     

胎牛血清对小鼠角膜上皮细胞生长和分化的影响

目的：探讨胎牛血清对小鼠角膜上皮细胞生长和分化的影响。方法：分别在无血清低钙培养基（KSFM）和含100mL／L胎牛血清的KSFM中培养小鼠角膜上皮细胞。比较两种培养基中角膜上皮细胞的群体倍增（PD）。通过RT-PCR和Westernblotting方法检测p63、角蛋白19以及involucrin的表达。结果：在KSFM中,小鼠角膜上皮细胞可稳定传代超过25代,但在含胎牛血清的培养基中,细胞仅能存活3代。在KSFM中,培养细胞呈典型铺路石样外观,RT-PCR和Westernblotting结果显示细胞表达p63、角蛋白19以及involucrin。当培养基中加入胎牛血清后,细胞形态明显增大,呈扁平状;involucrin表达显著增强。结论：胎牛血清可抑制小鼠角膜上皮细胞增生、诱导其分化。     

胎牛血清对小鼠角膜上皮细胞生长和分化的影响(英文)

目的:探讨胎牛血清对小鼠角膜上皮细胞生长和分化的影响。方法:分别在无血清低钙培养基(KSFM)和含100mL/L胎牛血清的KSFM中培养小鼠角膜上皮细胞。比较两种培养基中角膜上皮细胞的群体倍增(PD)。通过RT-PCR和Western blotting方法检测p63、角蛋白19以及involucrin的表达。结果:在KSFM中,小鼠角膜上皮细胞可稳定传代超过25代,但在含胎牛血清的培养基中,细胞仅能存活3代。在KSFM中,培养细胞呈典型铺路石样外观,RT-PCR和Western blotting结果显示细胞表达p63、角蛋白19以及in-volucrin。当培养基中加入胎牛血清后,细胞形态明显增大,呈扁平状; involucrin表达显著增强。结论:胎牛血清可抑制小鼠角膜上皮细胞增生、诱导其分化。     

转谷氨酰胺酶交联胶原凝胶构建三维角膜基质

目的检测转谷氨酰胺酶交联胶原凝胶对三维培养的角膜基质细胞的影响,探讨可提高机械性能的组织工程角膜基质层新途径。方法胶原酶消化法获取原代兔角膜基质细胞,以加入转谷氨酰胺酶与胶原凝胶交联为实验组,不加酶交联为对照组。倒置显微镜下每日观察细胞生长情况、Alamar-Blue试剂检测细胞增生、免疫荧光法检测凝胶内细胞波形蛋白、检测透光度、酶消化法检测胶原凝胶抗消化能力。结果实验组细胞胶原凝胶内附着和生长优于对照组,细胞在凝胶内呈树枝状生长。2组细胞均随培养时间延长明显增生（P=0.000）。共焦显微镜下见2组细胞胞浆波形蛋白均阳性表达,实验组细胞伪足更丰富。实验组透光度稍差于对照组。实验组抵抗胶原酶消化的能力显著增强。结论酶交联的胶原凝胶对角膜基质细胞无毒性作用,重构的基质层结构更加稳定,有利于组织工程角膜基质层的构建。     

牛角膜基质细胞的两步酶消化法高效分离及体外培养观察

背景高效、低成本分离出生物学功能活性高的角膜基质细胞是开展角膜基础研究的需要。目前的分离方法成本高、分离效率低，而通过培养达到扩增细胞数会导致细胞表型快速改变。应用成本较低的Ⅰ型胶原酶，通过改良的两步酶消化法可能达到高效、快速、低成本分离牛角膜原代基质细胞的目的。目的评价设计的Ⅰ型胶原酶两步酶消化法分离原代牛角膜基质细胞的效果，并观察体外培养原代牛角膜基质细胞的形态学变化。方法分别用基础培养液配制的0．5g／L及1．0g／L Ⅰ型胶原酶以两步酶消化法顺序消化牛角膜组织，分离角膜基质细胞，以细胞计数板进行计数，检测基质细胞收获效率；锥虫蓝染色法检测收获细胞的存活率；分离的细胞进行原代培养，倒置显微镜下观察细胞形态和生长的变化；应用Alexa488标记的鬼笔环肽检测原代培养的牛角膜基质细胞中F—actin的分布。结果牛角膜经两步酶消化法基质逐步解离和降解，绝大多数细胞得以释放和分离，分离的牛角膜基质细胞呈圆形，透亮且大小均匀。每个角膜收获（2．109±0．142）×10。个基质细胞，细胞存活率（91．693±3．551）％，贴壁率（81．195±1．214）％。原代培养的牛角膜基质细胞贴壁呈树突样，铺伸至星状，融合时树突连接呈网状，其F—aetin局限性分布于细胞皮质。结论两步酶消化法可使牛角膜基质完全消化降解，具有高细胞收获率、高细胞存活率和操作简便等特点。原代培养的牛角膜基质细胞呈树突状，F—actin分布于细胞皮质。     

兔角膜内皮、上皮及基质细胞体外培养扩增的研究

目的 建立角膜上皮、基质及内皮细胞体外培养扩增的简单稳定的方法，为组织工程化角膜的构建提供种子细胞。方法 内皮细胞与后弹力层在培养基中孵育后消化法获原代细胞，胰酶消化去除表层上皮后取角膜缘，组织块法培养角膜缘上皮细胞，基质细胞应用胶原酶消化法获原代培养，各细胞融合后胰酶消化依次传代培养。结果 原代内皮细胞4—5d融合成单层细胞，可连续传6—7代。上皮细胞1周左右生长融合，连续传3—4代后细胞形态改变。基质细胞接种6—7d后近融合，传代后增殖明显，可连续传10代。结论依据角膜组织特征选择合适的方法体外分离、培养角膜3种细胞成分，可获连续传代扩增的角膜细胞。     

异种角膜基质材料的制备和体外细胞种植的实验研究

目的研究异种角膜基质生物支架材料的制备方法和体外种植兔角膜基质细胞后细胞在材料上的生长、增殖情况。方法将York猪全层角膜用去垢剂联合0．25％胰蛋白酶、DNA-RNA酶祛除猪角膜基质细胞并冻干制备成支架材料；将兔角膜组织块用胶原酶消化后，用含10％血清的DMEM培养液体外培养，并做波形丝蛋白，角蛋白免疫组织化学染色检测；将培养的兔角膜基质细胞的2～3代接种在材料上，培养5d后，做HE染色、扫描电镜观察。结果猪角膜基质片经脱细胞处理后，细胞成分祛除干净并保留了角膜组织的三维网格状结构，网状间隙明显增大，利于细胞生长；体外培养的兔角膜基质细胞波形丝蛋白染色为阳性、角蛋白染色为阴性；HE染色、扫描电镜结果显示兔角膜基质细胞在支架材料上生长、增殖良好。结论异源性角膜经祛脱细胞处理而获得的生物支架材料利于异种细胞的黏附和增殖，可进一步用于组织工程角膜的研究。     

一种培养原代小鼠角膜基质细胞的新方法

目的改良小鼠角膜基质细胞分离培养方法 ,为角膜基质细胞生物学和角膜组织工程等研究提供更好的种子细胞。方法采用Dispase酶消化法联合组织块贴壁法分离、培养原代小鼠角膜基质细胞,倒置显微镜下观察细胞生长情况,通过间接免疫荧光化学染色Vimentin表型和RT-PCR检测Vimentin、Lumican和CK12基因表达对培养的细胞进行鉴别。结果倒置显微镜下可见小鼠角膜基质细胞呈三角形和树枝状,细胞间连接明显,可形成网状连接;免疫荧光化学鉴定小鼠角膜基质细胞表达Vimentin阳性;RT-PCR显示Vimentin和Lumican基因表达阳性,CK12表达阴性。结论 Dispase酶消化法联合组织块贴壁法培养可获得具有角膜基质细胞特性的细胞,本方法为体外获得单纯小鼠角膜基质细胞提供了简单高效的途径。     

小鼠角膜基质细胞分泌的转化生长因子β2及前列腺素E2对树突状细胞成熟过程的抑制作用

背景研究表明,位于角膜中央区的树突状细胞（DCs）完全处于未成熟状态,而位于角膜周边区的DCs则大多处于成熟状态。角膜内的DCs广泛参与多种角膜相关疾病以及角膜移植免疫排斥反应,研究角膜内DEs的成熟状态具有重要意义。目的探讨小鼠角膜基质细胞（CSCs）是否通过分泌转化生长因子β2（TGF—β2）以及前列腺素E：（PGE2）抑制DCs的成熟。方法获取DCs、T细胞以及CSCs培养上清液。通过酶联免疫吸附实验（ELISA）测定CSCs培养上清液以及新鲜RPMI1640培养基内PGE2和TGF—β2的质量浓度。在DCs成熟过程中,应用TGF—β2中和抗体以及PGE：受体阻滞剂AH6809,并按照处理方式的不同分为对照组、CSCs培养上清液组、AH6809组、TGF—β2中和抗体组、AH6809＋TGF—β2中和抗体组。采用流式细胞技术检测DCs细胞表型CDllc、CD80、CD86和MHC-Ⅱ的表达情况,通过葡聚糖内吞实验检测抗原吞噬功能,并通过混合淋巴细胞反应检测刺激T细胞增生的能力。结果ELISA检测结果显示,与新鲜RPMI1640培养基相比,CSCs培养上清液内含有较高质量浓度的TGF—β2和PGE2。与CSCs培养上清液组比较,TGF—β2中和抗体组DCsCD80、CD86和MHC-Ⅱ的表达均升高,差异均有统计学意义（P〈0．05）,葡聚糖的表达降低（P〈0．05）,刺激指数（SI）增大（P〈0．05）;AH6809组CD86和MHC-Ⅱ的表达均升高,葡聚糖的表达降低,SI增大,差异均有统计学意义（P〈0．05）;TGF—β2中和抗体＋AH6809组DCsMHC-Ⅱ的表达和SI提高,差异均有统计学意义（P〈0．05）。与对照组比较,TGF—β2中和抗体＋AH6809组DCsCD80、CD86的表达和SI均较低,差异均有统计学意义（P〈0．05）。结论体外培养的小鼠CSCs可以通过分泌TGF—β2及PGE2抑制DCs成熟,且这两种细胞因子可发挥叠加效应。     

牛角膜基质细胞的两步酶消化法高效分离及体外培养观察

背景 高效、低成本分离出生物学功能活性高的角膜基质细胞是开展角膜基础研究的需要.目前的分离方法成本高、分离效率低,而通过培养达到扩增细胞数会导致细胞表型快速改变.应用成本较低的I型胶原酶,通过改良的两步酶消化法可能达到高效、快速、低成本分离牛角膜原代基质细胞的目的.目的 评价设计的I型胶原酶两步酶消化法分离原代牛角膜基...     

Preservation and expansion of the primate keratocyte phenotype by downregulating TGF-beta signaling in a low-calcium, serum-free medium

PURPOSE: To demonstrate whether the original keratocyte phenotype is maintained with proliferative activity by suppressing TGF-beta signaling in rhesus monkey keratocytes expanded in a serum-free and low-[Ca2+] medium. METHODS: Rhesus monkey keratocytes were isolated from central corneal buttons by collagenase digestion for 16 hours, seeded on plastic in Dulbecco's modified Eagle's medium (DMEM) containing insulin-transferrin-sodium selenite (ITS) supplement (DMEM/ITS) or 10% fetal bovine serum (DMEM/10% FBS), or in a defined keratinocyte serum-free medium (KSFM). After confluence, cells in KSFM were continuously subcultured at a 1-to-3 split. Cellular proliferation was analyzed by immunostaining for Ki67 and the MTT assay. The cellular phenotype was determined by immunostaining for aldehyde dehydrogenase (ALDH), keratocan, and CD34 and by the expression of keratocan promoter-driven enhanced cyan fluorescent protein (ECFP). The stability of the keratocyte phenotype was examined by switching KSFM to DMEM/ITS and DMEM/10% FBS. TGF-beta signaling was monitored by measuring the promoter activity of TGF-beta1, -beta2, and -beta RII after transient adenoviral transfection, and cytolocalization of Smad2 and Smad4. RESULTS: In KSFM, monkey keratocytes proliferated while maintaining the expression of keratocan, CD34, and ALDH proteins and keratocan promoter-driven ECFP for at least 15 passages. The nuclear accumulation of Smad2 and Smad4 and the promoter activities of TGF-beta1 and -beta RII were significantly downregulated in KSFM compared with DMEM/10% FBS. In KSFM, an increase of [Ca2+] to 1.8 mM and addition of 10% FBS synergistically downregulated the keratocan promoter activity, facilitated Smad2 and Smad4 nuclear translocation, and upregulated TGF-beta1 and -beta RII promoter activities. CONCLUSIONS: The normal monkey keratocyte phenotype can be maintained in a low-calcium, serum-free medium by downregulating Smad-mediated TGF-beta signaling.     

Loss of alpha3(IV) collagen expression associated with corneal keratocyte activation

PURPOSE: To determine whether changes in the expression of type IV alpha1, alpha2, or alpha3 collagen isoforms are stringently associated with corneal stromal cell activation. METHODS: Keratocytes isolated from rabbit corneal stroma by collagenase digestion were plated in serum-free or insulin-, bFGF/heparin sulfate (HS)-, TGF-beta1-, or fetal bovine serum (FBS)-supplemented DMEM/F12 medium. Expression of type IV collagen isoforms and keratan sulfate proteoglycans (KSPGs) was evaluated by immunocytochemical analysis, Western blot analysis, or both. Concentrations of mRNAs were estimated by quantitative RT-PCR using SYBR Green RT-PCR reagents. RESULTS: Immunohistochemical analysis indicated that type IV alpha1, alpha2, and alpha3 collagens were expressed in normal rabbit corneal stroma and in keratocytes cultured in serum-free and insulin-supplemented media. However, alpha3(IV) collagen was not detectable in the regenerating stroma after photorefractive keratectomy (PRK) in rabbit or in corneal stromal cells cultured in media supplemented with FBS, bFGF/HS, or TGF-beta1. alpha3(IV) collagen mRNA levels were also diminished in the stromal cells cultured in these growth factor-supplemented media. KSPGs (lumican and keratocan) were expressed and secreted in serum-free medium. Although the expression of KSPGs was promoted by insulin, the expression and intracellular levels of lumican and keratocan mRNAs were downregulated by TGF-beta1 and FBS. bFGF/HS promoted the downregulation of intracellular keratocan but not lumican mRNA levels. CONCLUSIONS: The loss in the expression of alpha3(IV) collagen is a stringent phenotypic change associated with activation of keratocytes in vivo and in vitro. This phenotypic change in activated corneal stromal cells is induced by bFGF/HS and by TGF-beta1, and it accompanies the downregulation of keratocan expression.     

Human keratocytes cultured on amniotic membrane stroma preserve morphology and express keratocan

PURPOSE: To develop a new method of expanding human corneal keratocytes in serum while maintaining their characteristic morphology and keratocan expression. METHODS: Human keratocytes were isolated from central corneal buttons by digestion in 1 mg/mL of collagenase A in DMEM and seeded on plastic or the stromal matrix of human amniotic membrane (AM) in DMEM with different concentrations of FBS. On confluence, cells on AM were continuously subcultured for six passages on AM or plastic. In parallel, cells cultured on plastic at passages 3 and 11 were reseeded on AM. Cellular morphology and cell-cell networks were assessed by phase-contrast microscopy and a cell viability assay, respectively. Expression of keratocan was determined by RT-PCR and Western blot analysis. RESULTS: Trephined stroma yielded 91,600 +/- 26,300 cells (ranging from 67,000 to 128,000 cells per corneal button). Twenty-four hours after seeding, cells appeared dendritic on AM, even in 10% FBS but fibroblastic on plastic. Such a difference in morphology correlated with expression of keratocan assessed by RT-PCR and Western blot, which was high and continued at least to passage 6 on AM, even in 10% FBS, but was rapidly lost each time when cells on AM were passaged on plastic. Fibroblasts continuously cultured on plastic to passages 3 and 11 did not reverse their morphology or synthesize keratocan when reseeded on plastic in 1% FBS or on AM. CONCLUSIONS: Human keratocytes maintain their characteristic morphology and keratocan expression when subcultured on AM stromal matrix even in the presence of high serum concentrations. This method can be used to engineer a new corneal stroma.     

The heterogeneous murine corneal stromal cell populations in vitro

PURPOSE: To demonstrate that the murine corneal stroma is inhabited by heterogeneous cell populations that include cells expressing nestin. METHODS: Collagenase-isolated corneal stroma cells obtained from newborn and adult mice (2nd and 12th postnatal weeks, respectively), were seeded at low (5 cells/mm2), intermediate (50 cells/mm2), and high (500 cells/mm2) densities in DMEM/F12 containing insulin, transferrin, selenium, and 1% nonessential amino acids. Corneal stroma cells cultured at 500 cells/mm2 were treated with 10 ng/mL human recombinant transforming growth factor (TGF)-beta1 for 5 days. Cell morphology and expression of alpha-smooth muscle actin, choline acetyltransferase, CD45, glial fibrillary acidic protein (GFAP), keratocan, nestin, neurofilaments, protein gene product 9.5, tyrosine hydroxylase, and vimentin were examined. RESULTS: Phase-contrast microscopy demonstrated that freshly isolated corneal stromal cells are heterogeneous in morphology and include dendritic, stellate, neuronal, and small polyhedral cells. Immunostaining of primary cultures of 2- and 12-week-old mice, 24 hours after seeding at the intermediate density, showed that 100% of cells expressed vimentin and 97.7% +/- 2.7% expressed keratocan. alpha-Smooth muscle actin was expressed by 0.2% +/- 0.05% of cells in the 2-week-old group and 0.1% +/- 0.07% in 12-week-old group. Neurofilament was expressed by 0.5% +/- 0.03% and 0.7% +/- 0.03% of cells in the 2- and 12-week-old groups, respectively. No cell expressed GFAP or nestin. After 5 days in culture, cells seeded at high density aggregated as clusters that were immunoreactive to nestin in both groups. Cell clusters and migrating cells reacted to pgp 9.5, and migrating cells, but not the cell clusters, reacted to tyrosine hydroxylase. Cell cluster formation and nestin expression were abolished by culturing in the presence of TGF-beta1. CONCLUSIONS: Normal murine corneal stroma contains heterogeneous cell populations including cells with the potential to form clusters and express the progenitor marker nestin. This potential is disrupted by the addition of TGF-beta1 to the culture medium.     

In vivo gene delivery and visualization of corneal stromal cells using an adenoviral vector and keratocyte-specific promoter

PURPOSE: This study was conducted to determine whether intrastromal injection of adenoviral construct could be used to transfect corneal stroma cells effectively in vivo and to determine whether a tissue-specific promoter could be used to express exogenous genes in keratocytes. METHODS: An adenoviral construct with a cytomegalovirus (pCMV)-driven enhanced green fluorescent protein (EGFP) reporter gene was injected into the stroma of murine corneas. In vivo expression was quantitated and samples were analyzed by in vivo stereomicroscopy, and ex vivo expression was determined by confocal three dimensional (3-D) reconstruction. The 3.2-kb keratocan promoter was used to drive tissue-specific reporter gene expression in vivo. RESULTS: EGFP expression was first detected in vivo 11 hours after injection of adeno-EGFP in the corneal stroma, with a duration of approximately 3 weeks. Ex vivo wholemount cornea confocal analysis with 3-D reconstruction allowed visualization of EGFP expression in corneal stroma cells, to accurately assess cellular architecture and distribution in the corneal stroma. Naked pCMV-EGFP plasmid DNA did not express the reporter gene to the levels of the adeno-EGFP. The 3.2-kb keratocan promoter was capable of driving EGFP tissue-specific expression in the cornea. CONCLUSIONS: Intrastromal injection of adenovirus packaged DNA constructs is a rapid and efficient way to deliver and express genes in the corneal stroma. Intrastromal injection is also capable of delivering tissue-specific promoter constructs to the corneal stroma for gene expression. Furthermore, 3-D reconstruction provides a powerful tool for enhanced visualization of the corneal stroma environment and cellular biology.     

Effect of calcium on the proliferation and differen-tiation of murine corneal epithelial cells in vitro

AIM: To investigate the effect of calcium on the proliferation and differentiation of murine corneal epithelial cells in vitro.METHODS: Mouse corneal epithelial cells were cultured in serum-free low-Ca2+ medium (KSFM) and KSFM supplemented with 0.9mmol/L Ca2+.Population doublings (PDs) were determined.The expression of corneal epithelial cell markers p63,keratin 19 (K19) and involucrin was investigated by RT-PCR analysis and semiquantitative analysis of Western blotting.RESULTS: Cells in KSFM were stably subcultured over 25 passages,however,none of the cell lines could pass P4 in KSFM with Ca2+.In KSFM,the cells was were homogeneous and small cells with typical cobblestone appearance;and expressed p63,K19 and involucrin.After medium was supplemented with calcium,cells became a heterogeneous mix of small and large cells.Furthermore,semiquantitative analysis of Western blotting showed that the expression of involucrin was increased significantly.CONCLUSION: Calcium has the effect of inhibiting proliferation and triggering differentiation on mouse corneal epithelial cells.     

Effect of calcium on the proliferation and differen-tiation of murine corneal epithelial cells in vitro

AIM: To investigate the effect of calcium on the proliferation and differentiation of murine corneal epithelial cells in vitro. METHODS: Mouse corneal epithelial cells were cultured in serum-free low-Ca2+ medium (KSFM) and KSFM supplemented with 0.9mmol/L Ca2+. Population doublings (PDs) were determined. The expression of corneal epithelial cell markers p63, keratin 19 (K19) and involucrin was investigated by RT-PCR analysis and semiquantitative analysis of Western blotting. RESULTS: Cells in KSFM were stably subcultured over 25 passages, however, none of the cell lines could pass P4 in KSFM with Ca2+. In KSFM, the cells was were homogeneous and small cells with typical cobblestone appearance; and expressed p63, K19 and involucrin. After medium was supplemented with calcium, cells became a heterogeneous mix of small and large cells. Furthermore, semiquantitative analysis of Western blotting showed that the expression of involucrin was increased significantly. CONCLUSION: Calcium has the effect of inhibiting pro- liferation and triggering differentiation on mouse corneal epithelial cells.     

Effect of fetal bovine serum on the proliferation and differentiation of murine corneal epithelial cells in vitro

AIM: To investigate the effect of fetal bovine serum (FBS) on the proliferation and differentiation of murine corneal epithelial cells in vitro . METHODS: Mouse corneal epithelial cells (MCEs) were cultured in serum-free low-Ca²⁺ medium (KSFM) and KSFM supplemented with 100mL/L FBS, respectively. Population doublings (PDs) were determined. The expressions of corneal epithelial cell markers p63, keratin 19 (K19) and involucrin were investigated by RT-PCR and Western blotting analyses. RESULTS: Cells in KSFM were stably subcultured over 25 passages; however, none of the cell lines could pass P3 in KSFM with FBS. In KSFM, the cells showed typical cobblestone appearance and expressed p63, K19 and involucrin. After medium was supplemented with FBS, cells became homogeneous, large and squamous. Furthermore, both RT-PCR and Western blotting analyses showed that the expression of involucrin was increased significantly. CONCLUSION: FBS has effects of inhibiting proliferation and triggering differentiation of MCEs.