人晶状体上皮细胞的体外培养

目的建立一种简单可行的人晶状体上皮细胞体外培养的方法.方法利用组织块贴片法,对人晶状体的前囊膜和赤道部囊膜进行培养.对培养的细胞进行形态学观察和鉴定.结果组织块贴壁48～72h后可见人晶状体上皮细胞从组织块边缘长出,具有上皮细胞的形态特点,10～15 d后融合.在体外细胞可传五代,但第三代以后细胞表型向成纤维细胞转化.SABC法染色结果细胞胞浆内α-晶状体蛋白染色阳性.结论成功地建立起人晶状体上皮细胞体外培养模型,可用于后囊膜混浊发病机理和药物试验研究.     

鼠晶状体上皮细胞的体外培养

目的:建立鼠晶状体上皮细胞体外培养的模型。方法:应用组织块贴片法和酶逐步消化法对10~14d的SD大鼠晶状体上皮细胞进行体外培养,在相差显微镜下观察其生长规律。结果:组织块贴片法在加入培养基4~5d后见细胞生长,2wk细胞融合。而酶逐步消化法在加入培养基后7d左右见细胞贴壁,2wk左右见细胞融合。结论:鼠晶状体上皮细胞体外培养较困难,本试验采用酶逐步消化方法和组织块贴片法。成功地建立了鼠晶状体上皮细胞体外培养的模型,为研究后发性白内障发病机制提供了基础。     

体外培养的晶状体上皮细胞株的确定及生长、分化规律

目的建立牛、兔、人晶状体上皮细胞的体外培养，进一步认识晶状体上皮细胞生长、分化规律。方法应用组织块培养方法进行３种晶状体上皮细胞的体外培养，经Ｇｉｍｓａ染色，在倒置显微镜下对培养的晶状体上皮细胞的生长、分化规律进行观察。结果培养至６ｗｋ的人胎儿晶状体上皮细胞中有特征性的“晶状体小体”形成；牛、兔晶状体上皮细胞去分化是发生在第３代，而人晶状体上皮细胞在第４代开始出现去分化；它们传代至第８代时生长都趋于停止，出现老化表现；来自人的晶状体上皮细胞生长增殖率与年龄呈负相关关系（ｒ＝－０．９９６）。结论“晶状体小体”的形成可作为确定晶状体上皮细胞株的一项特征性依据，而体外培养的人、牛、兔晶状体上皮细胞具有相同的有限生长潜能，在相同的条件下，牛、兔晶状体上皮细胞的生长增殖速度比人晶状体上皮细胞快，但易于发生去分化；此外，人晶状体上皮细胞的生长增殖率与年龄密切相关，年龄越小，晶状体上皮细胞的生长增殖速度越快。     

人外伤性白内障晶状体上皮细胞的组织块培养

目的建立人外伤性白内障晶状体上皮细胞体外培养的简单有效方法，观察晶状体上皮细胞的体外生长规律和特点。方法应用改良组织块贴附培养法对儿童及成人外伤性白内障的晶状体上皮细胞进行体外培养，倒置显微镜下观察其生长规律。结果儿童和成人外伤性白内障晶状体上皮细胞都具有增生能力，晶状体上皮细胞均可传3代，晶状体上皮细胞多次传代后生长缓慢。结论儿童和成人外伤性白内障晶状体上皮细胞体外培养增生能力有限，儿童晶状体上皮细胞增生能力较强。改良组织块贴附培养法简单易行，重复性好，是晶状体上皮细胞体外培养的较好方法。     

人晶状体上皮细胞的组织块培养

目的建立人晶状体上皮细胞体外培养的简单有效方法,观察不同年龄人晶状体上皮细胞的体外生长规律和特点。方法应用改良组织块培养法对胎儿、成人和年龄相关性白内障的晶状体上皮细胞进行体外培养,在倒置显微镜下观察其生长、分化规律。结果胎儿、成人和年龄相关性白内障晶状体上皮细胞都具有增殖能力,胎儿和成人晶状体上皮细胞可传3代,年龄相关性白内障晶状体上皮细胞传代培养基本不能增殖。结论人晶状体上皮细胞体外培养困难,不同年龄人晶状体上皮细胞体外均能增殖,但增殖能力均很有限;改良组织块培养法是晶状体上皮细胞体外培养的较好方法。     

角膜缘上皮细胞体外培养、冻存和复苏的实验研究

目的 建立兔角膜缘上皮细胞体外培养、冻存和复苏的方法。方法 兔角膜缘上皮细胞组织块接种培养。取第三代细胞进行冻存。于冻存后第2周，3、6个月复苏细胞。用MTT法测细胞生长曲线。结果 兔角膜缘上皮细胞体外生长良好。培养细胞AE1单克隆抗体染色阳性，PAS染色阴性。冻存细胞复苏成功。冻存细胞复苏后生长曲线良好。结论 兔角膜缘上皮细胞可以在体外培养、冻存和复苏。     

小牛晶状体上皮细胞传代培养的细胞学特征

目的通过建立小牛晶状体上皮细胞的传代培养,观察晶状体上皮细胞的离休生长特性。方法组织块接种培养;用计数法及ＭＴＴ法测细胞生长曲线;绘制细胞分裂指数曲线。结果采用组织块培养法晶状体上皮细胞原代及传代培养生长良好;ＭＴＴ及细胞计数法所测细胞生长过程基本一致;细胞分裂指数曲线显示细胞在培养第５天达分裂高峰。结论组织块法是晶状体上皮细胞离体培养的较好方法;晶状体上皮细胞具有较好的离体生长能力;ＭＴＴ比色法是检测晶状体上皮细胞的有效方法。     

小牛晶状体上皮细胞传代培养的细胞学特性

目的 通过建立小牛晶状体上皮细胞的传代培养，观察晶状体上皮细胞的离体生长特性。方法 组织块接和培养；用计数法及ＭＴＴＩ地测细胞生长曲线；绘制细胞分裂指数曲线。结果 采用组织块培养法晶状体上皮细胞原代及传代培养生长良好；ＭＴＴ及细胞计数法所测细胞生长过程基本一致；细胞分裂指数曲线显示细胞在培养第５天达分裂高峰。结论组织块法是晶状体上皮细胞离体培养的较好方法；晶状体上皮细胞具有较好的离体生长能力；ＭＴ     

晶状体上皮细胞培养及Ⅳ型胶原表达

目的体外培养小牛晶状体上皮细胞，免疫组织化学SABC法检测1V型胶原表达。方法小牛晶状体前囊组织块培养，晶状体上皮细胞原代和传代培养。传代2次后免疫组织化学法检测细胞内1V型胶原表达。结果原代培养2-3周后细胞成单层后传代培养，传代细胞易贴壁，9～10d后可再传代，免疫组织化学检测发现细胞质内有大量Ⅳ型胶原表达，形成细胞的骨架成分。结论晶状体上皮细胞在增生时有大量Ⅳ型胶原表达，其与晶状体后囊混浊有关。     

人结膜上皮细胞的培养鉴定及液氮冻存

目的：探索人眼结膜上皮细胞体外培养和细胞保存的最佳方法，建立人结膜上皮细胞，进一步研究人结膜的病理、生理特点及为毒理试验提供可靠的细胞模型。方法：分别用组织块培养法、机械分离法及混合消化液培养法体外培养正常成年人结膜上皮细胞，通过观察细胞形态、生长特性并用原位免疫组化方法鉴定培养细胞；收集第３代和第４代融合的细胞液氮冻存，保存３０天后复苏，观察复苏成功率。结果：３种取材方法中，混合消化液培养法细胞     

Different Sensitivities to Apoptotic Induction by Camptothecin between Normal and Senescent Lens Epithelial Cells

PURPOSE: To investigate whether normal and senescent lens epithelial cells have different defense abilities to apoptotic induction factor in vitro. METHODS: Rabbit lens epithelial cells were cultured, passed. When reaching confluence, cells from the first and seventh passage were stained by x-gal staining to detect cell senescence. Cell apoptosis was detected by TUNEL(Roche). 10 micromol/L camptothecin was used to induce cell apoptosis from the lens epithelial cells of the first and seventh passage to distinguish different sensitivities to apoptotic induction factor between normal and senescent cells. RESULTS: The senescent cells (41.17% +/- 5.24%) were detected in the lens epithelial cell culture of the seventh passage, which are higher than those of the first passage (0.98% +/- 0.39%). There was no apoptotic cell detected in the cell cultures undisturbed. Exposure of the first passage cells to camptothecin resulted in death of approximately 23.87% +/- 3.45% of the cells during a 36 hour exposure period. In contrast, significantly more lens epithelial cells died through the apoptosis (38.29% +/- 4.01%) from the seventh passage. CONCLUSION: Senescent cells increased with cell passage. Senescence lens epithelial cells do not undergo apoptosis if they were not disturbed. But the vulnerabilities to apoptotic induction between health and senescence cells were different.     

Identification of caveolae and their signature proteins caveolin 1 and 2 in the lens

This study shows that caveolae are present in lens epithelia of rabbit and guinea pig under normal conditions. Caveolae are unique lipid membrane microdomains observed in many cell types. They are believed to play crucial roles in a variety of basic physiological functions including signal transduction, lipid and transcellular transport. Using TEM, immunocytochemistry and immunoblotting we show for the first time the existence of caveolae and the co-localization of their signature marker integral proteins, caveolin-1 and caveolin-2, in the intact lens of rabbit and guinea pig. Thin-section TEM shows that among several species studied, lens epithelia of rabbit and guinea pig exhibited a large number of caveolae. The caveolae were pear shaped, approximately 70 nm in diameter, and were found frequently along the lateral membranes of epithelial cells in the intact lens. In the intact cortical fibers, only a small number of caveolae was seen in the superficial cells. In cultured lens epithelial cells, however, caveolae were observed along all membrane surfaces, but were more abundant at the apical membrane of the cells. Immunofluorescence and immunoblot analyses confirmed the presence of caveolin-1 and caveolin-2 in the lens epithelium. In addition, caveolin-1 and caveolin-2 co-exist in the lens epithelium of both rabbit and guinea pig. HRP tracer study demonstrated that caveolae could carry out endocytosis, suggesting their involvement in molecular transport. Cultured rabbit lens epithelial cells (line N/N1003A) were used to examine the response of caveolae to methyl-beta-cyclodextrin (MBCD), a specific cholesterol-depleting drug. The lens epithelial cells were incubated in freshly prepared MEM medium plus 8% rabbit serum containing 10mm MBCD for 0 (control), 15, 30 or 60 min. Controls for MBCD treatment were cultured in MEM plus 8% rabbit serum. MBCD treatment for 30 min revealed that depletion of cholesterol abolished the majority of caveolae in cultured lens epithelial cells. This result strongly suggests that caveolae are cholesterol-rich lipid rafts that are likely to play important roles in the lens.     

抗兔晶状体上皮细胞单克隆抗体的制备及特异性研究

目的 为防治白内障术后因晶状体上皮细胞增殖而产生的后发性白内障,制备抗家兔晶状体上皮细胞的单克隆抗体,从而更进一步以其为载体与细胞毒素偶联,特异性抑制晶状体上皮细胞生长而不损伤眼内其他组织。为防治后发性白内障奠定实验基础。方法：应用家兔晶状体上皮细胞与佐剂混合,免疫ＢＡＬＢ／ｓ小鼠,通过聚乙二醇（ＰＥＧ－４０００）使被免疫的小鼠脾细胞与同系小鼠骨髓瘤细胞融合。细胞融合之后龙过ＨＡＴ选择性培养液培养,用间接免疫荧光抗体法和免疫组化ＳＰ法检测杂交瘤细胞上清液中的抗体、筛选出呈阳性反应的杂交瘤细胞上清夜中的抗体,筛选出呈阳性反应的杂交瘤细胞,再经３次甲基纤维素克隆化培养以保证单克隆抗体的特性,最后将此单克隆抗体对人眼组织进行交叉反应。结果 被免疫的小鼠脾细胞与骨髓瘤细胞ＳＰ２／０通过ＰＥＧ－４０００融合后,经ＨＡＴ选     

Distribution of caveolin-1 in bovine lens and redistribution in cultured bovine lens epithelial cells upon confluence

The distribution of caveolin-1 in the lens and lens epithelial cells was determined to assess possible roles in cholesterol trafficking, cell to cell communication and signal transduction. Bovine lenses and cultured bovine lens epithelial cells (BLEC) were divided into subcellular fractions and the distribution of proteins recognized by three different caveolin-1 antibodies determined. The immunolocalization of caveolin-1 in the lens epithelium and in subconfluent and confluent cultured BLEC was probed by fluorescence microscopy and laser scanning confocal microscopy. EGF induced phosphorylation of caveolin-1 was detected by Western blotting with an anti-phosphotyrosine antibody to immunoprecipitated caveolin-1 from BLEC and human cancer cells. Monomeric caveolin-1 of about 26 kDa was detected in the epithelial cell membrane of cultured BLEC and fresh epithelia and in the plasma membrane fraction of lens cortical fiber cells. Caveolin-1 of cultured BLEC redistributed from the cytoplasm to plasma membrane as the cells proceeded from subconfluent to confluent states. The apparent abundance of caveolin-1 in cortical fiber cell plasma membrane is consistent with possible roles in distribution of lens membrane cholesterol and membrane structure. The presence of caveolin-1 in the plasma membrane of epithelial cells at - but not before - confluency is consistent with a role of caveolin-1 in cell to cell communications. EGF stimulated phosphorylation of caveolin-1 in human A431 cells but not lens cells.     

Telomerase activity in lens epithelial cells of normal and cataractous lenses

Telomerase is a ribonucleoprotein responsible for maintaining telomere length, preventing chromosomal degradation and recombination, and repairing DNA strand breaks. These activities are believed to be important in preventing cell senescence. Telomerase activity is normally found in germinal, neoplastic and stem cells, but not any ocular tissue studied to date. The epithelium of the crystalline lens is comprised of a population of cells with diverse mitotic potential including the germinative epithelium which contains cells with the potential for unlimited replicative capacity, equatorial cells which terminally differentiate into lens fibers, and the central epithelium which are considered to be quiescent and nonreplicative under normal circumstances.We speculated that the germinative region of lens epithelial cells might have telomerase activity, and that dysregulation of its activity might be associated with cataractogenesis. We investigated these hypotheses in lens capsule specimens from normal and cataractous dogs and from cultures of canine lens epithelial cells using standard assays for telomerase activity and telomere length. Telomerase activity was found in normal canine lens epithelial cells in the central, germinative and equatorial regions of the anterior lens capsule at equivalent levels. Similar findings were made in feline and murine lens epithelial cells, indicating that the presence of telomerase activity in the lens was not species specific. Lens fiber cells, corneal epithelium and endothelium and nonpigmented ciliary epithelium were telomerase negative. Telomerase activity and telomere lengths were significantly greater in lens epithelia from cataractous lenses when compared with normal lenses.Since telomerase activity is associated with an immortal phenotype, the presence of telomerase activity in the lens epithelial cells may function to prevent conversion to senescence. It was, therefore, difficult to explain why these cells cannot be passaged more than four times in culture. We found that telomerase activity and telomere lengths gradually decreased with increased passages until telomerase activity was no longer present at passage two. Consistent with these findings, there were no senescent cells present on the lens capsule when the lens was initially dissected for culture, but an increasing number of cells were senescent with each passage, correlating well with the loss of telomerase activity.Telomerase activity is likely important in the germinative epithelium to maintain its proliferative potential and prevent cell senescence. Telomerase may function in the quiescent, central lens to maintain telomeres damaged by oxidative stress and ultraviolet light exposure, thereby preventing accelerated loss of these elements which triggers cell senescence. It remains to be determined if the increase in telomerase activity in lens epithelial cells from cataractous lenses is a primary dysregulation that may have a role in the development of the cataract, or is secondary to cataract formation.     

人晶体上皮细胞的体外培养

目的:提供一种简单可行,易于掌握的体外培养人晶体上皮细胞的方法。方法:用无齿显微镊子将晶体囊膜分离出来,剪碎后直接移至细胞培养瓶中培养,当细胞长出融合后,用胰蛋白酶消化传代。结果:接种培养4天后,可见晶体上皮细胞开始长出,并以贴壁方式生长。结论:用此方法体外培养人晶体上皮细胞,具有简单、快捷、成功率高的优点。眼科学报1997;13:170—172。     

Both human and newborn rabbit lens epithelial cells exhibit similar limited growth properties in tissue culture

Human lens cells from 5-91-year old individuals were cultured in 8 different basal media containing fetal bovine, adult bovine, rabbit or human serum or human plasma or in a serum-containing medium supplemented with insulin, epidermal growth factor, fibroblast growth factor plus other hormones or trace elements. Cultures were initiated from explants of the capsule and epithelium or following enzymatic dissociation of cells from the capsule. Under all conditions the epithelial cells had a limited doubling potential. As a function of time in culture, cells enlarged, displayed numerous filaments and exhibited apparent in vitro senescence. Lens epithelia from 4-6 day old rabbits cultured under identical conditions mimicked the behavior of human lens cells. Lens epithelia from newborn rabbits may be a suitable model for investigating the basis of apparent in vitro senescence in this cell type and could help in defining the conditions required for the long-term growth of human lens cells. The limited growth of human lens epithelia suggests that these cells require tissue-specific nutrients or hormonal supplements not present in standard tissue culture media.     

Protease activities in cultured beef lens epithelial cells peak and then decline upon progressive passage

Beef lens cells in culture are readily obtained and provide many opportunities to study phenomena related to cell differentiation and maturation, environmental stress, disease, and perhaps mechanisms of transformation. Although altered rates of proteolysis are known to accompany these phenomena, the proteolytic activities available in cultured beef lens epithelial cells have not been documented. In this work are documented the specific activities, based on protein and DNA content, of neutral exo- and endopeptidase, cathepsins B- and D-like enzymes and acid phosphatase in lens epithelial cortical and core tissue and in cultured epithelial cells at passages 1-43. Maximal activity of each protease occurs almost routinely at passage 5 or 9, reaching values of approx. 1400-, 0.77-, 4520-nmol min-1 per mg protein for neutral exopeptidase (passage 5), neutral endopeptidase (passage 5) and cathepsin B (passage 5) respectively, and 7.1 micrograms trichloroacetic acid soluble peptide min-1 per mg protein for cathepsin D (passage 15). On a microgram-1 DNA basis, the maximal specific activities for the same enzymes were 48 (passage 5), 0.03 (passage 5), 283 (passage 9), and 0.5 (passage 9) respectively. In subsequent passages, the specific activities declined to values which were similar to or lower than the specific activities observed for these proteases in lens epithelial tissue.