大鼠视网膜干细胞与神经干细胞体外增殖、分化特点比较

目的 通过对大鼠视网膜干细胞和神经干细胞体外增殖、分化特点进行比较,进一步明确视网膜于细胞自我更新及向神经细胞方向分化的能力.方法 实验研究.分离出生10 d大鼠睫状体区组织及新生大鼠脑组织,分别应用酶消化法将两种组织制成单细胞悬液,放入含有20 μg/L碱性成纤维细胞生长因子、20μg/L表皮生长因子及1×B27添加剂的无血清DMEM/F12培养液中培养,观察并比较视网膜干细胞及神经干细胞体外增殖的特点.分别取第2代细胞,应用免疫细胞化学染色法检测干细胞特异性抗原神经巢蛋白（nestin）及细胞分裂增殖标志物5-溴脱氧尿核苷（BrdU）的表达.同时,应用含50 ml/L的胎牛血清及1×N2添加剂的培养基促进其分化,观察两种细胞向神经细胞方向分化的特点：分别应用免疫细胞化学染色法对分化后的细胞nestin、神经无标志物神经元特异性烯醇酶（NSE）、神经胶质细胞标志物神经胶质酸性蛋白（GFAP）进行检测,并应用卡方检验对两种干细胞分化后的NSE及GFAP阳性细胞数比例进行比较.结果 两种细胞原代培养48 h后均可见小的球状细胞团悬浮生长,折光性强.原代培养约7 d后传代,传代后细胞能重新形成球状细胞团,应用免疫细胞化学染色方法均可检测到细胞内nestin及BrdU的阳性表达,视网膜干细胞体外增殖的能力较神经干细胞弱.两种细胞均可在血清诱导条件下转变为贴壁生长,并分化出具有神经细胞形态的细胞.诱导第7天进行免疫细胞化学染色,检测出两种干细胞表达nestin阳性细胞数比例分别为（9.5±3.5）%及（9.1±0.7）%.视网膜干细胞分化后NSE及GFAP的阳性细胞数比例分别为（11.2±2.8）%及（18.9＋2.1）%,低于神经干细胞分化后两种标志物阳性细胞数比例[（34.1±63）%及（41.9±3.3）%],NSE、GFAP在两组表达的差异均有统计学意义（x2=103.23,P＜0.05;x2=74.36,P＜0.05）.结论 来源于睫状体区的大鼠视网膜干细胞形态、体外增殖及可分化特性与神经干细胞相似,但其增殖及分化为神经细胞的能力较神经干细胞弱.     

冻存复苏后大鼠视网膜干细胞的增生及分化特性

目的研究视网膜干细胞冻存复苏后的成活率及再培养后的增生分化特性。方法对胎龄17 d Long Evans的大鼠眼视网膜干细胞进行分离与体外培养。利用无血清培养基短期体外培养大鼠胚胎来源的视网膜干细胞，将传代三代后的视网膜干细胞以冻存液［体积分数为80%的改良基础培养基（DMEM）/F12，10%牛血清白蛋白（BSA），10%二甲基亚砜（DMSO），碱性成纤维细胞生长因子（bFGF）20 ng/ml］于液氮中冻存，于1、2、4、8、12、16周分别复苏，计数活细胞比例进行再培养，并进一步诱导分化，采用免疫细胞荧光化学方法检测视网膜干细胞的增生及分化特性。结果不同的冻存时间对冻存后细胞存活率的影响无显著差异(P＞0.05)，再培养生长良好，具有视网膜干细胞特异性标志，并可进一步诱导分化为视网膜各种类型的细胞。结论大鼠视网膜干细胞的冻存复苏并不影响其原有的增生及分化特性。(中华眼底病杂志, 2007, 23: 94-97)     

人视网膜祖细胞和脑神经干细胞的体外培养和诱导分化研究

目的比较人视网膜祖细胞和脑神经干细胞的体外分化潜能。方法分离8-12周人胎儿神经视网膜和脑皮质、纹状体神经干细胞,进行无血清体外培养;采用光镜和免疫细胞化学或荧光免疫细胞化学染色方法,分别观察在无血清和10％胎牛血清培养条件下,两种来源的神经干细胞分化后的细胞特性。结果两种来源的神经干细胞,均能在体外有或无血清培养条件下增殖并分化。视网膜祖细胞不但表达视网膜祖细胞标志物Pax-6,也可表达神经干细胞标志物．巢蛋白（Nestin）、成熟神经元标志物-微管相关蛋白2（Map2）、星形胶质细胞标志物-胶质纤维酸性蛋白（GFAP）、节细胞标志物Thy-1和视杆细胞标志物视紫红质（Rhodopsin）;脑神经干细胞也能表达这些特异性细胞标志物。血清诱导分化时,视网膜祖细胞较难贴壁,贴壁细胞球伸出少而短的突起,单个细胞形态不清;而脑神经干细胞球易贴壁并伸出较长突起交织成网,大量细胞从细胞球中沿突起徙出,单个细胞形态清晰。结论人胎儿视网膜祖细胞和脑神经干细胞体外培养均具有向神经元、胶质细胞及视网膜终末细胞分化的能力;两种干细胞在进行血清诱导分化时,细胞的贴壁、迁移能力及分化后的细胞形态均存在差异。（中华腠科杂志,2006,42：901．907）     

角膜干细胞增殖与分化表达实验研究

目的 了解角膜缘干细胞体外生长的增殖分化特性,检测上皮细胞生长因子对干细胞增殖的促进作用。方法 采用ＤＭＥＭ和Ｆ１２培养基进行兔角膜上皮细胞培养,用克隆形成率（ＣＦＥ）、免疫组化染色和蛋白质免疫印迹等方法检测细胞的增殖力和分化表达状况。结果角膜缘干细胞（ＬＣ）在本培养条件下能够正常传代生长５代,ＣＦＥ为（５．０７±２．３５）％,而角膜中央上皮细胞（ＣＣ）仅第１次传代生长,ＣＦＥ为（１．１２±０．８     

胎儿视网膜前体细胞的分离培养

目的建立视网膜前体细胞的培养方法。方法分离8~12周流产胎儿的视网膜神经上皮细胞，采用悬浮和贴壁两种方法分别进行培养和传代，取传代细胞用含5%胎牛血清的、无碱性成纤维细胞生长因子（bFGF）的培养基诱导分化培养14 d，并采用免疫荧光法检测培养细胞诱导分化前后前体细胞和视网膜终末细胞标记物表达的改变。结果悬浮培养的细胞形成神经球并表达神经干细胞的标记物巢蛋白nestin，但无法成功传代扩增；贴壁培养的细胞可连续传代并表达nestin，传代细胞诱导分化后表达视网膜终末细胞的标记物胶质原纤维酸性蛋白(GFAP)、β微管蛋白(β-tubulin)和恢复蛋白recoverin。结论从8～12周的人胚胎视网膜神经上皮分离培养的视网膜前体细胞具有体外扩增和多分化潜能。（中华眼底病杂志，2007，23：98-100）     

碱性成纤维细胞生长因子和表皮生长因子对角膜中期保存液保存人角膜内皮细胞的影响

目的探讨碱性成纤维细胞生长因子(bFGF)和表皮生长因子(EGF)对中期保存角膜内皮细胞活性的影响。方法角膜中期保存液保存人角膜环,对照组为角膜中期保存液,实验组分为A、B、C、D组,分别为角膜中期保存液中加入bFGF(5ng/ml)、bFGF(20ng/ml)、EGF及bFGF+EGF,在保存角膜第3、7、14天后分别取保存角膜环复温观察,锥虫蓝茜素红联合染色检测角膜内皮活细胞率,电镜检测细胞超微结构的改变。结果保存角膜环第14天角膜内皮活细胞率,对照组为(10.35±1.32)%,A组为(62.18±1.56)%,B组为(92.57±0.90)%,C组为(71.01±2.67)%,D组(82.59±1.45)%,与对照组比较,各保存时间各实验组活细胞率均高,差异有统计学意义(P<0.01)。保存第14天,对照组保存的角膜环明显水肿、混浊不透明、内皮细胞形态结构不完整,超微结构显示角膜内皮细胞Y型连接断裂;而实验B、D组,保存的角膜环轻度水肿、后弹力层皱褶少、角膜透明度高、内皮细胞形态结构完整,超微结构显示保存角膜内皮细胞连接紧密,Y型连接无明显断裂,细胞表面可见较丰富的微绒毛,胞体大,核突起明显。结论bFGF和EGF在角膜中期保存液中均有促进细胞增殖、保持角膜细胞活性的作用,以bFGF作用更明显。     

表皮生长因子、碱性成纤维细胞生长因子对人视网膜色素上皮细胞DNA合成的影响

目的探索表皮生长因子(epidermal growth factor,EGF)、碱性成纤维细胞生长因子(basic fibroblast growth factor,bFGF)对培养的人视网膜色素上皮(retinal pigment epithelium,RPE)细胞促进DNA合成的最佳刺激浓度，并对两种因子的协同作用进行探讨。方法培养的人RPE细胞第6代用于本实验。应用氚标胸腺嘧啶核苷(³H-thymidine, ³H-TdR)掺入试验及放射自显影检测EGF、bFGF对RPE细胞的促DNA合成作用。结果EGF、bFGF均可引起剂量依赖的促有丝分裂作用。在含2%血清的培养液中,EGE、bFGF作用最佳浓度为1ng/ml,明显低于无血清培养液中EGF、bFGF作用的最佳浓度(10ng/ml)。联合应用10ng/mlEGF、10ng/mlbFGF约提高RPE细胞合成DNA能力2.96倍。结论EGF、bFGF对培养的人RPE细胞具有促进DNA合成作用，且两者可产生协同效应。(中华眼底病杂志,1998,14:98-100)     

表皮生长因子、碱性成纤维细胞生长因子对人视网膜色素上皮细胞DNA合成的影响

目的探索表皮生长因子（ｅｐｉｄｅｒｍａｌｇｒｏｗｔｈｆａｃｔｏｒ，ＥＧＦ）、碱性成纤维细胞生长因子（ｂａｓｉｃｆｉｂｒｏｂｌａｓｔｇｒｏｗｔｈｆａｃｔｏｒ，ｂＦＧＦ）对培养的人视网膜色素上皮（ｒｅｔｉｎａｌｐｉｇｍｅｎｔｅｐｉｔｈｅｌｉｕｍ，ＲＰＥ）细胞促进ＤＮＡ合成的最佳刺激浓度，并对两种因子的协同作用进行探讨。方法培养的人ＲＰＥ细胞第６代用于本实验。应用氚标胸腺嘧啶核苷（３Ｈ－ｔｈｙｍｉｄｉｎｅ，３Ｈ－ＴｄＲ）掺入试验及放射自显影检测ＥＧＦ、ｂＦＧＦ对ＲＰＥ细胞的促ＤＮＡ合成作用。结果ＥＧＦ、ｂＦＧＦ均可引起剂量依赖的促有丝分裂作用。在含２％血清的培养液中，ＥＧＦ、ｂＦＧＦ作用最佳浓度为１ｎｇ／ｍｌ，明显低于无血清培养液中ＥＧＦ、ｂＦＧＦ作用的最佳浓度（１０ｎｇ／ｍｌ）。联合应用１０ｎｇ／ｍｌＥＧＦ、１０ｎｇ／ｍｌｂＦＧＦ约提高ＲＰＥ细胞合成ＤＮＡ能力２．９６倍。结论ＥＧＦ、ｂＦＧＦ对培养的人ＲＰＥ细胞具有促进ＤＮＡ合成作用，且两者可产生协同效应。     

联合共培养系统诱导骨髓间充质干细胞分化为视网膜色素上皮样细胞

目的 探讨添加脑源性神经生长因子（BDNF）、表皮生长因子（EGF）、碱性成纤维细胞生长因子（bFGF）的培养基联合人类视网膜色素上皮细胞（HRPECs）共培养对骨髓间充质干细胞（BMSCs）定向诱导分化的影响.方法 实验研究.实验分三组：HRPECs＋BDNF、EGF、bFGF＋BMSCs共培养组、BDNF、EGF、bFGF＋BMSCs共培养组和对照组（单独BMSCs）.第一组取第3代HRPECs接种在双层培养板的上层,将第3代人BMSCs接种于下层培养板中,在双层六孔板的每孔中加入混合有20 ng/mlbFGF、20 ng/ml EGF、20 ng/ml BDNF及10%胎牛血清（FBS）的DMEM-LG培养液（需做免疫细胞化学染色应同时在下层放入18 mm×18 mm盖玻片进行细胞爬片）.第二组取第3代人BMSCs接种在六孔培养板中,每孔中加入含20 ng/ml bFGF、20 ng/ml EGF、20 ng/ml BDNF及10%FBS的DMEM-LG培养液.第三组将第3代人BMSCs接种于六孔培养板中,加入10%FBS的DMEM-LG培养液.在倒置相差显微镜下观察细胞形态学变化.2周后停止培养,采用免疫细胞化学染色法和RT-PCR检测角蛋白18、RPE65蛋白存诱导细胞中的表达.数据采用Holm-Sidak法进行分析.结果 诱导2周后,第一组BMSCs细胞呈圆形、类圆形、不规则形、短棒状外观,细胞内有色素颗粒形成,其他两组没有类似改变.三组间免疫细胞化学染色法检测RPE65蛋白、角蛋白18,光密度值结果显示第一组和第二组间、第一组和第三组间差异有统计学意义（RPE65：t=37.416、36.236,P＜0.05;角蛋白18：t=38.611、37.532,P＜0.05）.而第二组和第三组间差异没有统计学意义（RPE65：t=1.180,P＞0.05;角蛋白18：t=1.079,P＞0.05）.RT-PCR检测相对mRNA表达量,结果显示第一组和第二组间、第一组和第三组间差异有统计学意义（RPE65/β-actin：t=176.110、174.820,P＜0.05;角蛋白18/β-actin：t=243.230、241.560,P＜0.05）.而第二组和第三组间差异无统计学意义（RPE65/β-actin：t=1.283.P＞0.05;角蛋白18/β-actin：t=1.670,P＞0.05）.结论 利用BDNF、EGF、bFGF联合HRPECs共培养可以使BMSCs分化为视网膜色素上皮样细胞.     

Effect of growth factors on bovine retinal pigment epithelial cell migration and proliferation

BACKGROUND: To examine the effects of platelet-derived growth factor (PDGF), basic fibroblast growth factor (bFGF), acidic fibroblast growth factor (aFGF), insulin-like growth factor-1 (IGF-1), epidermal growth factor (EGF), and transforming growth factor beta 2 (TGF(beta2)) on bovine retinal pigment epithelial (RPE) cell migration and proliferation. MATERIALS AND METHODS: Cultured bovine RPE cells were treated with 10 ng/ml PDGF, bFGF, aFGF, IGF-1, EGF, or TGF(beta2). RPE cell migration studies were performed in multiwell plates confluently covered with RPE cells. After inhibition of proliferation and denudation of half of each well, cells were incubated with various growth factors. Migration was measured as the number of cells that had entered the denuded area after 20 h. RPE cell proliferation was determined by [(3)H]thymidine incorporation after growth factor stimulation for 24 h. RESULTS: RPE cell migration was significantly enhanced after incubation with PDGF (stimulation of 213% compared to the negative control, p = 0.002), bFGF (206%, p = 0.003), aFGF (175%, p = 0.003), IGF-1 (150%, p = 0.003), and EGF (144%, p = 0.003). RPE cell proliferation was stimulated by bFGF (322% compared to the negative control, p < 0.005), PDGF (119%, p < 0.005), aFGF (121%, p < 0.005), and EGF (94%, p < 0.005). IGF-1 showed no significant effect on RPE cell proliferation; TGF(beta2) displayed no effect on RPE cell migration nor on proliferation. CONCLUSIONS: The peptide growth factors PDGF, bFGF, aFGF, IGF-1, and EGF play an important role in initiating RPE cell migration. Basic FGF, PDGF, aFGF, and EGF stimulate RPE cell DNA synthesis.     

Isolation and characterization of cultured human conjunctival goblet cells

PURPOSE: To isolate and characterize goblet cells from normal human conjunctival tissue to determine whether epidermal growth factor (EGF) receptors are present and whether EGF can influence goblet cell proliferation. METHODS: Goblet cells were isolated from explant cultures established from normal conjunctival tissue harvested from patients during periocular surgery. The cells were grown in RPMI culture medium supplemented with 10% fetal bovine serum and characterized using morphology, histochemistry, indirect immunofluorescence microscopy, molecular biology, and biochemistry. Proliferation was determined with a MTT proliferation assay after exposing goblet cells, which had been serum deprived for 48 hours, to increasing concentrations of epidermal growth factor (EGF; 0-80 ng/mL) for 24 hours. RESULTS: Goblet cells were isolated from conjunctival explants by scraping nongoblet cells from the culture dish. Human goblet cells exhibited positive reactivity with alcian blue-periodic acid Schiff (PAS) reagent, goblet cell-specific cytokeratin-7, HPA lectin, and MUC5AC, but negative reactivity to the stratified squamous epithelial cell marker, cytokeratin-4. The mRNA for MUC5AC was detected using RT-PCR. The presence of the EGF receptors EGFR, ErbB2, and ErbB3 was confirmed through Western blot analysis of cell lysates. EGF elicited a concentration-dependent increase in goblet cell proliferation of 160% +/- 0.5%, 188% +/- 0.45%, 293% +/- 1.3%, and 220% +/- 0.5% of control values with 10, 20, 40, and 80 ng/mL EGF, respectively. CONCLUSIONS: Human goblet cells that retain characteristics of goblet cells in vivo can be cultured. EGF receptors are present in human goblet cells, and EGF stimulates their proliferation.     

Stem cells and retinal repair

Retinal stem cells (RSCs) are multipotent central nervous system (CNS) precursors that give rise to the retina during the course of development. RSCs are present in the embryonic eyecup of all vertebrate species and remain active in lower vertebrates throughout life. Mammals, however, exhibit little RSC activity in adulthood and thus little capacity for retinal growth or regeneration. Because CNS precursors can now be isolated from immature and mature mammals and expanded ex vivo, it is possible to study these cells in culture as well as following transplantation to the diseased retina. Such experiments have revealed a wealth of unanticipated findings, both in terms of the instructive cues present in the mature mammalian retina as well as the ability of grafted CNS precursors to respond to them. This review examines current knowledge regarding RSCs, together with other CNS precursors, from the perspective of investigators who wish to isolate, propagate, genetically modify, and transplant these cells as a regenerative strategy with application to retinal disease.     

bFGF、EGF和NGF对人角膜内皮细胞生长调控的实验研究

目的：探讨碱性成纤维细胞生长因子（Basicfibroblastgrowthfacfor，bFGF）、表皮细胞生长因子（Epidermalgrowthfactor，EGF）和神经细胞生长因子（Nervegrowthfactor，NGF）对体外培养的人角膜内皮细胞的生长调控作用。方法：将相同数量的人角膜内皮细胞接种于96孔板。加入浓度分别为0ng／ml、1ng／ml、3ng／ml、10ng／ml、30ng／ml、100ng／ml的EGF、bFGF和NGF进行培养。5天后MTT法用检测增殖情况。结果：在0ng／ml、1ng／ml、3ng／ml、10ng／ml、30ng／ml、100ng／ml浓度下bFGF组的平均OD值分别为：0．224±0．045、0．239±0．040、0．262±0．0342、0．278±0．0319、0．281±0．0324、0．260±0．0310。EGF组的平均OD值分别为：0．228±0．0304、0．245±0．0418、0．267±0．0454、0．275±0．0347、0．271±0．0449、0．250±0．0253。NGF组的平均OD值分别为：0．216±0．0187、0．228±0．0226、0．231±O．0225、0．242±0．0279、0．245±0．0294、0．247±0．0349。结论：bFGF在30ng／ml范围内对内皮细胞生长有促进作用，并具有剂量依赖性。高于100ng／ml时促生长作用降低。EGF在10ng／ml范围内对内皮细胞生长有促进作用，并具有剂量依赖性。高于30ng／ml时促生长作用降低。NGF本次实验剂量范用内对角膜内皮细胞生长无明显作用。     

胚胎与成人视网膜神经细胞培养

目的 建立胚胎及成人视网膜神经细胞体外培养系统，为视网膜神经细胞的基础研究与药物开发提供实验模型。 方法 10～13周龄胎儿及20～40岁成人视网膜神经层用不同的酶进行消化，分散的细胞接种于预先经过包被的细胞培养盘内，加入或不加入表皮生长因子(epidermal growth factor, EGF)、成纤维细胞生长因子(fibroblast growth factor, FGF)、脑源性神经营养因子(brainderived neurotrophic factor, BDNF)、神经营养素 4(neurotrophic-4，NT-4)等培养。通过BrdU掺入、免疫组织化学及免疫荧光等方法检测培养细胞增殖并辨别细胞成分。 结果 胚胎及成人视网膜细胞可在体外连续培养100及180 d以上。加入EGF、FGF、BDNF或NT-4可明显促进胚胎与成人视网膜神经元存活，胎儿视网膜细胞增殖。与对照组相比，处理组神经元或神经节细胞的百分率较高。 结论 胚胎及成人视网膜神经细胞培养技术为视网膜神经细胞基础研究及药物开发提供了一种十分有价值的手段，加入外源性的生长因子可促进培养的视网膜神经细胞存活、增殖与分化。 (中华眼底病杂志, 2002, 18: 279-282)     

Culture of retinal capillary endothelial cells

The culture of retinal capillary endothelial cells involves certain problems concerning contamination by pericytes, the maintenance of differentiation and the duration of culture viability. A procedure for the isolation and culture of capillary endothelial cells from bovine retina which overcomes these difficulties, is described. Microvessel fragments isolated by mechanical dispersion and filtration techniques adhere strongly to dishes coated with extracellular matrix produced by bovine corneal endothelial cells. The first migrating cells emerge from the original microvessel fragments two days after plating. This technique and subsequent cloning provides migrating and proliferating cells derived only from the retinal capillaries and uncontaminated by other cell types such as pericytes. Endothelial cells were grown on gelatin coated dishes in a serum supplemented medium (10% calf serum). Cell proliferation was significantly enhanced by the addition of basic fibroblast growth factor (1 ng/ml) to the culture medium. In these culture conditions, retinal capillary endothelial cells can be repeatedly passing without the loss of their principal morphological characteristics and some of the differentiated properties of endothelial cells. Primary cultures and subcultures, at least up to the 8th passage, formed a monolayer of small, elongated, tightly-packed, contact inhibited cells which expressed Factor VIII-related antigen. Ultrastructural examination by transmission electron microscopy of confluent bovine retinal capillary endothelial cells showed many tight junctions and Webel Palade granules. These studies provide new means for the isolation and culture of retinal capillary endothelial cells and presents evidence for growth factor requirements for the ability of cells to be repeatedly passing.     

表皮生长因子、碱性成纤维细胞生长因子及5-氟尿嘧啶对培养的人视网膜色素上皮损伤愈合的体外研究

OBJECTIVE: To study the effects of epidermal growth factor (EGF), basic fibroblast growth factor (bFGF) and 5-fluorouracil (5-Fu) on the cell migration and proliferation. METHODS: Phase-contrast microscopy, cell proliferation assay and wound -closure were used to study the process of cell proliferation and wound healing in a model of human retinal pigment epithelial (RPE) cell damage. RESULTS: It was found that EGF mainly stimulated proliferation and the migration of individual RPE cells from the wound edge, and induced cellular elongation, while bFGF mainly promoted proliferation and spread of the confluent monolayer into the wound defect, and induced enlargement and flattening of cells. But the effects of EGF, bFGF on wound closure were not very significant; 5-Fu inhibited the spread and proliferation of RPE cells, but had no effects on cell migration. CONCLUSIONS: EGF and bFGF have no significant effects on wound-healing, perhaps their effects on cell morphology are very important in cell transformation in proliferative vitreoretinopathy (PVR), and 5-Fu can only be a subsidiary drug to prevent PVR.     

Retinal stem cells transplanted into models of late stages of retinitis pigmentosa preferentially adopt a glial or a retinal ganglion cell fate

PURPOSE: To characterize the potential of newborn retinal stem cells (RSCs) isolated from the radial glia population to integrate the retina, this study was conducted to investigate the fate of in vitro expanded RSCs transplanted into retinas devoid of photoreceptors (adult rd1 and old VPP mice and rhodopsin-mutated transgenic mice) or partially degenerated retina (adult VPP mice) retinas. METHODS: Populations of RSCs and progenitor cells were isolated either from DBA2J newborn mice and labeled with the red lipophilic fluorescent dye (PKH26) or from GFP (green fluorescent protein) transgenic mice. After expansion in EGF+FGF2 (epidermal growth factor+fibroblast growth factor), cells were transplanted intravitreally or subretinally into the eyes of adult wild-type, transgenic mice undergoing slow (VPP strain) or rapid (rd1 strain) retinal degeneration. RESULTS: Only limited migration and differentiation of the cells were observed in normal mice injected subretinally or in VPP and rd1 mice injected intravitreally. After subretinal injection in old VPP mice, transplanted cells massively migrated into the ganglion cell layer and, at 1 and 4 weeks after injection, harbored neuronal and glial markers expressed locally, such as beta-tubulin-III, NeuN, Brn3b, or glial fibrillary acidic protein (GFAP), with a marked preference for the glial phenotype. In adult VPP retinas, the grafted cells behaved similarly. Few grafted cells stayed in the degenerating outer nuclear layer (ONL). These cells were, in rare cases, positive for rhodopsin or recoverin, markers specific for photoreceptors and some bipolar cells. CONCLUSIONS: These results show that the grafted cells preferentially integrate into the GCL and IPL and express ganglion cell or glial markers, thus exhibiting migratory and differentiation preferences when injected subretinally. It also appears that the retina, whether partially degenerated or already degenerated, does not provide signals to induce massive differentiation of RSCs into photoreceptors. This observation suggests that a predifferentiation of RSCs into photoreceptors before transplantation may be necessary to obtain graft integration in the ONL.     

Basic fibroblast growth factor stimulates 3H-thymidine uptake in retinal venular and capillary endothelial cells in vivo

Recent studies have found basic fibroblast growth factor (bFGF), an angiogenic peptide, in retina and have suggested that bFGF is responsible for retinal vascular proliferation. To test the hypothesis that bFGF stimulates 3H-thymidine uptake in retinal vascular cells in vivo, we injected bFGF (100 ng) into the vitreous cavity of six cats at 0 hr and again at 24 hr. Eight control eyes received boiled bFGF or no injection. After 46 hr, 3H-thymidine was injected into the vitreous cavity of all eyes and 2 hr later the eyes were enucleated. Intense 3H-thymidine uptake was seen in eyes with bFGF (56 +/- 20 SD positive cells per section) but not in control eyes (7-10 positive cells per section (P less than 0.001). Trypsin digest preparations showed that the thymidine uptake was predominantly in the venular (89%) and capillary (10%) endothelium and not in arterioles (1%) (P less than 0.001). The data suggest that retinal venular endothelial cells respond preferentially to exogenous bFGF, and in part may explain their prominent role in the neovascular process. In a second group of experiments to test the hypothesis that retinal ischemia releases a diffusable factor similar to bFGF that can cause 3H-thymidine uptake in retinal vascular cells, we created branch retinal vein occlusion in six cat eyes. The fellow eyes received no injections. In the eyes with branch vein occlusion there was an intense 3H-thymidine uptake within the distribution of the occluded vein (84 +/- 77 SD positive cells per section), but none in the areas outside the occluded vein (P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)