兔角膜缘干细胞的体外培养

目的 探寻兔角膜缘干细胞体外培养方法。方法 分别用20％小牛血清营养液和20％胎牛血清营养液兔角膜缘干细胞行体外培养，观察细胞贴壁生长情况；同时对生长良好的原代细胞进行消化传代，进一步观察传代细胞的形态和生长情况。结果 20％胎牛血清营养液组，角膜缘干细胞在培养48－72h有80％贴壁生长，7－10天形成良好单层，细胞呈圆形、卵圆形或多边形，类似角膜上皮细胞；传代培养细胞形态仍正常，生长良好，但混有成纤维细胞。20％小牛血清营养液培养72h，仅有20％细胞贴壁生长，且细胞形态极不规则，有细胞“拉网”现象，培养14天仍未形成单层。结论 角膜缘干细胞的培养较常规细胞培养难，需要特殊培养基。20％胎牛血清营养液能作为角膜缘干细胞培养的基础液。     

角膜缘干细胞基础研究新进展

本总结了近年来关于角膜缘干细胞基础理论的研究，以及角膜缘干细胞的生物学特征、理化特性、组织学鉴定、增殖调控及其受体，有助于深入认识角膜缘干细胞的特性及其在机体中的重要作用。     

角膜缘干细胞在重建眼表中的作用研究进展

正常角膜上邓小平的完整性依赖于基底层角膜缘干细胞的不断增殖。角膜缘于细胞对角膜上皮的再生起着重要的作用。如果角膜缘干细胞因各种原因严重缺乏，会导致持续性角膜上皮糜烂、角膜新生血管和假性翼状胬肉形成，角膜的完整性和透明性将受到破坏。本对角膜缘干细胞的性质、特点、分布、检测、各种干细胞移植术、干细胞的体外培养及其适宜的载体等进行综述，以便对角膜缘干细胞进行更深入的研究。     

人角膜缘干细胞在体外不同载体上培养的实验研究

目的 寻找人角膜缘干细胞体外培养的载体。方法 人角膜缘干细胞原代培养单细胞层传代到羊膜、卵壳膜、聚乳酸膜、藻酸盐凝胶4种载体和6种培养板中,倒置显微镜观察、记录细胞生长情况。对6孔板传代细胞行生物特性检测,对载体上培养细胞行组织学检测。结果 6孔板中传代细胞对AE－5,4G10．3表达阳性。羊膜、卵壳膜和聚乳酸膜上有细胞生长,7天左右形成单层;藻酸盐凝胶载体上未见细胞生长。结论 传代细胞具有角膜缘干细胞生物特性;羊膜、卵壳膜和聚乳酸膜适合角膜缘干细胞传代培养。     

角膜缘干细胞克隆化培养影响因素的研究

目的探讨丝裂霉素C处理Swiss3T3成纤维细胞作为饲细胞的条件,了解兔角膜缘干细胞克隆化培养的增殖状况。设计对照实验研究。研究对象兔角膜缘干细胞单纯培养组,兔角膜缘干细胞与Swiss3T3成纤维细胞作为饲细胞的混合培养组。方法采用DMEM/F12培养基进行细胞培养,观察4.0μg/ml丝裂霉素C作用不同时间后3T3细胞数量的变化。DispaseⅡ酶消化兔角膜缘上皮细胞,与饲细胞混合接种,观察干细胞克隆形成情况,比较各代、各组的细胞克隆形成率(CFE)。用EDTA去除饲细胞,间接免疫荧光染色检测角膜缘干细胞克隆团表达增殖细胞核抗原(PCNA)情况。主要指标细胞数/毫升,细胞克隆形成率。结果4.0μg/ml丝裂霉素C处理2.5小时的Swiss3T3细胞,培养期间(约12日)细胞数量无明显变化,可作为饲细胞。与饲细胞共同培养的兔角膜缘干细胞形成细胞克隆团,细胞的平均CFE比较:有饲细胞组角膜缘干细胞明显高于无饲细胞组(t=2.982,P<0.01)。兔角膜缘干细胞冻存复苏后平均CFE比较,有饲细胞组明显高于无饲细胞组(t=3.007,P<0.01)。兔角膜缘干细胞克隆团中细胞PCNA染色为阳性。结论角膜缘干细胞与作为饲细胞的Swiss3T3成纤维细胞共同培养形成细胞克隆,其中含有干细胞,且具有高增殖力。     

角膜缘干细胞不同载体培养的研究进展

角膜缘干细胞缺乏所致眼表疾病已成为重要的致盲角膜病之一,而体外培养的角膜缘干细胞移植是治疗眼表疾病的重要途径。其中载体的选择是成功的关键。本文将从不同载体的生物特性,用于培养干细胞的可行性及优缺点等方面,阐述选择合适的载体培养角膜缘干细胞的研究进展。     

培养的角膜缘干细胞移植研究进展

由于传统治疗方法的局限性，培养的角膜缘干细胞移植成为近年来眼表疾病研究的核心内容之一。动物实验和基础临床研究证实，培养的角膜缘干细胞移植能有效恢复眼表正常结构，具有较多优越性，但仍有诸多问题亟待解决。本就其近年的进展进行综述。     

人角膜缘干细胞体外培养的增殖与分化研究

目的了解角膜缘干细胞体外培养的增殖分化规律。方法组织块法培养细胞,测定细胞克隆形成率（ＣＦＥ）,免疫荧光染色检测干细胞表达角质蛋白Ｋ３的状况。结果原代培养２１天左右细胞生长达到饱和,传第１代７～１０天形成单层,ＣＦＥ为９．５２％±４．９７％;传第２代７天,ＣＦＥ为４．２５％±２．１０％（Ｐ＜０．０１）。正常角膜缘基底细胞不表达角质蛋白Ｋ３;原代培养的干细胞亦不表达Ｋ３,传第１代细胞有部分表达。结论人角膜干细胞位于角膜缘基底部,培养的角膜缘干细胞早期具有较高的增殖力并保持干细胞的分化特性。     

角膜缘干细胞移植治疗角膜疾病的研究进展

角膜缘干细胞在维持正常角膜上皮完整性以及角膜损伤修复中有重要作用.角膜缘干细胞损伤所致的角膜缘干细胞缺失可导致严重的角膜病变.目前治疗角膜缘干细胞缺失的主要方法是细胞移植治疗.本文就角膜缘干细胞的体外培养、鉴定、移植方法以及新的细胞来源等问题进行综述.     

人角膜缘干细胞的体外培养及鉴定

目的探讨人自体角膜缘干细胞（LSCs）体外培养及鉴定的方法。方法将供体新鲜人角膜缘组织在制备的含20％胎牛血清DMEM／F12培养基的羊膜载体上应用组织块培养法进行体外培养,对培养获得的LSCs用苏木精-伊红染色在倒置显微镜下进行形态学观察,用免疫荧光技术鉴定培养的LSCs细胞。结果组织块静置2h后贴壁良好,3～4d细胞从组织块边缘荫出,7～10d细胞出现生长高峰,12～14d形成良好的细胞单层。细胞形态呈多边彤、圆形、卵圆形和梭形。第14天时行间接免疫荧光染色,可见大量细胞表达p63,呈细胞质的绿色荧光;少量细胞表达AE5,呈细胞质的绿色荧光和细胞核的红色荧光。结论组织块培养法体外培养的人LSCs具有与正常人LSCs相一致的生物学特性。     

Long-term effectiveness of autologous cultured limbal stem cell grafts in patients with limbal stem cell deficiency due to chemical burns

Background: Chemical burns cause depletion of limbal stem cells and eventually lead to corneal opacity and visual loss. We investigated the long‐term effectiveness of autologous cultured limbal stem cell grafts in patients with limbal stem cell deficiency. Design: Prospective, non‐comparative interventional case series. Participants: Sixteen eyes from 16 patients with severe, unilateral limbal stem cell deficiency caused by chemical burns. Methods: Autologous ex vivo cultured limbal stem cells were grafted onto the recipient eye after superficial keratectomy. Main Outcome Measures: Clinical parameters of limbal stem cell deficiency (stability/transparency of the corneal epithelium, superficial corneal vascularization and pain/photophobia), visual acuity, cytokeratin expression on impression cytology specimens and histology on excised corneal buttons. Results: At 12 months post‐surgery, evaluation of the 16 patients showed that 10 (62.6%) experienced complete restoration of a stable and clear epithelium and 3 (18.7%) had partially successful outcomes (re‐appearance of conjunctiva in some sectors of the cornea and instable corneal surface). Graft failure (no change in corneal surface conditions) was seen in three (18.7%) patients. Penetrating keratoplasty was performed in seven patients, with visual acuity improving up to 0.8 (best result). For two patients, regeneration of the corneal epithelium was confirmed by molecular marker (p63, cytokeratin 3, 12 and 19, mucin 1) analysis. Follow‐up times ranged from 12 to 50 months. Conclusions: Grafts of autologous limbal stem cells cultured onto fibrin glue discs can successfully regenerate the corneal epithelium in patients with limbal stem cell deficiency, allowing to perform successful cornea transplantation and restore vision.     

人角膜缘干细胞的原代培养和生物学鉴别

目的 探讨人角膜缘干细胞（stem cell,SC)体外培养方法并观察其生物学活性。方法 应用消化培养法对人角膜缘组织进行原代培养,记录其生长特性。待细胞生长至80％汇合时,分别采用针对64KD角蛋白的AE5、针对一组酸性角蛋白的AE1单克隆抗体,抗增殖细胞核抗原单克隆抗体（anti-proliferatin cell nuclear antigen,PCNA),针对50KD烯醇酶特异的单克隆抗体4G 10．3,通过间接免疫荧光细胞化学染色对培养细胞进行鉴别。结果 人角膜缘组织应用消化培养法在6－7d达到80％汇合状态,应用间接免疫细胞化学染色,AE1、AE5染色,胞浆染色呈阳性。PCNA染色、细胞核染色阳性,4G 10．3亦可见阳性结果。结论 应用消化培养法可成功地对人角膜缘组织进行原代培养,培养后细胞既可保持角膜上皮特性,又含有具有强增殖潜力的原始细胞,适合用于临床移植治疗眼表疾病。     

角膜缘干细胞培养及研究进展

角膜缘干细胞是一种特殊类型的细胞,位于角膜缘基底上皮层,在角膜上皮更新和创伤愈合中起重要作用。对于角膜缘干细胞缺乏或功能障碍的疾病,培养角膜缘干细胞进行移植将是一种重要且有效的治疗方法。对角膜缘干细胞的生物学特性和解剖定位、影响培养的干细胞增殖的调控因素、培养的角膜缘于细胞移植、移植所需载体的选择等方面的研究进展作一综述。     

Identification and characterization of limbal stem cells

The maintenance of a healthy corneal epithelium under both normal and wound healing conditions is achieved by a population of stem cells (SC) located in the basal epithelium at the corneoscleral limbus. In the light of the development of strategies for reconstruction of the ocular surface in patients with limbal stem cell deficiency, a major challenge in corneal SC biology remains the ability to identify stem cells in situ and in vitro. Until recently, the identification of limbal stem cells mainly has been based on general properties of stem cells, e.g. lack of differentiation, prolonged label-retaining, indefinite capacity of proliferation exemplified by the clonogenic assay as well as their special role in corneal wound healing. During the last years, a number of molecular markers for the limbal SC compartment has been proposed, however, their role in distinguishing limbal SC from their early progeny is still under debate. Data reported from the literature combined with our own recent observations suggest, that the basal epithelial cells of the human limbus contain ABCG2, K19, vimentin, KGF-R, metallothionein, and integrin alpha9, but do not stain for K3/K12, Cx43, involucrin, P-cadherin, integrins alpha2, alpha6, and beta4, and nestin, when compared to the basal cells of the corneal epithelium. A relatively higher expression level in basal limbal cells was observed for p63, alpha-enolase, K5/14, and HGF-R, whereas there were no significant differences in staining intensity for beta-catenin, integrins alphav, beta1, beta2, and beta5, CD71, EGF-R, TGF-beta-RI, TGF-beta-RII, and TrkA between limbal and corneal basal epithelial cells. Therefore, a combination of differentiation-associated markers (e.g. K3/K12, Cx43, or involucrin) and putative SC-associated markers (e.g. ABCG2, K19, vimentin, or integrin alpha9) may provide a suitable tool for identification of human limbal SC. While most putative SC markers label the majority of limbal basal cells and, therefore, may not distinguish SC from progenitor cells, only ABCG2 was strictly confined to small clusters of basal cells in the limbal epithelium. At present, ABCG2 therefore appears to be the most useful cell surface marker for the identification and isolation of corneal epithelial SC. Moreover, the characteristics of the specific microenvironment of corneal SC, as provided by growth factor activity and basement membrane heterogeneity in the limbal area, could serve as additional tools for their selective enrichment and in vitro expansion for the purpose of ocular surface reconstruction.     

角膜缘干细胞培养体系的研究进展

正常角膜上皮形态稳定和功能的维持是依靠角膜缘干细胞的不断增殖和移行来实现。近年来，角膜缘干细胞的重要作用逐渐被人们所认识。本文从角膜缘干细胞的定位、体外取材、分离培养、培养条件的选择、常用体外培养的载体、鉴别方法等对角膜缘干细胞培养体系进行综述。     

大鼠角膜缘上皮细胞培养与同体移植的实验研究

目的：观察以明胶为载体培养的角膜缘上皮细胞移植治疗角膜缘干细胞缺乏症的疗效。 方法：大鼠角膜缘上皮细胞在铺有明胶载体的细胞培养板上进行培养5d后,角膜上皮细胞移植术前24h用3H胸腺嘧啶核苷标记培养的角膜缘上皮细胞,培养标记的角膜缘上皮细胞对角膜缘干细胞缺乏的大鼠动物模型行角膜缘上皮细胞同体移植术,对移植术后角膜进行观察、病理学检查及同位素检测。 结果：大鼠角膜缘上皮细胞可以在明胶载体上培养、增殖、分化为密集角膜上皮细胞层;角膜缘上皮细胞移植术后角膜上皮完整、基质细胞浸润减轻、新生血管减少。病理学检查角膜缘及周边部上皮细胞为多层结构,角膜新生血管消失及基质中炎性细胞浸润减轻。角膜缘上皮细胞移植术后4wk受眼角膜仍可测到3H胸腺嘧啶核苷。 结论：角膜缘上皮细胞移植治疗角膜缘干细胞缺乏症可恢复角膜缘干细胞缺乏病变角膜上皮结构的完整性,减少角膜新生血管的形成,维持角膜缘干细胞的屏障功能,为角膜移值提供更好的条件。     

角膜缘干细胞识别的研究进展

角膜干细胞存在于角巩膜缘被人们所认识已有20年了。随着对角膜缘干细胞研究的深入，发现其对角膜的完整性及功能至关重要。正常情况下角膜缘干细胞具有上皮屏障的作用，能阻止结膜上皮及血管向角膜内生长。角膜缘干细胞缺乏将导致各种眼表功能异常。角膜缘干细胞的定位和分离，对临床上应用角膜缘干细胞移植治疗各种眼表异常具有重要意义。就国内外对角膜缘干细胞识别的研究做一综述。     

原代培养角膜缘干细胞与ΔNp63蛋白表达的年龄相关性研究

目的建立兔角膜缘干细胞（LSCs）原代培养体系,了解年龄的增长对兔LSCs的ΔNp63蛋白表达的影响。方法选取3月龄、1.5年龄及3年龄新西兰白兔各10只,用含10%胎牛血清的DMEM/F12培养液对LSCs的细胞悬液进行体外原代培养。应用逆转录聚合酶链反应（RT-PCR）技术和间接免疫荧光法分别检测培养细胞中ΔNp63蛋白的表达量。结果接种3d后大部分细胞贴壁,6d左右形成良好的细胞单层,细胞呈圆形、椭圆形或多边形,类似角膜上皮细胞。年龄越大,ΔNp63的表达量越低。不同年龄组之间ΔNp63表达量的差异有统计学意义（P〈0.05）。结论含10%胎牛血清的DMEM/F12培养液能作为LSCs培养的基础液;ΔNp63蛋白的表达具有明显的年龄相关性,随年龄的增长ΔNp63表达量的下调可能是LSCs老化的分子机制之一。     

Allo-limbal transplantation in patients with limbal stem cell deficiency

AIM: To report the outcome of a series of patients with stem cell deficiency who underwent allo-limbal transplantation and to describe a technique for this procedure. METHODS: Six consecutive patients underwent allo-limbal stem cell transplantation. The primary diagnosis included alkali burn (n = 2), trachoma (n = 1), chronic rosacea blepharitis and kerato-conjunctivitis (n = 1), aniridia (n = 1), and Stevens-Johnson syndrome (n = 1). The limbal rim consisted of peripheral cornea and perilimbal sclera. FK-506 was used postoperatively for immunosuppression. RESULTS: The length of follow up ranged from 3 to 24 months (mean follow up 11.8 (SD 9.3) months). The outcome was considered satisfactory in five of six cases. The corneal surface was completely epithelialised within 2 weeks, and there was a substantial improvement in vision and symptoms. One patient had recurrent epithelial defects related to eyelid abnormalities. No side effects associated with systemic immunosuppression were noted. CONCLUSION: Allo-limbal transplantation, with systemic immunosuppression with FK-506 is useful in reconstruction of the ocular surface with improvement in vision in patients with severe stem cell deficiency.