体外共培养诱导人羊膜间充质干细胞分化为眼表上皮细胞的研究

A pilot study on differentiation of human amnion mesenchymal stem cells into ocular surface epithelial cells by co-culture in vitro

背景 人羊膜间充质干细胞（hAMSCs）在体外能诱导分化为多种体细胞,但目前有关hAMSCs分化为眼表细胞的研究鲜有报道. 目的 探讨体外共培养诱导hAMSCs向眼表细胞分化的可能性及其分化机制.方法 本研究经广州医科大学第二附属医院伦理委员会批准,在健康产妇的知情同意下从人胎盘中分离hAMSCs并进行培养,采用流式细胞术计数分析CD44、CD45、CD73、CD90在培养细胞中的表达以鉴定细胞,此外通过成骨诱导分化实验和成脂诱导分化实验对培养细胞进行体外分化鉴定.在患者知情同意下获取眼科手术中弃用的人眼球结膜组织,用组织块培养法分离和培养人球结膜成纤维细胞（hBCFs）,将hAMSCs与hBCFs在Transwell培养体系中进行共培养,分为hAMSCs培养组和hAMSCs与hBCFs共培养组,用含质量分数5％胎牛血清（FBS）的DMEM高糖/F12培养基培养7d,采用免疫荧光技术检测hAMSCs中对上皮细胞角蛋白19（CK19）的表达,评价hAMSCs向眼表细胞分化的程度,并检测hAMSCs中α-平滑肌肌动蛋白（α-SMA）的表达,评价其分化过程与间质上皮化转换（MET）过程的关系.结果 传代至3～7代的hAMSCs均为细长形,但随着传代增加,细胞体积增大,细胞中CD44、CD73、CD90表达呈强阳性,但不表达CD45.经成骨或成脂诱导分化后3～4周,细胞中茜素红S（ARS）染色或油红O染色阳性.hAMSCs与hBCFs共培养后1周,hAMSCs形态由细长形变为类上皮细胞型,共培养组的部分细胞中CK19表达阳性,所有细胞α-SMA表达呈微弱阳性,而hAMSCs细胞培养组可见呈绿色荧光的α-SMA阳性细胞,但不表达CK19. 结论 通过体外共培养可诱导hAMSCs向人眼表细胞分化,其分化机制可能与MET过程相关.

Background Recent studies indicated that human amnion mesenchymal stem cells （hAMSCs） can be induced to differentiate into multiple types of cells in vitro,but whether the hAMSCs can differentiate into ocular surface cells has not been reported yet.Objective This study was to investigate the feasibility of inducing differentiation of hAMSCs into ocular surface cells by co-culturing with human bulbar conjunctiva fibroblasts （hBCFs）.Methods This study was approved by Ethic Committee of Affiliated Second Hospital of Guangzhou Medical University.HAMSCs were isolated from placenta under the informed consent of healthy delivery women.hAMSCs were cultured,passaged and identified by detecting the expressions of CD44,CD45,CD73,CD90 in the cells with flow cytometer,osteogenesis and adipogenic differentiation experiments.Human conjunctival tissue was obtained during the eye operation under the informed consent of patients and hBCFs were isolated and cultured with explant culture.The cells were divided into the hAMSCs culture group and the hAMSCs and hBCFs co-culture group and cultivated in Transwell chambers for 7 days.The expressions of cytokeratin 19 （CK19） and α-smooth muscle actin （α-SMA） in the cells were assayed by immnofluorescence technique.Results Cultured hAMSCs showed the slender shape and cell body enlarged with passage.CD44,CD73 and CD90 were expressed in the cells,and the expression of CD45 was absent.After 3-4 weeks of osteogenesis and adipogenic induce,the cells showed red staining for alizarin and oil red O.In the co-culture group of hAMSCs and hBCFs,hAMSCs presented the epithelioid cell-like in shape and showed the positive response for CK19 and weaker response for α-SMA.However,in the hAMSCs culture group,the cells showed the positive response for α-SMA and absent response for CK19.Conclusions The hAMSCs can differentiate into ocular surface cells after being induced by hBCFs.And the differentiation mechanism is possibly relevant to mesenchymal cells epithelium.