人羊膜不同位置上皮细胞的类胚胎干细胞性质差异研究

Disparity of stem cell-like characteristics among human amniotic epithelial cells in different areas

目的了解足月人羊膜上皮不同位置上皮细胞在类胚胎干细胞性质方面的异质性。方法分层消化收集人羊膜上皮近表层与近基底层细胞,运用流式细胞术、免疫荧光、免疫组织化学等方法观察测定其干细胞表面抗原及分子标记物Nanog、Oct4、Sox2、SSEA1、SSEA3、SSEA4、TRA1-60、TRA1-81、CD73的表达情况;同时将足月人羊膜全层及经胰酶消化去上皮后的人羊膜行组织学染色,测定SSEA3、TRA1-60、TRA1-81表达情况。结果人羊膜上皮近基底层细胞表达Nanog、Oct4、Sox2、SSEA3、SSEA4、TRA1-60、TRA1-81普遍高于近表层细胞;表达SSEA4最强、最显著的细胞主要为较小的近圆形细胞,分布于羊膜上皮近基底层处。结论人羊膜上皮不同位置细胞的干细胞特性不同,近基底层细胞比近表层细胞具有更强的类胚胎干细胞性质,因而有望成为临床干细胞的来源。

Objective To determine the disparity of stem cell-like characteristics among human amniotic epithelial cells（hAEC） in different areas of human amnion epithelium.Methods Amnion epithelium was digested by two steps to separate into basal hAECs and superficial hAECs.Expression of surface antigens and molecule markers Nanog,Oct4,Sox2,SSEA1,SSEA3,SSEA4,TRA1-60,TRA1-81 and CD73 in fresh isolated cells were detected by flow cytometer,immune-fluorescence and immunehistochemistry,and expression of SSEA3,TRA1-60 and TRA1-81 in human term full-thickness amnion and epithelium-separated human amnion after trypsinization were determined by histological stain method.Results The hAECs in basal area expressed stem cell markers Nanog,Oct4,Sox2,SSEA3,SSEA4,TRA1-60 and TRA1-81 at a higher level than those in superficial area.The hAECs intensely expressing SSEA4 are the smaller and roundish cells distributed mostly in the basal layer of amnion epithelium.Conclusion The basal hAECs have more embryonic stem cell（ESC）-like characteristics than the superficial ones.The basal area of human amnion epithelium may be the most important zone of reservation of human amniotic epithelial stem cells.