The Nature Of The Study Of Human Amniotic Epithelial Cells

BackgroundMyocardial damage and necrosis induced by many heart diseases are one of the most primary causes of death in modern world. Although there are many kinds of therapeutic tools, curative effects for heart failure caused by myocardial damage and necrosis are not very good. As cell therapy and tissue engineering based on stem cells could repair injured myocardium, they have become a hotspot in Regenerative Medicine nowadays. It is the chief and key point researchers have to confront that how to choose a most suitable kind of seeded cells in clinical cell therapy. Human amnion derived stem cells especially human amniotic epithelial cells express many kinds of embryonic stem cell markers, have comprehensive differentiation potency, and they also have many unique advantages and properties which embryonic stem cell(ES) and adult stem cells lack such as abundant in cell reserve, easy acquisition, no ethical debate, no oncogenicity, low immunogenicity, and high safety without invasive procedures. It is all these characteristics that have made human amnion as an important potential source of seeded cells for Regenerative Medicine and human amnion derived stem cells maybe as the most appropriate type of seeded cells for clinical cell therapy.Objectives1 Determine ES-like characteristics difference between term human amniotic epithelial cell(hAEC) and term human amniotic mesenchymal stromal cell(hAMSC).2 Determine ES-like characteristics difference among term hAEC from different layers of amnion epithelium.Methods1 Make paraffin section of full-thick human amnion. Determine stem cell markers expression of hAEC and hAMSC by immunohistostaining.2 Digest and isolate hAEC and hAMSC respectively. Determine stem cell markers expression in fresh isolated cells by flow cytometry and immunofluorescence.3 Digest amnion epithelium by two steps at different time and isolate hAEC from different iayer of amnion epithelium. Determine stem cell markers expression in fresh isolated cells by flow cytometry and immunofluorescence.4 Make paraffin section of epithelium-separated human amnion by trypsinization. Determine stem cell markers expression and epithelial attribute of remaining cells by immunohistostaining.Results1 Human amnion epithelium is maily a simple cuboidal epithelium, while there are partly laminated configurations made up of many hAECs.2 hAEC express ES markers SSEA3,SSEA4,TRA1-60,TRA1-81 and pluripotent cell transcription factors Nanog,Oct4,Sox2 generally at a higher level than hAMSC, while there is no obvious difference of mesenchymal stem cell markers CD73 and CD 105 express between hAECs and hAMSC.3 Among hAEC, the basal group express ES markers SSEA3,SSEA4,TRA1-60,TRA1-81 and pluripotent cell transcription factors Nanog,Oct4,Sox2 at a higher level than the superficial group, while there is no difference of CD73 express. The ones most intensively expressing SSEA4 are mainly small and round cells and are mostly distributed in the basal layer of the amnion epithelium. However, SSEA1 and CK19 express are much more in the superficial group than the basal group.4 Remaining cells in epithelium-separated human amnion by trypsinization have epithelial attribute and much more intensively express ES markers SSEA3,SSEA4,TRA1-60,TRA1-81.Conclusions:1 Human amnion epithelium is not an absolutely monolayer. There are many hAEC arranging in laminated configuration.2 hAEC have more ES-like characteristics than hAMSC.3 hAEC especially that in the laminated epithelium have heterogeneity. The basal group of hAEC have more ES-like characteristics than the superficial group. It may explain the heterogeneity that there are hAEC of different development stage in human amnion epithelium. Embryonic stem cell marker SSEA4 may be an important and effective marker to screening hAEC with the most ES-like characteristics.4 In human amnion epithelium, ES-like cells may primarily reside in the transition 4 In human amnion epithelium, ES-like cells may primarily reside in the transition zone between epithelium base part and amnion stromal layer.The basal area of human amnion epithelium may be the most important reserve zone of human amniotic epithelial stem cells even human amnion derived stem cells.