291 ISOLATION AND CHARACTERIZATION OF MESENCHYMAL STEM CELLS DERIVED FROM HUMAN AMNIOTIC FLUID

Abstract

Adult stem cells have the capacity to differentiate into several different cell types, although their differentiation potential is limited compared with that of embryonic stem cells. Thus, adult stem cells are regarded as an exciting source for new cell therapies. Recent observations also indicate that stem cells derived from second-trimester amniocentesis are pluripotent – capable of differentiating into multiple lineages, including representatives of all 3 embryonic germ layers. In addition, amniotic fluid stem cells can be used in the generation of disease- or patient-specific stem cells, and amniotic fluid stem cells could be an ideal source for autologous cell replacement therapy in the later life of the fetus. The aim of the present study was to investigate isolation and characterisation of human amniotic fluid-derived mesenchymal stem cells (hAFS). We successfully isolated and characterised hAFS. Amniotic fluid samples were collected in the second trimester (median gestational age: 16 weeks, range: 15–17 weeks) for prenatal diagnosis. Specimens (2 mL) were centrifuged and incubated in low-glucose DMEM supplemented with 10% FBS, 25 ng of basic fibroblast growth factor, and 10 ng of epidermal growth factor at 37°C with 5% CO₂. Human amniotic fluid cell (passage 6) expression of stem cell specific markers OCT-4, SOX2, Rex1, FGF4, and NANOG was confirmed by RT-PCR. Flow cytometric analysis showed that hAFS (passage 10) were positive for CD44, CD29, CD146, STRO1, and CD90 but negative for CD19. Immunocytochemical analysis of hAFS (passage 11) also showed the expression of OCT-4, SSEA-1, CD44, CD29, CD146, STRO1, and CD90, but hAFS were negative for CD19 and CD14. In conclusion, according to the previous studies on other mammalians, hAFS are an appropriate source of pluripotent stem cells. Here, we demonstrated that hAFS have a high expression of stem cell specific marker, including embryonic stem cell marker and mesenchymal stem cell marker. Therefore, amniotic fluid may be a suitable alternative source of multipotent stem cells.