OBJECTIVETo isolate human amniotic mesenchymal cells (hAMCs) and investigate their transdifferentiation ability into islet-like cells in vitro.

METHODSHuman amnion was treated with the trypsin/EDTA to remove the amniotic epithelial cells and then incubated with collagenase I and dispase at 37 degrees celsius; overnight. The cells were collected by centrifugation and identified for the expressions of vimentin and SSEA-4 using immunofluorescence assay and for CD29, CD90, CD34, and CD45 using flow cytometry. RT-PCR was performed to detect the expressions of ACTG2, ACTA2, MMP2, Cripto, Sox2, LEFTYA, nanog, and Oct-4 in the cells. The differentiation potential of the isolated cells into inslet-like cells was assessed after a 14-day induction with the inducing factors by RT-PCR and immunofluorescence assay.

RESULTSThe hAMCs were capable of in vitro proliferation and passaging for 10 passages while retaining the normal karyotype. The isolated cells were positive for staining of vimentin and SSEA-4 and negative for CD34 and CD45; the CD29 and CD90 cells accounted for (91.5∓9.93)% and (48.7∓9.47)% of the cells, respectively. The hAMCs expressed several pluripotency-related genes, including Cripto, Sox2, LEFTYA, nanog, and Oct-4. After induction, endocrine-related genes were expressed in the islet-like cells, including PDX1, ngn3, insulin and glucagon.

CONCLUSIONWe have successfully established the method for isolating hAMCs, which possess the potential of differentiation into islet-like cells in vitro.