Enhanced differentiation of human amniotic fluid‐derived stem cells into insulin‐producing cells in vitro

AIMS/INTRODUCTION: To investigate the ability of human amniotic fluid stem cells (hAFSCs) to differentiate into insulin‐producing cells. MATERIALS AND METHODS: hAFSCs were induced to differentiate into pancreatic cells by a multistep protocol. The expressions of pancreas‐related genes and proteins, including pancreatic and duodenal homeobox‐1, insulin, and glucose transporter 2, were detected by polymerase chain reaction and immunofluorescence. Insulin secreted from differentiated cells was tested by enzyme‐linked immunosorbent assay. RESULTS: hAFSCs were successfully isolated from amniotic fluid that expressed the pluripotent markers of embryonic stem cells, such as Oct3/4, and mesenchymal stem cells, such as integrin β‐1 and ecto‐5′‐nucleotidase. Here, we first obtained the hAFSCs that expressed pluripotent marker stage‐specific embryonic antigen 1. Real‐time polymerase chain reaction analysis showed that pancreatic and duodenal homeobox‐1, paired box gene 4 and paired box gene 6 were expressed in the early phase of induction, and then stably expressed in the differentiated cells. The pancreas‐related genes, such as insulin, glucokinase, glucose transporter 2 and Nkx6.1, were expressed in the differentiated cells. Immunofluorescence showed that these differentiated cells co‐expressed insulin, C‐peptide, and pancreatic and duodenal homeobox‐1. Insulin was released in response to glucose stimulation in a manner similar to that of adult human islets. CONCLUSIONS: The present study showed that hAFSCs, under selective culture conditions, could differentiate into islet‐like insulin‐producing cells, which might be used as a potential source for transplantation in patients with type 1 diabetes mellitus.