Rajaei B, Sanati M H, Shamsara M and Massumi M
Posters-Accepted Abstracts: J Stem Cell Res Ther
Objectives: Pancreatic and duodenal homeobox 1 (PDX1), a member of the homeodomain- containing transcription factor family,
is a key transcription factor important for both pancreas development and mature β cell function. Induced overexpression of Pdx1
resulted in a significant upregulation of insulin and other pancreas-related genes. The generation of insulin-producing pancreatic
β-cells from human iPS cells in vitro would provide an unprecedented cell source for cell transplantation therapy in diabetes without
the ethical obstacle of embryonic stem cells and would bypass immune rejection.
Materials & Methods: Pdx1 overexpressed hiPS cells were produced by Lentiviral transduction system and the infected cells were
selected by puromycin. A differentiation process was carried out according to Kroon et al., 2008 protocol with some modifications
that converts human induced pluripotent stem cells to endocrine cells capable of synthesizing the pancreatic hormones insulin,
glucagon, somatostatin. This process mimics in vivo pancreatic organogenesis by directing cells through stages resembling definitive
endoderm, primitive gut-tube endoderm, posterior foregut, pancreatic endoderm and endocrine precursor which lead to cells that
express endocrine hormones. We characterized the differentiation process in each stage at the RNA and protein levels using realtime
PCR, western blotting, immunofluorescence and flow cytometry.
Results: The results indicated high expression level of each stage-specific marker including SOX17, FOXA2, and GSC in DE stage,
HNF4A in PG stage; PDX1 and HNF6 in PF stage, NKX6-1, NGN3, NKX2-2, PTF1A in PE stage and pancreatic hormones such as
insulin, glucagon, somatostatin were detected.
Conclusion: These results demonstrated that over expression of Pdx1 is an important new strategy for the efficient generation of
functionally immature insulin-producing β-islet cells from hiPS cells.