title: Differentiation of human-induced pluripotent stem cells into insulin-producing clusters.
abstract: OBJECTIVE
  In diabetes mellitus type 1, beta cells are mostly destroyed; while in diabetes mellitus type 2, beta cells are reduced by 40% to 60%. We hope that soon, stem cells can be used in diabetes therapy via pancreatic beta cell replacement. Induced pluripotent stem cells are a kind of stem cell taken from an adult somatic cell by "stimulating" certain genes. These induced pluripotent stem cells may be a promising source of cell therapy. This study sought to produce isletlike clusters of insulin-producing cells taken from induced pluripotent stem cells.
  
  
  METHODS
  A human-induced pluripotent stem cell line was induced into isletlike clusters via a 4-step protocol, by adding insulin, transferrin, and selenium (ITS), N2, B27, fibroblast growth factor, and nicotinamide. During differentiation, expression of pancreatic β-cell genes was evaluated by reverse transcriptase-polymerase chain reaction; the morphologic changes of induced pluripotent stem cells toward isletlike clusters were observed by a light microscope. Dithizone staining was used to stain these isletlike clusters. Insulin produced by these clusters was evaluated by radio immunosorbent assay, and the secretion capacity was analyzed with a glucose challenge test.
  
  
  RESULTS
  Differentiation was evaluated by analyzing the morphology, dithizone staining, real-time quantitative polymerase chain reaction, and immunocytochemistry. Gene expression of insulin, glucagon, PDX1, NGN3, PAX4, PAX6, NKX6.1, KIR6.2, and GLUT2 were documented by analyzing real-time quantitative polymerase chain reaction. Dithizone-stained cellular clusters were observed after 23 days. The isletlike clusters significantly produced insulin. The isletlike clusters could increase insulin secretion after a glucose challenge test.
  
  
  CONCLUSIONS
  This work provides a model for studying the differentiation of human-induced pluripotent stem cells to insulin-producing cells.
authors.affiliation: From the Department of Biology, Science and Research Branch, Islamic Azad University, Fars; and the Transplant Research Center, Shiraz University of Medical Science, Shiraz, Iran.
authors.forename: Anahita
authors.initials: A
authors.lastname: Shaer
authors.forename: Negar
authors.initials: N
authors.lastname: Azarpira
authors.forename: Akbar
authors.initials: A
authors.lastname: Vahdati
authors.forename: Mohammad Hosein
authors.initials: MH
authors.lastname: Karimi
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Shariati
mesh_terms: D002454:Cell Differentiation; D002460:Cell Line; D048430:Cell Shape; D005786:Gene Expression Regulation; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000378:metabolism*; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D010641:Phenotype; D012333:RNA, Messenger / Q000378:metabolism; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D007328:Insulin; D012333:RNA, Messenger; D014157:Transcription Factors