title: Mild electrical stimulation with heat shock guides differentiation of embryonic stem cells into Pdx1-expressing cells within the definitive endoderm.
abstract: Because of the increasing number of diabetic patients, it is important to generate pancreatic and duodenal homeobox gene 1 (Pdx1)-expressing cells, which are capable of differentiating into pancreatic endocrine β cells. Mild electrical stimulation was reported to modulate the differentiation of ES cells into ectoderm-derived neuronal cells or mesoderm-derived cardiac cells.
  
  
  
  In this study, we report that mild electrical stimulation with heat shock (MET) potentiates the differentiation of ES cells into definitive endoderm-derived Pdx1-expressing cells. MET has no effect when applied to early definitive endoderm on differentiation day 5. A 1.87-fold increase in the proportion of Pdx1-expressing cells was observed when stimulation was applied to the late definitive endoderm one day prior to the immergence of Pdx1/GFP-expressing cells on differentiation day 7. Pdx1 mRNA was also up-regulated by MET. The potentiating effect of MET synergized with activin and basic fibroblast growth factor into Pdx1-expressing cells. Moreover, MET stimulation on late definitive endoderm up-regulated heat shock protein 72 and activated various kinases including Akt, extracellular signal-regulated kinase, p38, and c-jun NH2-terminal kinase in ES cells.
  
  
  
  Our findings indicate that MET induces the differentiation of Pdx1-expressing cells within the definitive endoderm in a time-dependent manner, and suggest useful application for regenerative medicine.
authors.affiliation: Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan.|Present address: Department of Biochemistry, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan.
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Koga
authors.affiliation: Department of Stem Cell Biology, Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto, 860-0811, Japan.|Present address: Department of Biological Information, School and Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8550, Japan.
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Shiraki
authors.affiliation: Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan.
authors.forename: Shuichiro
authors.initials: S
authors.lastname: Yano
authors.affiliation: Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan.
authors.forename: Mary Ann
authors.initials: MA
authors.lastname: Suico
authors.affiliation: Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan.
authors.forename: Saori
authors.initials: S
authors.lastname: Morino-Koga
authors.affiliation: Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Sato
authors.affiliation: Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Shuto
authors.affiliation: Department of Stem Cell Biology, Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto, 860-0811, Japan. skume@bio.titech.ac.jp.|Present address: Department of Biological Information, School and Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8550, Japan. skume@bio.titech.ac.jp.
authors.forename: Shoen
authors.initials: S
authors.lastname: Kume
authors.affiliation: Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan. hirokai@gpo.kumamoto-u.ac.jp.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Kai
mesh_terms: D002454:Cell Differentiation / Q000502:physiology; D002460:Cell Line; D002478:Cells, Cultured; D004558:Electric Stimulation; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000502:physiology*; D004707:Endoderm / Q000378:metabolism*; D018869:Heat-Shock Response / Q000502:physiology; D006361:Heating; D006801:Humans; D040542:Mechanotransduction, Cellular / Q000502:physiology; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000502:physiology; D009474:Neurons / Q000166:cytology* / Q000502:physiology
keywords: Differentiation; ES cells; Electrical stimulation; Pancreatic β cells