title: Self-contained induction of neurons from human embryonic stem cells.
abstract: BACKGROUND
  Neurons and glial cells can be efficiently induced from mouse embryonic stem (ES) cells in a conditioned medium collected from rat primary-cultured astrocytes (P-ACM). However, the use of rodent primary cells for clinical applications may be hampered by limited supply and risk of contamination with xeno-proteins.
  
  
  RESULTS
  We have developed an alternative method for unimpeded production of human neurons under xeno-free conditions. Initially, neural stem cells in sphere-like clusters were induced from human ES (hES) cells after being cultured in P-ACM under free-floating conditions. The resultant neural stem cells could circumferentially proliferate under subsequent adhesive culture, and selectively differentiate into neurons or astrocytes by changing the medium to P-ACM or G5, respectively. These hES cell-derived neurons and astrocytes could procure functions similar to those of primary cells. Interestingly, a conditioned medium obtained from the hES cell-derived astrocytes (ES-ACM) could successfully be used to substitute P-ACM for induction of neurons. Neurons made by this method could survive in mice brain after xeno-transplantation.
  
  
  CONCLUSIONS
  By inducing astrocytes from hES cells in a chemically defined medium, we could produce human neurons without the use of P-ACM. This self-serving method provides an unlimited source of human neural cells and may facilitate clinical applications of hES cells for neurological diseases.
authors.affiliation: Advanced Medical Research Laboratory, Mitsubishi Tanabe Pharma Corporation, Osaka, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Okuno
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakayama
authors.forename: Nae
authors.initials: N
authors.lastname: Konishi
authors.forename: Hideo
authors.initials: H
authors.lastname: Michibata
authors.forename: Koji
authors.initials: K
authors.lastname: Wakimoto
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Shinji
authors.initials: S
authors.lastname: Nito
authors.forename: Toshio
authors.initials: T
authors.lastname: Inaba
authors.forename: Imaharu
authors.initials: I
authors.lastname: Nakano
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Muramatsu
authors.forename: Makoto
authors.initials: M
authors.lastname: Takano
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Kondo
authors.forename: Nobuo
authors.initials: N
authors.lastname: Inoue
mesh_terms: D000818:Animals; D001483:Base Sequence; D002454:Cell Differentiation; D017077:Culture Media, Conditioned; D017931:DNA Primers; D018274:Electroporation; D053595:Embryonic Stem Cells / Q000166:cytology*; D006801:Humans; D051379:Mice; D009474:Neurons / Q000166:cytology*; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D033581:Stem Cell Transplantation
chemical_list: D017077:Culture Media, Conditioned; D017931:DNA Primers