title: The neuronal differentiation potential of Ldb1-null mutant embryonic stem cells is dependent on extrinsic influences.
abstract: LIM-domain binding protein 1 (Ldb1) is a multiadaptor protein that mediates the action of transcription factors, including LIM-homeodomain proteins. To elucidate the functional role of Ldb1 in the neuronal differentiation of embryonic stem (ES) cells, we have generated Ldb1-null mutant (Ldb1-/-) ES cells and examined neuronal differentiation potentials in vitro using two different neuronal differentiation protocols. When subjected to a five-stage protocol that recapitulates in vivo conditions of neuronal differentiation, wild-type ES cells differentiated into a wide spectrum of neuronal cell types. However, Ldb1-/- ES cells did not differentiate into neuronal cells; instead, they differentiated into sarcomeric alpha-actinin-positive muscle cells. In contrast, when an adherent monolayer culture procedure (which is based on the default mechanism of neural induction and eliminates environmental influences) was applied, both wild-type and Ldb1-/- ES cells differentiated into MAP2-positive mature neurons. Comparison of the results obtained when two different neuronal differentiation protocols were used suggests that Ldb1-/- ES cells have an innate potential to differentiate into neuronal cells, but this potential can be inhibited by environmental influences. Disclosure of potential conflicts of interest is found at the end of this article.
authors.affiliation: Graduate School of Medicine, Korea University, Seoul, Korea.
authors.forename: Minyoung
authors.initials: M
authors.lastname: Hwang
authors.forename: Marat
authors.initials: M
authors.lastname: Gorivodsky
authors.forename: Minjung
authors.initials: M
authors.lastname: Kim
authors.forename: Heiner
authors.initials: H
authors.lastname: Westphal
authors.forename: Dongho
authors.initials: D
authors.lastname: Geum
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D004268:DNA-Binding Proteins / Q000172:deficiency / Q000235:genetics; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000502:physiology; D007150:Immunohistochemistry; D060588:LIM Domain Proteins; D051379:Mice; D018345:Mice, Knockout; D009474:Neurons / Q000166:cytology* / Q000502:physiology*; D016548:Prosencephalon / Q000166:cytology / Q000196:embryology / Q000502:physiology; D012016:Reference Values; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D004268:DNA-Binding Proteins; D060588:LIM Domain Proteins; C102084:Ldb1 protein, mouse