title: Overexpression of bone morphogenetic protein 4 in STO fibroblast feeder cells represses the proliferation of mouse embryonic stem cells in vitro.
abstract: Embryonic stem cells (ESCs) can be propagated in vitro on feeder layers of mouse STO fibroblast cells. The STO cells secrete several cytokines that are essential for ESCs to maintain their undifferentiated state. In this study, we found significant growth inhibition of mouse ESCs (mESCs) cultured on STO cells infected with adenovirus containing a dominant-negative mutant form of IκB (rAd-dnIκB). This blockage of the NF-κB signal pathway in STO cells led to a significant decrease in [(3)H]thymidine incorporation and colony formation of mESCs. Expression profile of cytokines secreted from the STO cells revealed an increase in the bone morphogenetic protein4 (BMP4) transcript level in the STO cells infected with adenoviral vector encoding dominant negative IκB (rAd-dnIκB). These results suggested that the NF-κB signaling pathway represses expression of BMP4 in STO feeder cells. Conditioned medium from the rAd-dnIκB-infected STO cells also significantly reduced the colony size of mESCs. Addition of BMP4 prevented colony formation of mESCs cultured in the conditioned medium. Our finding suggested that an excess of BMP4 in the conditioned medium also inhibits proliferation of mESCs.
authors.affiliation: School of Biological Sciences, Ulsan University Hospital and School of Medicine, University of Ulsan, Ulsan 680-749, Korea.
authors.forename: Gu-Hee
authors.initials: GH
authors.lastname: Kim
authors.forename: Gong-Rak
authors.initials: GR
authors.lastname: Lee
authors.forename: Hyung-Im
authors.initials: HI
authors.lastname: Choi
authors.forename: Neung-Hwa
authors.initials: NH
authors.lastname: Park
authors.forename: Hun Taeg
authors.initials: HT
authors.lastname: Chung
authors.forename: In-Seob
authors.initials: IS
authors.lastname: Han
mesh_terms: D000818:Animals; D055415:Bone Morphogenetic Protein 4 / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics; D049109:Cell Proliferation; D017077:Culture Media, Conditioned; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism; D061252:Feeder Cells / Q000166:cytology / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D005786:Gene Expression Regulation / Q000235:genetics; D020672:I-kappa B Proteins / Q000235:genetics / Q000378:metabolism; D066298:In Vitro Techniques; D051379:Mice; D009154:Mutation; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction
chemical_list: C525810:Bmp4 protein, mouse; D055415:Bone Morphogenetic Protein 4; D017077:Culture Media, Conditioned; D020672:I-kappa B Proteins; D016328:NF-kappa B