title: Pluripotency associated genes are reactivated by chromatin-modifying agents in neurosphere cells.
abstract: Chromatin architecture in stem cells determines the pattern of gene expression and thereby cell identity and fate. The chromatin-modifying agents trichostatin A (TSA) and 5-Aza-2'-deoxycytidine (AzaC) affect histone acetylation and DNA methylation, respectively, and thereby influence chromatin structure and gene expression. In our previous work, we demonstrated that TSA/AzaC treatment of neurosphere cells induces hematopoietic activity in vivo that is long-term, multilineage, and transplantable. Here, we have analyzed the TSA/AzaC-induced changes in gene expression by global gene expression profiling. TSA/AzaC caused both up- and downregulation of genes, without increasing the total number of expressed genes. Chromosome analysis showed no hot spot of TSA/AzaC impact on a particular chromosome or chromosomal region. Hierarchical cluster analysis revealed common gene expression patterns among neurosphere cells treated with TSA/AzaC, embryonic stem (ES) cells, and hematopoietic stem cells. Furthermore, our analysis identified several stem cell genes and pluripotency-associated genes that are induced by TSA/AzaC in neurosphere cells, including Cd34, Cd133, Oct4, Nanog, Klf4, Bex1, and the Dppa family members Dppa2, 3, 4, and 5. Sox2 and c-Myc are constitutively expressed in neurosphere cells. We propose a model in which TSA/AzaC, by removal of epigenetic inhibition, induces the reactivation of several stem cell and pluripotency-associated genes, and their coordinate expression enlarges the differentiation potential of somatic precursor cells.
authors.affiliation: Institute for Biomedical Engineering, Department of Cell Biology, Rheinisch-Westfälische Technische Hochscule Aachen University, Aachen, Germany.
authors.forename: David
authors.initials: D
authors.lastname: Ruau
authors.forename: Roberto
authors.initials: R
authors.lastname: Ensenat-Waser
authors.forename: Timo C
authors.initials: TC
authors.lastname: Dinger
authors.forename: Duttu S
authors.initials: DS
authors.lastname: Vallabhapurapu
authors.forename: Alexandra
authors.initials: A
authors.lastname: Rolletschek
authors.forename: Christine
authors.initials: C
authors.lastname: Hacker
authors.forename: Thomas
authors.initials: T
authors.lastname: Hieronymus
authors.forename: Anna M
authors.initials: AM
authors.lastname: Wobus
authors.forename: Albrecht M
authors.initials: AM
authors.lastname: Müller
authors.forename: Martin
authors.initials: M
authors.lastname: Zenke
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002843:Chromatin / Q000235:genetics* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects / Q000235:genetics*; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology; D000090062:Kruppel-Like Factor 4; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D039904:Pluripotent Stem Cells / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D016548:Prosencephalon / Q000166:cytology / Q000187:drug effects / Q000502:physiology
chemical_list: D002843:Chromatin; D006877:Hydroxamic Acids; C000715467:KLF4 protein, human; C000715468:Klf4 protein, mouse; D000090062:Kruppel-Like Factor 4; C012589:trichostatin A