title: ATF5, a possible regulator of osteogenic differentiation in human adipose-derived stem cells.
abstract: The regulatory pathways involved in maintaining the pluripotency of embryonic stem cells are partially known, whereas the regulatory pathways governing adult stem cells and their "stem-ness" are characterized to an even lesser extent. We, therefore, screened the transcriptome profiles of 20 osteogenically induced adult human adipose-derived stem cell (ADSC) populations and investigated for putative transcription factors that could regulate the osteogenic differentiation of these ADSC. We studied a subgroup of donors' samples that had a disparate osteogenic response transcriptome from that of induced human fetal osteoblasts and the rest of the induced human ADSC samples. From our statistical analysis, we found activating transcription factor 5 (ATF5) to be significantly and consistently down-regulated in a randomized time-course study of osteogenically differentiated adipose-derived stem cells from human donor samples. Knockdown of ATF5 with siRNA showed an increased sensitivity to osteogenic induction. This evidence suggests a role for ATF5 in the regulation of osteogenic differentiation in adipose-derived stem cells. To our knowledge, this is the first report that indicates a novel role of transcription factors in regulating osteogenic differentiation in adult or tissue specific stem cells.
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore 117456, Singapore. cheltwd@nus.edu.sg
authors.forename: David Tai
authors.initials: DT
authors.lastname: Leong
authors.forename: Mohan Chothirakottu
authors.initials: MC
authors.lastname: Abraham
authors.forename: Anurag
authors.initials: A
authors.lastname: Gupta
authors.forename: Thiam-Chye
authors.initials: TC
authors.lastname: Lim
authors.forename: Fook Tim
authors.initials: FT
authors.lastname: Chew
authors.forename: Dietmar Werner
authors.initials: DW
authors.lastname: Hutmacher
mesh_terms: D051696:Activating Transcription Factors / Q000235:genetics / Q000378:metabolism*; D000273:Adipose Tissue / Q000166:cytology*; D053687:Adult Stem Cells / Q000166:cytology*; D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology*; D002478:Cells, Cultured; D006801:Humans; D010012:Osteogenesis / Q000235:genetics / Q000502:physiology*
chemical_list: C507532:ATF5 protein, human; D051696:Activating Transcription Factors