title: Activation of the amino acid response modulates lineage specification during differentiation of murine embryonic stem cells.
abstract: In somatic cells, a collection of signaling pathways activated by amino acid limitation have been identified and referred to as the amino acid response (AAR). Despite the importance of possible detrimental effects of nutrient limitation during in vitro culture, the AAR has not been investigated in embryonic stem cells (ESC). AAR activation caused the expected increase in transcription factors that mediate specific AAR pathways, as well as the induction of asparagine synthetase, a terminal AAR target gene. Neither AAR activation nor stable knockdown of activating transcription factor (Atf) 4, a transcriptional mediator of the AAR, adversely affected ESC self-renewal or pluripotency. Low-level induction of the AAR over a 12-day period of embryoid body differentiation did alter lineage specification such that the primitive endodermal, visceral endodermal, and endodermal lineages were favored, whereas mesodermal and certain ectodermal lineages were suppressed. Knockdown of Atf4 further enhanced the AAR-induced increase in endodermal formation, suggesting that this phenomenon is mediated by an Atf4-independent mechanism. Collectively, the results indicate that, during differentiation of mouse embryoid bodies in culture, the availability of nutrients, such as amino acids, can influence the formation of specific cell lineages.
authors.affiliation: Department of Biochemistry and Molecular Biology, McKnight Brain Institute, Shands Cancer Center, and Center for Nutritional Sciences, University of Florida College of Medicine, Gainesville, Florida, USA.
authors.forename: Jixiu
authors.initials: J
authors.lastname: Shan
authors.forename: Takashi
authors.initials: T
authors.lastname: Hamazaki
authors.forename: Tiffany A
authors.initials: TA
authors.lastname: Tang
authors.forename: Naohiro
authors.initials: N
authors.lastname: Terada
authors.forename: Michael S
authors.initials: MS
authors.lastname: Kilberg
mesh_terms: D051701:Activating Transcription Factor 4 / Q000096:biosynthesis / Q000235:genetics; D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D001217:Aspartate-Ammonia Ligase / Q000378:metabolism; D015153:Blotting, Western; D002452:Cell Count; D002454:Cell Differentiation / Q000502:physiology*; D019070:Cell Lineage / Q000502:physiology*; D002478:Cells, Cultured; D053595:Embryonic Stem Cells / Q000378:metabolism*; D005434:Flow Cytometry; D051379:Mice; D014176:Protein Biosynthesis; D012313:RNA / Q000096:biosynthesis / Q000302:isolation & purification; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D014158:Transcription, Genetic
chemical_list: D000596:Amino Acids; C081452:Atf4 protein, mouse; D012333:RNA, Messenger; D051701:Activating Transcription Factor 4; D012313:RNA; D001217:Aspartate-Ammonia Ligase
keywords: activating transcription factor 4; embryoid bodies; endoderm; intrauterine growth restriction; protein restriction