title: Control of embryonic stem cell metastability by L-proline catabolism.
abstract: The molecular mechanisms controlling mouse embryonic stem cell (ESC) metastability, i.e. their capacity to fluctuate between different states of pluripotency, are not fully resolved. We developed and used a novel automation platform, the Cell(maker), to screen a library of metabolites on two ESC-based phenotypic assays (i.e. proliferation and colony phenotype) and identified two metabolically related amino acids, namely l-proline (l-Pro) and l-ornithine (l-Orn), as key regulators of ESC metastability. Both compounds, but mainly l-Pro, force ESCs toward a novel epiblast stem cell (EpiSC)-like state, in a dose- and time-dependent manner. Unlike EpiSCs, l-Pro-induced cells (PiCs) contribute to chimeric embryos and rely on leukemia inhibitor factor (LIF) to self-renew. Furthermore, PiCs revert to ESCs or differentiate randomly upon removal of either l-Pro or LIF, respectively. Remarkably, PiC generation depends on both l-Pro metabolism (uptake and oxidation) and Fgf5 induction, and is strongly counteracted by antioxidants, mainly l-ascorbic acid (vitamin C, Vc). ESCs ↔ PiCs phenotypic transition thus represents a previously undefined dynamic equilibrium between pluripotent states, which can be unbalanced either toward an EpiSC-like or an ESC phenotype by l-Pro/l-Orn or Vc treatments, respectively. All together, our data provide evidence that ESC metastability can be regulated at a metabolic level.
authors.affiliation: Stem Cell Fate Laboratory, Institute of Genetics and Biophysics A. Buzzati-Traverso, CNR, Naples, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Casalino
authors.forename: Stefania
authors.initials: S
authors.lastname: Comes
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Lambazzi
authors.forename: Benedetta
authors.initials: B
authors.lastname: De Stefano
authors.forename: Stefania
authors.initials: S
authors.lastname: Filosa
authors.forename: Sandro
authors.initials: S
authors.lastname: De Falco
authors.forename: Dario
authors.initials: D
authors.lastname: De Cesare
authors.forename: Gabriella
authors.initials: G
authors.lastname: Minchiotti
authors.forename: Eduardo Jorge
authors.initials: EJ
authors.lastname: Patriarca
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002460:Cell Line; D049109:Cell Proliferation; D002478:Cells, Cultured; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D016513:Mice, SCID; D039904:Pluripotent Stem Cells / Q000166:cytology / Q000378:metabolism; D011392:Proline / Q000378:metabolism*
chemical_list: D011392:Proline