title: Context-dependent regulation of embryonic stem cell differentiation by mGlu4 metabotropic glutamate receptors.
abstract: The mGlu5 receptor is the only metabotropic glutamate receptor subtype expressed by mouse embryonic stem (ES) cells grown under non-differentiating conditions [Cappuccio, I., Spinanti, P. Porcellini, A., Desiderati, F., De Vita, T., Storto, M., Capobianco, L., Battaglia, G., Nicoletti, F., Melchiorri, D., 2005. Endogenous activation of mGlu5 metabotropic glutamate receptors supports self-renewal of cultured mouse embryonic stem cells. Neuropharmacology 1, 196-205]. We now report that ES cells differentiating into embryoid bodies (EBs) progressively lose mGlu5 receptors and begin to express mGlu4 receptors at both mRNA and proteinc level. A 4-day treatment of EBs with the mGlu4 receptor agonist, L-2-amino-4-phosphonobutanoate (L-AP4), increased mRNA levels of the mesoderm marker, brachyury and the endoderm marker, H19, and decreased the expression of the transcript for the primitive ectoderm marker, fibroblast-growth factor-5 (FGF-5). These effects were prevented by the mGlu4 receptor antagonists, alpha-methylserine-O-phosphate (MSOP). Plating of EBs for 4 days in vitro in ITSFn medium induced cell differentiation towards a neural lineage, as reflected by the expression of the intermediate filament protein, nestin, and the homeobox protein, Dlx-2. Pharmacological activation of mGlu4 receptors during cell incubation in ITSFn medium increased the expression of both neural markers. Similar results were obtained when neural differentiation was induced by exposure of EBs to retinoic acid. These data suggest that differentiation of cultured ES cells is associated with changes in the expression pattern of mGlu receptors and that activation of mGlu4 receptors affects cell differentiation in a context-dependent manner.
authors.affiliation: Departments of Human Physiology and Pharmacology, University of Rome La Sapienza, Piazzale Aldo Moro 5, 00185 Rome, Italy.
authors.forename: Irene
authors.initials: I
authors.lastname: Cappuccio
authors.forename: Roberta
authors.initials: R
authors.lastname: Verani
authors.forename: Paola
authors.initials: P
authors.lastname: Spinsanti
authors.forename: Cristiano
authors.initials: C
authors.lastname: Niccolini
authors.forename: Roberto
authors.initials: R
authors.lastname: Gradini
authors.forename: Santa
authors.initials: S
authors.lastname: Costantino
authors.forename: Ferdinando
authors.initials: F
authors.lastname: Nicoletti
authors.forename: Daniela
authors.initials: D
authors.lastname: Melchiorri
mesh_terms: D033942:Adaptor Proteins, Vesicular Transport / Q000494:pharmacology; D000613:Aminobutyrates / Q000494:pharmacology; D000704:Analysis of Variance; D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology*; D002460:Cell Line; D004347:Drug Interactions / Q000502:physiology; D004622:Embryo, Mammalian / Q000166:cytology*; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005326:Fetal Proteins / Q000235:genetics / Q000378:metabolism; D051521:Fibroblast Growth Factor 5 / Q000235:genetics / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects / Q000502:physiology; D005998:Glycine / Q000031:analogs & derivatives / Q000494:pharmacology; D018398:Homeodomain Proteins / Q000378:metabolism; D007150:Immunohistochemistry / Q000379:methods; D051379:Mice; D010768:Phosphoserine / Q000494:pharmacology; D062085:RNA, Long Noncoding; D012333:RNA, Messenger / Q000096:biosynthesis; D022661:RNA, Untranslated / Q000235:genetics / Q000378:metabolism; D018094:Receptors, Metabotropic Glutamate / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D013234:Stem Cells / Q000187:drug effects / Q000502:physiology*; D020825:T-Box Domain Proteins / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D014212:Tretinoin / Q000494:pharmacology; D000098908:Brachyury Protein
chemical_list: D033942:Adaptor Proteins, Vesicular Transport; D000613:Aminobutyrates; D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; D005326:Fetal Proteins; D051521:Fibroblast Growth Factor 5; D005998:Glycine; D018398:Homeodomain Proteins; D010768:Phosphoserine; D062085:RNA, Long Noncoding; D012333:RNA, Messenger; D022661:RNA, Untranslated; D018094:Receptors, Metabotropic Glutamate; D020825:T-Box Domain Proteins; D014157:Transcription Factors; D014212:Tretinoin; D000098908:Brachyury Protein; C088334:Distal-less homeobox proteins; C094335:H19 long non-coding RNA; C118534:Itsn protein, mouse; C104331:cyclopropyl-4-phosphonophenylglycine; C120877:methylserine phosphate; C012729:2-amino-4-phosphonobutyric acid; C108823:metabotropic glutamate receptor 4