title: Maternal diabetes promotes mTORC1 downstream signalling in rabbit preimplantation embryos.
abstract: The mammalian target of rapamycin complex 1 (mTORC1) is known to be a central cellular nutrient sensor and master regulator of protein metabolism; therefore, it is indispensable for normal embryonic development. We showed previously in a diabetic pregnancy that embryonic mTORC1 phosphorylation is increased in case of maternal hyperglycaemia and hypoinsulinaemia. Further, the preimplantation embryo is exposed to increased L-leucine levels during a diabetic pregnancy. To understand how mTOR signalling is regulated in preimplantation embryos, we examined consequences of L-leucine and glucose stimulation on mTORC1 signalling and downstream targets in in vitro cultured preimplantation rabbit blastocysts and in vivo. High levels of L-leucine and glucose lead to higher phosphorylation of mTORC1 and its downstream target ribosomal S6 kinase 1 (S6K1) in these embryos. Further, L-leucine supplementation resulted in higher embryonic expression of genes involved in cell cycle (cyclin D1; CCND1), translation initiation (eukaryotic translation initiation factor 4E; EIF4E), amino acid transport (large neutral amino acid transporter 2; Lat2: gene SLC7A8) and proliferation (proliferating cell nuclear antigen; PCNA) in a mTORC1-dependent manner. Phosphorylation of S6K1 and expression patterns of CCND1 and EIF4E were increased in embryos from diabetic rabbits, while the expression of proliferation marker PCNA was decreased. In these embryos, protein synthesis was increased and autophagic activity was decreased. We conclude that mammalian preimplantation embryos sense changes in nutrient supply via mTORC1 signalling. Therefore, mTORC1 may be a decisive mediator of metabolic programming in a diabetic pregnancy.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Gürke
authors.forename: Maria
authors.initials: M
authors.lastname: Schindler
authors.forename: S Mareike
authors.initials: SM
authors.lastname: Pendzialek
authors.forename: René
authors.initials: R
authors.lastname: Thieme
authors.forename: Katarzyna J
authors.initials: KJ
authors.lastname: Grybel
authors.affiliation: Department of Anatomy and Cell BiologyFaculty of Medicine, Martin Luther University Halle-Wittenberg, Grosse Steinstrasse 52, D-06097 Halle (Saale), GermanyInstitute of Molecular Cell BiologyCenter for Molecular Biomedicine, Hans-Knoell-Straße 2, D-07745 Jena, GermanyCentre for Biological SciencesSouthampton General Hospital, University of Southampton, Mailpoint 840, Tremona Road, Southampton SO16 6YD, UK.
authors.forename: Regine
authors.initials: R
authors.lastname: Heller
authors.affiliation: Department of Anatomy and Cell BiologyFaculty of Medicine, Martin Luther University Halle-Wittenberg, Grosse Steinstrasse 52, D-06097 Halle (Saale), GermanyInstitute of Molecular Cell BiologyCenter for Molecular Biomedicine, Hans-Knoell-Straße 2, D-07745 Jena, GermanyCentre for Biological SciencesSouthampton General Hospital, University of Southampton, Mailpoint 840, Tremona Road, Southampton SO16 6YD, UK.
authors.forename: Katrin
authors.initials: K
authors.lastname: Spengler
authors.affiliation: Department of Anatomy and Cell BiologyFaculty of Medicine, Martin Luther University Halle-Wittenberg, Grosse Steinstrasse 52, D-06097 Halle (Saale), GermanyInstitute of Molecular Cell BiologyCenter for Molecular Biomedicine, Hans-Knoell-Straße 2, D-07745 Jena, GermanyCentre for Biological SciencesSouthampton General Hospital, University of Southampton, Mailpoint 840, Tremona Road, Southampton SO16 6YD, UK.
authors.forename: Tom P
authors.initials: TP
authors.lastname: Fleming
authors.forename: Bernd
authors.initials: B
authors.lastname: Fischer
authors.forename: Anne
authors.initials: A
authors.lastname: Navarrete Santos
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000378:metabolism / Q000473:pathology*; D015153:Blotting, Western; D002478:Cells, Cultured; D003921:Diabetes Mellitus, Experimental / Q000150:complications* / Q000378:metabolism / Q000473:pathology; D003922:Diabetes Mellitus, Type 1 / Q000150:complications* / Q000378:metabolism / Q000473:pathology; D005260:Female; D022124:Hyperammonemia / Q000209:etiology* / Q000378:metabolism / Q000473:pathology; D006943:Hyperglycemia / Q000209:etiology* / Q000378:metabolism / Q000473:pathology; D000076222:Mechanistic Target of Rapamycin Complex 1; D046912:Multiprotein Complexes / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D011247:Pregnancy; D012333:RNA, Messenger / Q000235:genetics; D011817:Rabbits; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D058570:TOR Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*
chemical_list: D046912:Multiprotein Complexes; D012333:RNA, Messenger; D000076222:Mechanistic Target of Rapamycin Complex 1; D058570:TOR Serine-Threonine Kinases