Suchergebnisse

Post-mortem tissues samples are a key resource for investigating patterns of gene expression. However, the processes triggered by death and the post-mortem interval (PMI) can significantly alter physiologically normal RNA levels. We investigate the impact of PMI on gene expression using data from multiple tissues of post-mortem donors obtained from the GTEx project. We find that many genes change expression over relatively short PMIs in a tissue-specific manner, but this potentially confounding effect in a biological analysis can be minimized by taking into account appropriate covariates. By comparing ante- and post-mortem blood samples, we identify the cascade of transcriptional events triggered by death of the organism. These events do not appear to simply reflect stochastic variation resulting from mRNA degradation, but active and ongoing regulation of transcription. Finally, we develop a model to predict the time since death from the analysis of the transcriptome of a few readily accessible tissues. ; We acknowledge and thank the donors and their families for their generous gifts of organ donation for transplantation and tissue donations for the GTEx research study. The Genotype-Tissue Expression (GTEx) project was supported by the Common Fund of the Office of the Director of the National Institutes of Health (commonfund.nih.gov/GTEx). We thank Anabela Nunes for help on image edition. This work was supported by the following grants and contracts: 1) From the US NIH: Contract HHSN261200800001E (Leidos Prime contract with NCI); Contracts 10XS170 (NDRI), 10XS171 (Roswell Park Cancer Institute), 10 × 172 (Science Care Inc.), and 12ST1039 (IDOX); Contract 10ST1035 (Van Andel Institute); Contract HHSN268201000029C (Broad Institute); R01 DA006227-17 (U Miami Brain Bank) 2) Ipatimup and i3s are partially funded by the Portuguese Foundation for Science and Technology (FCT); FEDER funds through the COMPETE 2020—Operacional Programme for Competitiveness and Internationalization (POCI), Portugal 2020, and by Portuguese funds through FCT/MCTES in the framework POCI-01-0145-FEDER-007274; 3) NORTE-01-0145-FEDER-000029, supported by NORTE 2020, under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF); 4) FCT Fellowships SFRH/BPD/89764/ 2012 to PO, PD/BD/128007/2016 to AS; Salary support to PGF by POPH—QREN Type 4.2, European Social Fund and MCTES, program Investigador FCT, IF/01127/2014. 5) BIO2014-57291-R from the Spanish Ministry of Economy and Competitiveness and "Plataforma de Recursos Biomoleculares y Bioinformáticos" PT13/0001/0007 from the ISCIII, and EU H2020-INFRADEV-1-2015-1 ELIXIR-EXCELERATE (ref. 6,676559) Spanish Ministry of Economy and Competitiveness, 'Centro de Excelencia Severo Ochoa 2013-2017' and CERCA Programme/Generalitat de Catalunya, 7) Ministerio de Educación, Cultura y Deporte, under the FPU programme (Formación de Profesorado Universitario) with pre-doctoral fellowship FPU15/03635 to MMA. 8) Award Number 1R01MH101814 and 3R01MH101814-03S1 from the National Human Genome Research Institute. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Human Genome Research Institute or the National Institutes of Health. European Research Council under the European Union's Seventh Framework Programme (FP7/2007-2013) / ERC grant agreement RNA-MAPS_294653, Ministerio de Economía, Industria y Competitividad, referencia MEIC BIO2015-70777-P y los Fondos Estructurales de la Unión Europea (FEDER) and ISCIII del Ministerio de Economía y Competitividad, referencia PT13/0001/0021 cofinaciada por el Fondo Europeo de Desarrollo Regional (FEDER). 9) MS received funding from CNPq (grant 310132/2015-0 and 427541/2016-6), and from FAPERJ (grant E_06/2015).

Sirtuins are key players of metabolic stress response. Originally described as deacetylases, some sirtuins also exhibit poorly understood mono-adenosine 5'-diphosphate (ADP)-ribosyltransferase (mADPRT) activity. We report that the deacetylase SirT7 is a dual sirtuin, as it also features auto-mADPRT activity. SirT7 mADPRT occurs at a previously undefined active site, and its abrogation alters SirT7 chromatin distribution. We identify an epigenetic pathway by which ADP-ribosyl-SirT7 is recognized by the ADP-ribose reader mH2A1.1 under glucose starvation, inducing SirT7 relocalization to intergenic regions. SirT7 promotes mH2A1 enrichment in a subset of nearby genes, many of them involved in second messenger signaling, resulting in their specific up- or down-regulation. The expression profile of these genes under calorie restriction is consistently abrogated in SirT7-deficient mice, resulting in impaired activation of autophagy. Our work provides a novel perspective on sirtuin duality and suggests a role for SirT7/mH2A1.1 axis in glucose homeostasis and aging. ; This work was supported by the Spanish Ministry of Economy and Competitiveness (MINECO) (SAF2011-25860, SAF2014-55964R, and SAF2017-88975R to A.V.; SAF2016-77830R to M.O.; and CTQ2016-80364-P to E.S.) and cofunded by FEDER funds/European Regional Development Fund (ERDF)–A Way to Build Europe, the Catalan government agency AGAUR (2014-SGR400 and 2017-SGR148 to A.V. and 2017-SGR595 to E.S.), a grant from Rutgers Human Genetics Institute of New Jersey (J.T. and L.S.), the German Center for Cardiovascular Research (DZHK), and the Deutsche Forschungsgemeinschaft (DFG SFB TRR81 A02 and SFB 1213 TP B02 to A.I. and T.B.).