7 research outputs found
GDF15 promotes weight loss by enhancing energy expenditure in muscle
Funding Information: We thank R. Seeley for sharing GFRAL-null mice; B. Lowell for sharing ÎČ-less mice; and J. Wu for shipping ÎČ-less mice to us. G.R.S. was supported by a Diabetes Canada Investigator Award (DI-5-17-5302-GS), a Canadian Institutes of Health Research Foundation Grant (201709FDN-CEBA-116200), a Tier 1 Canada Research Chair in Metabolic Diseases and a J. Bruce Duncan Endowed Chair in Metabolic Diseases; D.W. by Fellowship Grants from the McMaster Institute for Research on Aging (MIRA) at McMaster University; S.R. by a postdoctoral fellowship supported by MITACS and Novo Nordisk; L.K.T. by a CIHR Post-Doctoral Fellowship Award and Michael DeGroote Fellowship Award in Basic Biomedical Science; E.M.D. by a Vanier Canada Graduate Scholarship; G.P.H. by the Natural Sciences and Engineering Research Council of Canada (NSERC: 400362); G.J.D. and S.M.F. by NSERC-CGSM scholarships; L.D. by the Fonds de Recherche du QuĂ©bec-SantĂ© doctoral training award; D.P.B. by the GSK Chair in Diabetes of UniversitĂ© de Sherbrooke and a FRQS J1 salary award. The Genotype-Tissue Expression (GTEx) Project was supported by the Common Fund of the Office of the Director of the National Institutes of Health, and by the NCI, NHGRI, NHLBI, NIDA, NIMH and NINDS. Funding Information: S.B.J. and R.E.K. are employees of Novo Nordisk, a pharmaceutical company producing and selling medicine for the treatment of diabetes and obesity. G.R.S. is a co-founder and shareholder of Espervita Therapeutics. McMaster University has received funding from Espervita Therapeutics, Esperion Therapeutics, Poxel Pharmaceuticals and Nestle for research conducted in the laboratory of G.R.S. S.R. is supported by a MITACS postdoctoral fellowship sponsored by Novo Nordisk. H.C.G. holds the McMaster-Sanofi Population Health Institute Chair in Diabetes Research and Care. G.R.S., G.P. and H.C.G. are inventors listed on a patent for identifying GDF15 as a biomarker for metformin. G.R.S. has received consulting/speaking fees from Astra Zeneca, Eli Lilly, Esperion Therapeutics, Merck, Poxel Pharmaceuticals and Cambrian Biosciences. The other authors declare no competing interests. Publisher Copyright: © 2023, The Author(s).Peer reviewedPublisher PD
Dual leucine zipper kinase regulates expression of axon guidance genes in mouse neuronal cells
Study of the apelinergic system: Molecular determinants of biased signaling
Les principes de pharmacologie moderne suggĂšrent quâen liant un rĂ©cepteur Ă 7 domaines transmembranaires (7DTM), diffĂ©rents ligands peuvent activer prĂ©fĂ©rentiellement lâune ou lâautre des voies signalĂ©tiques en aval du rĂ©cepteur Ă lâĂ©tude. Afin dâappuyer ce concept de signalisation biaisĂ©e, aussi appelĂ© sĂ©lectivitĂ© fonctionnelle, nous avons Ă©mis lâhypothĂšse que lâeffet diffĂ©rentiel de deux ligands endogĂšnes du rĂ©cepteur APJ, soit lâapĂ©line-13 et lâELABELA, puisse dĂ©couler des changements spatiotemporels de lâinteractome protĂ©ique de ces complexes rĂ©cepteur-ligand respectifs. ConsidĂ©rant que le rĂ©cepteur APJ est exprimĂ© in vivo de façon abondante chez les cellules endothĂ©liales, notre objectif Ă©tait aussi dâen identifier lâinteractome propre Ă ce contexte cellulaire particulier.
Afin de valider cette hypothĂšse, nous avons couplĂ© le rĂ©cepteur APJ avec une ascorbate peroxydase mutĂ©e (APEX2) pour effectuer un essai de proximitĂ© en surexprimant cette protĂ©ine chimĂ©rique chez des cellules endothĂ©liales cardiaques de souris (MCEC) en culture. Nous avons confirmĂ©, par buvardage Ă la streptavidine-HRP, lâefficacitĂ© de la biotinylation des protĂ©ines environnantes gĂ©nĂ©rĂ©e par le rĂ©cepteur APJ-APEX2 en conditions basale et activĂ©e Ă lâapĂ©line-13 ou lâELABELA. La dĂ©tection des Ă©tiquettes incluses de part et dâautre de la construction chimĂ©rique nous a permis de vĂ©rifier par immunobuvardage lâintĂ©gritĂ© de celle-ci ainsi que la localisation cellulaire par microscopie confocale. Les protĂ©ines biotinylĂ©es ont Ă©tĂ© purifiĂ©es via des billes-streptavidine et dĂ©tectĂ©es par spectromĂ©trie de masse. Nos rĂ©sultats dâanalyse dĂ©montrent les partenaires dâinteraction communs et distincts du rĂ©cepteur APJ selon ses deux ligands endogĂšnes indiquant une signalisation propre Ă chaque ligand. Nous avons Ă©galement comparĂ© nos rĂ©sultats avec deux diffĂ©rentes bases de donnĂ©es dâinteractions protĂ©ine-protĂ©ine pour y observer des diffĂ©rences et des similitudes. Nous retrouvons entre autres des protĂ©ines de mĂȘmes familles pour lâATPase vacuolaire et le complexe rĂ©tromĂšre qui sont des protĂ©ines connues pour ĂȘtre impliquĂ©es dans la signalisation cellulaire des rĂ©cepteurs Ă 7DTM. De plus, nous avons comparĂ© les interactomes pour un mĂȘme ligand selon les diffĂ©rents temps de stimulation qui rĂ©vĂšle un changement dynamique de lâinteractome du rĂ©cepteur dans le temps. En somme, nos travaux dĂ©montrent pour la toute premiĂšre fois lâinteractome du rĂ©cepteur APJ en condition basale et stimulĂ©e pour les deux ligands endogĂšnes, lâApĂ©line-13 et lâELABELA, dans des cellules endothĂ©liales cardiaques de souris. La validation des partenaires de liaison dans le futur permettra dâapprofondir nos connaissances au niveau de la signalisation du rĂ©cepteur APJ.Abstract: The principles of modern pharmacology suggest that by binding a seven-transmembrane domain (7TM) receptor, different ligands can preferentially activate one or the other of the signaling pathways downstream of the receptor under study. In order to support this concept of biased signaling, also called functional selectivity, we hypothesized that the differential effect of two endogenous APJ receptor ligands, apelin-13 and ELABELA, may result from spatiotemporal changes of the protein interactome of these respective receptor-ligand complexes. Considering that the APJ receptor is abundantly expressed in vivo in endothelial cells, our objective was also to identify the interactome specific to this particular cellular context.
In order to validate this hypothesis, we coupled the APJ receptor with a mutated ascorbate peroxidase (APEX2) to perform a proximity assay by overexpressing this chimeric protein in cultured mouse cardiac endothelial cells (MCEC). We have confirmed, by streptavidin-HRP blotting, the efficiency of biotinylation of the surrounding proteins generated by the APJ-APEX2 receptor under basal and activated conditions apelin-13 or ELABELA. The detection of the labels included on both sides of the chimeric construction allowed us to verify by immunoblotting the integrity of the protein as well as its cellular localization by confocal microscopy. The biotinylated proteins were purified via streptavidin beads and detected by mass spectrometry. Our analysis results demonstrate the common and distinct interaction partners of the APJ receptor according to its two endogenous ligands indicating a signaling specific to each ligand. We also compared our results with two different protein-protein interaction databases to find differences and similarities. Among other things, we have found proteins of the same family for vacuolar ATPase and the retromer complex which are proteins known to be involved in cellular signaling of 7TM receptor. In addition, we compared the interactomes for the same ligand according to the different stimulation times, which demonstrates a dynamic change in the receptor interactome over time. In short, our work demonstrates for the very first time the interactome of the APJ receptor in basal conditions and stimulated for the two endogenous ligands, Apelin-13 and ELABELA, in mouse cardiac endothelial cells. The validation of some of these newly identified protein partners in the future will allow us to deepen our knowledge in terms of APJ receptor signaling
The apelinergic system as an alternative to catecholamines in low-output septic shock
Abstract Catecholamines, in concert with fluid resuscitation, have long been recommended in the management of septic shock. However, not all patients respond positively and controversy surrounding the efficacy-to-safety profile of catecholamines has emerged, trending toward decatecholaminization. Contextually, it is time to re-examine the âmaintaining blood pressureâ paradigm by identifying safer and life-saving alternatives. We put in perspective the emerging and growing knowledge on a promising alternative avenue: the apelinergic system. This target exhibits invaluable pleiotropic properties, including inodilator activity, cardio-renal protection, and control of fluid homeostasis. Taken together, its effects are expected to be greatly beneficial for patients in septic shock
Additional file 1: Table S1. of Dual leucine zipper kinase regulates expression of axon guidance genes in mouse neuronal cells
Primers used in this study. (PDF 60Â kb
Additional file 3: Table S3. of Dual leucine zipper kinase regulates expression of axon guidance genes in mouse neuronal cells
Genes up-regulated by two-fold or more in DLK-depleted cells. (PDF 103Â kb