Papel del sistema L-α-lisofosfatidilinositol/GPR55 en el desarrollo de esteatosis no alcohólica y esteatohepatitis

El receptor acoplado a proteína G 55 (GPR55) es un receptor cannabinoide putativo, y L-α-lisofosfatidilinositol (LPI) es su único ligando endógeno conocido. Aunque GPR55 está implicado en la homeostasis energética en diferentes órganos, su posible papel en el metabolismo lipídico del hígado y su contribución fisiopatológica en la enfermedad de hígado graso no alcohólica (NAFLD) es desconocido. Nosotros medimos 1) la expresión de GPR55 en el hígado de pacientes con NAFLD, comparándolo con los individuos sin la patología, y en diferentes modelos animales de NAFLD; 2) niveles de LPI en suero de pacientes con esteatosis (NAFL) y esteatohepatitis no alcohólica (NASH); 3) los efectos de LPI y la disrupción genética de GPR55 in vivo e in vitro. Encontramos que los niveles de LPI circulante y la expresión de GPR55 hepática están aumentados en pacientes con NASH. LPI induce la activación de la enzima acetil-CoA carboxilasa (ACC) por parte de la proteína kinasa activada por AMP (AMPK), incrementando el contenido lipídico en hepatocitos humanos y en el hígado de ratones por activación de la lipogénesis de novo e inhibición de la beta oxidación. La inhibición de GPR55 y ACCα bloquea los efectos de LPI, y el silenciamiento hepático de GPR55 in vivo es suficiente para mejorar el daño hepático en ratones alimentados con dieta alta en grasa y en ratones alimentados con dieta deficiente en metionina y colina. LPI también es capaz de desencadenar la activación de células estelares hepáticas estimulando GPR55 y ACC. Estos resultados muestran la importancia del sistema LPI/GPR55 en el desarrollo de NAFL y NASH vía ACC

The lipopolysaccharide-TLR4 axis regulates hepatic glutaminase 1 expression promoting liver ammonia build-up as steatotic liver disease progresses to steatohepatitis

Introduction Ammonia is a pathogenic factor implicated in the progression of metabolic-associated steatotic liver disease (MASLD). The contribution of the glutaminase 1 (GLS) isoform, an enzyme converting glutamine to glutamate and ammonia, to hepatic ammonia build-up and the mechanisms underlying its upregulation in metabolic-associated steatohepatitis (MASH) remain elusive. Methods Multiplex transcriptomics and targeted metabolomics analysis of liver biopsies in dietary mouse models representing the whole spectra of MASLD were carried out to characterize the relevance of hepatic GLS during disease pathological progression. In addition, the acute effect of liver-specific GLS inhibition in hepatic ammonia content was evaluated in cultured hepatocytes and in in vivo mouse models of diet-induced MASLD. Finally, the regulatory mechanisms of hepatic GLS overexpression related to the lipopolysaccharide (LPS)/Toll-like receptor 4 (TLR4) axis were explored in the context of MASH. Results In mouse models of diet-induced MASLD, we found that augmented liver GLS expression is closely associated with the build-up of hepatic ammonia as the disease progresses from steatosis to steatohepatitis. Importantly, the acute silencing/pharmacological inhibition of GLS diminishes the ammonia burden in cultured primary mouse hepatocytes undergoing dedifferentiation, in steatotic hepatocytes, and in a mouse model of diet-induced steatohepatitis, irrespective of changes in ureagenesis and gut permeability. Under these conditions, GLS upregulation in the liver correlates positively with the hepatic expression of TLR4 that recognizes LPS. In agreement, the pharmacological inhibition of TLR4 reduces GLS and hepatic ammonia content in LPS-stimulated mouse hepatocytes and hyperammonemia animal models of endotoxemia. Conclusions Overall, our results suggest that the LPS/TLR4 axis regulates hepatic GLS expression promoting liver ammonia build-up as steatotic liver disease progresses to steatohepatitis.TC Delgado is funded by “Ayuda RYC2020-029316-I financiada por MCIN/AEI/10.13039/501100011033 y por El FSE invierte en tu future”. This work was supported by the Gilead Sciences Research Scholars Program in Global Liver (to TCD), Nanostring® grant (to TCD); grant from Ministerio de Ciencia, Innovación y Universidades (MICINN: PID2022-139395OB-100 integrado en el Plan Estatal de Investigación Científica y Técnica e Innovación, con Fondos FEDER); grants from Ministerio de Ciencia, Innovación y Universidades MICINN: PID2020-117116RB-I00 CEX2021-001136-S integrado en el Plan Estatal de Investigación Científica y Técnica e Innovación, cofinanciado con Fondos FEDER for (MLM-C); Project funded by CIBEREHD; La Caixa Scientific Foundation (HR17-00601) (for MLM-C); ERA-Net E-Rare EJP RD Joint Translational Call for Rare Diseases FIGHT-CNNM2 (EJPRD19-040), and from Instituto Carlos III, Spain (for MLM-C, JH); the Basque Department of Education (IT1739-22) (for JH). JH and TCD are members of the European Reference Network for Rare Hereditary Metabolic Disorders (MetabERN) Project ID No. 739543

Splicing factor SF3B1 is overexpressed and implicated in the aggressiveness and survival of hepatocellular carcinoma

Splicing alterations represent an actionable cancer hallmark. Splicing factor 3B subunit 1 (SF3B1) is a crucial splicing factor that can be targeted pharmacologically (e.g. pladienolide-B). Here, we show that SF3B1 is overexpressed (RNA/protein) in hepatocellular carcinoma (HCC) in two retrospective (n = 154 and n = 172 samples) and in five in silico cohorts (n > 900 samples, including TCGA) and that its expression is associated with tumor aggressiveness, oncogenic splicing variants expression (KLF6-SV1, BCL-XL) and decreased overall survival. In vitro, SF3B1 silencing reduced cell viability, proliferation and migration and its pharmacological blockade with pladienolide-B inhibited proliferation, migration, and formation of tumorspheres and colonies in liver cancer cell lines (HepG2, Hep3B, SNU-387), whereas its effects on normal-like hepatocyte-derived THLE-2 proliferation were negligible. Pladienolide-B also reduced the in vivo growth and the expression of tumor-markers in Hep3B-induced xenograft tumors. Moreover, SF3B1 silencing and/or blockade markedly modulated the activation of key signaling pathways (PDK1, GSK3b, ERK, JNK, AMPK) and the expression of cancer-associated genes (CDK4, CD24) and oncogenic SVs (KLF6-SV1). Therefore, the genetic and/or pharmacological inhibition of SF3B1 may represent a promising novel therapeutic strategy worth to be explored through randomized controlled trials.Las alteraciones en el splicing son un rasgo distintivo del cáncer. La subunidad 1 del factor de splicing 3B (SF3B1) es un factor de splicing crucial que puede ser objeto de tratamiento farmacológico (por ejemplo, pladienolide-B). En este estudio demostramos que SF3B1 está sobreexpresado (ARN/proteína) en el carcinoma hepatocelular (CHC) en dos cohortes retrospectivas (n = 154 y n = 172 muestras) y en cinco cohortes in silico (n > 900 muestras, incluyendo TCGA) y que su expresión está asociada con la agresividad tumoral, la expresión de variantes de splicing oncogénicas (KLF6-SV1, BCL-XL) y la disminución de la supervivencia global. In vitro, el silenciamiento de SF3B1 redujo la viabilidad, proliferación y migración celular, y su bloqueo farmacológico con pladienolide-B inhibió la proliferación, migración y formación de esferas tumorales y colonias en líneas celulares de cáncer de hígado (HepG2, Hep3B, SNU-387), mientras que sus efectos sobre la proliferación de THLE-2 derivadas de hepatocitos de tipo normal fueron insignificantes. Pladienolide-B también redujo el crecimiento in vivo y la expresión de marcadores tumorales en tumores xenoinjertados inducidos por Hep3B. Además, el silenciamiento y/o bloqueo de SF3B1 moduló notablemente la activación de vías de señalización clave (PDK1, GSK3b, ERK, JNK, AMPK) y la expresión de genes asociados al cáncer (CDK4, CD24) y de SV oncogénicos (KLF6-SV1)

RICORS2040 : The need for collaborative research in chronic kidney disease

Chronic kidney disease (CKD) is a silent and poorly known killer. The current concept of CKD is relatively young and uptake by the public, physicians and health authorities is not widespread. Physicians still confuse CKD with chronic kidney insufficiency or failure. For the wider public and health authorities, CKD evokes kidney replacement therapy (KRT). In Spain, the prevalence of KRT is 0.13%. Thus health authorities may consider CKD a non-issue: very few persons eventually need KRT and, for those in whom kidneys fail, the problem is 'solved' by dialysis or kidney transplantation. However, KRT is the tip of the iceberg in the burden of CKD. The main burden of CKD is accelerated ageing and premature death. The cut-off points for kidney function and kidney damage indexes that define CKD also mark an increased risk for all-cause premature death. CKD is the most prevalent risk factor for lethal coronavirus disease 2019 (COVID-19) and the factor that most increases the risk of death in COVID-19, after old age. Men and women undergoing KRT still have an annual mortality that is 10- to 100-fold higher than similar-age peers, and life expectancy is shortened by ~40 years for young persons on dialysis and by 15 years for young persons with a functioning kidney graft. CKD is expected to become the fifth greatest global cause of death by 2040 and the second greatest cause of death in Spain before the end of the century, a time when one in four Spaniards will have CKD. However, by 2022, CKD will become the only top-15 global predicted cause of death that is not supported by a dedicated well-funded Centres for Biomedical Research (CIBER) network structure in Spain. Realizing the underestimation of the CKD burden of disease by health authorities, the Decade of the Kidney initiative for 2020-2030 was launched by the American Association of Kidney Patients and the European Kidney Health Alliance. Leading Spanish kidney researchers grouped in the kidney collaborative research network Red de Investigación Renal have now applied for the Redes de Investigación Cooperativa Orientadas a Resultados en Salud (RICORS) call for collaborative research in Spain with the support of the Spanish Society of Nephrology, Federación Nacional de Asociaciones para la Lucha Contra las Enfermedades del Riñón and ONT: RICORS2040 aims to prevent the dire predictions for the global 2040 burden of CKD from becoming true

Hepatic levels of S-adenosylmethionine regulate the adaptive response to fasting

26 p.-6 fig.-1 tab.-1 graph. abst.There has been an intense focus to uncover the molecular mechanisms by which fasting triggers the adaptive cellular responses in the major organs of the body. Here, we show that in mice, hepatic S-adenosylmethionine (SAMe)—the principal methyl donor—acts as a metabolic sensor of nutrition to fine-tune the catabolic-fasting response by modulating phosphatidylethanolamine N-methyltransferase (PEMT) activity, endoplasmic reticulum-mitochondria contacts, β-oxidation, and ATP production in the liver, together with FGF21-mediated lipolysis and thermogenesis in adipose tissues. Notably, we show that glucagon induces the expression of the hepatic SAMe-synthesizing enzyme methionine adenosyltransferase α1 (MAT1A), which translocates to mitochondria-associated membranes. This leads to the production of this metabolite at these sites, which acts as a brake to prevent excessive β-oxidation and mitochondrial ATP synthesis and thereby endoplasmic reticulum stress and liver injury. This work provides important insights into the previously undescribed function of SAMe as a new arm of the metabolic adaptation to fasting.M.V.-R. is supported by Proyecto PID2020-119486RB-100 (funded by MCIN/AEI/10.13039/501100011033), Gilead Sciences International Research Scholars Program in Liver Disease, Acción Estratégica Ciberehd Emergentes 2018 (ISCIII), Fundación BBVA, HORIZON-TMA-MSCA-Doctoral Networks 2021 (101073094), and Redes de Investigación 2022 (RED2022-134485-T). M.L.M.-C. is supported by La CAIXA Foundation (LCF/PR/HP17/52190004), Proyecto PID2020-117116RB-I00 (funded by MCIN/AEI/10.13039/501100011033), Ayudas Fundación BBVA a equipos de investigación científica (Umbrella 2018), and AECC Scientific Foundation (Rare Cancers 2017). A.W. is supported by RTI2018-097503-B-I00 and PID2021-127169OB-I00, (funded by MCIN/AEI/10.13039/501100011033) and by “ERDF A way of making Europe,” Xunta de Galicia (Ayudas PRO-ERC), Fundación Mutua Madrileña, and European Community’s H2020 Framework Programme (ERC Consolidator grant no. 865157 and MSCA Doctoral Networks 2021 no. 101073094). C.M. is supported by CIBERNED. P.A. is supported by Ayudas para apoyar grupos de investigación del sistema Universitario Vasco (IT1476-22), PID2021-124425OB-I00 (funded by MCIN/AEI/10.13039/501100011033 and “ERDF A way of making Europe,” MCI/UE/ISCiii [PMP21/00080], and UPV/EHU [COLAB20/01]). M.F. and M.G.B. are supported by PID2019-105739GB-I00 and PID2020-115472GB-I00, respectively (funded by MCIN/AEI/10.13039/501100011033). M.G.B. is supported by Xunta de Galicia (ED431C 2019/013). C.A., T.L.-D., and J.B.-V. are recipients of pre-doctoral fellowships from Xunta de Galicia (ED481A-2020/046, ED481A-2018/042, and ED481A 2021/244, respectively). T.C.D. is supported by Fundación Científica AECC. A.T.-R. is a recipient of a pre-doctoral fellowship from Fundación Científica AECC. S.V.A. and C.R. are recipients of Margarita Salas postdoc grants under the “Plan de Recuperación Transformación” program funded by the Spanish Ministry of Universities with European Union’s NextGeneration EU funds (2021/PER/00020 and MU-21-UP2021-03071902373A, respectively). T.C.D., A.S.-R., and M.T.-C. are recipients of Ayuda RYC2020-029316-I, PRE2019/088960, and BES-2016/078493, respectively, supported by MCIN/AEI/10.13039/501100011033 and by El FSE invierte en tu futuro. S.L.-O. is a recipient of a pre-doctoral fellowship from the Departamento de Educación del Gobierno Vasco (PRE_2018_1_0372). P.A.-G. is recipient of a FPU pre-doctoral fellowship from the Ministry of Education (FPU19/02704). CIC bioGUNE is supported by Ayuda CEX2021-001136-S financiada por MCIN/AEI/10.13039/501100011033. A.B.-C. was funded by predoctoral contract PFIS (FI19/00240) from Instituto de Salud Carlos III (ISCIII) co-funded by Fondo Social Europeo (FSE), and A.D.-L. was funded by contract Juan Rodés (JR17/00016) from ISCIII. A.B.-C. is a Miguel Servet researcher (CPII22/00008) from ISCIII.Peer reviewe

Neddylation of phosphoenolpyruvate carboxykinase 1 controls glucose metabolism

Neddylation is a post-translational mechanism that adds a ubiquitin-like protein, namely neural precursor cell expressed developmentally downregulated protein 8 (NEDD8). Here, we show that neddylation in mouse liver is modulated by nutrient availability. Inhibition of neddylation in mouse liver reduces gluconeogenic capacity and the hyperglycemic actions of counter-regulatory hormones. Furthermore, people with type 2 diabetes display elevated hepatic neddylation levels. Mechanistically, fasting or caloric restriction of mice leads to neddylation of phosphoenolpyruvate carboxykinase 1 (PCK1) at three lysine residues—K278, K342, and K387. We find that mutating the three PCK1 lysines that are neddylated reduces their gluconeogenic activity rate. Molecular dynamics simulations show that neddylation of PCK1 could re-position two loops surrounding the catalytic center into an open configuration, rendering the catalytic center more accessible. Our study reveals that neddylation of PCK1 provides a finely tuned mechanism of controlling glucose metabolism by linking whole nutrient availability to metabolic homeostasis.Ministerio de Ciencia, Innovación y Universidades PID2020-117116RB-I00, BFU2017-87721, RTI2018-101840-BI00, PID2021-126096NB-I00, RED2018-102379-TXunta de Galicia 2021-CP085, 2020-PG0157Fundación BBVA RTC2019-007125-1Proyectos Investigación en Salud DTS20/00138, DTS20/00138European Community 2019-WATCH- 81033

p63 controls metabolic activation of hepatic stellate cells and fibrosis via an HER2-ACC1 pathway

The p63 protein has pleiotropic functions and, in the liver, participates in the progression of nonalcoholic fatty liver disease (NAFLD). However, its functions in hepatic stellate cells (HSCs) have not yet been explored. TAp63 is induced in HSCs from animal models and patients with liver fibrosis and its levels positively correlate with NAFLD activity score and fibrosis stage. In mice, genetic depletion of TAp63 in HSCs reduces the diet-induced liver fibrosis. In vitro silencing of p63 blunts TGF-β1-induced HSCs activation by reducing mitochondrial respiration and glycolysis, as well as decreasing acetyl CoA carboxylase 1 (ACC1). Ectopic expression of TAp63 induces the activation of HSCs and increases the expression and activity of ACC1 by promoting the transcriptional activity of HER2. Genetic inhibition of both HER2 and ACC1 blunt TAp63-induced activation of HSCs. Thus, TAp63 induces HSC activation by stimulating the HER2-ACC1 axis and participates in the development of liver fibrosis.ACKNOWLEDGMENTS: This work has been supported by grants from FEDER/Ministerio de Ciencia, Innovación y Universidades-Agencia Estatal de Investigación (M.L.M.-C.: RTC2019-007125-1and SAF2017-87301-R; C.D.: PID2020-116628GB-100; R.N.: PID2021-126096NB-I00 and RED2018-102379-T; M.V.-R.: PID2020- 119486RB-100; A.W.: PID2021-127169OB-I00), Xunta de Galicia (R.N.: 2021-CP085 and 2020-PG015), Fundación BBVA (R.N., M.L.M.-C., and G.S.), Proyectos Investigación en Salud (M.L.M.-C.: DTS20/00138), Fundacion Araucaria (R.N.), and European Foundation for the Study of Diabetes (R.N.). This research also received funding from the European Community’s H2020 Framework Programme (ERC Synergy Grant-2019-WATCH- 810331, to R.N., V.P., and M.S. and ERC Consolidator grant no. 865157 to A.W.; MSCA Doctoral Networks 2021 no. 101073094 to A.W. and M.V.-R.). Centro de Investigación Biomédica en Red (CIBER) de Fisiopatología de la Obesidad y Nutrición (CIBERobn), Centro de Investigación Biomédica en Red (CIBER) de Enfermedades Hepáticas y Digestivas (CIBERehd). CIBERobn, and CIBERehd are initiatives of the Instituto de Salud Carlos III (ISCIII) of Spain, which is supported by FEDER funds. We thank MINECO for the Severo Ochoa Excellence Accreditation to CIC bioGUNE (SEV-2016-0644)

Hepatocyte-specific O-GlcNAc transferase downregulation ameliorates nonalcoholic steatohepatitis by improving mitochondrial function

Objective O-GlcNAcylation is a post-translational modification that directly couples the processes of nutrient sensing, metabolism, and signal transduction, affecting protein function and localization, since the O-linked N-acetylglucosamine moiety comes directly from the metabolism of glucose, lipids, and amino acids. The addition and removal of O-GlcNAc of target proteins are mediated by two highly conserved enzymes: O-linked N-acetylglucosamine (O-GlcNAc) transferase (OGT) and O-GlcNAcase (OGA), respectively. Deregulation of O-GlcNAcylation has been reported to be associated with various human diseases such as cancer, diabetes, and cardiovascular diseases. The contribution of deregulated O-GlcNAcylation to the progression and pathogenesis of NAFLD remains intriguing, and a better understanding of its roles in this pathophysiological context is required to uncover novel avenues for therapeutic intervention. By using a translational approach, our aim is to describe the role of OGT and O-GlcNAcylation in the pathogenesis of NAFLD. Methods We used primary mouse hepatocytes, human hepatic cell lines and in vivo mouse models of steatohepatitis to manipulate O-GlcNAc transferase (OGT). We also studied OGT and O-GlcNAcylation in liver samples from different cohorts of people with NAFLD. Results O-GlcNAcylation was upregulated in the liver of people and animal models with steatohepatitis. Downregulation of OGT in NAFLD-hepatocytes improved diet-induced liver injury in both in vivo and in vitro models. Proteomics studies revealed that mitochondrial proteins were hyper-O-GlcNAcylated in the liver of mice with steatohepatitis. Inhibition of OGT is able to restore mitochondrial oxidation and decrease hepatic lipid content in in vitro and in vivo models of NAFLD. Conclusions These results demonstrate that deregulated hyper-O-GlcNAcylation favors NAFLD progression by reducing mitochondrial oxidation and promoting hepatic lipid accumulation.ACKNOWLEDGEMENTS. This work was supported by grants from: FEDER/Ministerio de Ciencia, Innovación y Universidades-Agencia Estatal de Investigación (MLM-C: PID2020-117116RB-I00; CD: BFU2017-87721; ML: RTI2018e101840-B-I00; RN: PID2021-126096NB-I00 and RED2018-102379-T); Xunta de Galicia (RN: 2021-CP085 and 2020-PG0157); Fundación BBVA (to RN); Subprograma Retos Colaboración RTC2019-007125-1 (to MLM-C); Proyectos Investigación en Salud DTS20/00138 (to MLM-C); Proyectos Investigación en Salud (MLMC: DTS20/00138); Fundación Atresmedia (to ML and RN), Fundación La Caixa (to ML and RN); la Caixa Foundation Program HR17-00601 (to MLM-C); Gilead Sciences International Research Scholars Program in Liver Disease (to MVR); and the European Foundation for the Study of Diabetes (to RN and GS). This research also received funding from the European Community’s H2020 Framework Programme (ERC Synergy Grant-2019-WATCH-810331, to RN, VP and MS). The Centro de Investigación Biomédica en Red (CIBER) de Fisiopatología de la Obesidad y Nutrición (CIBERobn) and the Centro de Investigación Biomédica en Red (CIBER) de Enfermedades Hepáticas y Digestivas (CIBERehd) are initiatives of the Instituto de Salud Carlos III (ISCIII) of Spain, which is supported by FEDER funds. We thank MINECO for the Severo Ochoa Excellence Accreditation bioGUNE (SEV-2016- 0644) to CIC

The L-Alpha-Lysophosphatidylinositol/G Protein-Coupled Receptor 55 System Induces the Development of Nonalcoholic Steatosis and Steatohepatitis

Background and Aims G protein-coupled receptor (GPR) 55 is a putative cannabinoid receptor, and l-alpha-lysophosphatidylinositol (LPI) is its only known endogenous ligand. Although GPR55 has been linked to energy homeostasis in different organs, its specific role in lipid metabolism in the liver and its contribution to the pathophysiology of nonalcoholic fatty liver disease (NAFLD) remains unknown. Approach and Results We measured (1) GPR55 expression in the liver of patients with NAFLD compared with individuals without obesity and without liver disease, as well as animal models with steatosis and nonalcoholic steatohepatitis (NASH), and (2) the effects of LPI and genetic disruption of GPR55 in mice, human hepatocytes, and human hepatic stellate cells. Notably, we found that circulating LPI and liver expression of GPR55 were up-regulated in patients with NASH. LPI induced adenosine monophosphate-activated protein kinase activation of acetyl-coenzyme A carboxylase (ACC) and increased lipid content in human hepatocytes and in the liver of treated mice by inducing de novo lipogenesis and decreasing beta-oxidation. The inhibition of GPR55 and ACC alpha blocked the effects of LPI, and the in vivo knockdown of GPR55 was sufficient to improve liver damage in mice fed a high-fat diet and in mice fed a methionine-choline-deficient diet. Finally, LPI promoted the initiation of hepatic stellate cell activation by stimulating GPR55 and activation of ACC. Conclusions The LPI/GPR55 system plays a role in the development of NAFLD and NASH by activating ACC.Supported by grants from the Fondo Europeo de Desarrollo Regional (FEDER)/Ministerio de Ciencia, Innovacion y Universidades (MCIU)/Agencia Estatal de Investigacion (AEI) (C.D.: BFU2017-87721; M.L.: RTI2018-101840-B-I00; R.N.: BFU2015-70664R; A.G.-R.: PI16/00823; C.G.-M.: PI17/00535), Xunta de Galicia (M.L.: 2015-CP079 and 2016-PG068; R.N.: 2015-CP080 and 2016-PG057), Fundacion Banco Bilbao Vizcaya Argentaria (BBVA; to R.N.), Fundacion Atresmedia (M.L. and R.N.), European Foundation for the Study of Diabetes (R. N.), and Fundacion Francisco Cobos (A.G.-R.). MCIU/AEI/FEDER, European Union, (RTI2018-095134-B-100 to P.A.) provided aid to support the research groups of Sistema Universitario Vasco (IT971-16 to P. A). MCIU provided SAF2017-87301-R and RTI2018-096759-1-100, which were integrated into the Plan Estatal de Investigacion Cientifica y Tecnica e Innovacion and were cofinanced with FEDER (to M.L.M.-C. and T.C. D. respectively), and La Caixa Foundation Program and 2018 Fundacion BBVA Grants for Scientific Research Teams (to M.L.M.-C.). The research leading to these results has also received funding from the European Community's H2020 Framework Programme under the following grant: European Research Council Synergy Grant 2019-WATCH-810331 to R.N. Centro de Investigacion Biomedica en Red (CIBER) de Fisiopatologia de la Obesidad y Nutricion and CIBER de Enfermedades Hepaticas y Digestivas are initiatives of the Instituto de Salud Carlos III (ISCIII) of Spain, which is supported by FEDER funds, Gilead Sciences International Research Scholars Program in Liver Disease (to MVR), PI16/01548 (to MM) and the Red de Trastornos Adictivos-RTA (RD16/0017/0023). This article was partially supported by grants from the Fondo Nacional de Desarrollo Cientifico y Tecnologico grants 1191145 (to M.A.), 1200227 to JPA and 1191183 (to F. B.) and by the Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT, AFB170005, CARE Chile UC, Basal Centre for Excellence in Science and Technology; to M.A.). We thank MINECO for the Severo Ochoa Excellence Accreditation provided to the Center for Cooperative Research in Biosciences (SEV-2016-0644)

Neddylation of phosphoenolpyruvate carboxykinase 1 controls glucose metabolism

Neddylation is a post-translational mechanism that adds a ubiquitin-like protein, namely neural precursor cell expressed developmentally downregulated protein 8 (NEDD8). Here, we show that neddylation in mouse liver is modulated by nutrient availability. Inhibition of neddylation in mouse liver reduces gluconeogenic capacity and the hyperglycemic actions of counter-regulatory hormones. Furthermore, people with type 2 diabetes display elevated hepatic neddylation levels. Mechanistically, fasting or caloric restriction of mice leads to neddylation of phosphoenolpyruvate carboxykinase 1 (PCK1) at three lysine residues-K278, K342, and K387. We find that mutating the three PCK1 lysines that are neddylated reduces their gluconeogenic activity rate. Molecular dynamics simulations show that neddylation of PCK1 could re-position two loops surrounding the catalytic center into an open configuration, rendering the catalytic center more accessible. Our study reveals that neddylation of PCK1 provides a finely tuned mechanism of controlling glucose metabolism by linking whole nutrient availability to metabolic homeostasis.This work was supported by grants from: FEDER/Ministerio de Ciencia, Innovación y Universidades-Agencia Estatal de Investigación (M.L.M.-C.: PID2020-117116RB-I00; C.D.: BFU2017-87721; M.L.: RTI2018-101840-B-I00; R.N.: PID2021-126096NB-I00 and RED2018-102379-T); Xunta de Galicia (R.N.: 2021-CP085 and 2020-PG0157); Fundación BBVA (to R.N.); Subprograma Retos Colaboración RTC2019-007125-1 (to M.L.M.-C.); Proyectos Investigación en Salud DTS20/00138 (to M.L.M.-C.); Proyectos Investigación en Salud (M.L.M.-C.: DTS20/00138); Fundación Atresmedia (to M.L. and R.N.); and Fundación La Caixa (to M.L., M.L.M.-C., and R.N.). This research also received funding from the European Community’s H2020 Framework Programme (ERC Synergy Grant-2019-WATCH- 810331, to R.N., V.P., and M.S.). The Centro de Investigación Biomédica en Red (CIBER) de Fisiopatología de la Obesidad y Nutrición (CIBERobn) and the Centro de Investigación Biomédica en Red (CIBER) de Enfermedades Hepáticas y Digestivas (CIBERehd) are initiatives of the Instituto de Salud Carlos III (ISCIII) of Spain, which is supported by FEDER funds. We thank MINECO for the Severo Ochoa Excellence Accreditation bioGUNE (SEV-2016-0644) to CIC.Peer reviewe