6533b7d4fe1ef96bd1263267

RESEARCH PRODUCT

Mboat7 down-regulation by hyper-insulinemia induces fat accumulation in hepatocytes.

Amalia GastaldelliStefano GattiMiriam LongoMiriam LongoStefano RomeoStefano RomeoStefano RomeoMelania GagginiPaola DongiovanniSara BadialiNicholas O. DavidsonAnna Ludovica FracanzaniAnna Ludovica FracanzaniGuido BaselliSerena PelusiSerena PelusiRaffaela RamettaMarica MeroniMarica MeroniFabrizia CarliLuca ValentiLuca ValentiMarco Maggioni

subject

Research paperTGFβ Transforming Growth Factor BetaIntracellular SpaceCRISPR Clustered Regularly Interspaced Short Palindromic RepeatshHEPS Human HepatocytesMice0302 clinical medicineLPIAT1DAG Diacylglyceroli.p. Intraperitonealmedia_commonFatty AcidsGeneral Medicine3. Good health030220 oncology & carcinogenesisHOMA-IR homeostasis Model Assessment of Insulin ResistanceMPO morpholinolcsh:Medicine (General)medicine.medical_specialtyPE Phosphatidyl-EthanolamineNashGeneral Biochemistry Genetics and Molecular Biology03 medical and health sciencesTNFα tumor Necrosis Factor AlphaLDL Low Density LipoproteinsHyperinsulinismNAFLDSD Standard Dietmedia_common.cataloged_instanceHumansCPT1 Carnitine Palmitoyltransferase IPhosphatidylinositolGene SilencingEuropean unionVLDL Very Low Density Lipoproteinlcsh:RhHSC Human Hepatic Stellate Cellsmedicine.diseaseLipid MetabolismOA Oleic AcidCI Confidence IntervalMboat7 Membrane bound O-acyltransferase domain containing 7MCD methionine choline deficient diet030104 developmental biologyEndocrinologychemistryCDP Cytidine-DiphosphateFOXO1 Forkhead Box protein O1NAFLD nonalcoholic fatty liver diseaseSteatohepatitisBMI Body Mass IndexCL CardiolipinAcyltransferases0301 basic medicineAlcoholic liver diseaseCXCL10 C-X-C Motif Chemokine 10lcsh:Medicinechemistry.chemical_compoundNon-alcoholic Fatty Liver DiseaseIFG Impaired Fasting GlucoseAPOB Apolipoprotein BNonalcoholic fatty liver diseasePIP Phosphatidyl-Inositol-PhosphateSteatohepatitisqRT-PCR quantitative Real Time Polymerase Chain ReactionMice Knockoutlcsh:R5-920ORO Oil Red O StainingPI PhosphatidylinositolFatty liverTM6SF2 Transmembrane 6 Superfamily Member 2PhospholipidTAG TriglyceridesNASH Nonalcoholic SteatohepatitisLipogenesisLPA Lyso-Phosphatidic AcidPhosphatidylinositolSignal TransductionPS Phosphatidyl-SerinePA Palmitic AcidALD alcoholic liver diseasePC Phosphatidylcholinei.v. IntravenousFATP1 Fatty Acid Transport Protein 1Models BiologicalInternal medicinemedicineAnimalsNonalcoholic fatty liver diseasePPARα Peroxisome Proliferator-Activated Receptor alphaObesityG3P Glyceraldehyde-3-PhosphateSREBP1c Sterol Regulatory Element-Binding Protein 1HDL High Density Lipoproteinsbusiness.industryPI3K Phosphatidylinositol 3 KinaseMembrane ProteinsNHEJ Non-Homologues End JoiningPNPLA3 Patatin-like Phospholipase Domain-containing-3MTTP Microsomal Triglyceride Transfer ProteinLPIAT1 Lysophosphatidylinositol Acyltransferase 1TMC4 Transmembrane Channel-Like 4Disease Models AnimalGene Expression RegulationHepatocytesFOXA2 Forkhead Box A2mTOR mammalian target of RapamycinSteatosisInsulin ResistancebusinessPG Phosphatidyl-GlycerolFABP1 Fatty Acid-Binding Protein 1 FAS Fatty Acid SynthaseT2DM Type 2 Diabetes Mellitus

description

Background: Naturally occurring variation in Membrane-bound O-acyltransferase domain-containing 7 (MBOAT7), encoding for an enzyme involved in phosphatidylinositol acyl-chain remodelling, has been associated with fatty liver and hepatic disorders. Here, we examined the relationship between hepatic Mboat7 down-regulation and fat accumulation. Methods: Hepatic MBOAT7 expression was surveyed in 119 obese individuals and in experimental models. MBOAT7 was acutely silenced by antisense oligonucleotides in C57Bl/6 mice, and by CRISPR/Cas9 in HepG2 hepatocytes. Findings: In obese individuals, hepatic MBOAT7 mRNA decreased from normal liver to steatohepatitis, independently of diabetes, inflammation and MBOAT7 genotype. Hepatic MBOAT7 levels were reduced in murine models of fatty liver, and by hyper-insulinemia. In wild-type mice, Mboat7 was down-regulated by refeeding and insulin, concomitantly with insulin signalling activation. Acute hepatic Mboat7 silencing promoted hepatic steatosis in vivo and enhanced expression of fatty acid transporter Fatp1. MBOAT7 deletion in hepatocytes reduced the incorporation of arachidonic acid into phosphatidylinositol, consistently with decreased enzymatic activity, determining the accumulation of saturated triglycerides, enhanced lipogenesis and FATP1 expression, while FATP1 deletion rescued the phenotype. Interpretation: MBOAT7 down-regulation by hyper-insulinemia contributes to hepatic fat accumulation, impairing phosphatidylinositol remodelling and up-regulating FATP1. Funding: LV was supported by MyFirst Grant AIRC n.16888, Ricerca Finalizzata Ministero della Salute RF-2016–02,364,358, Ricerca corrente Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico; LV and AG received funding from the European Union Programme Horizon 2020 (No. 777,377) for the project LITMUS-“Liver Investigation: Testing Marker Utility in Steatohepatitis”. MM was supported by Fondazione Italiana per lo Studio del Fegato (AISF) ‘Mario Coppo’ fellowship. Keywords: LPIAT1, NAFLD, Nash, Nonalcoholic fatty liver disease, Steatohepatitis, Phospholipid, Phosphatidylinositol

yearjournalcountryeditionlanguage
2020-02-01EBioMedicine
10.1016/j.ebiom.2020.102658https://pubmed.ncbi.nlm.nih.gov/32058943