6533b824fe1ef96bd1280106

RESEARCH PRODUCT

Effects of peroxisome proliferator-activated receptor alpha activation on pathways contributing to cholesterol homeostasis in rat hepatocytes

Catherine Le Jossic-corcosSandrine DuclosGrégory ChevillardLeyla C. RamirezThierry PineauIsabelle ZaghiniPaulette BournotPascal G.p. Martin

subject

MaleCarboxy-Lyases[SDV]Life Sciences [q-bio]Receptors Cytoplasmic and NuclearAcetatesClofibric AcidMicechemistry.chemical_compound0302 clinical medicineMice KnockoutCarbon Isotopes0303 health sciencesFenofibrateFibric AcidsPeroxisomeUp-RegulationHMG-COA REDUCTASEDNA-Binding ProteinsCholesterolCHOLESTEROL METABOLISM030220 oncology & carcinogenesisHMG-CoA reductaseCholesteryl esterPeroxisome Proliferatorslipids (amino acids peptides and proteins)Peroxisome proliferator-activated receptor alphaSterol Regulatory Element Binding Protein 1Cell DivisionSignal Transductionmedicine.drugmedicine.medical_specialtyMevalonic AcidPeroxisome ProliferationBiologyCholesterol 7 alpha-hydroxylaseBile Acids and Salts03 medical and health sciencesInternal medicinemedicineAnimalsRNA MessengerMolecular Biology030304 developmental biologyCell BiologyRAT HEPATOCYTEPPARA-NULL MOUSERatsSterol regulatory element-binding proteinMice Inbred C57BLPyrimidinesEndocrinologychemistryFIBRATECCAAT-Enhancer-Binding ProteinsHepatocytesbiology.proteinHydroxymethylglutaryl CoA ReductasesTranscription Factors

description

International audience; Peroxisome proliferator-activated receptor alpha (PPARa) activation by fibrates controls expression of several genes involved in hepatic cholesterol metabolism. Other genes could be indirectly controlled in response to changes in cellular cholesterol availability. To further understand how fibrates may affect cholesterol synthesis, we investigated in parallel the changes in the metabolic pathways contributing to cholesterol homeostasis in liver. Ciprofibrate increased HMG-CoA reductase and FPP synthase mRNA levels in rat hepatocytes, together with cholesterogenesis from [14C] acetate and [3H] mevalonate. The up-regulation observed in fenofibrate- and WY-14,643-treated mice was abolished in PPARa-null mice, showing an essential role of PPAR a. Among the three sterol regulatory element-binding protein (SREBP) mRNA species, only SREBP-1c level was significantly increased. In ciprofibrate-treated hepatocytes, cholesterol efflux was decreased, in parallel with cholesteryl ester storage and bile acids synthesis. As expected, AOX expression was strongly induced, supporting evidence of the peroxisome proliferation. Taken together, these results show that fibrates can cause cholesterol depletion in hepatocytes, possibly in part as a consequence of an important requirement of cholesterol for peroxisome proliferation, and increase cholesterogenesis by a compensatory phenomenon afterwards. Such cholesterogenesis regulation could occur in vivo, in species responsive to the peroxisome proliferative effect of PPARa ligands.

yearjournalcountryeditionlanguage
2004-01-01
10.1016/j.bbalip.2004.04.004https://hal.inrae.fr/hal-02679542