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RESEARCH PRODUCT

Age-dependent regulation of antioxidant genes by p38α MAPK in the liver

Ana M. TormosSergio Rius-pérezAngel R. NebredaJuan SastreRaquel Taléns-viscontiIsabela FinamorSalvador Pérez

subject

ROS Reactive oxygen species;RSK1 Ribosomal S6 kinase10301 basic medicineMAPK/ERK pathwayAgingHPLC High-performance liquid chromatographyAntioxidantmedicine.medical_treatmentTBP TATA-binding proteinClinical BiochemistryDEN Diethyl nitrosamine;MKP-1 MAPK phosphatase-1IκB kinaseGCLc Glutamate cysteine ligase catalytic subunitp38 Mitogen-Activated Protein KinasesG6PDH Glucose-6-phosphate dehydrogenaseBiochemistryAntioxidantsMicechemistry.chemical_compoundSuperoxide Dismutase-1Akt Protein kinase B0302 clinical medicineNrf2 Nuclear factor erythroid 2-related factor-2IL InterleukinSOD1 Cu/Zn-superoxide dismutaselcsh:QH301-705.5Mice KnockoutMK2 MAP-activated protein kinase 2;PGC-1α Peroxisome proliferator-activated receptor gamma coactivator 1-alphachemistry.chemical_classificationlcsh:R5-920Trx ThioredoxinGlutathione DisulfideTNF-α Tumor necrosis factor-alphabiologyLPS Lipopolysaccharide;GSSG Oxidized glutathione;MEF Mouse embryonic fibroblastsNF-kappa BGstm1 Glutathione S-transferase mu 1CatalaseEndoplasmic Reticulum StressGlutathioneLiverGSH Reduced glutathione;Catalase030220 oncology & carcinogenesisJNK c-Jun N-terminal kinaselcsh:Medicine (General)Research Papermedicine.medical_specialtyNF-E2-Related Factor 2Glutamate-Cysteine LigaseMKK MAPK kinaseAP-1 Activator protein-1IKK IƙB KinaseGene Expression Regulation EnzymologicSuperoxide dismutase03 medical and health sciencesInternal medicineGlutamate cysteine ligaseEGFR Epidermal growth factor receptormedicineAnimalsNuclear factor ƙBAnd catalaseChIP Chromatin immunoprecipitation;Protein kinase BNF-ƙB Nuclear factor kappa BSuperoxide DismutaseSuperoxide dismutase 1Superoxide dismutase 2Organic ChemistryGlutathioneASK1 Apoptosis signal-regulating kinase 1ATF2 activating transcription factor 2;030104 developmental biologyEndocrinologyEnzymeHsp Heat shock proteinlcsh:Biology (General)chemistrybiology.proteinSOD2 Mn-superoxide dismutaseMAPK mitogen activated protein kinaseNEM N-ethyl maleimide;

description

p38α is a redox sensitive MAPK activated by pro-inflammatory cytokines and environmental, genotoxic and endoplasmic reticulum stresses. The aim of this work was to assess whether p38α controls the antioxidant defense in the liver, and if so, to elucidate the mechanism(s) involved and the age-related changes. For this purpose, we used liver-specific p38α-deficient mice at two different ages: young-mice (4 months-old) and old-mice (24 months-old). The liver of young p38α knock-out mice exhibited a decrease in GSH levels and an increase in GSSG/GSH ratio and malondialdehyde levels. However, old mice deficient in p38α had higher hepatic GSH levels and lower GSSG/GSH ratio than young p38α knock-out mice. Liver-specific p38α deficiency triggered a dramatic down-regulation of the mRNAs of the key antioxidant enzymes glutamate cysteine ligase, superoxide dismutase 1, superoxide dismutase 2, and catalase in young mice, which seems mediated by the lack of p65 recruitment to their promoters. Nrf-2 nuclear levels did not change significantly in the liver of young mice upon p38α deficiency, but nuclear levels of phospho-p65 and PGC-1α decreased in these mice. p38α-dependent activation of NF-κB seems to occur through classical IκB Kinase and via ribosomal S6 kinase1 and AKT in young mice. However, unexpectedly the long-term deficiency in p38α triggers a compensatory up-regulation of antioxidant enzymes via NF-κB activation and recruitment of p65 to their promoters. In conclusion, p38α MAPK maintains the expression of antioxidant genes in liver of young animals via NF-κΒ under basal conditions, whereas its long-term deficiency triggers compensatory up-regulation of antioxidant enzymes through NF-κΒ.

https://doi.org/10.1016/j.redox.2018.02.017