title: DHA inhibits protein degradation more efficiently than EPA by regulating the PPARγ/NFκB pathway in C2C12 myotubes.
abstract: This study was conducted to evaluate the mechanism by which n-3 PUFA regulated the protein degradation in C2C12 myotubes. Compared with the BSA control, EPA at concentrations from 400 to 600 µM decreased total protein degradation (P < 0.01). However, the total protein degradation was decreased when the concentrations of DHA ranged from 300 µM to 700 µM (P < 0.01). DHA (400 µM, 24 h) more efficiently decreased the I κ B α phosphorylation and increased in the I κ B α protein level than 400 µM EPA (P < 0.01). Compared with BSA, 400 µM EPA and DHA resulted in a 47% or 68% induction of the NF κ B DNA binding activity, respectively (P < 0.01). Meanwhile, 400 µM EPA and DHA resulted in a 1.3-fold and 2.0-fold induction of the PPAR γ expression, respectively (P < 0.01). In C2C12 myotubes for PPAR γ knockdown, neither 400 µM EPA nor DHA affected the levels of p-I κ B α , total I κ B α or NF κ B DNA binding activity compared with BSA (P > 0.05). Interestingly, EPA and DHA both still decreased the total protein degradation, although PPAR γ knockdown attenuated the suppressive effects of EPA and DHA on the total protein degradation (P < 0.01). These results revealed that DHA inhibits protein degradation more efficiently than EPA by regulating the PPAR γ /NF- κ B pathway in C2C12 myotubes.
authors.affiliation: Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Wang
authors.forename: Qiao-wei
authors.initials: QW
authors.lastname: Lin
authors.forename: Pei-pei
authors.initials: PP
authors.lastname: Zheng
authors.forename: Jian-song
authors.initials: JS
authors.lastname: Zhang
authors.forename: Fei-ruo
authors.initials: FR
authors.lastname: Huang
mesh_terms: D000818:Animals; D004281:Docosahexaenoic Acids / Q000494:pharmacology*; D015118:Eicosapentaenoic Acid / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects; D055785:Gene Knockdown Techniques; D020672:I-kappa B Proteins; D051379:Mice; D018485:Muscle Fibers, Skeletal / Q000187:drug effects / Q000378:metabolism*; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000378:metabolism*; D047495:PPAR gamma / Q000235:genetics / Q000378:metabolism*; D059748:Proteolysis / Q000187:drug effects*; D034622:RNA Interference; D015398:Signal Transduction / Q000187:drug effects* / Q000235:genetics; D014162:Transfection
chemical_list: D020672:I-kappa B Proteins; D016328:NF-kappa B; C000606205:Nfkbia protein, mouse; D047495:PPAR gamma; D000072000:NF-KappaB Inhibitor alpha; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid