title: Reactive nitrogen species induce nuclear factor-kappaB-mediated protein degradation in skeletal muscle cells.
abstract: Recently, a role for NF-kappaB in upregulation of proteolytic systems and protein degradation has emerged. Reactive nitrogen species (RNS) have been demonstrated to induce NF-kappaB activation. The aim of this study was to investigate whether RNS caused increased proteolysis in skeletal muscle cells, and whether this process was mediated through the activation of NF-kappaB. Fully differentiated L6 myotubes were treated with NO donor SNAP, peroxynitrite donor SIN-1, and authentic peroxynitrite, in a time-dependent manner. NF-kappaB activation, the activation of the ubiquitin-proteasome pathway and matrix metalloproteinases, and the levels of muscle-specific proteins (myosin heavy chain and telethonin) were investigated under the conditions of nitrosative stress. RNS donors caused NF-kappaB activation and increased activation of proteolytic systems, as well as the degradation of muscle-specific proteins. Antioxidant treatment, tyrosine nitration inhibition, and NF-kappaB molecular inhibition were proven effective in downregulation of NF-kappaB activation and slowing down the degradation of muscle-specific proteins. Peroxynitrite, but not NO, causes proteolytic system activation and the degradation of muscle-specific proteins in cultured myotubes, mediated through NF-kappaB. NF-kappaB inhibition by antioxidants, tyrosine nitration, and molecular inhibitors may be beneficial for decreasing the extent of muscle damage induced by RNS.
authors.affiliation: Department of Anatomy and Cell Biology, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, P.O. Box 9649, Haifa 31096, Israel.
authors.forename: Marina
authors.initials: M
authors.lastname: Bar-Shai
authors.forename: Abraham Z
authors.initials: AZ
authors.lastname: Reznick
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D002478:Cells, Cultured; D008666:Metalloendopeptidases / Q000378:metabolism; D008981:Molsidomine / Q000031:analogs & derivatives / Q000494:pharmacology; D032342:Muscle Cells / Q000378:metabolism; D018485:Muscle Fibers, Skeletal / Q000187:drug effects / Q000201:enzymology; D009124:Muscle Proteins / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000166:cytology / Q000378:metabolism; D018995:Myosin Heavy Chains / Q000378:metabolism*; D016328:NF-kappa B / Q000819:agonists / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D010396:Penicillamine / Q000031:analogs & derivatives / Q000494:pharmacology; D030421:Peroxynitrous Acid / Q000494:pharmacology; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism* / Q000494:pharmacology; D051381:Rats; D026361:Reactive Nitrogen Species / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism; D025801:Ubiquitin / Q000819:agonists
chemical_list: D000975:Antioxidants; D009124:Muscle Proteins; D016328:NF-kappa B; D020030:Nitric Oxide Donors; D026361:Reactive Nitrogen Species; C110881:S-nitro-N-acetylpenicillamine; C507454:Tcap protein, rat; D025801:Ubiquitin; D030421:Peroxynitrous Acid; D014443:Tyrosine; C002385:linsidomine; D008981:Molsidomine; D008666:Metalloendopeptidases; D046988:Proteasome Endopeptidase Complex; D018995:Myosin Heavy Chains; D010396:Penicillamine