title: Proteomic analysis of vascular smooth muscle cells treated with ouabain.
abstract: Apoptosis of vascular smooth muscle cells (VSMC) plays an important role in remodeling the vessel walls, one of the major determinants of long-term blood pressure elevation and an independent risk factor for cardiovascular morbidity and mortality. Apoptosis in VSMC can be inhibited by inversion of the intracellular [Na+]/[K+] ratio after the sustained blockage of the Na+,K+-ATPase by ouabain. Using two-dimensional gel electrophoresis followed by tandem mass spectroscopy, we compared proteomes of control VSMC and of those with ouabain-inhibited Na+,K+-ATPase and found that ouabain treatment led to overexpression of numerous soluble and membrane-bound proteins. Among proteins, which showed the highest level of ouabain-induced expression, we identified mortalin (also known as GRP75 or PBP-74), a member of the heat shock protein 70 superfamily and a marker for cellular mortal and immortal phenotypes. Further experiments showed that mortalin RNA and protein levels are induced in ouabain-treated VSMC, and that transient transfection of cells with mortalin cDNA inhibited serum deprivation-induced apoptosis via inactivation of the tumor suppressor gene, p53.
authors.affiliation: Department of Medical Genetics, St. Justine Hospital, Montreal, Quebec, Canada.
authors.forename: Alexey V
authors.initials: AV
authors.lastname: Pshezhetsky
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002478:Cells, Cultured; D015180:Electrophoresis, Gel, Two-Dimensional; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010042:Ouabain / Q000494:pharmacology*; D020543:Proteome / Q000032:analysis*; D040901:Proteomics / Q000379:methods; D051381:Rats; D011914:Rats, Inbred BN; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D053719:Tandem Mass Spectrometry; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: D020543:Proteome; D016159:Tumor Suppressor Protein p53; D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase