title: Caveolin: a possible biomarker of degradable metallic materials toxicity in vascular cells.
abstract: Iron-based materials could constitute an interesting option for cardiovascular biodegradable stent applications due to their appropriate ductility compared with their counterparts, magnesium alloys. However, the predicted degradation rate of pure iron is considered to be too slow for such applications. We explored manganese (35 wt.%) as an alloying element in combination with iron to circumvent this problem through powder metallurgical processing (Fe-35Mn). Manganese, on the other hand, is highly cytotoxic. We recently explored a new method to better characterize the safety of degradable metallic materials (DMMs) by establishing the gene expression profile (GEP) of cells (mouse 3T3 fibroblasts) exposed to Fe-35Mn degradation products in order to better understand their global response to a potentially cytotoxic DMM. We identified a number of up- and down-regulated genes and confirmed the regulation of a subset of them by quantitative real time polymerase chain reaction. Caveolin-1 (cav1), the structural protein of caveolae, small, smooth plasma membrane invaginations present in various differentiated cell types, was one of the most down-regulated genes in our GEPs. In the present study we further studied the potential of this 22 kDa protein to become a biomarker for cytotoxicity after exposure to degradable metallic elements. In order to better characterize cav1 expression in this context 3T3 mouse fibroblasts were exposed to either ferrous and manganese ions at cytostatic concentrations for 24 or 48 h. cav1 gene expression was not influenced by exposure to ferrous ions. On the other hand, exposure to manganese for 24h reduced cav1 gene expression by about 30% and by >65% after 48 h compared with control 3T3 cells. The cav1 cellular protein content was reduced to the same extent. The same pattern of expression of cav3 (the muscle-specific caveolin subtype) was also observed in this study. This strong and reproducible pattern of regulation of caveolins thus indicates potential as a biomarker for the toxicity of DMM elements.
authors.affiliation: Laval Hospital Research Center/Institut Universitaire de Cardiologie et de Pneumologie de Québec, Department of Medicine, Université Laval, 2725 Chemin Ste-Foy, Québec, Canada G1V 4G5; Laboratory for Biomaterials and Bioengineering, Department of Mining, Metallurgy and Materials Engineering, Pavilion Adrien-Pouliot 1745-E, Université Laval, 1065 Avenue de la Médicine, Québec, Canada G1V 0A6.
authors.forename: Agung
authors.initials: A
authors.lastname: Purnama
authors.forename: Diego
authors.initials: D
authors.lastname: Mantovani
authors.forename: Jacques
authors.initials: J
authors.lastname: Couet
mesh_terms: D016475:3T3 Cells; D000818:Animals; D015415:Biomarkers; D001808:Blood Vessels / Q000166:cytology* / Q000187:drug effects*; D051242:Caveolin 1 / Q000235:genetics / Q000378:metabolism; D051244:Caveolin 3 / Q000378:metabolism; D022461:Caveolins / Q000378:metabolism*; D002452:Cell Count; D015536:Down-Regulation / Q000187:drug effects; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D008670:Metals / Q000633:toxicity*; D051379:Mice; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats
chemical_list: D015415:Biomarkers; D051242:Caveolin 1; D051244:Caveolin 3; D022461:Caveolins; D008670:Metals; D012333:RNA, Messenger
keywords: Caveolin; Degradable metals; Fibroblasts; Smooth muscle cells