title: Tetracycline inhibits W7FW14F apomyoglobin fibril extension and keeps the amyloid protein in a pre-fibrillar, highly cytotoxic state.
abstract: A significant number of fatal diseases are classified as protein deposition disorders, in which a normally soluble protein is deposited in an insoluble amyloid form. It has been reported that tetracycline exhibits anti-amyloidogenic activity by inhibiting aggregate formation and disaggregating preformed fibrils. In this work, we examined the effect induced by the presence of tetracycline on the fibrillogenesis and cytotoxicity of the amyloid-forming apomyoglobin mutant W7FW14F. Like other amyloid-forming proteins, early prefibrillar aggregates formed by this protein are highly cytotoxic, whereas insoluble mature fibrils are not. The effect induced by tetracycline on the fibrillation process has been examined by atomic force microscopy, light scattering, DPH staining, and thioflavin T fluorescence. The cytotoxicity of the amyloid aggregates was estimated by measuring cell viability using MTT assay. The results show that tetracycline acts as anti-aggregating agent, which inhibits the fibril elongation process but not the early aggregation steps leading to the formation of soluble oligomeric aggregates. Thus, this inhibition keeps the W7FW14F mutant in a prefibrillar, highly cytotoxic state. In this respect, a careful usage of tetracycline as fibril inhibitor is indicated.
authors.affiliation: Dipartimento di Biochimica e Biofisica, Seconda Università di Napoli, Naples, Italy.
authors.forename: Clorinda
authors.initials: C
authors.lastname: Malmo
authors.forename: Silvia
authors.initials: S
authors.lastname: Vilasi
authors.forename: Clara
authors.initials: C
authors.lastname: Iannuzzi
authors.forename: Silvia
authors.initials: S
authors.lastname: Tacchi
authors.forename: Cesare
authors.initials: C
authors.lastname: Cametti
authors.forename: Gaetano
authors.initials: G
authors.lastname: Irace
authors.forename: Ivana
authors.initials: I
authors.lastname: Sirangelo
mesh_terms: D000682:Amyloid / Q000378:metabolism*; D000818:Animals; D001059:Apoproteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002470:Cell Survival / Q000187:drug effects; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D009154:Mutation; D009211:Myoglobin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D041681:NIH 3T3 Cells; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D013752:Tetracycline / Q000494:pharmacology*
chemical_list: D000682:Amyloid; D001059:Apoproteins; D009211:Myoglobin; D011500:Protein Synthesis Inhibitors; C010857:apomyoglobin; D013752:Tetracycline