title: H ferritin silencing induces protein misfolding in K562 cells: A Raman analysis.
abstract: The redox state of the cell is involved in the regulation of many physiological functions as well as in the pathogenesis of several diseases, and is strictly dependent on the amount of iron in its catalytically active state. Alterations of iron homeostasis determine increased steady-state concentrations of Reactive Oxygen Species (ROS) that cause lipid peroxidation, DNA damage and altered protein folding. Ferritin keeps the intracellular iron in a non-toxic and readily available form and consequently plays a central role in iron and redox homeostasis. The protein is composed by 24 subunits of the H- and L-type, coded by two different genes, with structural and functional differences. The aim of this study was to shed light on the role of the single H ferritin subunit (FHC) in keeping the native correct protein three-dimensional structure. To this, we performed Raman spectroscopy on protein extracts from K562 cells subjected to FHC silencing. The results show a significant increase in the percentage of disordered structures content at a level comparable to that induced by H2O2 treatment in control cells. ROS inhibitor and iron chelator were able to revert protein misfolding. This integrated approach, involving Raman spectroscopy and targeted-gene silencing, indicates that an imbalance of the heavy-to-light chain ratio in the ferritin composition is able to induce severe but still reversible modifications in protein folding and uncovers new potential pathogenetic mechanisms associated to intracellular iron perturbation.
authors.affiliation: Department of Experimental and Clinical Medicine, Magna Græcia University of Catanzaro, Salvatore Venuta Campus, Catanzaro, Italy, 88100.
authors.forename: Fabiana
authors.initials: F
authors.lastname: Zolea
authors.affiliation: Department of Experimental and Clinical Medicine, Magna Græcia University of Catanzaro, Salvatore Venuta Campus, Catanzaro, Italy, 88100.
authors.forename: Flavia
authors.initials: F
authors.lastname: Biamonte
authors.affiliation: BioNEM Laboratory, Department of Experimental and Clinical Medicine, Magna Græcia University of Catanzaro, Salvatore Venuta Campus, Catanzaro, Italy, 88100.
authors.forename: Patrizio
authors.initials: P
authors.lastname: Candeloro
authors.affiliation: Department of Experimental and Clinical Medicine, Magna Græcia University of Catanzaro, Salvatore Venuta Campus, Catanzaro, Italy, 88100.
authors.forename: Maddalena
authors.initials: M
authors.lastname: Di Sanzo
authors.affiliation: San Raffaele Scientific Institute, Division of Neuroscience, Milano, Italy, 20132.
authors.forename: Anna
authors.initials: A
authors.lastname: Cozzi
authors.affiliation: Department of Experimental and Clinical Medicine, Magna Græcia University of Catanzaro, Salvatore Venuta Campus, Catanzaro, Italy, 88100.
authors.forename: Anna
authors.initials: A
authors.lastname: Di Vito
authors.affiliation: Department of Experimental and Clinical Medicine, Magna Græcia University of Catanzaro, Salvatore Venuta Campus, Catanzaro, Italy, 88100.
authors.forename: Barbara
authors.initials: B
authors.lastname: Quaresima
authors.affiliation: Department of Experimental and Clinical Medicine, Magna Græcia University of Catanzaro, Salvatore Venuta Campus, Catanzaro, Italy, 88100.
authors.forename: Nadia
authors.initials: N
authors.lastname: Lobello
authors.affiliation: Department of Experimental and Clinical Medicine, Magna Græcia University of Catanzaro, Salvatore Venuta Campus, Catanzaro, Italy, 88100.
authors.forename: Francesca
authors.initials: F
authors.lastname: Trecroci
authors.affiliation: BioNEM Laboratory, Department of Experimental and Clinical Medicine, Magna Græcia University of Catanzaro, Salvatore Venuta Campus, Catanzaro, Italy, 88100; Physical Science & Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia, 23955-6900.
authors.forename: Enzo
authors.initials: E
authors.lastname: Di Fabrizio
authors.affiliation: San Raffaele Scientific Institute, Division of Neuroscience, Milano, Italy, 20132; University Vita-Salute San Raffaele, Milano, Italy, 20132.
authors.forename: Sonia
authors.initials: S
authors.lastname: Levi
authors.affiliation: Department of Experimental and Clinical Medicine, Magna Græcia University of Catanzaro, Salvatore Venuta Campus, Catanzaro, Italy, 88100.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Cuda
authors.affiliation: Department of Experimental and Clinical Medicine, Magna Græcia University of Catanzaro, Salvatore Venuta Campus, Catanzaro, Italy, 88100. Electronic address: fsc@unicz.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Costanzo
mesh_terms: D001052:Apoferritins / Q000737:chemistry* / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D055785:Gene Knockdown Techniques; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D020014:K562 Cells; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000502:physiology*; D017510:Protein Folding; D017382:Reactive Oxygen Species / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013059:Spectrum Analysis, Raman
chemical_list: D017382:Reactive Oxygen Species; D001052:Apoferritins
keywords: Ferritin heavy chain; K562; Oxidative stress; Protein misfolding; Raman spectroscopy