title: Shotgun proteomics analysis reveals new unsuspected molecular effectors of nitrogen-containing bisphosphonates in osteocytes.
abstract: Nitrogen-containing bisphosphonates (N-BPs) are therapeutic agents used to treat osteoporosis and promote osteoblast and osteocyte survival. The molecular mechanisms underlying this effect have been extensively studied, but the global changes induced by N-BPs at the protein level are not known. In this context, we investigated the effect of 10(-7)M Risedronate for 1h and 48h on MLO-Y4 osteocytic cells, through a quantitative, label free shotgun proteomic analysis. We described herein a preliminary proteome map of untreated MLO-Y4 cells, composed of 353 protein species. Moreover, we identified 10 and 15 differentially expressed proteins after 1h and 48h of Risedronate treatment, respectively. Among these, PARK7/DJ-1 protein levels were induced up to 3 times and this event was associated with the activation of the pro-survival Akt pathway that we propose as a novel player in the effect of N-BPs on osteocytes. Risedronate was also able to induce the expression and the secretion of the growth factor pro-granulin. In addition, protein prenylation inhibition appeared to be involved in the modulation of MLO-Y4 proteome by RIS in a protein-specific manner. In conclusion, these findings unveil novel functions targeted by N-BPs in osteocytes and could be useful to design novel pharmaceutical compounds.
authors.affiliation: Department of Medical and Biological Sciences, University of Udine, 33100 Udine, Italy.
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Bivi
authors.forename: Paola
authors.initials: P
authors.lastname: Picotti
authors.forename: Lukas N
authors.initials: LN
authors.lastname: Müller
authors.forename: Milena
authors.initials: M
authors.lastname: Romanello
authors.forename: Luigi
authors.initials: L
authors.lastname: Moro
authors.forename: Franco
authors.initials: F
authors.lastname: Quadrifoglio
authors.forename: Gianluca
authors.initials: G
authors.lastname: Tell
mesh_terms: D000818:Animals; D015153:Blotting, Western; D050071:Bone Density Conservation Agents / Q000494:pharmacology*; D004164:Diphosphonates / Q000494:pharmacology; D012968:Etidronic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D020869:Gene Expression Profiling; D051379:Mice; D010011:Osteocytes / Q000187:drug effects*; D017368:Protein Prenylation / Q000187:drug effects; D040901:Proteomics / Q000379:methods; D051057:Proto-Oncogene Proteins c-akt / Q000502:physiology; D000068296:Risedronic Acid; D053719:Tandem Mass Spectrometry
chemical_list: D050071:Bone Density Conservation Agents; D004164:Diphosphonates; D051057:Proto-Oncogene Proteins c-akt; D000068296:Risedronic Acid; D012968:Etidronic Acid