title: (18)F-Labeling of Mannan for Inflammation Research with Positron Emission Tomography.
abstract: Recently mannan from Saccharomyces cerevisiae has been shown to be able to induce psoriasis and psoriatic arthritis in mice, and the phenotypes resemble the corresponding human diseases. To investigate the pathological processes, we set out to label mannan with fluorine-18 ((18)F) and study the (18)F-labeled mannan in vitro and in vivo with positron emission tomography (PET). Accordingly, mannan has been transformed into (18)F-fluoromannan with (18)F-bicyclo[6.1.0]nonyne. In mouse aorta, the binding of [(18)F]fluoromannan to the atherosclerotic lesions was clearly visualized and was significantly higher compared to blocking assays (P < 0.001) or healthy mouse aorta (P < 0.001). In healthy rats the [(18)F]fluoromannan radioactivity accumulated largely in the macrophage-rich organs such as liver, spleen, and bone marrow and the excess excreted in urine. Furthermore, the corresponding (19)F-labeled mannan has been used to induce psoriasis and psoriatic arthritis in mice, which indicates that the biological function of mannan is preserved after the chemical modifications.
authors.affiliation: Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, FI-20520 Turku, Finland; Turku PET Centre, Åbo Akademi University, Kiinamyllynkatu 4-8, FI-20520 Turku, Finland.
authors.forename: Xiang-Guo
authors.initials: XG
authors.lastname: Li
authors.affiliation: Medical Inflammation Research, Medicity Research Laboratory, University of Turku, FI-20520 Turku, Finland; The National Doctoral Programme in Informational and Structural Biology, Tykistökatu 6, FI-20520 Turku, Finland.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Hagert
authors.affiliation: Turku PET Centre, University of Turku , Kiinamyllynkatu 4-8, FI-20520 Turku, Finland.
authors.forename: Riikka
authors.initials: R
authors.lastname: Siitonen
authors.affiliation: Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, FI-20520 Turku, Finland; Turku PET Centre, Turku University Hospital, Kiinamyllynkatu 4-8, FI-20520 Turku, Finland.
authors.forename: Helena
authors.initials: H
authors.lastname: Virtanen
authors.affiliation: Medical Inflammation Research, Medicity Research Laboratory, University of Turku , FI-20520 Turku, Finland.
authors.forename: Outi
authors.initials: O
authors.lastname: Sareila
authors.affiliation: Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, FI-20520 Turku, Finland; Turku Center for Disease Modeling, University of Turku, FI-20014 Turku, Finland.
authors.forename: Heidi
authors.initials: H
authors.lastname: Liljenbäck
authors.affiliation: Turku PET Centre, University of Turku , Kiinamyllynkatu 4-8, FI-20520 Turku, Finland.
authors.forename: Jouni
authors.initials: J
authors.lastname: Tuisku
authors.affiliation: Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, FI-20520 Turku, Finland; Turku PET Centre, Turku University Hospital, Kiinamyllynkatu 4-8, FI-20520 Turku, Finland.
authors.forename: Juhani
authors.initials: J
authors.lastname: Knuuti
authors.affiliation: Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, FI-20520 Turku, Finland; Turku PET Centre, Åbo Akademi University, Kiinamyllynkatu 4-8, FI-20520 Turku, Finland.
authors.forename: Jörgen
authors.initials: J
authors.lastname: Bergman
authors.affiliation: Medical Inflammation Research, Medicity Research Laboratory, University of Turku, FI-20520 Turku, Finland; Medical Inflammation Research, Department of Biochemistry and Biophysics, Karolinska Institute, SE-17177 Stockholm, Sweden.
authors.forename: Rikard
authors.initials: R
authors.lastname: Holmdahl
authors.affiliation: Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, FI-20520 Turku, Finland; Turku PET Centre, Turku University Hospital, Kiinamyllynkatu 4-8, FI-20520 Turku, Finland; Turku Center for Disease Modeling, University of Turku, FI-20014 Turku, Finland.
authors.forename: Anne
authors.initials: A
authors.lastname: Roivainen
keywords: Fluorine-18; inflammation; mannan; positron emission tomography; tetrazine ligation