title: Autophagy-linked FYVE containing protein WDFY3 interacts with TRAF6 and modulates RANKL-induced osteoclastogenesis.
abstract: Recently, autophagy-related proteins were shown to regulate osteoclast mediated bone resorption, a critical process in autoimmune diseases such as rheumatoid arthritis. However, the role of autophagy-linked FYVE containing protein, WDFY3, in osteoclast biology remains elusive. WDFY3 is a master regulator in selective autophagy for clearing ubiquitinated protein aggregates and has been linked with rheumatoid arthritis. Herein, we used a series of WDFY3 transgenic mice (Wdfy3(lacZ) and Wdfy3(loxP)) to investigate the function of WDFY3 in osteoclast development and function. Our data demonstrate that WDFY3 is highly expressed at the growth plate of neonatal mice and is expressed in osteoclasts in vitro cultures. Osteoclasts derived from WDFY3 conditional knockout mice (Wdfy3(loxP/loxP)-LysM-Cre(+)) demonstrated increased osteoclast differentiation as evidenced by higher number and enlarged size of TRAP(+) multinucleated cells. Western blot analysis also revealed up-regulation of TRAF6 and an increase in RANKL-induced NF-κB signaling in WDFY3-deficient bone marrow-derived macrophages compared to wild type cultures. Consistent with these observations WDFY3-deficient cells also demonstrated an increase in osteoclast-related genes Ctsk, Acp5, Mmp9 and an increase of dentine resorption in in vitro assays. Importantly, in vivo RANKL gene transfer exacerbated bone loss in WDFY3 conditional knockout mice, as evidenced by elevated serum TRAP, CTX-I and micro-CT analysis of distal femurs compared to wild type littermates. Taken together, our data highlight a novel role for WDFY3 in osteoclast development and function, which can be exploited for the treatment of musculoskeletal diseases.
authors.affiliation: Graduate Group in Immunology, University of California at Davis, United States; Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis, United States.
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: Wu
authors.affiliation: Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis, United States.
authors.forename: Ran
authors.initials: R
authors.lastname: Gu
authors.affiliation: Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis, United States.
authors.forename: Ritu
authors.initials: R
authors.lastname: Sarin
authors.affiliation: Department of Anatomy, Physiology and Cell Biology, University of California at Davis, United States.
authors.forename: Regina
authors.initials: R
authors.lastname: Zavodovskaya
authors.affiliation: Department of Statistics, University of California at Davis, United States.
authors.forename: Chia-Pei
authors.initials: CP
authors.lastname: Chen
authors.affiliation: Department of Orthopedic Surgery, University of California at Davis, United States.
authors.forename: Blaine A
authors.initials: BA
authors.lastname: Christiansen
authors.forename: Konstantinos S
authors.lastname: Zarbalis
authors.affiliation: Graduate Group in Immunology, University of California at Davis, United States; Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis, United States; Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children, Northern California, United States. Electronic address: iannis@ucdavis.edu.
authors.forename: Iannis E
authors.initials: IE
authors.lastname: Adamopoulos
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D001343:Autophagy / Q000502:physiology*; D000071183:Autophagy-Related Proteins; D015153:Blotting, Western; D001862:Bone Resorption / Q000378:metabolism; D056657:Cathepsin K / Q000378:metabolism; D002454:Cell Differentiation; D002478:Cells, Cultured; D005269:Femur / Q000000981:diagnostic imaging; D018014:Gene Transfer Techniques; D015726:Giant Cells / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D016328:NF-kappa B / Q000378:metabolism; D010006:Osteoblasts; D010010:Osteoclasts / Q000502:physiology; D010012:Osteogenesis / Q000502:physiology*; D061251:Primary Cell Culture; D053245:RANK Ligand / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D048029:TNF Receptor-Associated Factor 6 / Q000378:metabolism*; D000071681:Tartrate-Resistant Acid Phosphatase / Q000097:blood / Q000378:metabolism; D015854:Up-Regulation; D033921:Vesicular Transport Proteins / Q000235:genetics / Q000378:metabolism*; D055114:X-Ray Microtomography
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D000071183:Autophagy-Related Proteins; D016328:NF-kappa B; D053245:RANK Ligand; D048029:TNF Receptor-Associated Factor 6; C505689:Tnfsf11 protein, mouse; D033921:Vesicular Transport Proteins; C496370:Wdfy3 protein, mouse; C000605511:Acp5 protein, mouse; D000071681:Tartrate-Resistant Acid Phosphatase; D056657:Cathepsin K; C534132:Ctsk protein, mouse; D020780:Matrix Metalloproteinase 9; C501830:Mmp9 protein, mouse
keywords: Autophagy; Autophagy-linked FYVE containing protein; Musculoskeletal diseases; Osteoclast; TRAF6; WDFY3