title: Measles virus nucleocapsid protein increases osteoblast differentiation in Paget's disease.
abstract: Paget's disease (PD) is characterized by focal and dramatic bone resorption and formation. Treatments that target osteoclasts (OCLs) block both pagetic bone resorption and formation; therefore, PD offers key insights into mechanisms that couple bone resorption and formation. Here, we evaluated OCLs from 3 patients with PD and determined that measles virus nucleocapsid protein (MVNP) was expressed in 70% of these OCLs. Moreover, transgenic mice with OCL-specific expression of MVNP (MVNP mice) developed PD-like bone lesions that required MVNP-dependent induction of high IL-6 expression levels in OCLs. In contrast, mice harboring a knockin of p62P394L (p62-KI mice), which is the most frequent PD-associated mutation, exhibited increased bone resorption, but not formation. Evaluation of OCLs from MVNP, p62-KI, and WT mice revealed increased IGF1 expression in MVNP-expressing OCLs that resulted from the high IL-6 expression levels in these cells. IL-6, in turn, increased the expression of coupling factors, specifically ephrinB2 on OCLs and EphB4 on osteoblasts (OBs). IGF1 enhanced ephrinB2 expression on OCLs and OB differentiation. Importantly, ephrinB2 and IGF1 levels were increased in MVNP-expressing OCLs from patients with PD and MVNP-transduced human OCLs compared with levels detected in controls. Further, anti-IGF1 or anti-IGF1R blocked Runx2 and osteocalcin upregulation in OBs cocultured with MVNP-expressing OCLs. These results suggest that in PD, MVNP upregulates IL-6 and IGF1 in OCLs to increase ephrinB2-EphB4 coupling and bone formation.
authors.forename: Jumpei
authors.initials: J
authors.lastname: Teramachi
authors.forename: Yuki
authors.initials: Y
authors.lastname: Nagata
authors.forename: Khalid
authors.initials: K
authors.lastname: Mohammad
authors.forename: Yuji
authors.initials: Y
authors.lastname: Inagaki
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Ohata
authors.forename: Theresa
authors.initials: T
authors.lastname: Guise
authors.forename: Laëtitia
authors.initials: L
authors.lastname: Michou
authors.forename: Jacques P
authors.initials: JP
authors.lastname: Brown
authors.forename: Jolene J
authors.initials: JJ
authors.lastname: Windle
authors.forename: Noriyoshi
authors.initials: N
authors.lastname: Kurihara
authors.forename: G David
authors.initials: GD
authors.lastname: Roodman
mesh_terms: D000818:Animals; D016022:Case-Control Studies; D002454:Cell Differentiation; D002478:Cells, Cultured; D018920:Coculture Techniques; D036388:Ephrin-B2 / Q000378:metabolism; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D015850:Interleukin-6 / Q000502:physiology; D008459:Measles virus / Q000502:physiology*; D018345:Mice, Knockout; D019590:Nucleocapsid Proteins / Q000502:physiology*; D010001:Osteitis Deformans / Q000473:pathology* / Q000821:virology; D010006:Osteoblasts / Q000502:physiology*; D010010:Osteoclasts / Q000502:physiology; D036224:Receptor, EphB4 / Q000378:metabolism
chemical_list: D036388:Ephrin-B2; D015850:Interleukin-6; D019590:Nucleocapsid Proteins; C519530:insulin-like growth factor-1, mouse; D007334:Insulin-Like Growth Factor I; C086681:Ephb4 protein, mouse; D036224:Receptor, EphB4