title: The regenerative effects of CCN2 independent modules on chondrocytes in vitro and osteoarthritis models in vivo.
abstract: The role of CCN family proteins has been proven to be of extreme importance in the process of cartilage development and endochondral ossification. The second member, CCN2, consists of 4 conserved modules that interact with a number of cofactors to display multiple functions. Although the potentially therapeutic effect of intact CCN2 on cartilage regeneration has been indicated by a number of studies, the regenerative effect of independent modules comprising CCN2 has never been evaluated before. This study aims to discover a more robust and effective CCN2 derivative to induce regeneration through assessing the effect of CCN2 independent modules on regeneration in vitro and in vivo, in comparison to the full length CCN2. In vitro evaluation using human chondrocytic cells showed a remarkable enhancing effect of several single modules on the gene expression of cartilaginous extracellular matrix components; whereas combinations of 2 or 3 modules rather diminished such effects. Interestingly, combination of all 4 modules redeemed the effect of intact CCN2 in vitro. Suspecting the re-assembly of the 4 modules, interaction among the modules was examined by surface plasmon resonance analysis. However, the results did not support the possible formation of a tetramodular complex. Next, the thrombospondin 1 type 1 repeat module (TSP1), which was found most promising in the experiments in vitro, and the combination of 4 modules were forwarded further to in vivo confirmation using 2 rat osteoarthritis (OA) models. As a result, TSP1 displayed more prominent regenerative effects than intact CCN2 on damaged cartilage. Unexpectedly, the combination of 4 modules showed limited effects in vivo. These results indicate the utility of TSP1 in the regenerative therapeutics of OA. Possible molecular mechanism that enables conditional reconstruction of CCN2 by 4 modules is discussed as well.
authors.affiliation: Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan; Department of Dental Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
authors.forename: Tarek
authors.initials: T
authors.lastname: Abd El Kader
authors.affiliation: Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan; Advanced Research Center for Oral and Craniofacial Sciences, Okayama University Dental School, Okayama, Japan. Electronic address: kubota1@md.okayama-u.ac.jp.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kubota
authors.affiliation: Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Nishida
authors.affiliation: Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
authors.forename: Takako
authors.initials: T
authors.lastname: Hattori
authors.affiliation: Advanced Research Center for Oral and Craniofacial Sciences, Okayama University Dental School, Okayama, Japan.
authors.forename: Eriko
authors.initials: E
authors.lastname: Aoyama
authors.affiliation: Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
authors.forename: Danilo
authors.initials: D
authors.lastname: Janune
authors.affiliation: Department of Dental Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
authors.forename: Emilio S
authors.initials: ES
authors.lastname: Hara
authors.affiliation: Department of Dental Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Ono
authors.affiliation: Department of Biomaterials, Institute for Frontier Medical Sciences, Kyoto University, Kyoto, Japan.
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Tabata
authors.affiliation: Department of Dental Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
authors.forename: Takuo
authors.initials: T
authors.lastname: Kuboki
authors.affiliation: Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan; Advanced Research Center for Oral and Craniofacial Sciences, Okayama University Dental School, Okayama, Japan. Electronic address: takigawa@md.okayama-u.ac.jp.
authors.forename: Masaharu
authors.initials: M
authors.lastname: Takigawa
mesh_terms: D053674:Aggrecans / Q000235:genetics / Q000378:metabolism; D000818:Animals; D002356:Cartilage / Q000502:physiology; D002460:Cell Line; D019902:Chondrocytes / Q000378:metabolism*; D024043:Collagen Type II / Q000235:genetics / Q000378:metabolism; D055513:Connective Tissue Growth Factor / Q000737:chemistry / Q000378:metabolism*; D004195:Disease Models, Animal; D005780:Gelatin / Q000737:chemistry; D005786:Gene Expression Regulation; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry; D010003:Osteoarthritis / Q000235:genetics / Q000473:pathology*; D017434:Protein Structure, Tertiary; D051381:Rats; D012038:Regeneration; D020349:Surface Plasmon Resonance
chemical_list: D053674:Aggrecans; D024043:Collagen Type II; D055513:Connective Tissue Growth Factor; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D005780:Gelatin
keywords: CCN family; CCN2; IGFBP; Regeneration; TSP1