title: Carboxymethyl-chitin promotes chondrogenesis by inducing the production of growth factors from immune cells.
abstract: Many techniques have been tested for their ability to restore cartilage defects, but several problems still remain in the complete healing of injured cartilage. In our previous study, we found that a carboxymethyl-chitin/beta-tricalcium phosphate (CM-chitin/beta-TCP) composite induced cartilage regeneration in the osteochondral defects of rabbits in vivo. We also found that CM-chitin stimulated peritoneal exudate cells (PEC) in mice and induced several kinds of inflammatory cytokines and transforming growth factor beta-1 (TGF-beta1). In this study, we examined whether CM-chitin is responsible for the induction of chondrogenesis via the production of TGF-beta1 in vitro. The murine pluripotent cell line C3H10T1/2 was maintained as a micromass culture in conditioned medium prepared from PEC stimulated with and without CM-chitin. CM-chitin-conditioned medium induced RNA expression of the chondrogenic-factor Sox9 and the matrix proteins aggrecan, Col2a1, and Comp. Their expression levels were decreased in the presence of anti-TGF-beta1 antibody. The micromass tissues cultured in CM-chitin conditioned medium at day 21 were clearly stained by Toluidine blue or Alcian blue (histological staining) and collagen II antibody (immunohistological staining), showing the expression of acidic glycosaminoglycan and type II collagen. Similar results were observed in micromass tissue stimulated with TGF-beta1 as a positive control. However, no chondrogenesis occurred when CM-chitin was added directly to a C3H10T1/2 cell culture. These results indicated that CM-chitin is a potent inducer of chondrogenesis via the induction of TGF-beta1 in immune cells.
authors.affiliation: Department of Nanostructure and Advanced Materials, Graduate School of Science and Engineering, Kagoshima University, Kagoshima, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kariya
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Yoshihara
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Nakao
authors.forename: Nobuko
authors.initials: N
authors.lastname: Sakurai
authors.forename: Masaru
authors.initials: M
authors.lastname: Ueno
authors.forename: Masahito
authors.initials: M
authors.lastname: Hashimoto
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Suda
mesh_terms: D000818:Animals; D000906:Antibodies / Q000276:immunology; D015415:Biomarkers / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D002686:Chitin / Q000031:analogs & derivatives* / Q000494:pharmacology; D020219:Chondrogenesis / Q000187:drug effects* / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects; D007107:Immune System / Q000166:cytology*; D036341:Intercellular Signaling Peptides and Proteins / Q000096:biosynthesis*; D051379:Mice; D039904:Pluripotent Stem Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D053773:Transforming Growth Factor beta1 / Q000276:immunology / Q000494:pharmacology
chemical_list: D000906:Antibodies; D015415:Biomarkers; D036341:Intercellular Signaling Peptides and Proteins; D012333:RNA, Messenger; D053773:Transforming Growth Factor beta1; D002686:Chitin; C044872:O-(carboxymethyl)chitin