title: Hyaline cartilage formation and enchondral ossification modeled with KUM5 and OP9 chondroblasts.
abstract: What is it that defines a bone marrow-derived chondrocyte? We attempted to identify marrow-derived cells with chondrogenic nature and immortality without transformation, defining "immortality" simply as indefinite cell division. KUM5 mesenchymal cells, a marrow stromal cell line, generated hyaline cartilage in vivo and exhibited enchondral ossification at a later stage after implantation. Selection of KUM5 chondroblasts based on the activity of the chondrocyte-specific cis-regulatory element of the collagen alpha2(XI) gene resulted in enhancement of their chondrogenic nature. Gene chip analysis revealed that OP9 cells, another marrow stromal cell line, derived from macrophage colony-stimulating factor-deficient osteopetrotic mice and also known to be niche-constituting cells for hematopoietic stem cells expressed chondrocyte-specific or -associated genes such as type II collagen alpha1, Sox9, and cartilage oligomeric matrix protein at an extremely high level, as did KUM5 cells. After cultured OP9 micromasses exposed to TGF-beta3 and BMP2 were implanted in mice, they produced abundant metachromatic matrix with the toluidine blue stain and formed type II collagen-positive hyaline cartilage within 2 weeks in vivo. Hierarchical clustering and principal component analysis based on microarray data of the expression of cell surface markers and cell-type-specific genes resulted in grouping of KUM5 and OP9 cells into the same subcategory of "chondroblast," that is, a distinct cell type group. We here show that these two cell lines exhibit the unique characteristics of hyaline cartilage formation and enchondral ossification in vitro and in vivo.
authors.affiliation: Department of Reproductive Biology and Pathology, National Institute for Child and Health Development, Tokyo 157-8535, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Sugiki
authors.forename: Taro
authors.initials: T
authors.lastname: Uyama
authors.forename: Masashi
authors.initials: M
authors.lastname: Toyoda
authors.forename: Hideo
authors.initials: H
authors.lastname: Morioka
authors.forename: Shoen
authors.initials: S
authors.lastname: Kume
authors.forename: Kenji
authors.initials: K
authors.lastname: Miyado
authors.forename: Kenji
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Saito
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Tsumaki
authors.forename: Yoriko
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Toyama
authors.forename: Akihiro
authors.initials: A
authors.lastname: Umezawa
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D001846:Bone Development; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology* / Q000378:metabolism; D020219:Chondrogenesis; D024043:Collagen Type II; D020869:Gene Expression Profiling; D006132:Growth Plate / Q000502:physiology* / Q000637:transplantation; D051457:Hyaline Cartilage / Q000166:cytology* / Q000378:metabolism; D059630:Mesenchymal Stem Cells / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D020411:Oligonucleotide Array Sequence Analysis; D010012:Osteogenesis; D017154:Stromal Cells / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D053782:Transforming Growth Factor beta3 / Q000494:pharmacology
chemical_list: D015415:Biomarkers; C525719:Bmp2 protein, mouse; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D024043:Collagen Type II; D016212:Transforming Growth Factor beta; D053782:Transforming Growth Factor beta3