title: Generation of hyaline cartilaginous tissue from mouse adult dermal fibroblast culture by defined factors.
abstract: Repair of cartilage injury with hyaline cartilage continues to be a challenging clinical problem. Because of the limited number of chondrocytes in vivo, coupled with in vitro de-differentiation of chondrocytes into fibrochondrocytes, which secrete type I collagen and have an altered matrix architecture and mechanical function, there is a need for a novel cell source that produces hyaline cartilage. The generation of induced pluripotent stem (iPS) cells has provided a tool for reprogramming dermal fibroblasts to an undifferentiated state by ectopic expression of reprogramming factors. Here, we show that retroviral expression of two reprogramming factors (c-Myc and Klf4) and one chondrogenic factor (SOX9) induces polygonal chondrogenic cells directly from adult dermal fibroblast cultures. Induced cells expressed marker genes for chondrocytes but not fibroblasts, i.e., the promoters of type I collagen genes were extensively methylated. Although some induced cell lines formed tumors when subcutaneously injected into nude mice, other induced cell lines generated stable homogenous hyaline cartilage–like tissue. Further, the doxycycline-inducible induction system demonstrated that induced cells are able to respond to chondrogenic medium by expressing endogenous Sox9 and maintain chondrogenic potential after substantial reduction of transgene expression. Thus, this approach could lead to the preparation of hyaline cartilage directly from skin, without generating iPS cells.
authors.affiliation: Department of Bone and Cartilage Biology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Hiramatsu
authors.forename: Satoru
authors.initials: S
authors.lastname: Sasagawa
authors.forename: Hidetatsu
authors.initials: H
authors.lastname: Outani
authors.forename: Kanako
authors.initials: K
authors.lastname: Nakagawa
authors.forename: Hideki
authors.initials: H
authors.lastname: Yoshikawa
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Tsumaki
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology*; D017690:Cell Transplantation; D002478:Cells, Cultured; D024042:Collagen Type I / Q000235:genetics / Q000378:metabolism; D020405:Dermis / Q000166:cytology*; D005347:Fibroblasts / Q000166:cytology / Q000502:physiology*; D006801:Humans; D051457:Hyaline Cartilage / Q000166:cytology* / Q000502:physiology; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008819:Mice, Nude; D008822:Mice, Transgenic; D009369:Neoplasms / Q000473:pathology; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics / Q000378:metabolism; D055758:SOX9 Transcription Factor / Q000235:genetics / Q000378:metabolism
chemical_list: D015415:Biomarkers; D024042:Collagen Type I; C000715467:KLF4 protein, human; C000715468:Klf4 protein, mouse; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors; D016271:Proto-Oncogene Proteins c-myc; D055758:SOX9 Transcription Factor; C527933:Sox9 protein, mouse