Direct conversion of human fibroblasts into functional osteoblasts by defined factors.
Osteoblasts produce calcified bone matrix and contribute to bone formation and remodeling. In this study, we established a procedure to directly convert human fibroblasts into osteoblasts by transducing some defined factors and culturing in osteogenic medium. Osteoblast-specific transcription factors, Runt-related transcription factor 2 (Runx2), and Osterix, in combination with Octamer-binding transcription factor 3/4 (Oct4) and L-Myc (RXOL) transduction, converted ∼ 80% of the fibroblasts into osteocalcin-producing cells. The directly converted osteoblasts (dOBs) induced by RXOL displayed a similar gene expression profile as normal human osteoblasts and contributed to bone repair after transplantation into immunodeficient mice at artificial bone defect lesions. The dOBs expressed endogenous Runx2 and Osterix, and did not require continuous expression of the exogenous genes to maintain their phenotype. Another combination, Oct4 plus L-Myc (OL), also induced fibroblasts to produce bone matrix, but the OL-transduced cells did not express Osterix and exhibited a more distant gene expression profile to osteoblasts compared with RXOL-transduced cells. These findings strongly suggest successful direct reprogramming of fibroblasts into functional osteoblasts by RXOL, a technology that may provide bone regeneration therapy against bone disorders.
Departments of Immunology, Dental Medicine, and.
Kenta
K
Yamamoto
Departments of Immunology.
Tsunao
T
Kishida
Departments of Immunology, Dental Medicine, and.
Yoshiki
Y
Sato
Departments of Immunology.
Keisuke
K
Nishioka
Departments of Immunology.
Akika
A
Ejima
Orthopedics, Kyoto Prefectural University of Medicine, Kamigyo-ku, Kyoto 602-8566, Japan.
Hiroyoshi
H
Fujiwara
Orthopedics, Kyoto Prefectural University of Medicine, Kamigyo-ku, Kyoto 602-8566, Japan.
Toshikazu
T
Kubo
Dental Medicine, and.
Toshiro
T
Yamamoto
Dental Medicine, and.
Narisato
N
Kanamura
Departments of Immunology, mazda@koto.kpu-m.ac.jp.
Osam
O
Mazda
D000818:Animals; D001861:Bone Regeneration; D016723:Bone Remodeling; D001842:Bone and Bones / Q000473:pathology; D002114:Calcinosis; D050659:Core Binding Factor Alpha 1 Subunit / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology* / Q000378:metabolism; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D005881:Gingiva / Q000378:metabolism; D006801:Humans; D008297:Male; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D050814:Octamer Transcription Factor-3 / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D010006:Osteoblasts / Q000166:cytology* / Q000378:metabolism; D010641:Phenotype; D016271:Proto-Oncogene Proteins c-myc / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D000076182:Sp7 Transcription Factor; D014157:Transcription Factors / Q000378:metabolism
D050659:Core Binding Factor Alpha 1 Subunit; D050814:Octamer Transcription Factor-3; C494173:POU5F1 protein, human; D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger; C493709:RUNX2 protein, human; D000076182:Sp7 Transcription Factor; C478163:SP7 protein, human; D014157:Transcription Factors
direct reprogramming; osteoblasts; regenerative medicine