title: Ddit3 suppresses the differentiation of mouse chondroprogenitor cells.
abstract: Endochondral ossification is an essential skeletal development process which is strongly linked to chondrocyte differentiation. DNA damage-inducible transcript 3 (Ddit3), a member of the CCAAT/enhancer-binding protein family of transcription factors, is highly expressed in the cartilage plate. However, the role of DNA damage-inducible transcript 3 in chondrocyte differentiation remains to be investigated. Immunofluorescent staining was used to detect Ddit3 expression in the mouse growth plate and in the mouse chondroprogenitor cell line ATDC5. A lentivirus system was employed to overexpress Ddit3 and silence its endogenous expression in ATDC5 cells. The differentiation abilities of ATDC5 cells were examined through quantitative reverse transcription polymerase chain reaction (qRT-PCR) and chondrogenic and hypertrophic-related staining. Western blot analysis was performed to detect the protein expression of sex-determining region Y-type high-mobility group box 9 and CCAAT/enhancer-binding protein β. Ddit3 was expressed in the proliferative and hypertrophic zones of the mouse growth plate. Ddit3 knockdown significantly enhanced the expression of chondrogenic and hypertrophic markers, whereas Ddit3 overexpression decreased the expression of these markers. This finding was also evidenced by Alcian blue staining, proteoglycan synthesis and alkaline phosphatase assay. Additionally, Ddit3 down-regulation significantly led to Sox9 up-regulation. These results suggest that Ddit3 suppresses the differentiation of ATDC5 cells. The function of Ddit3 might partially be regulated by Sox9 expression during chondrogenic and hypertrophic differentiation.
authors.affiliation: The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, Hubei 430079, China. Electronic address: yumiao@whu.edu.cn.
authors.forename: Miao
authors.initials: M
authors.lastname: Yu
authors.affiliation: The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, Hubei 430079, China. Electronic address: yisiqi@whu.edu.cn.
authors.forename: Si-Qi
authors.initials: SQ
authors.lastname: Yi
authors.affiliation: The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, Hubei 430079, China. Electronic address: 569794558@qq.com.
authors.forename: Yan-Ru
authors.initials: YR
authors.lastname: Wu
authors.affiliation: The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, Hubei 430079, China. Electronic address: sunhualing@163.com.
authors.forename: Hua-Ling
authors.initials: HL
authors.lastname: Sun
authors.affiliation: The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, Hubei 430079, China. Electronic address: 841627893@qq.com.
authors.forename: Fang-Fang
authors.initials: FF
authors.lastname: Song
authors.affiliation: The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, Hubei 430079, China. Electronic address: wangjwei@hotmail.com.
authors.forename: Jia-Wei
authors.initials: JW
authors.lastname: Wang
mesh_terms: D000818:Animals; D022782:CCAAT-Enhancer-Binding Protein-beta / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation; D019902:Chondrocytes / Q000166:cytology*; D015536:Down-Regulation; D006132:Growth Plate / Q000166:cytology; D051379:Mice; D055758:SOX9 Transcription Factor / Q000235:genetics / Q000378:metabolism; D051742:Transcription Factor CHOP / Q000378:metabolism*
chemical_list: D022782:CCAAT-Enhancer-Binding Protein-beta; D055758:SOX9 Transcription Factor; C527933:Sox9 protein, mouse; D051742:Transcription Factor CHOP
keywords: ATDC5 cell line; Chondrogenic differentiation; Ddit3; Endochondral ossification; Hypertrophic differentiation