title: Constitutive L-Sox5 overexpression delays differentiation of ATDC5 cells into chondrocytes and correlates with reduced expression of differentiation markers.
abstract: L-Sox5 is a member of sex-determining region Y-type high mobility group box (SOX) family of transcription factors. We assessed the effects of retroviral overexpression of L-Sox5 on chondrocyte differentiation using the clonal murine cell line ATDC5. We observed a temporal-restricted expression pattern of L-Sox5 in insulin-induced ATDC5 cells differentiating toward chondrocyte lineage. The protein expression levels of L-Sox5 showed a drastic decrease in contrast to unaltered mRNA levels during differentiation. L-Sox5 delayed the differentiation of ATDC5 cells as evidenced by Alcian blue staining for proteoglycan synthesis. The mRNA levels of chondrocyte and hypertrophic/osteoarthritic markers were markedly decreased or delayed in L-Sox5 overexpressing cells. L-Sox5 abrogated the promoter activity of Runx2. These results suggest that L-Sox5 protein expression may diminish along with the progress of chondrogenic differentiation. L-Sox5 may act as a negative regulator if expressed aberrantly at least in part by regulating the critical fate of chondrogenesis.
authors.affiliation: Key Laboratory of Molecular Epigenetics of Ministry of Education of China, Northeast Normal University, Renmin Street 5268, Changchun, 130024, Jilin, China.
authors.forename: Dongmei
authors.initials: D
authors.lastname: Sun
authors.forename: Vishwa
authors.initials: V
authors.lastname: Deepak
authors.forename: Ping
authors.initials: P
authors.lastname: Mu
authors.forename: Haiying
authors.initials: H
authors.lastname: Jiang
authors.forename: Xiuming
authors.initials: X
authors.lastname: Shi
authors.forename: Zhongbo
authors.initials: Z
authors.lastname: Liu
authors.forename: Xianlu
authors.initials: X
authors.lastname: Zeng
authors.forename: Wenguang
authors.initials: W
authors.lastname: Liu
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002454:Cell Differentiation; D002460:Cell Line; D019902:Chondrocytes / Q000166:cytology / Q000502:physiology*; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics; D007328:Insulin / Q000378:metabolism; D051379:Mice; D012333:RNA, Messenger / Q000235:genetics; D012190:Retroviridae / Q000235:genetics; D055755:SOXD Transcription Factors / Q000235:genetics* / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D050659:Core Binding Factor Alpha 1 Subunit; D007328:Insulin; D012333:RNA, Messenger; C493716:Runx2 protein, mouse; D055755:SOXD Transcription Factors; C089186:Sox5 protein, mouse