Sun, DongmeiDeepak, VishwaMu, PingJiang, HaiyingShi, XiumingLiu, ZhongboZeng, XianluLiu, Wenguang2016-02-122015-03Sun, D, Deepak, V, Mu, P, Jiang, H, Shi, X, Liu, Z, Zeng, X & Liu, W 2015, 'Constitutive L-Sox5 overexpression delays differentiation of ATDC5 cells into chondrocytes and correlates with reduced expression of differentiation markers', Molecular and Cellular Biochemistry, vol. 401, no. 1-2, pp. 21-26.0300-8177 (print)1573-4919 (online)10.1007/s11010-014-2288-8http://hdl.handle.net/2263/51344L-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 insulininduced 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.en© Springer Science+Business Media New York 2014. The original publication is available at : http://link.springer.comjournal/11010.L-Sox5ChondrogenesisRunx2HypertrophyAsporinOsteoarthritisPostprint Article