Biological functions of transcription factor SOX5 in osteoarthritis cartilage cells

ZHANG Lei; NING Yu-hui; LI Guo-shun; HE Tao; MOU Zong-you; LI Ming; GUO Jin-quan

doi:10.3969/j.issn.2095-252X.2017.12.011

Abstract：Objective To investigate biological functions of transcription factor SOX5 in osteoarthritis cartilage cells. Methods Human osteoarthritic cartilage chondrocytes ( OA cartilage cells ) were isolated and cultured. OA cartilage cells were transfected with siSOX5 using lipidosome 2000 and named as OA-siSOX5 cells, while OA cartilage cells transfected with NCsiRNA served as negative control. Levels of SOX5, interleukin 6 ( IL-6 ), IL-1β, Collagen II ( COL2A1 ), protein polysaccharide ( ACAN ) mRNA expression in OA cartilage cells transfected with siSOX5 or NCsiRNA were detected using Real time PCR. Concentration of IL-6 and IL-1β in culture supernatants of OA cartilage cells transfected with siSOX5 or NCsiRNA were measured using ELISA. The levels of SOX5, matrix metalloproteinase 1 ( MMP-1 ) and MMP-13 protein expression were detected using Western blot and apoptosis was measured using AnnexinV-FITCI and flow cytometry. Results Levels of IL-6 ( 0.72 ± 0.05 ) and IL-1β mRNA ( 0.64 ± 0.07 ) in OA-siSOX5 cells were significantly higher than OA-NCsiRNA cells ( 1.32 ± 0.08, 1.64 ± 0.09 ) ( P < 0.05 ), while the levels of COL2A1 ( 1.27 ± 0.08 ) and ACAN mRNA ( 2.38 ± 0.17 ), and the concentration IL-6 ( 175.2 ± 14.5 ) pg / ml and IL-1β ( 102.6 ± 20.3 ) pg / ml in OA-siSOX5 cells were notable lower compared with OA-NCsiRNA cells [ ( 584.6 ± 74.5 ) pg / ml, ( 268.4 ± 25.3 ) pg / ml; P < 0.05 ]. The levels of MMP-1 ( 0.53 ± 0.05 ) and MMP-13 protein ( 0.46 ± 0.08 ) in OA-siSOX5 cells were significantly lower than OA-NCsiRNA cells ( 1.95 ± 0.11, 2.48 ± 0.24; P < 0.05 ). Conclusions Down-expressed SOX5 could relieve the development of OA by inhibiting the expression of matrix metalloproteinase, apoptosis and inflammation, promoting synthesis and excretion of the extracellular matrix.