Abstract: PURPOSE: The aim of present study was to explore the effect of strontium ranelate (SrR) on the proliferation and chondrogenic differentiation of rat bone mesenchymal stem cells (BMSCs). METHODS: Rat BMSCs were isolated and cultured in chondrogenic differentiation medium containing 0.25-2.0 mmol/L strontium ranelate. CCK-8 assay was used to study the influence of cell proliferation. Toluidine blue staining and alizarin blue staining were used to observe chondrogenic differentiation. Quantitative hydroxyproline (Hyp) activity assay was conducted. PCR and Western blots were used to detect the expression of related genes and proteins. Statistical analysis was performed using SPSS 22.0 software package. RESULTS: 0.25 mmol/L strontium ranelate did not inhibit the proliferation of BMSCs and promote the expression of chondroitin sulfate and proteoglycan. Hyp assay showed a higher content of collagen fibers in extracellular matrix in 0.25 mmol/L SrR treatment group. PCR and WB also showed up-regulated expression of Sox-9, Col-Ⅱ gene and protein, Aggrecan protein, and suppressed expression of MMP-9 gene. CONCLUSIONS: 0.25 mmol/L SrR could significantly promote chondrogenic differentiation of BMSCs.

Key words: Strontium Ranelate, Bone mesenchymal stem cells, Chondrogenic Differentiation