Enhancement of Glycosaminoglycan-Rich Matrix Production in Human Marrow-Derived Mesenchymal Stem Cell Chondrogenic Culture by Lithium Chloride and SB216763 Treatment

Cartilage mass produced from mesenchymal stem cell (MSC) differentiation would be a suitable candidate for use in regenerative medicine. Since the proper function of cartilage tissue is largely dependent on matrix glycosaminoglycan (GAG) contents, the objective of this study was to investigate the enhancing effect of two GSK3 inhibitors on the GAG content of cartilage produced by human marrow MSCs in vitro chondrogenesis. MSCs that were used in this experimental study were derived from human marrow aspirates and confirmed using standard assays. Optimal concentrations of Lithium chloride and SB216763 were determined based on the yield of viable cell numbers in MSC cultures treated with varying concentrations of either Lithium chloride or SB216763. Passaged-3 MSCs were then centrifuged into small aggregates and provided with a chondrogenic medium supplemented with either lithium or SB216763 reagent at the optimal concentration determined in the previous experiment. Three weeks after, GAG contents of the culture were quantified and compared to each other and the control. According to our data, the cultures treated with 5 mM Lithium and 1 µM SB216763 tended to have comparatively more viable cells; therefore these concentrations were used in the differentiation experiments. The addition of either SB216763 or lithium to chondrogenic cultures appeared to significantly enhance cartilage matrix production. In SB216763 and Lithium-treated cultures average GAG concentrations were 6.17 ± 0.7 and 6.12 ± 1.1 µg/ml compared to 2.00 ± 0.3 µg/ml in the control (p<0.05). Using SB216763 and Lithium as supplements in human marrow MSC chondrogenic culture can lead to the production of cartilage mass high in GAG content.