Intra-articular adipose-derived mesenchymal stem cells from rheumatoid arthritis patients maintain the function of chondrogenic differentiation.

Objectives: To evaluate the chondrogenic potential, phenotype and percentage of IA adipose-derived mesenchymal stem cells (ADSCs) from RA patients in comparison with OA patients. The effect of TNF treatment on ADSC differentiation was also examined.
Methods: Adipose tissue was obtained from RA and OA patients. ADSCs were isolated and cultured until passage 4. After that period, the phenotype and percentage of these cells were analysed by flow cytometry. Passage 4 cells were cultured in chondrogenic medium with or without TNF. After 3 weeks of differentiation the expression of Sox9, aggrecan (Acan) and collagen 2a (Col2a) mRNA was assessed by RT-PCR and GAG deposition by alcian blue staining.
Results: The phenotype and percentage of ADSCs were similar in both RA and OA. The results of alcian blue staining showed effective chondrogenesis in RA and OA ADSCs. TNF inhibited GAG deposition in both RA and OA samples similarly. Sox9, Acan and Col2a mRNA expression was significantly increased in chondrogenic-medium-treated cells (P<0.05) and decreased after TNF exposure (P<0.01). No statistically significant differences between RA and OA were observed.
Conclusion: ADSCs from RA and OA patients are similar with regard to their phenotype, percentage in IA tissue and chondrogenic potential, which is reduced after exposure to TNF.