Original Article Comparison of the efficacy of bone marrow mononuclear cells and bone mesenchymal stem cells in the treatment of osteoarthritis in a sheep model

* Equal contributors. Received January 20, 2014; Accepted February 4, 2014; Epub March 15, 2014; Published April 1, 2014 Abstract: Objective: To evaluate the therapeutic efficacy of uncultured bone marrow mononuclear cells (BMMCs) and bone mesenchymal stem cells in an osteoarthritis (OA) model of sheep. Methods: Induction of sheep OA was performed surgically through anterior cruciate ligament transection and medial meniscectomy. After 12 weeks, concentrated BMMCs obtained from autologous bone marrow harvested from anterior iliac crest or a single dose of 10 million autologous bone mesenchymal stem cells (BMSCs) suspended in phosphate-buffered saline (PBS) was delivered to the injured knee via direct intra-articular injection. Animals of the PBS group received vehicle alone. The contra-lateral joints were selected randomly as the control group. Knees of the four groups were compared macroscopically and histologically, and glycosaminoglycan (GAG) contents normalized to cartilage wet weight were measured at lesions of cartilage from medial condyle of the femur head. Gene expression levels of type II collagen (Col2A1), Aggrecan and matrix metalloproteinase-13 (MMP-13) in cartilage were measured based on RT-PCR and prostaglandin E2 (PGE2), Tumor Necrosis Factor-α (TNF-α) and Transforming Growth Factor beta (TGF-β) concentra- tions in synovial fluid were determined with ELISA assays at 8 weeks after injection. Results: At 8 weeks post cell transplantation, partial cartilage repair was observed in the cell therapy, but not the PBS group (P<0.05). The BM- SCs group showed higher regeneration of cartilage and lower proteoglycan loss than the BMMCs group (P<0.05). Concentrated BMMCs injection led to a weaker treatment effect, but also inhibited PGE2, TNF-α and TGF-β levels in synovial fluid and promoted higher levels of Aggrecan and Col2A1 and downregulation of MMP-13 in sheep chon - drocytes in a similar manner to BMSCs, compared with the PBS group. Conclusions: Bone marrow cells showed therapeutic efficacy in a sheep model of OA. Despite similar therapeutic potential, the easier and faster process of collection and isolation of BMMCs supports their utility as an effective alternative for OA treatment in the clinic.