Isolation and Characterization of Human Mesenchymal Stem Cells Derived From Synovial Fluid in Patients With Osteochondral Lesion of the Talus

Abstract

Background: Recently, mesenchymal stem cells (MSCs) have been suggested as a source for cell-based treatment of cartilage lesions based on the ability of these cells to differentiate into chondrocytes. Purpose: To characterize MSCs derived from the synovial fluid in ankle joints with osteochondral lesion of the talus (OLT). Study Design: Controlled laboratory study. Methods: Synovial fluid was collected from the ankle joints of 28 patients with OLT who underwent arthroscopic marrow stimulation between September 2011 and April 2012. Epitope profiles and multilineage differentiation were assessed to characterize the synovial fluid MSCs. To clarify the origin of synovial fluid MSCs, we assessed gene profiles of MSCs derived from various mesenchymal tissues by reverse transcription–polymerase chain reaction (RT-PCR) analysis. Results: Synovial fluid MSCs expressed CD90 and CD105, showed low expression of CD14 and CD34, and underwent multilineage differentiation in vitro. The RT-PCR revealed strong expression of CD90, CD44, and CD73, whereas CD45 and CD133 were not detected. The colony number of synovial fluid MSCs from OLT significantly increased in stages C and D, as defined by arthroscopic classification. Gene expression profiles indicated that synovial fluid MSCs derived from the patients with OLT were more similar to MSCs from synovium than to MSCs from bone marrow and adipose tissue. Conclusion: This study confirmed that human synovial fluid is a good source of MSCs, with the capacity to differentiate toward several cell lineages. Further study with matched controls of synovial fluid MSCs derived from ankle joints without OLT is required for a more accurate evaluation of synovial fluid MSCs. Clinical Relevance: The findings of this study provide a platform for exploring the potential role of synovial fluid MSCs in OLT and their therapeutic potential in novel joint regeneration strategies.