Cells isolated from fat pad and synovial fluid. are they suitable for cartilage repair?

Garica, J.K.; Mennan, C.; Richardson, J.; Wright, K.; Roberts, S.

Abstract

Purpose: Autologous Chondrocyte Implantation (ACI) is used as a cellular therapy for treating defects in articular cartilage. Successful ACI depends on high cell number and quality of the cells which varies between patients. Alternative cell sources within the joint may provide a more preferable treatment for OA. The aim of this study is to evaluate the clinical suitability of infrapatellar fat pad (FP) and synovial fluid (SF) cells for cartilage repair by determining their MSC-like profile and response to an inflammatory stimulus in vitro.

Methods: Fat pad and synovial fluid were obtained with consent from the knees of patients undergoing ACI treatment. Cells were isolated from FP by enzymatic digestion with Collagenase I for 1 h at 37oC followed by centrifugation. Synovial fluid cells were obtained by centrifuging the synovial fluid. Resulting cell pellets were seeded onto tissue culture plastic in DMEM-F12, 10 % FCS and Penicillin/Streptomycin. Expression of cell surface markers was assessed using Flow cytometry (FACSCanto II). The multipotency of these cells was tested by culturing in monolayer in osteogenic and adipogenic media. Chondrogenesis was assessed in 3D pellet culture for 21 days. To evaluate the immunoresponsive nature of FP and SF cells, the expression of co-stimulatory markers CD40, CD80, CD86, and Major Histocompatibility complex II (HLA-DR) was tested before and after stimulation (48 h) with low (25ng/ml) and high (500ng/ml) concentrations of interferon-γ (IFN-γ). Results were compared to those obtained from bone marrow derived mesenchymal stem cells (BMSCs).

Results: SF and FP cells showed the ability to differentiate down osteogenic, adipogenic and chondrogenic lineages as shown by positive alkaline phosphatase (bone), Oil Red O (lipid) and Toluidine blue (glycosaminoglycan) staining.

Cells from both SF and FP were positive for the MSC markers CD73, CD90, CD105 and negative for HLA-DR. Following stimulation with IFN-γ, both SF and FP cells upregulated CD40 and HLA-DR. In comparison, BMSCs upregulated HLA-DR after IFN- γ stimulation but not the co-stimulatory marker CD40.

Conclusion: Cells isolated from FP and SF of osteoarthritic joints display immunogenic properties after stimulation with the pro-inflammatory cytokine IFN-γ which may make them unsuitable as alternative cell sources for ACI. Despite the production of co-stimulatory markers (CD40) and up regulation of HLA-DR as mentioned above, these cells do show multipotency via their ability to differentiate down osteogenic, adipogenic and chondrogenic lineages and they express the MSC markers CD73, 90 and 105. Their immunoresponsive nature needs to be studied further before these cells could be considered for routine applications for cartilage repair.

Citation

Garica, J., Mennan, C., Richardson, J., Wright, K., & Roberts, S. (2014). Cells isolated from fat pad and synovial fluid. are they suitable for cartilage repair?. Osteoarthritis and Cartilage, 22, S445. https://doi.org/10.1016/j.joca.2014.02.843

• Journal Article Type: Conference Paper
• Conference Name: 2014 World Congress
• Conference Location: Paris, France
• Publication Date: 2014-04
• Deposit Date: Jun 8, 2023
• Journal: Osteoarthritis and Cartilage
• Print ISSN: 1063-4584
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 22
• Pages: S445
• DOI: https://doi.org/10.1016/j.joca.2014.02.843
• Keywords: Orthopedics and Sports Medicine; Biomedical Engineering; Rheumatology
• Additional Information: Conference dates;; 24-27 April 2014