RF3.4 Synovium-derived primary cells show comparable mesenchymal stem/ stromal cell-like properties in between patients with early OA and non-OA patients

Abstract

Mesenchymal stem cells (MSCs) present basic tools for cellular therapies in regenerative medicine. Synovium-derived MSCs in particular have shown superior chondrogenic properties in comparison with MSCs derived from other tissues such as bone marrow. Degenerative joint disorders like osteoarthritis (OA) might impair the ability of tissue-resident MSCs for tissue regeneration. Hence, the optimal donor and tissue source of MSCs needs to be carefully evaluated. In the current study we aimed to compare synovium-derived MSCs between the patients with early hip degeneration (early OA) with those with no degeneration (non-OA) patients.We included 16 patients undergoing hip arthroscopy (8 early OA and 8 non-OA patients). Tissues from three synovial sites of the hip (paralabral synovium, cotyloid fossa, inner surface of peripheral capsule) were collected along with peripheral trabecular bone. Primary cells were isolated, culture expanded and characterized for their in vitro MSC-like properties. Gene expression profiling for human skeletal stem cell markers, namely podoplanin (PDPN), CD146, CD164 and CD73 was performed. Our results showed that synovium-derived and bone-derived MSCs from early OA patients possess comparable clonogenicity, cumulative population doublings, osteogenic, adipogenic and chondrogenic potential, and immunophenotype to those of non-OA patients.Gene expression profiling showed high PDPN/ low CD146 profile (reminiscent of human skeletal stem cells) mainly in MSCs from early OA, while low PDPN/ high CD146 mainly defined non-OA MSCs. These data suggest that MSCs from early OA patients are not affected by degenerative changes in the hip. Moreover, the synovium represents an alternative source of MSCs for patient-derived stem cell therapies, as comparable to bone. The expression profile reminiscent of skeletal stem cells suggest the combination of low PDPN and high CD146 as potential biomarkers in early OA.