POS0337 CHARACTERIZATION OF CIRCULATING CHONDROPROGENITOR CELLS IN PATIENTS AFFECTED BY OSTEOARTHRITIS

Background Osteoarthritis (OA) is a common chronic degenerative disease caused by progressive cartilage degradation [1]. In OA, regenerative medicine based on mesenchymal stem cells (MSCs) considered the most promising method for restoring articular [2]. However, high heterogeneity of MSCs together with invasive and painful procedures cell isolation represent main challenges tissue engineering technology (3)[4]. this regard, homogeneous population MSCs, chondroprogenitor (CPs), have been recently discovered in human bone [5]. Objectives light these considerations, purpose study was to identify CPs OA. addition, we aimed differentiate circulating into chondrocytes their vitro characterization. Methods For study, 10 patients affected widespread OA [10F; median age 62 years, IQR 9; duration 19 4] related healthy donors (HD) matched sex were enrolled. A blood sample collected from each participant characterization three CP populations summary, after CD45- 500 μl whole using anti-CD45+ magnetic beads, samples labeled anti-CD146-PE, anti-CD73-APC, anti-CD164 – FITC PDPN PerCP/Cyanine5.5 antibodies. The acquisition performed FACSCalibur cytometer. Data analyzed Cell Quest Pro software. culture peripheral mononuclear (PBMCs) isolated Ficoll-gradient protocol cultured DMEM supplemented 20% FBS 1% antibiotic–antimycotic. At 60–80% confluence, adherent Complete Chondrogenesis Differentiation Medium 7 days. end chondrogenesis, morphological analysis bright-field microscopy. After differentiation, anti-CD44-PerCP, anti-CD151-APC anti-CD49c-PE antibodies, chondrogenic capacity. apoptosis AV-FITC PI detection kit. Results Flow Cytometry identified blood. Interestingly, two CD45-, +, CD146-, CD73 CD164+ CD73-, CD164 + significantly decreased compared HD (0.82% ± 0.46 vs 4.13% 1.92, 0.65% 0.22 3.74% 1.10, p = 0.0065 0.0022, respectively) (Figure 1a). During expansion, numerically lower than 1b). Moreover, showed more rounded shape volumetric enlargement, which are features typical chondrocyte hypertrophy 1c). cytometry results that superficial markers, i.e CD44, CD151, CD49c, (p=0.0009, p=0.0042 p=0.0002, 1d). Lastly, higher (p=0.004) 1e). Conclusion demonstrated percentage HD. Furthermore, reduced capacity supported number hypertrophic an increase levels. Further studies need clarify possible application therapy. References [1]Poole, Robin. “Osteoarthritis as joint disease.” doi:10.1007/s11420-011-9248-6 [2]Xiang et al. Mesenchymal stromal cell-based therapy regeneration knee osteoarthritis. doi: 10.1186/s13287-021-02689-9 [3]Sipp, D (2018). doi:10.1038/d41586-018-06756-9 [4]Cooper K, Viswanathan C. Establishment bank.doi: 10.4061/2011/905621. [5]Chan CKF Al., Identification Human Skeletal Stem Cell.doi: 10.1016/j.cell.2018.07.029. Acknowledgements: NIL. Disclosure Interests None Declared.