Osteoarthritis (OA) is a leading pathological condition resulting in the degeneration and destruction of articular cartilage. The presence of inherent mesenchymal progenitor cells (MPCs) within the articular cartilage has led to explore the possible reparative mechanisms to regenerate and restore the functional and mechanical properties of hyaline cartilage. The present in vitro study was aimed to identify and characterize the MPCs derived from OA cartilage. MPCs derived from the explant culture of OA cartilage were analyzed in terms of cellular and biological properties, and multilineage differentiation abilities. Upon cell surface marker analysis, MPCs were CD73+, CD90+, CD166+, CD146-, CD34-, CD45-, and HLA-DR-, whose expression defines stemness and chondroprogenitor status. MPCs exhibited a higher proliferative index and limited or no senescence activity till later passages. Trilineage differentiation towards osteogenesis, adipogenesis, and chondrogenesis was observed with cytochemical staining and also by mRNA expression of lineage-specific markers by RT-qPCR. The results showed that OA cartilage harbors a viable pool of MPCs with greater chondrogenic potential. These cell niches could serve as a superior cell source for cartilage regeneration due to their committed progeny and hence could prevent heterotypic cartilage formation.
Key words: Articular cartilage; Osteoarthritis; Mesenchymal progenitor cells; Chondrogenesis; In vitro.