The self-renewal capacity of chondrocytes in osteoarthritis (OA) joints is limited, and mesenchymal stem cells (MSCs) are
crucial in disease treatment. This study established an OA model from equine bone marrow–derived mesenchymal stem cells
(eBMSCs). The eBMSCs were cultured and differentiated into chondrocytes to generate cartilage pellets, which were induced
for 7 d with inflammatory cytokines, interleukin-1 beta (IL-1?) and tumor necrosis factor-alpha (TNF-?) to mimic OA conditions. Treated culture medium was collected to estimate enzyme activity (MMP-2, MMP-3, and MMP-9) using zymography,
and the cartilage pellets were collected to estimate both anabolic gene (COL2A1) and catabolic gene expression (MMP2,
MMP3, and MMP9) using qRT-PCR. Cartilage degradation was observed when induced with IL-1? +TNF-? on cartilage pellets. IL-1?+TNF-? decreased the expression levels of COL2A1 and MMP2 genes, and enhanced their enzymatic activities,
while Alcian blue–positive glycosaminoglycan in cartilage pellets induced by IL-1?+TNF-? groups decreased. These results
suggested that IL-1?+TNF-? induced on cartilage pellets from eBMSCs could be used as an in vitro OA model in horses.