BMP-9 and TGFß-3 as potential candidates for chondrogenic differentiation of synovial fluid derived stem cells in bovines

Synovial fluid mesenchymal stem cells can be obtained easily by non-invasive methods. They are frequently used both for therapeutic purposes and in research due to their high chondrogenic differentiation capacity. It is important to imitate the natural structure of articular cartilage in studies related to joint diseases in order to obtain an efficient result from the study. In our study, in order to imitate the natural structure of the joint in transwell culture, chondrocytes in the upper layer and synovial fluid mesenchymal stem cells at the bottom of the plate were located. It was thought that thanks to the paracrine secretion of the cartilage, it would increase the chondrogenic differentiation of mesenchymal stem cells. In this culture system, it was aimed to culture the stem cells with TGF-ß3 and BMP-9 added to the chondrogenic differentiation medium and thus to further increase the chondrogenesis of the stem cells. Isolation and characterization studies of isolated bovine synovial fluid mesenchymal stem cells were performed. In this direction, differentiation potentials of these cells and real-time PCR analyzes were performed. At the same time, after 21 days of culturing with chondrogenic differentiation medium in the transwell system, COL2A1, ACAN, SOX9 and COL10A1 gene expressions were examined in real-time PCR. Besides, the differentiation potentials were confirmed by immunofluorescence and histological stainings. As a result, it was observed that cartilage and synovial fluid mesenchymal stem cells combined in transwell culture successfully increased chondrogenic differentiation. At the same time, it was determined that TGF-ß3 and BMP-9 added to the chondrogenic differentiation medium further increased differentiation. However, determining the effects of different doses of TGF-ß3 and BMP-9 by combining them or using them alone is important for a better understanding of the chondrogenic differentiation mechanism. In addition, adding different time periods to the study and testing the study in vivo will further increase its importance.