Culture of human synovium-derived mesenchymal stem cells from human knee joint and its multipotent differentiation in vitro.

Abstract

：Objective To study themethod of isolating and culturing human synovium-derived mes-enchymal stem cels (SMSCs)from osteoarthritic knee joints and to investigate whether SMSCs could differ-entiate intoosteoblasts, adipocytes and chondrocytes in vitro. Methods Cell populations wereenzymatieally released from the synovial membrane obtained from human knee joints withend-stage osteoarthritis. Mono-clone was obtained by seleeting as primary SMSCs. SMSCswere characterized by FACS-analysis. SMSCs at passage 3 were used to investigate theirmulti-lineage potential in vitro. Upon treatments, phenotypes of cell cultures wereanalyzed by histo- and immunohistochemistry and by semi-quantitative reversetranscription-polymerase ehain reaction for the expression of lineage-related markers.Results Primary SMSCs, showed polygon and star shape. After passaged, it exhibited roundeels and spindle cells. Consequently, homoge-neous populations of fibroblast-like cellswere observed. SMSCs were positive for CD90 and CD44, negative for CD34, CD45 and CD71,respectively. Under appropriate euhure conditions, SMSCs were induced to dif-ferentiate tothe adipocyte, osteocyte, and chondrocyte lineages, which were stained positively by OilRed O staining, ALP staining, Alizarin red staining and Toluidine blue staining,respectively. Expression of adi-pogenic markers (Lipoprotein lipase, Adiponectin and PPARγ2)and osteogenic markers (ALP, Osteopontin and Osteocalein) were all detected. Type Ⅱ collagen was stained positivelyby immunohistochemistry stain-ing. Conclusion Human SMSCs can be isolated from knee jointsof end-stage OA. These cells have the a-bility to proliferate extensively in culture, andthey have the potential to differentiate into adipogenic, os-teogenic and chondrogeniclineage in vitro. Key words: Synovialmembrane; Mesenchymal stem cell; Cell differentiation; Adipocytes; Os-teoblasts; Chondrocytes